Breeding

Pair Formation

Some individuals remain paired on breeding territories throughout the year (e.g., 100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 212 Gentry, K. M. (2015). Territorial defense strategies in the Northern Cardinal (Cardinalis cardinalis): Who is the bigger threat? M.S. thesis, University of Southern Mississippi, Hattiesburg, MS, USA. Close ). Among individuals that join winter flocks, some males may leave flock to claim territories and are later joined by females (293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close ), or pairs may leave winter flocks together (280 Ganier, A. F. (1941). Through the seasons with the Cardinal. Migrant 12: 1–4. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). It is not known if this difference corresponds to whether these birds were mated in the previous breeding season. Courtship displays first reported in February in southern Ontario and West Virginia (293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close , 281 Land, H. C. (1952). The seasonal shifting of behavioral patterns related to territorialism in the Cardinal. M.S. thesis, Ohio State University, Columbus, OH, USA. Close ), as early as January in southern Mississippi (JMJ). On basis of less clearly defined criteria, “pair formation” reported mid-January–early April in southern Indiana (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Timing of pair formation, courtship initiation, and the beginning of nesting has not been compared between first-year breeders and older or previously paired birds. Upon divorce (separation of pairs with both mates surviving) or death, mates are replaced with non-mated individuals or neighboring individuals that have lost a mate themselves (SLH, SUL; see 269 Breitwisch, R., A. J. Schilling, and J. B. Banks (1999). Parental behavior of a bigamous male Northern Cardinal. Wilson Bulletin 111(2): 283–286. Close for record of bigamy by a male after a neighboring individual died; also observed by SLH in Wisconsin). New pairs form during breeding season, or even in autumn (October) as result of death or divorce of mate (SLH, SUL, 278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close ). Divorces reported within and between breeding seasons (28 Filliater, T. S., and R. Breitwisch (1997). Nestling provisioning by the extremely dichromatic Northern Cardinal. Wilson Bulletin 109: 145–153. Close , SUL).

Jawor et al. (113 Jawor, J. M., S. U. Linville, S. M. Beall, and R. Breitwisch (2003). Assortative mating by multiple ornaments in Northern Cardinals (Cardinalis cardinalis). Behavioral Ecology 14(4): 515–520. Close ) found that newly mated pairs mate assortatively by plumage and bill coloration, but not by face mask expression or crest length. Newly mated pairs did not mate assortatively by measures of condition and more ornamented pairs were not more successful in reproduction.

Nest-Building

Begins late February to mid-April (278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close , 100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 62 Bent, A. C. (1968). Life histories of North American cardinals, grosbeaks, towhees, finches, sparrows, and allies (Part 1). United States National Museum Bulletin 237. Close ). In Tennessee, building begins “as soon as the thickets begin to turn green with early leaves” (280 Ganier, A. F. (1941). Through the seasons with the Cardinal. Migrant 12: 1–4. Close : 1); in Iowa, while there is still snow on the ground (277 Hodges, J. (1949). A study of the Cardinal in Iowa. Proceedings of the Iowa Academy of Science 56: 347–361. Close ). The first nest may take 2–3 wk to build (280 Ganier, A. F. (1941). Through the seasons with the Cardinal. Migrant 12: 1–4. Close , JMJ, MSD, DPS); shorter building times reported for later nests (see Nest).

First Brood per Season

See Figure 1. First eggs laid in March or April. Generally later nesting at higher latitudes, but many exceptions. Earliest dates at which eggs have been found: Baja California, 22 March; Texas, 24 March; Florida, 30 March; Georgia, 19 April; Ontario, 13 April; and Michigan, 20 April; but 2 March was reported as early (possibly unreliable) egg date for New Jersey (62 Bent, A. C. (1968). Life histories of North American cardinals, grosbeaks, towhees, finches, sparrows, and allies (Part 1). United States National Museum Bulletin 237. Close , 301 Peck, G. K., and R. D. James (1987). Breeding Birds of Ontario: Nidiology and Distribution. Volume 2: Passerines. Miscellaneous Publications of the Royal Ontario Museum, Toronto, ON, Canada. Close ). See Bent (62 Bent, A. C. (1968). Life histories of North American cardinals, grosbeaks, towhees, finches, sparrows, and allies (Part 1). United States National Museum Bulletin 237. Close ) for data from additional locations. Incubation lasts 11–13 d, nestling period 7–13 d, in first and later broods (see Eggs and Parental Care). First nests in a population seem fairly synchronized, which may be linked to environmental conditions (JMJ). Early-season nests are more consistently incubated by females than nests later in the season (measured as time on nest, and number and length of off-nest bouts, 99 Jawor, J. M. (2002). Multiple ornaments and sexual selection in a socially monogamous passerine, the Northern Cardinal (Cardinalis cardinalis). Ph.D. dissertation, University of Southern Mississippi, Hattiesburg, MS, USA. Close ). Females with redder underwing ornamentation were found to produce their first nests earlier in the season (15 Jawor, J. M., N. Gray, S. M. Beall, and R. Breitwisch (2004). Multiple ornaments correlate with aspects of condition and behaviour in female Northern Cardinals, Cardinalis cardinalis. Animal Behaviour 67(5): 875–882. Close ). Males with redder breast coloration (76 Wolfenbarger, L. L. (1999). Red coloration of male northern cardinals correlates with mate quality and territory quality. Behavioral Ecology 10:80–90. Close ) and greater brightness (273 Rodewald, A. D., D. P. Shustack, and T. M. Jones (2011). Dynamic selective environments and evolutionary traps in human-dominated landscapes. Ecology 92: 1781–1788. Close ) had mates that nested earlier in rural populations, but brightness was not related to earlier breeding in urban populations (273 Rodewald, A. D., D. P. Shustack, and T. M. Jones (2011). Dynamic selective environments and evolutionary traps in human-dominated landscapes. Ecology 92: 1781–1788. Close ).

Second/Later Broods per Season

High rate of nest failure at all stages (43 Filliater, T. S., R. Breitwisch, and P. M. Nealen (1994). Predation on cardinal nests: Does choice of nest site matter? Condor 96: 761–768. Close , and references therein) leads to desynchronized nesting of pairs living in same area. In southern Ontario, mean 5.5 d ± 1.4 SD (range 3–16, n = 84) between day of nest failure and day first egg laid in new nest (302 Scott, D. M., R. E. Lemon, and J. A. Darley (1987). Relaying interval after nest failure in Gray Catbirds and Northern Cardinals. Wilson Bulletin 99: 708–712. Close ); elsewhere, considerable individual variation exists in time taken to renest after failure (JMJ). When nests are successful, time to re-nesting varies with number of fledglings: Kinser (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ) reported that when a single young fledged (n = 4), female started new nest 13–14 d after fledging, but that when > 1 fledgling survived (n = 6), female waited an average of 19.2 d after fledging to start the next nest. No latitudinal trend for last nesting dates; across range, latest dates for eggs in active nests tend to be in late August (293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close , 62 Bent, A. C. (1968). Life histories of North American cardinals, grosbeaks, towhees, finches, sparrows, and allies (Part 1). United States National Museum Bulletin 237. Close ), although autumn nests have been reported as “fairly common” in West Virginia, where an active nest with 3 eggs was found on 19 October (M. Brooks in 279 Christy, B. H. (1942). The Cardinal: The bird itself. Cardinal 5: 173–186. Close ). In Tennessee (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close ) and Wisconsin (SLH), last young fledge in late August or September. In Mississippi, recently fledged young observed at feeders in late October (JMJ). Drought or low temperatures may end nesting season early by reducing availability of insect prey used to feed young (280 Ganier, A. F. (1941). Through the seasons with the Cardinal. Migrant 12: 1–4. Close , 293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close ). Nest predation rates tend to be high, ~70% of nests are depredated (43 Filliater, T. S., R. Breitwisch, and P. M. Nealen (1994). Predation on cardinal nests: Does choice of nest site matter? Condor 96: 761–768. Close , 29 Linville, S. U., R. Breitwisch, and A. J. Schilling (1998). Plumage brightness as an indicator of parental care in male and female Northern Cardinals. Animal Behaviour 55: 119–127. Close , 30 DeVries, M. S., and J. M. Jawor (2013). Natural variation in circulating testosterone does not predict nestling provisioning rates in the Northern Cardinal, Cardinalis cardinalis. Animal Behavior 85: 957–965. Close ). Nest survival increases as the breeding season progresses, although per-nest fledgling production remains similar throughout the breeding season (54 Shustack, D. P., and A. D. Rodewald (2011). Nest predation reduces benefits to early clutch initiation in Northern Cardinals Cardinalis cardinalis. Journal of Avian Biology 42: 204–209. Close ).

