Diet and Foraging

Main Foods Taken

Varies with season. Mainly invertebrates, especially marine mollusks, crustaceans, and worms during nonbreeding; insects, spiders, and berries during breeding.

Microhabitat For Foraging

See Habitat, above. On breeding grounds, forages over dwarf-shrub meadow tundra where food items picked from surface or probed for within basal vegetation; also in graminoid meadows and freshwater wetlands ranging in size from 0.1 to dozens of hectares. In Norway, prelaying males foraged more than expected in crowberry-dominated peat bogs and females more in wet cottongrass (Eriophorum) bogs (Larsen 1993 Larsen, T. (1993). Information parasitism in foraging Bar-tailed Godwits Limosa lapponica. Ibis 135:271-276. Close ). On nonbreeding grounds, including fall staging in Alaska, almost entirely coastal, usually on soft substrates where foods probed for to depth of bill length and in water up to 15 cm deep. Significant nonrandom use of microhabitat by sexes found in Netherlands Wadden Sea with females foraging at tide line and males on exposed mudflats (C. Both unpubl.). In n. Poland, 80% of postbreeding individuals fed in water (54% in water >10 cm deep); remainder fed on sand beach (18%) and on mudflats (2%; Stawarczyk 1984 Stawarczyk, T. (1984). Aggression and its suppression in mixed-species wader flocks. Ornis Scandinavica 15:23-37. Close ). In Ghana, required water depth ≤10 cm (Ntiamoa-Baidu et al. 1998 Ntiamoa-Baidu, Y., T. Piersma, P. Wiersma, M. Poot, P. Battley and C. Gordon. (1998). Water depth selection, daily feeding routines and diets of waterbirds in coastal lagoons in Ghana. Ibis 140:89-103. Close ). In Alaska, postbreeders often feed on tundra adjacent to intertidal feeding areas (McCaffery 1998b McCaffery, B. J. (1998b). Implications of frequent habitat switches in foraging Bar-tailed Godwits. Auk 115:494-497. Close ). In North America away from Alaska, reported primarily from outer coast on ocean beaches and estuaries (see Distribution: the Americas, above).

Food Capture And Consumption

Active forager day and night; prey location either visual or tactile (Evans 1976b Evans, P. R. (1976b). Energy balance and optimal foraging strategies in shorebirds: some implications for their distributions and movements in the non-breeding season. Ardea 64:117-139. Close ). On breeding grounds, picks items from surface while walking or probes for items in matted vegetation (lichens, mosses, grasses), often inserting and twisting bill (see below). Items usually swallowed with head down, but will sometimes raise head to horizontal to swallow berries. Away from breeding grounds probes for food or, in case of tundra-foraging birds during fall staging, picks individual fruits (mostly crowberry). Latter averaged 13.9 berries/min ± 0.5 SE (n = 132; McCaffery 1998b McCaffery, B. J. (1998b). Implications of frequent habitat switches in foraging Bar-tailed Godwits. Auk 115:494-497. Close ). On soft substrates, uses variety of capture techniques. Mostly probes vertically, often rotating head as bill inserted into substrate (Evans 1975b Evans, P. R. (1975b). Notes on the feeding of waders on Heron Island. Sunbird 6:25-30. Close , Pierre 1994 Pierre, J. P. (1994). Effects of sexual dimorphism on feeding behavior of the Bar-tailed Godwit (Limosa lapponica) at Southern Hemisphere wintering site. New Zealand Natural Sciences 21:109-112. Close ); bill often inserted to base and, if foraging in shallow water, will submerge entire head (REG, BJM). Also uses shallow probes and "stitching" action (rapid series of probes, usually shallow, and close together), both behaviors as in Long-billed Dowitcher (Limnodromus scolopaceus). Recorded using "mowing" action similar to several Tringinae in which bird walks moving head from side to side with tip of bill just touching mud and lower mandible vibrating to disturb prey (Cramp and Simmons 1983 Cramp, S., and K. E. L. Simmons (1983). The Birds of the Western Palearctic, Volume 3: Waders to Gulls. Oxford University Press, Oxford, UK. Close ). Also gleans from surface of substrate and has been seen fluttering above breaking waves taking unidentified prey, raking muddy sand with feet, and feeding on insect larvae on roots of Casuarina exposed by digging of turtles (Higgins and Davies 1996 Higgins, P. J., and S. J. J. F. Davies (editors). (1996). Handbook of Australian, New Zealand & Antarctic birds. Volume 3. Melbourne: Oxford University Press. Close ).

