Behavior

Not analyzed.

Not analyzed.

Postures and behavior associated with territorial defense include crown raising, soliciting, tail spreading, chases, supplanting, flying past, physical contact during fighting, and type II song (Ficken and Ficken 1968a Ficken, M. S. and R. W. Ficken. (1968a). Courtship of Blue-winged Warblers, Golden-winged Warblers and their hybrids. Wilson Bulletin 80:161-172. Close ).

Territory Size

Recorded territory sizes range from 0.2 to 6.0 ha. Boundaries often determined by edge or row of tall trees and by interactions with neighboring males. In n. Wisconsin, Roth and Lutz (2004) reported a mean territory area of 0.82 ha in seedling aspen clearcuts (less than 10-years post-harvest) and 0.18 to 0.54 in sapling and pole-sized clearcuts (11-25 years post-harvest). They speculated that territory area in seedling-sized clearcuts was primarily influenced by neighboring males, and territory area in older clearcuts was largely constrained by the shape of the occupied forest openings where aspen regeneration was poor. In the Lower Peninsula of Michigan, Murray and Gill (1976) reported mean territory area as 1.9 ha and 2.7 ha for two tamarack swamp sites, and Will (1986) observed a mean area of 1.0 in a forest-field ecotone.

In Kentucky, in hilltop removal sites territory size averaged 1.2 ha in sites with only Golden-winged Warblers and 1.7 ha in sites sympatric with Blue-winged Warblers (range = 0.2 to 5.8 ha) (Patton et al. in press). Density may influence territory size; e.g., one male sang from trees around the perimeter of a field 300 x 300 m and responded to taped playbacks throughout this area. The next season an additional male moved into the field and the territory size of the returning male was halved (JLC).

Individual Distance / Territoriality

Territories are distributed where habitat is most suitable and consequently appear as neighborhoods in heterogeneous habitat mosaics (Reitsma et al. unpubl. data). Territories can overlap to some degree, but such boundaries often remain in dispute. Nests are often within 30 m of each other. In one case in New Hampshire, two nests were 32 m apart, both within the same male's territory, suggesting a polygamous male.

Mating System And Sex Ratio

Usually socially monogamous, although 2 of 61 territorial males in New York fed young at two nests, which indicates polygamy. Extra-pair offspring were found in 56% of broods in Ontario (Vallender et al. 2007) and 61% of broods in Kentucky and New York (PJH, JLC). Extra pair young from those studies accounted for 32% and 41% of all nestlings, respectively.

Sex ratio skew has been observed in Kentucky, with only 67% pairing success of Golden-winged Warbler males (PJH).

Breeding Behavior

Males decrease singing frequency during active pair formation (while following females), but renew singing when a nest is destroyed, or incubation starts, or if female leaves territory. Courtship displays of Golden-winged and Blue-winged warblers are similar, including several aspects of songs and calls (Ficken and Ficken (Ficken and Ficken 1968a Ficken, M. S. and R. W. Ficken. (1968a). Courtship of Blue-winged Warblers, Golden-winged Warblers and their hybrids. Wilson Bulletin 80:161-172. Close ; see Vocalizations). Shortly after females arrive, males spend considerable time following and even chasing potential mates, sometimes lunging at females before chase. Females rarely approach males, but often give tzips (Ficken and Ficken 1968a), perhaps stimulating pair formation. Tzips dwindle as nest building begins.

"Tail Spreading," rare in intrapair displays, is common between males. "Pivoting"-perched bird rotates the body without moving the feet-and "Wing and Tail Flicking" are occasionally performed by the male; each suggests a conflict of motivation. "Crown Raising" may occur when a male approaches its mate. Male flight displays near the female include "Moth Flight" and "Gliding". Moth Flight: slow, deep wing beats as male flies away from female; male Blue-winged and Brewster's may use similar display while flying away from another male after a chase (Meyerriecks and Baird 1986). Gliding is more prevalent than moth flight as male approaches female (Ficken and Ficken 1968a).

Pair occasionally pecks at or grasps each other's bill: "Bill Dueling." Dueling pairs sometimes fall to the ground with clasped bills. Female's primary sexual display is "Soliciting," which resembles that of many passerines-neck extended, breast lowered, tail markedly raised and wings vibrated (Ficken and Ficken 1986a).

Generally not a social species.

Overlap of territories is common where Golden-winged and Blue-winged warblers breed sympatrically. Interaction between males of the two species is infrequent in many populations (Ficken and Ficken 1968d Ficken, M. S. and R. W. Ficken. (1968d). Territorial relationships of Blue-winged Warblers, Golden-winged Warblers and their hybrids. Wilson Bulletin 80:442-451. Close , Gill and Murray 1972a, Confer and Knapp 1977, Murray and Gill 1976, Will 1986), but common in a highly introgressed, sympatric population in Kentucky (PJH).

Golden-winged Warblers have disappeared from many regions within 50 yr of the arrival of Blue-winged Warblers (Gill 1980). This is perhaps due to behaviorally dominant Blue-winged Warblers driving Golden-winged Warblers into inferior habitat (Will 1986), but other observations counter such a behavioral dominance hypothesis (Gill and Lanyon 1964, Ficken and Ficken 1968d, 1969, Gill and Murray 1972a, Confer and Knapp 1977). In n.-central New York (1990-1991), Golden-winged Warblers dominated 32 of 51 interspecies interactions (Confer et al. 2003), suggesting Golden-wing dominance, but not statistically significant. Golden-winged Warblers are slightly larger than Blue-winged Warblers (Will 1986) and dominance by a larger congener is known from studies of other species (Alatola et al. 1985).

May associate with Black-capped Chickadees (Parus atricapillus) on breeding territories and during migration, perhaps as a result of social mimicry (Ficken and Ficken 1974). Families with fledged young may join mixed species flocks in July (F. Gill pers. comm.). Occurs in mixed-species flocks on wintering grounds (Costa Rica; Tramer and Kemp 1980).

Nest predation rates of 53% and 40% recorded in Kentucky (PJH) and Tennessee (Bullock et al. 2008), respectively. Survey in s. New York showed that Mayfield estimates of the probability of nest failure was 36% in swamp forests and 59% in uplands. Almost all failures were due to predation and the higher rate in the uplands was likely due to predation by eastern chipmunks and black rat snakes, which were absent from the swamp forests (JLC).