Selection Process

Although female alone builds nest, both adults may select site (243 Shaver, J. M., and M. B. Roberts (1933). A brief study of the courtship of the Eastern Cardinal. Journal of the Tennessee Academy of Science 8: 116–123. Close ). Female visits various locations, fluffing feathers and turning; male follows, and both mates call and manipulate nesting material with bill (243 Shaver, J. M., and M. B. Roberts (1933). A brief study of the courtship of the Eastern Cardinal. Journal of the Tennessee Academy of Science 8: 116–123. Close ); this behavior observed 5–16 d before construction of first nests in Indiana (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ).

Microhabitat

Constructed in thick tangles of vines or twigs, usually in shrubs or small trees. In southern Michigan, 53 species of shrubs and saplings were used (n = 334 nests); 21% were found in hawthorn (Crataegus), 19% dogwood (Cornus asperifolia, C. florida), 9% honeysuckle (Lonicera), 8% wild grape; conifers with nests included eastern redcedar (Juniperus virginiana), white spruce (Picea glauca), pines (Pinus spp.), eastern hemlock (Tsuga canadensis), and northern white-cedar (Thuja occidentalis) (W. P. Nickell in 288 Burns, R. D. (1963). Michigan cooperative Cardinal study nesting data. Jack Pine Warbler 41: 56–61. Close ). In Ohio (n = 121 nests), 65% were located in honeysuckle or multiflora rose (Rosa multiflora), and 7% eastern redcedar (43 Filliater, T. S., R. Breitwisch, and P. M. Nealen (1994). Predation on cardinal nests: Does choice of nest site matter? Condor 96: 761–768. Close ). In Indiana (n = 140 nests), 34% were located in American elm (Ulmus americana), 21% hawthorn, 15% sugar maple (Acer saccharum), and 13% eastern redcedar, with remainder in wild grape, dogwood, black locust (Robinia pseudoacacia), honeysuckle, boxelder (Acer negundo), elderberry (Sambucus), and rose (Rosa) (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ); Indiana nests also reported in privet (Ligustrum sp.), yew (Taxus sp.), English ivy (Hedera sp.), osage orange (Maclura pomifera), and crabapple (Pyrus sp.) (294 Richmond, A. (1978). An experimental study of advantages of monogamy in the Cardinal. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). In south-central Wisconsin, nests primarily in honeysuckle shrubs and under leafy canopy of grapevines growing over shrubs or lower tree branches (SLH). In southeastern Arizona, in riparian habitats, Arizona sycamore (Platanus wrightii) and netleaf hackberry (Celtis reticulata) frequently chosen for nesting (194 Powell, B. F., and R. J. Steidl (2002). Habitat selection by riparian songbirds breeding in southern Arizona. Journal of Wildlife Management 66(4): 1096–1103. Close ). In central Tennessee, nests in blackberry brier thickets and shrubs and small trees, often those covered with vines (303 Shaver, J. M., and M. B. Roberts (1930). Some nesting habits of the Cardinal. Journal of the Tennessee Academy of Science 5: 157–170. Close ). In Mississippi, nests frequently in wild blueberry or honeysuckle shrubs, wisteria vines, and small trees, nest sites often heavily covered with leaves (JMJ). In central Ohio, occasionally nests in the spine clusters growing from the trunks of honey locust (Gleditsia triacanthos) (304 Shustack, D. P. (2008). Reproductive timing in passerines in urbanizing landscapes. Ph.D. dissertation, The Ohio State University, Columbus, OH, USA. Close ).

Site Characteristics

Nests concealed in forks of twigs and small branches; nest height above ground 0.25–12 m (mean 1–2 m) (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , W. P. Nickell in 288 Burns, R. D. (1963). Michigan cooperative Cardinal study nesting data. Jack Pine Warbler 41: 56–61. Close , 305 Johnston, R. F. (1964). The breeding birds of Kansas. Miscellaneous Publications of the University of Kansas Museum of Natural History 12: 575–655. Close ). In Indiana (n = 108), mean height 2 m (range 0.5–4.5) and nest height increased over the season (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ), which is similar to the pattern observed in central Ohio (52 Rodewald, A. D., D. P. Shustack, and L. E. Hitchcock (2010). Exotic shrubs as ephemeral ecological traps for nesting birds. Biological Invasions 12(1): 33–39. Close ). In Ohio, mean height 2.1 m ± 1.6 SD (range 0.7–12, n = 121) (43 Filliater, T. S., R. Breitwisch, and P. M. Nealen (1994). Predation on cardinal nests: Does choice of nest site matter? Condor 96: 761–768. Close ). In Wisconsin, most nests about 1.5 m above ground (SLH). In Mississippi, most nests about 1.5–2 m above ground (JMJ). Appears to respond to experience of success or failure in prior nesting attempt and perceived risk of nest predation by placing within-season renests in more concealed microsites (306 Kearns, L. J., and A. D. Rodewald (2013). Within-season use of public and private information on predation risk in nest-site selection. Journal of Ornithology 154(1): 163–172. Close ).

Construction Process

Female does most building; male occasionally brings nesting material (280 Ganier, A. F. (1941). Through the seasons with the Cardinal. Migrant 12: 1–4. Close , 100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 288 Burns, R. D. (1963). Michigan cooperative Cardinal study nesting data. Jack Pine Warbler 41: 56–61. Close , 43 Filliater, T. S., R. Breitwisch, and P. M. Nealen (1994). Predation on cardinal nests: Does choice of nest site matter? Condor 96: 761–768. Close ). Female crushes twigs by chewing them with mandibles, then bends them around her body; turning in the nest while working, she pushes out with her feet to form the nest cup. Male feeds mate during nest-building (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Construction reported in morning and mid-afternoon; trips reduced 50% when temperature > 25°C in afternoon (243 Shaver, J. M., and M. B. Roberts (1933). A brief study of the courtship of the Eastern Cardinal. Journal of the Tennessee Academy of Science 8: 116–123. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ).

Structure and Composition Matter

Nest is not attached to substrate; it is wedged into position. Bowl-shaped structure is composed of 4 layers: rough outer material, leafy mat, grapevine bark, and grassy lining (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ); may contain weed stems, pliable twigs, strips of bark, grasses, vines, rootlets, leaves, and pine needles (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close ). Paper and plastic common in outer cup (SLH, JMJ). One report of shed snakeskin being used (278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close ).