Quantitative data on foraging of birds while in Alaska mostly restricted to McCaffery 1998b McCaffery, B. J. (1998b). Implications of frequent habitat switches in foraging Bar-tailed Godwits. Auk 115:494-497. Close . Elsewhere degree of feeding activity (time spent feeding, rate of probing) varies depending on tide, weather, day length, season, and behavior of prey (e.g., Goss-Custard et al. 1977a Goss-Custard, J. D., R. A. Jenyon, R. E. Jones, P. E. Newbery and R. le B. Williams. (1977a). The ecology of the Wash. II. Seasonal variation in the feeding conditions of wading birds (Charadrii). Journal of Applied Ecology 14:701-720. Close , Piersma 1982a Piersma, T. (1982a). "Foraging of Bar-tailed Godwits." In Wintering waders of the Banc d'Arguin, Mauritania., edited by W. Altenburg, M. Engelmoer, R. Mes and T. Piersma, 136-148. Leiden, The Netherlands: Communication no. 6. Wadden Sea Working Group. Close , Zwarts et al. 1990b Zwarts, L., A. Blomert, B. Ens, R. Hupkes and T. van Spanje. (1990b). Why do waders reach high feeding densities on the intertidal flats of the Banc d'Arguin, Mauritania? Ardea 79:39-52. Close ). In Europe, females tended to feed in deeper water than males, with males feeding in deeper water less successfully than males at tide line. Females equally successful in both locations. Birds feeding singly had lower rates of prey capture than those in flocks. In flocks , averaged 76.4 probes/min ± 3.1 SD with 1.9 ± 0.2 SD items swallowed/min; single birds averaged 50.3 probes/min ± 11.5 SD and 0.7 items/min ± 0.3 SD. Individuals also detect fewer prey when drop in ambient temperature slows activity of prey (Smith and Evans 1973 Smith, P. C. and P. R. Evans. (1973). Studies of shorebirds at Northumberland. I. Feeding ecology and behavior of the Bar-tailed Godwit. Wildfowl 24:135-139. Close , Evans and Smith 1975 Evans, P. R. and P. C. Smith. (1975). Studies of shorebirds at Lindisfarne, Northumberland, II. Fat and pectoral muscle indicators of body condition in the Bar-tailed Godwit. Wildfowl 26:64-76. Close , Smith 1975d Smith, P. C. (1975d). A study of the winter feeding ecology and behavior of the Bar-tailed Godwit Limosa lapponica. Unpubl. Ph.D. thesis, Univ. of Durham, Durham, U.K. Close ; but see Goss-Custard Goss-Custard 1977 Goss-Custard, J. D. (1977). The ecology of the Wash. III. Density-related behavior and the possible effects of loss of feeding grounds on wading birds (Charadrii). Journal of Applied Ecology 14:721-739. Close , Goss-Custard 1984 Goss-Custard, J. D. (1984). "Intake rates and food supply in migrating and wintering shorebirds." In Behavior of marine animals, edited by J. Burger and B. L. Olla, 233-270. New York: Plenum Press. Close ). In Netherlands in fall and spring, birds averaged 17.2 and 20.3 probes/min, respectively, and 2.8 and 2.1 items swallowed/min, or 189-216 g food ingested/low-tide feeding period (Smit and Wolff 1981 Smit, C. J. and W. J. Wolff. (1981). Birds of the Wadden Sea. Rotterdam, The Netherlands: A. A. Balkema. Close ). In New Zealand, female baueri probe rate 26.5 probes/4-min period (1.6 times that of males), but feeding success similar between sexes; success by "tapping" behavior (<50% of bill inserted into mud) significantly greater for males (Pierre 1994 Pierre, J. P. (1994). Effects of sexual dimorphism on feeding behavior of the Bar-tailed Godwit (Limosa lapponica) at Southern Hemisphere wintering site. New Zealand Natural Sciences 21:109-112. Close ). In Banc d'Arguin, Mauritania, steps/min and probe rate not different between sexes, but males more successful than females in finding prey (Piersma 1982a Piersma, T. (1982a). "Foraging of Bar-tailed Godwits." In Wintering waders of the Banc d'Arguin, Mauritania., edited by W. Altenburg, M. Engelmoer, R. Mes and T. Piersma, 136-148. Leiden, The Netherlands: Communication no. 6. Wadden Sea Working Group. Close ). In Australia, search rate for prey on wet sand substrate 110-130 paces/min, with males probing more and having more success than females (Dann 1979 Dann, P. (1979). Food robbing of Bar-tailed Godwits by Silver Gulls in Westport Bay, Victoria. Corella 3:84-85. Close ); at 2 sites, 3-7 polychaetes ingested/min (Evans 1975b Evans, P. R. (1975b). Notes on the feeding of waders on Heron Island. Sunbird 6:25-30. Close ) and 2.1-2.8 items ingested/100 s (Dann 1979 Dann, P. (1979). Food robbing of Bar-tailed Godwits by Silver Gulls in Westport Bay, Victoria. Corella 3:84-85. Close ). In Australia, piracy of foods by Silver Gulls (Larus novaehollandiae) markedly reduced both feeding rate (more time spent avoiding gulls) and items ingested by godwits (Dann 1979 Dann, P. (1979). Food robbing of Bar-tailed Godwits by Silver Gulls in Westport Bay, Victoria. Corella 3:84-85. Close , Taylor et al. 1996 Taylor, I. R., S. G. Taylor and G. N. Larmour. (1996). The effect of food stealing by Silver Gulls Larus novaehollandiae on the foraging efficiency of Bar-tailed Godwits Limosa lapponica. Emu 96:234-239. Close ).