Dimensions

In Indiana, mean nest measurements: height 67 mm ± 6.2 SD; inside depth 36 mm ± 4.3 SD; outside diameter 108 mm ± 4.8 SD; inside diameter 73 mm ± 4.3 SD; mean weight 17 g ± 3.5 SD (n = 50) (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). In Ohio (n = 41), mean dry weight 17.6 g ± 4.1 SD; highly variable in size and composition; largest nest was 6 times volume of smallest and heaviest was 3 times weight of lightest (R. Breitwisch and D. Szczepanik, unpublished data).

Microclimate

Nest typically concealed by foliage, even though nests built early in season may be more exposed because shrubs have not leafed out. Frequently uses sites deep in tangled thickets and briers (303 Shaver, J. M., and M. B. Roberts (1930). Some nesting habits of the Cardinal. Journal of the Tennessee Academy of Science 5: 157–170. Close , SUL, JMJ). Territories with successful nests have higher foliage density and patchiness at 2 m throughout territory than do territories with unsuccessful nests (50 Conner, R. N., M. E. Anderson, and J. F. Dickson (1986). Relationships among territory size, habitat, song and nesting success of Northern Cardinals. Auk 103: 23–31. Close , 76 Wolfenbarger, L. L. (1999). Red coloration of male northern cardinals correlates with mate quality and territory quality. Behavioral Ecology 10:80–90. Close ). Nest concealment, height of nest, proximity to edge habitat, accessibility, choice of shrub species in which nests were constructed, and distance to human activity had no relationship to rates of predation on nests in southwestern Ohio (43 Filliater, T. S., R. Breitwisch, and P. M. Nealen (1994). Predation on cardinal nests: Does choice of nest site matter? Condor 96: 761–768. Close ), although in central Ohio populations, nesting in non-native shrubs was linked to increased nest predation (307 Borgmann, K. L., and A. D. Rodewald (2004). Nest predation in an urbanizing landscape: The role of exotic shrubs. Ecological Applications 14(6): 1757–1765. Close , 52 Rodewald, A. D., D. P. Shustack, and L. E. Hitchcock (2010). Exotic shrubs as ephemeral ecological traps for nesting birds. Biological Invasions 12(1): 33–39. Close ). Multiflora rose and Lonicera honeysuckle were the major non-native shrubs used for nesting in all three studies. Differences in outcomes may depend on seasonal effects, factors specific to the study sites including range of shrub sizes available, distribution of native and non-native vegetation, predators, and predation rates; or sample sizes.

Maintenance or Reuse of Nests, Alternate Nests

Rarely reuses nests (278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close ), but presence of old nests may function as protection against predation. In Virginia, experimental sites with more empty cardinal nests added had lower removal rates of plastic artificial eggs in an adjacently placed cardinal nest: 90% for single nests, 60% in 3-nest groups, and 50% in 6-nest groups (n = 5 replicates of each condition) (308 Watts, B. D. (1987). Old nest accumulation as a possible protection mechanism against search-strategy predators. Animal Behaviour 35: 1566–1568. Close ). Although nests themselves are rarely reused, specific nest sites on a territory have been reused after old nests fall apart (JMJ).

Shape

Ovate.

Size

C. c. cardinalis: mean length × breadth: 24.88 mm (range 22.47–27.16) × 18.58 mm (range 17.04–19.66, n = 23 clutches, 71 eggs) (Western Foundation of Vertebrate Zoology). Six other subspecies measured were not significantly different.

Eggs can be distinguished from those of Brown-headed Cowbird (Molothrus ater) by size. In southern Ontario, for cardinal (n = 25), mean length 24.8 mm ± 1.1 SD, width 18.2 mm ± 0.6 SD; for cowbird (n = 20), mean length 21.7 mm ± 1.1 SD, width 16.5 mm ± 0.5 SD (293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close ).

Eggs are significantly smaller in first clutches than in subsequent clutches, and egg size is inversely related to total clutch size (266 Gottfried, B. M. (1976). Intrapopulational variation in the territory size of Cardinals (Cardinalis cardinalis). Ph.D. dissertation, Miami University, Oxford, OH, USA. Close ).

Mass

In southern Ontario, mean 4.9 g (n = 16) (41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ).

Color

From Bent (62 Bent, A. C. (1968). Life histories of North American cardinals, grosbeaks, towhees, finches, sparrows, and allies (Part 1). United States National Museum Bulletin 237. Close ): Ground color ranges from grayish white to buffy white to greenish white. Speckled or spotted with pale gray to medium brown marks. In most cases, spots are distributed over the entire shell, but tend to concentrate at larger end of egg. Speckling varies from sparse to thick, obscuring ground or forming blotches. Last egg in each clutch is always more lightly marked with spots and streaks than the others (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ; D. Scott, personal communication). Abernathy and Peer (309 Abernathy, V. E., and B. D. Peer (2016). Reduced ultraviolet reflectance does not affect egg rejection by Northern Cardinals (Cardinalis cardinalis). Wilson Journal of Ornithology 128: 334–342. Close ) noted significant variation among eggs in reflectance in both the near ultraviolet and visual color spectrums. Reflectance in eggs varied in the near ultraviolet range peaking at ~300 nm, then decreased to a low at ~350 nm, and then rose through the visual range, with 4 successively higher peaks, the last and highest at ~700 nm.

Surface Texture

Smooth, somewhat glossy.

Composition

Winters (268 Winters, C. P. (2011). Ornamentation, behavior, and maternal effects in the female Northern Cardinal. M.S. thesis, University of Southern Mississippi, Hattiesburg, MS, USA. Close ) found no differences in egg-yolk testosterone across eggs from first clutches of the breeding season with known laying order. However, egg-yolk carotenoid content varied with highest levels of carotenoids found in first laid eggs, and with lesser, and equal, amounts in second and third eggs. Carotenoids assessed were canthaxanthin and beta-carotein (268 Winters, C. P. (2011). Ornamentation, behavior, and maternal effects in the female Northern Cardinal. M.S. thesis, University of Southern Mississippi, Hattiesburg, MS, USA. Close ); other types likely occur and need assessment.

Clutch Size

Clutches include 1–5 eggs; reported averages include: 2.78 eggs in southern Ontario (n = 254 clutches; 301 Peck, G. K., and R. D. James (1987). Breeding Birds of Ontario: Nidiology and Distribution. Volume 2: Passerines. Miscellaneous Publications of the Royal Ontario Museum, Toronto, ON, Canada. Close ); 3.31 eggs in Kansas (range 3–5, n = 25 clutches; 310 Johnston, R. F. (1960). Directory of the bird-life of Kansas. Miscellaneous Publications of the University of Kansas Museum of Natural History No. 23. University of Kansas, Lawrence, KS, USA. Close ); averages of 2.4 to 3.22 eggs across 9 study sites (311 Crowell, K. L., and S. I. Rothstein (1981). Clutch sizes and breeding strategies among Bermudan and North American passerines. Ibis 123: 42–50. Close ); 3 eggs in Tennessee (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close ); and 2 eggs in Iowa (277 Hodges, J. (1949). A study of the Cardinal in Iowa. Proceedings of the Iowa Academy of Science 56: 347–361. Close ). Reported single-egg clutches may have suffered predation undetected by researchers. See Demography and Populations: Measures of Breeding Activity.

Egg Laying

Begins 1–8 days after nest completion. According to Kinser (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ), 1–8 d (mean 2.4, n = 25); according to Lemon (293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close ), 1–5 d (mean 2.04, n = 23). Female lays 1 egg/d (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close , 268 Winters, C. P. (2011). Ornamentation, behavior, and maternal effects in the female Northern Cardinal. M.S. thesis, University of Southern Mississippi, Hattiesburg, MS, USA. Close ), usually early in morning; mean of 69.7 min ± 13.2 SD after sunrise (n = 10 females, each contributing 1 oviposition record; 312 Scott, D. M. (1991). The time of day of egg laying by the Brown-headed Cowbird and other icterines. Canadian Journal of Zoology 69: 2093–2099. Close ); most times between 0450 and 1000 (177 Sutton, G. M. (1959). The nesting fringillids of the Edwin S. George Reserve, southeastern Michigan (part III). Jack Pine Warbler 37: 76–101. Close , 288 Burns, R. D. (1963). Michigan cooperative Cardinal study nesting data. Jack Pine Warbler 41: 56–61. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Interval from nest completion to initiation of egg-laying shortens as breeding season progresses (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Male guards female while she is fertile; see Behavior: Sexual Behavior.

No indication that females replace eggs lost to predation; when entire clutch is lost, builds new nest, and may even do so after partial clutch loss (JMJ). Up to 8–10 clutches may be initiated in a breeding season (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close , 43 Filliater, T. S., R. Breitwisch, and P. M. Nealen (1994). Predation on cardinal nests: Does choice of nest site matter? Condor 96: 761–768. Close , 99 Jawor, J. M. (2002). Multiple ornaments and sexual selection in a socially monogamous passerine, the Northern Cardinal (Cardinalis cardinalis). Ph.D. dissertation, University of Southern Mississippi, Hattiesburg, MS, USA. Close ), although seldom are > 2–3 successful. See Demography and Populations: Measures of Breeding Activity.

Intraspecific egg-dumping appears to be rare. In Ohio (75 Linville, S. U. (1997). Sexual selection and plumage ornamentation in a socially monogamous passerine, the Northern Cardinal (Cardinalis cardinalis). Ph.D. dissertation, University of Dayton, Dayton, OH, USA. Close ), DNA-fingerprinting confirmed egg-dumping in two years: 2 of 48 nestlings in 1 of 20 nests in 1994, and 1 of 45 nestlings in 1 of 19 nests in 1995. In each case, male was identified as genetic father, but female attending nest was excluded as genetic mother. In a Mississippi population, during observations of egg laying and egg marking for laying order, no behavioral evidence of intraspecific brood parasitism was observed (268 Winters, C. P. (2011). Ornamentation, behavior, and maternal effects in the female Northern Cardinal. M.S. thesis, University of Southern Mississippi, Hattiesburg, MS, USA. Close , 19 Winters, C. P., and J. M. Jawor (2017). Melanin ornament brightness and aggression at the nest in female Northern Cardinals (Cardinalis cardinalis). Auk 134: 128–136. Close ).

Onset of Broodiness and Incubation in Relation to Laying

True incubation begins on day last egg is laid (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ), although female occasionally sleeps on nest after second of 3 eggs is laid (177 Sutton, G. M. (1959). The nesting fringillids of the Edwin S. George Reserve, southeastern Michigan (part III). Jack Pine Warbler 37: 76–101. Close ). From Kinser (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ), females (n = 7) remained on nest for average 15 min (range 7–22) during visit in which first or second eggs were laid in 3-egg nests. These females sat on nest for 3–6 periods averaging 38 min, mostly in afternoon, during first two days of egg-laying. They usually stayed on nest and initiated incubation after the third egg was laid.

Incubation Patches

Reported only in female; around 33 mm maximum diameter (313 Quay, W. B. (1989). Timing of sperm releases and inseminations in resident emberizids: A comparative study. Condor 91: 941–961. Close ). Approximately oval, but precise shape and location not described. Assessment of females captured during breeding period found incubation patches on the lower half of the abdomen that were concealed by feathers from surrounding feather tracts (JMJ, MSD).

Incubation Period

Lasts 11–13 d (314 Nice, M. M. (1931). The Birds of Oklahoma, Revised Edition. Publication of the University of Oklahoma, Biological Survey 3. Close , 278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close , 100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Average 12.8 d ± 0.32 SD for 27 nests in southern Indiana, possibly slightly longer early in breeding season (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ); average of 12.3 d for 16 nests in southern Ontario (41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ).

Parental Behavior

Roles and Attention to Eggs and Incubating Mate

Incubation apparently by female alone; males have been observed to sit on nests for short periods, though the extent of contact between the body and the eggs is unknown (62 Bent, A. C. (1968). Life histories of North American cardinals, grosbeaks, towhees, finches, sparrows, and allies (Part 1). United States National Museum Bulletin 237. Close , 259 Vondrasek, J. R. (2006). Nest-sitting by a male Northern Cardinal (Cardinalis cardinalis). Raven 77(1): 13–15. Close ). Male brings food to incubating female, either at or away from nest (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close , 272 Jawor, J. M., and R. Breitwisch (2006). Is mate provisioning predicted by ornamentation? A test with Northern Cardinals (Cardinalis cardinalis). Ethology 112(9): 888–895. Close ). Vocalizations may coordinate feeding visits by male (see Sounds and Vocal Behavior: Vocalizations). In southern Indiana, males fed incubating females about 3 times/h (combining feedings at and away from nest; no information given on number of pairs or hours of observation; 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). In an Ohio population, males fed females at a rate of 0.62 ± 0.40 feedings/h with a range of 0–1.4 feedings/h (n = 33 pairs); feeding rates were not impacted by day of incubation nor indicated by male ornamentation (272 Jawor, J. M., and R. Breitwisch (2006). Is mate provisioning predicted by ornamentation? A test with Northern Cardinals (Cardinalis cardinalis). Ethology 112(9): 888–895. Close ). In male removal experiments, incubating females did not abandon their nests when their mates disappeared; rate of nest destruction by predators was higher during incubation periods with male present, but lower during nestling periods with male present (294 Richmond, A. (1978). An experimental study of advantages of monogamy in the Cardinal. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ).

Incubation Rhythm; Duration of Attentive Periods

Few published data. During observations of 1 nest on day 7 of incubation (10 July, southern Indiana), female left nest a total of 21 times between 0510 and 2020, for periods averaging 9.4 min (range 2–15) and totaling 30% of daylight hours (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Periods on nest averaged 35.2 min (range 2–112). Another female was reported to leave nest 11–12 times/d (315 Nice, M. M. (1943). Studies in the life history of the Song Sparrow, part 2. Transactions of the Linnaean Society of New York 6: 1–328. Close : 220, reporting data from W. E. Schantz; location and day of incubation not specified). In an Ohio population, females were observed on 5 consecutive days for 1 hour periods each day (days 3–7 of incubation); some females did not leave the nest during the hour of observation, while others left for up to 30 min, with up to 6 instances of leaving the nest/h (99 Jawor, J. M. (2002). Multiple ornaments and sexual selection in a socially monogamous passerine, the Northern Cardinal (Cardinalis cardinalis). Ph.D. dissertation, University of Southern Mississippi, Hattiesburg, MS, USA. Close ). In a central Ohio population, females (n = 125) incubated for an average of 31 min ± 1.73 SE (range 0–60) over a 1-hour observation period when air temperatures were at least 10°C (296 Smith-Castro, J. R., and A. D. Rodewald (2010). Effects of recreational trails on Northern Cardinals (Cardinalis cardinalis) in forested urban parks. Natural Areas Journal 30: 328–337. Close ). Female ornamentation was not found to co-vary with incubation behavior (99 Jawor, J. M. (2002). Multiple ornaments and sexual selection in a socially monogamous passerine, the Northern Cardinal (Cardinalis cardinalis). Ph.D. dissertation, University of Southern Mississippi, Hattiesburg, MS, USA. Close ).