Major Food Items

Information limited from breeding grounds. Upon arrival in spring, feeds on previous summer's berries, particularly crowberry but possibly Vaccinium spp. During nesting feeds on insects, especially beetles (Carabidae), larval and adult crane flies (Tipulidae), spiders (Araneae), and berries (REG). Stomach of adult male from riparian zone of n. Alaska in mid-Jul contained 70 land snails (Succinea strigita; Maher 1959 Maher, W. J. (1959). Habitat distribution of birds breeding along the upper Kaolak River, northern Alaska. Condor 61:351-368. Close ), while 2 stomachs from Seward Peninsula, AK, held mostly beetles (Carabidae), berries, and land snails (REG; see below). Stomachs of breeding birds from Asia contained beetles (Carabidae, Chrysomelidae, Curculionidae), dipteran flies (including Tipulidae), and larval lepidopterans; elsewhere also annelid worms and occasional seeds and berries, including crowberry (Dement'ev et al. 1951 Dement'ev, G. P., R. N. Meklenburtsev, A. M. Sudilovskaya, and E. P. Spangenberg (1968). Birds of the Soviet Union. Volume 2. Israel Program for Scientific Translations, Jerusalem, Israel. Close , Glutz Von Blotzheim et al. 1977 Glutz Von Blotzheim, U. N., K. M. Bauer and E. Bezzel. (1977). Handbuch der Vögel Mitteleuropas, Band 7: Charadriiformes (2.Teil). Wiesbaden, Germany: Akademische Verlagsgesellschaft. Close , V. Krechmar in Cramp and Simmons 1983 Cramp, S., and K. E. L. Simmons (1983). The Birds of the Western Palearctic, Volume 3: Waders to Gulls. Oxford University Press, Oxford, UK. Close ). Once birds shift to coastal Alaska beginning midsummer, diet almost entirely marine (but see McCaffery 1998b McCaffery, B. J. (1998b). Implications of frequent habitat switches in foraging Bar-tailed Godwits. Auk 115:494-497. Close ); bivalves (Macoma spp.), amphipods, polychaetes, and seeds major prey items (REG). On nonbreeding grounds of Australasia, adults eat seeds (Poaceae); annelid, polychaete, and oligochaete worms; crustaceans (crabs Macrophthalmus latifrons); insect larvae; moths (Noctuidae); and rarely fruits, domestic grains, fish, and tadpoles (Lane 1987 Lane, B. A. (1987). Shorebirds in Australia. Nelson, Melbourne, Australia. Close , Higgins and Davies 1996 Higgins, P. J., and S. J. J. F. Davies (editors). (1996). Handbook of Australian, New Zealand & Antarctic birds. Volume 3. Melbourne: Oxford University Press. Close , Taylor et al. 1996 Taylor, I. R., S. G. Taylor and G. N. Larmour. (1996). The effect of food stealing by Silver Gulls Larus novaehollandiae on the foraging efficiency of Bar-tailed Godwits Limosa lapponica. Emu 96:234-239. Close ,). In Europe (Cramp and Simmons 1983 Cramp, S., and K. E. L. Simmons (1983). The Birds of the Western Palearctic, Volume 3: Waders to Gulls. Oxford University Press, Oxford, UK. Close ), nonbreeding and migrant birds take mostly annelids (Arenicola, Nereis, Lumbricus, Heteromastus), small crustaceans (Corophium, Carcinus, Crangon, Talitrus), and small mollusks (including Macoma, Hydrobia, Littorina); on occasion, small fish (e.g., Ammodytes) and tadpoles; in grasslands, takes cranefly larvae and lumbricids in grassland.