Hardiness of Eggs Against Temperature Stress; Effect of Egg Neglect

No information.

Preliminary Events and Vocalizations

Bump appears on surface of egg, with no break in shell, approximately 12–16 hours before hatching (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Vocalizations of hatching young, if any, not described.

Shell-Breaking and Emergence

Based on 278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close , 100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , and 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close . Most eggs hatch early in morning. Chick generally takes 12–24 hours to break through shell, although one report of 20 minutes from first break in shell until female carried shell away from hatched nestling. In 3-egg clutches, all 3 eggs usually hatch in same day. Second egg laid may hatch before first, and third before second.

Parental Assistance and Disposal of Eggshells

Based on 278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close , 100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , and 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close . Rarely, female assists in hatching, by pulling or even occasionally breaking shell away from nestling. Either parent may eat eggshells or carry them away; one female fed shells to newly hatched young.

Condition at Hatching

Altricial; naked except for sparse fine gray down along feather tracts. Eyes closed. Able to hold head up and open mouth. Skin transparent, giving chicks a yellowish coloration. Gape red-orange, with yellow edge in region where mandibles join (rictal flanges).

Young Brown-headed Cowbird nestlings remarkably similar, but down light buffy yellow to white; rictal flanges white in eastern subspecies (ater) and central subspecies (artemisiae), but yellow in at least some western obscurus (316 Lowther, P. E. (1993). Brown-headed Cowbird (Molothrus ater). In The Birds of North America, No. 47 (A. Poole and F. Gill, Editors). Academy of Natural Sciences, Philadelphia, PA and American Ornithologists' Union, Washington, DC, USA. Close ).

Growth and Development

In southern Ontario, mean hatchling mass 3.5 g (n = 10) ( 41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ). Nestling mass follows sigmoid growth pattern in an Ohio population: mean nestling mass on day 1 (n = 6), 6.3 g ± 0.6 SD; day 2 (n = 10), 9.5 g ± 0.8 SD; day 4 (n = 15), 16.6 g ± 2.2 SD; day 6 (n = 17), 23.1 g ± 2.6 SD; day 8 (n = 8), 25.8 g ± 2.1 SD. Mean tarsus length: day 1 (n = 2), 11.06 mm ± 0.0 SD; day 2 (n = 2), 13.0 mm ± 1.4 SD; day 4 (n = 8), 17.9 mm ± 1.1 SD; day 6 (n = 10), 22.8 mm ± 1.4 SD; day 8 (n = 4), 24.9 mm ± 1.2 SD (42 Eckerle, K. P., and R. Breitwisch (1997). Reproductive success of the Northern Cardinal, a large host of Brown-headed Cowbirds. Condor 99: 169–178. Close , SUL). Mass gain for days 1–6 is higher for nests with a single nestling than for nests with ≥ 2 nestlings (266 Gottfried, B. M. (1976). Intrapopulational variation in the territory size of Cardinals (Cardinalis cardinalis). Ph.D. dissertation, Miami University, Oxford, OH, USA. Close ).

Nestlings remain inactive until parent arrives with food, then stretch neck upward and gape. Nestlings do not compete for food other than by begging competitively when parent is present. Begging is loud by day 5; will beg if nest is disturbed. By day 8, alert, and handling may cause premature fledging (SUL, JMJ).

Nestling physiology unknown; on basis of decrease in brooding (see Parental Care: Brooding), chicks probably begin to regulate their body temperature on day 3.

Brooding

Young are brooded exclusively by female throughout nestling period, for decreasing amounts of time as they get older. Brooding on day 0 (day of hatching), day 1, and day 2 may be almost continuous. Mean brooding duration for females in an Ohio population: day 3 (n = 17 nests), 29.0 min/h ± 14.7 SD; day 4 (n = 19), 21.9 min/h ± 20.3 SD; day 5 (n = 23), 14.2 min/h ± 18.5 SD; day 6 (n = 22), 3.1 min/h ± 7.1 SD; day 7 (n = 21), 6.8 min/h ± 16.6 SD; day 8 (n = 19), 5.3 min/h ± 11.8 SD (SUL).

In Indiana, shading nestlings from sun is infrequent, but female will shade during extreme high temperatures, standing over nest with wings slightly spread, maintaining position for 5–12 min (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ); shading behavior also observed in late season nests in a Mississippi population (JMJ).

Feeding

Commences soon after hatching. As during incubation, early in nestling life (first 2 days) male may bring food to female either at or away from nest (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close , 99 Jawor, J. M. (2002). Multiple ornaments and sexual selection in a socially monogamous passerine, the Northern Cardinal (Cardinalis cardinalis). Ph.D. dissertation, University of Southern Mississippi, Hattiesburg, MS, USA. Close ), male feeds nestlings directly as they age. Published feeding rates range from 2 visits/h (294 Richmond, A. (1978). An experimental study of advantages of monogamy in the Cardinal. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ) to 4.7 visits/h (287 Brackbill, H. (1952). A joint nesting of Cardinals and Song Sparrows. Auk 69: 302–307. Close ); SLH observed at least 8 feeding visits (11:05–12:05) on day of hatching at a nest with 2 nestlings. In an Ohio population (28 Filliater, T. S., and R. Breitwisch (1997). Nestling provisioning by the extremely dichromatic Northern Cardinal. Wilson Bulletin 109: 145–153. Close ), feeding rates were higher for larger than for smaller broods; in 23 pairs, males fed nestlings at higher rates (2.3 visits/h) than did females (1.8 visits/h). Feeding rates increase as nestlings age (28 Filliater, T. S., and R. Breitwisch (1997). Nestling provisioning by the extremely dichromatic Northern Cardinal. Wilson Bulletin 109: 145–153. Close , 15 Jawor, J. M., N. Gray, S. M. Beall, and R. Breitwisch (2004). Multiple ornaments correlate with aspects of condition and behaviour in female Northern Cardinals, Cardinalis cardinalis. Animal Behaviour 67(5): 875–882. Close ). Male proportion of feeding visits varied from 33% to 76%. In same Ohio population (29 Linville, S. U., R. Breitwisch, and A. J. Schilling (1998). Plumage brightness as an indicator of parental care in male and female Northern Cardinals. Animal Behaviour 55: 119–127. Close ), males fed proportionately more as nestlings aged; mean 40% of feeding visits on day 3 and 60% on day 8. Feeding effort by mates can be correlated (272 Jawor, J. M., and R. Breitwisch (2006). Is mate provisioning predicted by ornamentation? A test with Northern Cardinals (Cardinalis cardinalis). Ethology 112(9): 888–895. Close ), with mating of good providers to good providers, although this is not true for all populations (30 DeVries, M. S., and J. M. Jawor (2013). Natural variation in circulating testosterone does not predict nestling provisioning rates in the Northern Cardinal, Cardinalis cardinalis. Animal Behavior 85: 957–965. Close ). Feeding visits/hour were positively correlated with brood size (n = 27 nests; 266 Gottfried, B. M. (1976). Intrapopulational variation in the territory size of Cardinals (Cardinalis cardinalis). Ph.D. dissertation, Miami University, Oxford, OH, USA. Close ). Filliater and Breitwisch (28 Filliater, T. S., and R. Breitwisch (1997). Nestling provisioning by the extremely dichromatic Northern Cardinal. Wilson Bulletin 109: 145–153. Close ) found that females with large broods have a lower per nestling feeding rate; however, this was not found by Jawor et al. (15 Jawor, J. M., N. Gray, S. M. Beall, and R. Breitwisch (2004). Multiple ornaments correlate with aspects of condition and behaviour in female Northern Cardinals, Cardinalis cardinalis. Animal Behaviour 67(5): 875–882. Close ) when using similar methods and the same population. There was no correlation between a male’s rate of bringing food to the incubating female during incubation, and his later rate of bringing food to the nest for nestlings during the nestling period (272 Jawor, J. M., and R. Breitwisch (2006). Is mate provisioning predicted by ornamentation? A test with Northern Cardinals (Cardinalis cardinalis). Ethology 112(9): 888–895. Close ). In a Mississippi population, testosterone levels were not found to co-vary with feeding rates (30 DeVries, M. S., and J. M. Jawor (2013). Natural variation in circulating testosterone does not predict nestling provisioning rates in the Northern Cardinal, Cardinalis cardinalis. Animal Behavior 85: 957–965. Close ) in males or females. Breitwisch et al. (269 Breitwisch, R., A. J. Schilling, and J. B. Banks (1999). Parental behavior of a bigamous male Northern Cardinal. Wilson Bulletin 111(2): 283–286. Close ) recorded behavior of a bigamously mated male cardinal: the bigamous male fed nestlings at both nests at rates similar to a male caring for one set of nestlings (his summed feeding rate was therefore double that typical of a male caring for one set of nestlings).

Nestlings are fed primarily insects. Because cardinals transport food deep in their bills and only large items project beyond the margins, it is difficult to observe and identify food types being carried (see Diet and Foraging: Diet). Parents may occasionally feed by regurgitation (317 Harvey, G. F. (1903). The diary of a Cardinal's nest. Auk 20: 54–57. Close ; R. Breitwisch, personal communication; JMJ), but they usually bring in whole items that they manipulate in the bill before feeding them to nestlings (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , MSD, JMJ).

In Indiana, male removal experiments at nests from which Brown-headed Cowbird eggs were removed by the experimenter, showed no significant difference in nest failure between nests with the male present and nests with the male absent (294 Richmond, A. (1978). An experimental study of advantages of monogamy in the Cardinal. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). In successional old field habitat with shrubby borders, of 34 nests with the male present, 82% failed, compared to 86% of 22 nests where the male had been removed. On an urban university campus, among 27 nests with the male present, 63% failed, compared to 80% of 5 nests where the male had been removed. Almost all failures were due to predation. Females increased feeding rates to compensate for their mate's absence. There was no brood reduction; average daily weight gain of nestlings was only slightly higher in 8 nests in successional habitat with males present, than in 7 nests with males absent; among campus nests, average daily weight gain of nestlings was significantly higher in 13 nests with the male present, than in 5 nests with male absent. Jawor and Breitwisch (272 Jawor, J. M., and R. Breitwisch (2006). Is mate provisioning predicted by ornamentation? A test with Northern Cardinals (Cardinalis cardinalis). Ethology 112(9): 888–895. Close ) found that male nestling provisioning rate did not covary with reproductive success in unmanipulated nests.

Nest Sanitation

Nestlings defecate in the nest. Both parents remove fecal sacs after feeding nestlings, either ingesting them (until nestling day five) or carrying them from the nest. Female removes more fecal sacs than male (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , SUL). Tremble-Thrusting behavior also seen: Female thrusts her bill deep into nest cup with a trembling motion, only during brooding; may help rid nests of parasites (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ; see Demography and Populations: Disease and Body Parasites).

One report of a juvenile bringing food to nestlings and to the adult female at the same nest, and carrying away “what seemed to be a dropping” (318 Brackbill, H. (1944). Juvenile Cardinal helping at a nest. Wilson Bulletin 56: 50. Close : 50). Rare reports of 2 adult females incubating at the same nest, sometimes simultaneously while facing in opposite directions (315 Nice, M. M. (1943). Studies in the life history of the Song Sparrow, part 2. Transactions of the Linnaean Society of New York 6: 1–328. Close : 206, 319 Hawksley, O., and A. P. McCormack (1951). Doubly-occupied nests of the Eastern Cardinal, Richmondena cardinalis. Auk 68: 515–516. Close , 293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close , 320 Rice, O. O. (1969). Record of female Cardinals sharing nest. Wilson Bulletin 81: 216. Close ). In 2 such cases, eggs were known to hatch; at 1 nest, both females and a male fed the nestlings (320 Rice, O. O. (1969). Record of female Cardinals sharing nest. Wilson Bulletin 81: 216. Close ). In another case, in which no eggs hatched, the females had different mates, and the second female added her eggs and joined the first female on the nest 7 d after the first female had begun incubation (319 Hawksley, O., and A. P. McCormack (1951). Doubly-occupied nests of the Eastern Cardinal, Richmondena cardinalis. Auk 68: 515–516. Close ).

Identity of Parasitic Species

Brown-headed Cowbird in the eastern United States and Canada (321 Friedmann, H., and L. F. Kiff (1985). The parasitic cowbirds and their hosts. Proceedings of the Western Foundation of Vertebrate Zoology 2:226–302. Close , 40 Scott, D. M., P. J. Weatherhead, and C. D. Ankney (1992). Egg-eating by female Brown-headed Cowbirds. Condor 94: 579–584. Close ); Bronzed Cowbird (Molothrus aeneus) in the southwestern United States and southward through Mexico (322 Ellison, K., and P. E. Lowther (2020). Bronzed Cowbird (Molothrus aeneus), version 1.0. In Birds of the World (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. Close ).

Frequency of Occurrence, Seasonal or Geographic Variation

Comprehensive data limited to Ontario and Ohio. In southern Ontario (1955–1961), highest parasitism 30 April–2 July, when 71–100% of nests parasitized; mean number of Brown-headed Cowbird eggs per parasitized nest ranged from 1.0 to 3.3 (n = 187 parasitized nests, weekly means calculated 23 April–30 July; 38 Scott, D. M. (1963). Changes in the reproductive activity of the Brown-headed Cowbird within the breeding season. Wilson Bulletin 75: 123–129. Close ). An overlapping data set from May and June, 1960–1968, in southern Ontario showed 81% of 85 nests parasitized, and a mean of 1.8 cowbird eggs/nest (39 Scott, D. M. (1977). Cowbird parasitism on the Gray Catbird at London, Ontario. Auk 94: 18–27. Close ). For 1955–1968 in same southern Ontario population, among 106 nests examined 24 April–2 July, the number of cowbird eggs present was: 0 eggs in 19 nests (18%), 1 egg in 37 nests (35%), 2 eggs in 24 nests (23%), 3 eggs in 14 nests (13%), > 3 eggs in 12 nests (11%); mean 2.1 eggs/nest (41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ).

In Ohio (1993–1995), Brown-headed Cowbird eggs were found in 55 of 115 nests (47.8%) examined 24 April–13 July; mean 1.3 eggs/parasitized nest ± 0.6 SD; highest percentage of nests (75%) parasitized in early May (42 Eckerle, K. P., and R. Breitwisch (1997). Reproductive success of the Northern Cardinal, a large host of Brown-headed Cowbirds. Condor 99: 169–178. Close ). Parasitic frequency and intensity were highest early in season in both southern Ontario and Ohio, perhaps because of availability of other hosts later in season; in addition, Northern Cardinal continues to breed after cowbirds have stopped laying (293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close ). A study of a separate population in Ohio found seasonal and locational impacts on parasitism; early nests located away from habitat edges were less likely to be parasitized, whereas late nests located away from habitat edges were more likely to be parasitized (323 Stoklosa, S. K., L. J. Kearns, and A. D. Rodewald (2014) Risky edges: Temporal variation in brood parasitism of Northern Cardinals. Wilson Journal of Ornithology 126: 94–97. Close ). Across forested regions of Missouri, frequency of parasitism of Northern Cardinal nests declined from ~22% to ~10% over a 20-year period (1991–2010); statewide cowbird abundances also declined over this same time period (324 Cox, W. A., F. R. Thompson III, B. Root, and J. Faaborg (2012). Declining Brown-Headed Cowbird (Molothrus ater) populations are associated with landscape-specific reductions in brood parasitism and increases in songbird productivity. PLoS One 7: e47591. Close ).