Quantitative Analysis

Information for L. l. baueri limited. Six stomachs from nonbreeders in Jun on Walrus Is., AK, contained by volume 76.6% Diptera (Chironomidae and Scatophagidae), 17.0% Coleoptera (Salpingidae, Carabidae, Staphylinidae, Curculionidae), 3.6% mollusks (Littorina spp.), 1.3% polychaetes (Nereidae), and 1.0% "vegetable matter" (Preble and McAtee 1923a Preble, E. A., and W. L. McAtee (1923a). A biological survey of the Pribilof Islands, Alaska: I. Birds and Mammals. North American Fauna no. 46, U.S. Department of Agriculture, Biological Survey, Washington, DC, USA. Close ). From 18 fall-staging birds collected on intertidal areas of w. Alaska in late 1970s (REG), bivalves (Macoma balthica) only food common to all. As percent of total items (n = 1,945): 88% Macoma, 11% seeds (Potamogeton and Potentilla spp.), and <1% amphipods (Anisogammarus pugettensis) and polychaetes (Eteone california and Arenicolidae). Two birds from Alaska breeding grounds in mid-Jun contained (expressed as range of percentage of dry mass and items, with no range given for taxa found in only 1 bird; REG): 1-4% Chironomidae (n = 2-40), 12% Tipulidae (Prionocera sp.; n = 4), 14-19% Carabidae (n = 26-39), 3% Curculionidae (n = 8), 2% Tenebrionidae (n = 4), 11-22% unidentified Coleoptera parts, 1-3% gastropods (land snails; n = 9-28), and 4% crowberry (n = 10-13). From 3 sites in Australia, polychaetes made up 86.7-88.2% of ingested items (n = 918); remaining 11.8-13.3% unidentified (n = 132; Taylor et al. 1996 Taylor, I. R., S. G. Taylor and G. N. Larmour. (1996). The effect of food stealing by Silver Gulls Larus novaehollandiae on the foraging efficiency of Bar-tailed Godwits Limosa lapponica. Emu 96:234-239. Close ). Polychaetes also important in diet of godwits wintering in w. Africa (Piersma 1982a Piersma, T. (1982a). "Foraging of Bar-tailed Godwits." In Wintering waders of the Banc d'Arguin, Mauritania., edited by W. Altenburg, M. Engelmoer, R. Mes and T. Piersma, 136-148. Leiden, The Netherlands: Communication no. 6. Wadden Sea Working Group. Close , Engelmoer et al. 1984 Engelmoer, M., T. Piersma, W. Altenberg and R. Mes. (1984). "The Banc d'Arguin (Mauritania)." In Coastal waders and wildfowl in winter., edited by P. R. Evans, J. D. Goss-Custard and W. J. Hale, 293-310. Cambridge, U.K: Cambridge Univ. Press. Close ). In W Europe during winter, 99.6% diet’s biomass consists out of polychaete worms, including on average 79% Nereis (Hediste) diversicolor, 17% Alitta virens and 2% Arenicola marina (Duijns et al. 2013 Duijns, S., Hidayati, N.A. and Piersma, T. (2013). Bar-tailed Godwits Limosa l. lapponica eat polychaete worms wherever they winter in Europe. Bird Study. 60(4): 509–517. Close ).