Timing of Laying in Relation to Host's Laying

In southern Ontario, number of Brown-headed Cowbird eggs laid on successive days of Northern Cardinal laying (n = 142 eggs): prelaying (14%); day 1 (9%); day 2 (31%); day 3 (25%); day 4 (12%); day 5 (5%); from day 6 on (4%) (41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ).

Response to Parasitic Mother, Eggs, or Nestlings

In southern Ontario (39 Scott, D. M. (1977). Cowbird parasitism on the Gray Catbird at London, Ontario. Auk 94: 18–27. Close ), nest attentiveness by Northern Cardinal may discourage laying by Brown-headed Cowbird. Percentage of nests 16 May–27 June with cardinal on or next to nest during census 0600–0759, just after the time when cowbirds usually lay eggs: day –1 (day before first cardinal egg laid; n = 17), 12%; day 1 (n = 31), 48%; day 2 (n = 33), 52%; day 3 (n = 25), 68%; days 4 and 5 (n = 30), 83%. During day –1 through day 2 (presumably before the onset of incubation), nest attentiveness was higher 0600–0759 than later in day, beyond the known laying time for cowbirds. Scott and Lemon (41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ) suggested that disappearance of cowbird eggs is more likely due to removal by other cowbirds than to removal by cardinal hosts. Nests rarely abandoned, even when cowbird lays before cardinal: 3 of 18 such nests were abandoned in southern Ontario (293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close , 41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ); cowbirds had also laid the first egg in the 2 parasitized nests (out of 55) that were abandoned in Ohio (42 Eckerle, K. P., and R. Breitwisch (1997). Reproductive success of the Northern Cardinal, a large host of Brown-headed Cowbirds. Condor 99: 169–178. Close ). Northern Cardinal occasionally buries cowbird eggs by adding new nesting material on top of them (41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close , 42 Eckerle, K. P., and R. Breitwisch (1997). Reproductive success of the Northern Cardinal, a large host of Brown-headed Cowbirds. Condor 99: 169–178. Close ). Observation in Ohio population of a female Northern Cardinal discovering a female cowbird at a nest where the cardinal had been incubating for at least two days; female cardinal did not attack female cowbird, but abandoned the nest immediately and was not observed on subsequent nest watches; a new nest for this female cardinal was found soon after (JMJ). Abernathy and Peer (309 Abernathy, V. E., and B. D. Peer (2016). Reduced ultraviolet reflectance does not affect egg rejection by Northern Cardinals (Cardinalis cardinalis). Wilson Journal of Ornithology 128: 334–342. Close ) altered ultraviolet reflectance by applying commercial sunscreen with 3% avobenzone to a small number of Brown-headed Cowbird eggs (n = 17) and Northern Cardinal eggs (n = 16) to determine adult cardinal response (either sex, ejection events not observed): neither cowbird nor cardinal eggs with reduced ultraviolet reflectance were rejected at a higher rate compared to eggs that were unmodified, suggesting that UV reflectance (or, in any case, the changes in UV reflectance caused by this avobenzone treatment) may not be impactful for cardinals recognizing cowbird parasitism or their own eggs in their nests.

Effects of Parasitism on Host

Loss of eggs from Northern Cardinal nests is associated with Brown-headed Cowbird parasitism. In Ohio during egg-laying period, 0.6 eggs lost/parasitized nest (n = 23 nests) versus 0.2 eggs lost/unparasitized nest (n = 18 nests); however, no significant difference in number of cardinal eggs at onset of incubation (2.4 eggs/parasitized nest ± 0.7 SD [n = 23 nests]; 2.7 eggs/unparasitized nest ± 0.6 SD [n = 18 nests]), or in number of cardinal nestlings hatched (2.1 nestlings/parasitized nest ± 0.7 SD [n = 28 nests]; 2.2 nestlings/unparasitized nest ± 0.8 SD [n = 21 nests]; 42 Eckerle, K. P., and R. Breitwisch (1997). Reproductive success of the Northern Cardinal, a large host of Brown-headed Cowbirds. Condor 99: 169–178. Close ); higher cardinal egg loss during egg-laying period in parasitized nests was partially counteracted by higher cardinal egg loss during incubation in unparasitized nests. Nestling cowbirds do not beg at higher rates than nestling cardinals and do not receive higher percentages of feedings (42 Eckerle, K. P., and R. Breitwisch (1997). Reproductive success of the Northern Cardinal, a large host of Brown-headed Cowbirds. Condor 99: 169–178. Close ). Aside from egg loss, nestling cowbirds do not appear to have a detrimental impact on cardinals during the nestling stage. Of 44 nests that fledged cowbirds in central Ohio, 39 also fledged cardinal young (from 2004–2007; D. Shustack and A. Rodewald, unpublished data).

Success of Parasite with This Host

Brown-headed Cowbird reproductive success in Northern Cardinal nests is very low. In southern Ontario (41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ), cowbird egg mortality was 85%, mostly because of predation of entire nest contents, removal of single cowbird eggs (probably by cowbirds or cardinals), or desertion of nests by cardinal after > 1 cardinal and/or cowbird egg had been removed. Reproductive success from laying to fledging (n = 148 eggs) was 5.4%. Cowbird nestling mortality was high for eggs that hatched after cardinals: 8 of 12 cowbird nestlings fledged when cowbird hatched before or with cardinal eggs, 1 of 9 cowbird nestlings fledged when hatched after cardinal eggs. Higher proportion of cowbirds fledged from cowbird-only broods (11 of 22 cowbird nestlings fledged) than from mixed broods (16 of 39). Body mass of cowbird nestlings “close to fledging” from cowbird-only broods was significantly greater (28.0 g ± 0.9 SD, n = 8 nestlings) than from mixed broods (24.8 g ± 1.4 SD, n = 8 nestlings). Cowbird nestling survival and fledgling survival were lower with 3 cardinal nestmates than with 1 or 2, suggesting one advantage gained by cowbirds that remove eggs from nests they parasitize.

Two instances observed (1 in Ohio, 1 in Indiana) of dead cowbird nestlings in cardinal nests that were known to have successfully fledged cardinals (JMJ). In one instance, adult cardinals were seen trying to induce the cowbird nestling to fledge (adults approaching nest with food in bill, but not delivering food to nestling cowbird), the cowbird nestling did not leave the nest and was later found dead in the nest.

Departure from Nest

Young depart nest at 7–13 d, though 9–10 d is most common when young are not disturbed (278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close , 100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close , 62 Bent, A. C. (1968). Life histories of North American cardinals, grosbeaks, towhees, finches, sparrows, and allies (Part 1). United States National Museum Bulletin 237. Close , 41 Scott, D. M., and R. E. Lemon (1996). Differential reproductive success of Brown-headed Cowbirds with Northern Cardinal and three other hosts. Condor 98: 259–271. Close ). At fledging, young have small crest and very short tail; often they can fly, though only for short distances (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close , SLH, SUL, JMJ). Generally, depart nest in morning, less often in afternoon (278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close , 277 Hodges, J. (1949). A study of the Cardinal in Iowa. Proceedings of the Iowa Academy of Science 56: 347–361. Close , 67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Young leave on their own; parents may encourage young to depart by reducing rate of feeding at nest on morning of departure (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ), offering food away from nest (277 Hodges, J. (1949). A study of the Cardinal in Iowa. Proceedings of the Iowa Academy of Science 56: 347–361. Close ; JMJ), and/or giving chip calls to young (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close , SUL). Young may or may not leave together; Kinser (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ) reported 2 nests in which 3 young departed within 30 min of one another, but another 4 nests with approximately 20 hr between departure of first and last young.

Growth

Few data on growth of fledglings, which are difficult to find and catch. At day 10 after fledging, one brood had “distinct crests” and tails about 3.8 cm long; 3 days later, their tails had grown to 6.4 cm and they “approached the size of the female” (245 McClung, R. M. (1968). Red bird fly up. Massachusetts Audubon 52: 6–11. Close : 11).

Association with Parents or Other Young

From Kinser (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ), and others as noted: For first 11 days after fledging, young rarely move from branches on which they are perched; in one Indiana study, each fledgling was fed a mean of 8 times/hr (range 4–15, n = 60 hours of observation), with feedings usually in a series of trips in rapid succession. From about 12 to 20 days after fledging, young move around more, occasionally leaving parental territory, but still receiving almost all food from parents. After this, young continue to be fed at least occasionally until 25–56 days after fledging; last young of season receive food over longer period than earlier broods (315 Nice, M. M. (1943). Studies in the life history of the Song Sparrow, part 2. Transactions of the Linnaean Society of New York 6: 1–328. Close , 293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close ). When just 1 young fledges, both parents feed it initially, but after ~12 days, female generally stops to start new nest (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ). Prior to female's re-nesting, fledged brood may be divided among parents (280 Ganier, A. F. (1941). Through the seasons with the Cardinal. Migrant 12: 1–4. Close , 208 Smith, P. C. (1969). Survival and dispersal of juvenal Cardinals. M.S. thesis, University of Western Ontario, London, ON, Canada. Close ); afterward, male feeds all young until next brood hatches (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close ), and occasionally for a couple of days longer (314 Nice, M. M. (1931). The Birds of Oklahoma, Revised Edition. Publication of the University of Oklahoma, Biological Survey 3. Close ). In southern Ontario, across breeding season, young are fed for average 32 d after fledging (n = 13 clutches; 293 Lemon, R. E. (1957). A study of nesting Cardinals (Richmondena cardinalis) at London, Canada. M.S. thesis, University of Western Ontario, London, ON, Canada. Close ); in southern Indiana, for average 39.2 d after hatching (n = 16 clutches). Young may permanently leave parental territory by themselves, or they may be driven away.

Ability to Get Around, Feed, and Care for Self

Young fly well enough to evade capture by hand at or before 3 days after fledging (SUL, SLH), and “fly strongly” at 8 days after fledging (278 Wanamaker, J. F. (1942). A study of the courtship and nesting of the Eastern Cardinal Richmondena c. cardinalis (Linnaeus). M.S. thesis, Cornell University, Ithaca, NY, USA. Close ). Daily survival rates increase substantially from 0.83 during first 3 days post fledging, to 0.97 or higher after day 3 (325 Ausprey, I. J., and A. D. Rodewald (2011). Postfledgling survivorship and habitat selection across a rural-to-urban landscape gradient. Auk 128: 293–302. Close ). Young occasionally eat insects by themselves before they have been out of nest for 12 days (67 Kinser, G. W. (1973). Ecology and behavior of the Cardinal, Richmondena cardinalis (L), in southern Indiana. Ph.D. dissertation, Indiana University, Bloomington, IN, USA. Close ); can attain independence from parental feeding 25–56 days after fledging. Using locations determined from radiotracking (n = 45 fledglings), fledglings selected locations with more vegetation cover than provided around nest sites or at random points. Fledglings were found lower in some substrates (e.g., 2.1 m ± 0.09 SD in honeysuckle [Lonicera] shrubs) compared to other substrates (5.2 m ± 0.20 SD) (325 Ausprey, I. J., and A. D. Rodewald (2011). Postfledgling survivorship and habitat selection across a rural-to-urban landscape gradient. Auk 128: 293–302. Close ). Data from a subset (n = 21) of those radiomarked fledglings that survived at least 41 days showed that fledglings in more urban sites and locations with a greater amount of honeysuckle shrubs moved less far, compared to fledglings in rural sites and locations with less honeysuckle (210 Ausprey, I. J., and A. D. Rodewald (2013). Post-fledging dispersal timing and natal range size of two songbird species in an urbanizing landscape. Condor 115(1): 102–114. Close ). Based on 95% minimum convex polygon analysis, fledglings had a natal range of 0.93 ha (0.13 SE), with fledglings from nests located farther from the forest edge having a larger natal range than fledglings from nests located closer to the habitat edge (210 Ausprey, I. J., and A. D. Rodewald (2013). Post-fledging dispersal timing and natal range size of two songbird species in an urbanizing landscape. Condor 115(1): 102–114. Close ). See also Breeding: Immature Stage and Movement and Migrations: Dispersal and Site Fidelity for information on dispersal of young.

Ausprey and Rodewald (210 Ausprey, I. J., and A. D. Rodewald (2013). Post-fledging dispersal timing and natal range size of two songbird species in an urbanizing landscape. Condor 115(1): 102–114. Close ) assessed home range of juvenile cardinals in relation to forest edge and presence of invasive Amur honeysuckle (Lonicera maackii) and found where honeysuckle cover was extensive, fledglings did not move far from the territories where they had hatched. Juveniles (up to 71 days post fledging) in more urbanized Ohio landscapes did not experience higher mortality rates compared to more rural landscapes (325 Ausprey, I. J., and A. D. Rodewald (2011). Postfledgling survivorship and habitat selection across a rural-to-urban landscape gradient. Auk 128: 293–302. Close ). Thirteen of 20 radiotracked fledglings permanently departed the natal home range between 35 and 55 days post-fledgling; the remaining 7 fledglings did not permanently depart the home range during the 71-day observation period. Some fledglings made exploratory movements outside the natal home range during the fledgling period in advance of dispersal (210 Ausprey, I. J., and A. D. Rodewald (2013). Post-fledging dispersal timing and natal range size of two songbird species in an urbanizing landscape. Condor 115(1): 102–114. Close ). See also Breeding: Fledgling Stage and Movement and Migrations: Dispersal and Site Fidelity for information on dispersal of young.

Immature birds may flock together. A flock of at least 18 hatch-year females, 11 hatch-year males, and 2 adult females were foraging on berries within 100-m-diameter area in Alabama 14–20 August (K. McGraw, personal communication).

Beak attains adult color 65–80 days after young hatch, although tip of upper mandible may remain dark for several months (100 Laskey, A. R. (1944). A study of the Cardinal in Tennessee. Wilson Bulletin 56: 27–44. Close ). Assessment of known age individuals in early spring and summer did not find first-year cardinals to be predictably different in ornamentation when compared to older individuals (113 Jawor, J. M., S. U. Linville, S. M. Beall, and R. Breitwisch (2003). Assortative mating by multiple ornaments in Northern Cardinals (Cardinalis cardinalis). Behavioral Ecology 14(4): 515–520. Close ). See Appearance for information on plumages and molts.