Little known. In Australia, L. lapponica preyed exclusively on polychaete worms 2-9 cm in length (Taylor et al. 1996 Taylor, I. R., S. G. Taylor and G. N. Larmour. (1996). The effect of food stealing by Silver Gulls Larus novaehollandiae on the foraging efficiency of Bar-tailed Godwits Limosa lapponica. Emu 96:234-239. Close ). In Great Britain, this godwit takes much higher proportion of smaller prey (polychaete Scoloplos armiger) as substrate temperatures decrease below 3°C (Smith 1975d Smith, P. C. (1975d). A study of the winter feeding ecology and behavior of the Bar-tailed Godwit Limosa lapponica. Unpubl. Ph.D. thesis, Univ. of Durham, Durham, U.K. Close , Evans 1976b Evans, P. R. (1976b). Energy balance and optimal foraging strategies in shorebirds: some implications for their distributions and movements in the non-breeding season. Ardea 64:117-139. Close ). Not known to store food.

In England, estimated to take 97 kcal of polychaetes (Nereis spp.) plus 148 kcal of bivalves (Macoma spp.)/d; calculated daily basal metabolic rate (BMR) of about 34 kcal/d (M. Greenhalgh and W. Hale in Cramp and Simmons 1983 Cramp, S., and K. E. L. Simmons (1983). The Birds of the Western Palearctic, Volume 3: Waders to Gulls. Oxford University Press, Oxford, UK. Close ). In w. Africa, L. l. lapponica with BMR of 27.9-31.2 kcal/d and daily intake of 19.7-22.0 g ash-free dry weight/d (Engelmoer et al. 1984 Engelmoer, M., T. Piersma, W. Altenberg and R. Mes. (1984). "The Banc d'Arguin (Mauritania)." In Coastal waders and wildfowl in winter., edited by P. R. Evans, J. D. Goss-Custard and W. J. Hale, 293-310. Cambridge, U.K: Cambridge Univ. Press. Close ). No information pertaining to young birds. Mixing of fruit and invertebrates in digestive tracts of staging birds may chemically enhance nutrient assimilation, physically facilitate break-down or passage of food items, and/or maximize rate of nutrient accumulation (McCaffery 1998b McCaffery, B. J. (1998b). Implications of frequent habitat switches in foraging Bar-tailed Godwits. Auk 115:494-497. Close ).

Northbound e. Atlantic migrants (L. l. taymyrensis) maintain water balance during long flights by flying at optimal altitudes whereby ambient temperature sufficiently low to dissipate heat by convection and minimize water loss through evaporative cooling (Landys et al. 2000 Landys, M., T. Piersma, G. Visser, J. Jukema and A. Wuker. (2000). Water balance during real and simulated long-distance migratory flight in the Bar-tailed Godwit. Condor 102:645-652. Close ). At Banc d'Arguin, Mauritania, godwits apparently not heat-stressed during extreme temperatures (Klaassen 1990 Klaassen, M. (1990). Short note on the possible occurrence of heat stress in roosting waders on the Banc d'Arguin, Mauritania. Ardea 78:63-65. Close ), but 1,000 km farther south in Guinea-Bissau, T. Piersma (pers. comm.) ob-served godwits swimming in intertidal waters (water temperature 32-34°C) during high tide rather than flying to roost area on beaches (air temperatures 36-43°C). Thermostatic costs influence winter distribution and within-winter movements of L. l. lapponica at sites in German Wadden Sea (Scheiffarth 1996 Scheiffarth, G. (1996). How expensive is wintering in the Wadden Sea? Thermostatic costs of Bar-tailed Godwits (Limosa lapponica) in the northern part of the Wadden Sea. Proc. German Zool. Soc. 89:178. Close ); L. l. baueri depart Alaska in fall before similar cold conditions set in (see Migration: timing and routes of migration, above).

Drinks fresh and brackish water by dipping bill in water and tipping head up slightly. Pellet-casting noted in nominate L. l. lapponica on winter grounds in England (Goss-Custard et al. 1977b Goss-Custard, J. D., R. E. Jones and P. E. Newbery. (1977b). The ecology of the Wash. I. Distribution and diet of wading birds (Charadrii). Journal of Applied Ecology 14:681-700. Close ). Regularly defecates at high-tide roosts (REG).