Time and Energy Budgets of American Black Ducks in Winter

Morton, John M.; Fowler, Ada C.; Kirkpatrick, Roy L.

doi:10.2307/3801143

Cited by 41 publications

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“…Estimates of daily energy expenditure (DEE) were 631 kJ d-' for wigeon (Mayhew 1988), 683 kJ d-' for mallard (Morton et al 1989), 660 kJ d-l for pintail (interpolated for a body mass of 900 g from values for wigeon and mallard) and 842 kJ d-' for brant (Drent et al 1978/79). We measured gross energies of Z. japonica leaves, rhizomes and seeds (kJ g-l],,) with micro-bomb calorimetry.…”

Section: Methodsmentioning

confidence: 99%

Expansion of seagrass habitat by the exotic Zostera lapontca. and its use by dabbling ducks and brant in Boundary Bay, British Columbia

Baldwin¹

1994

Mar. Ecol. Prog. Ser.

102

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The exotic seagrass Zostera japonica was first documented on the Pacific Coast of North America in the late 1950s, and has extensively colonized formerly unvegetated tidal flats and dramatically altered the habitat structure. In Boundary Bay, British Columbia, Canada, there was an almost 17-fold increase in Z. japonica coverage between 1970 and 1991. In Boundary Bay's 6385 ha of intertidal and shallow subtidal area (tidal range 4.7 m), Z. japonica occurred mostly from 0 to -1.8 m Mean Water Level (MWL) and covered 3845 ha in October 1991 The native 2. marina occurred mostly from -0.9 to -5.5 m MWL, and covered 3444 ha including 1684 ha of overlap with Z. japonica. Standing stock of Z. japonica, mostly in formerly unvegetated areas, measured 520 metric tonnes (t) above ground and 235 t below ground in October 1991 Thls introduced species provides an important feedlng habitat for many migratory waterfowl. Percent dry mass of Z. japonica in esophagus contents of birds collected in Boundary Bay was 57.2 % (n = 62) in brant Branta bernicla, 84.8 % (n = 45) in American wigeon Anas arnencana, 72.3 % (n = 20) in mallard A. platyrhynchos, 48.3 % (n = 54) in northern pintail A. acuta, and 1.7 % (n = 14) in green-winged teal A. crecca. Percent dry mass of the native Z. marina was 41.2% in esophagi of brant but only 0.1 to 4.6% in the other species. Grazing by brant and dabbling ducks, with peak numbers of about 80 000 in early December, removed 50% (262 t) of the above-ground biomass and 43 % (100 t) of the below-ground biomass of Z. japonica. This exotic seagrass thereby supported almost 4.6 million use days by these birds.

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Section: Methodsmentioning

confidence: 99%

Expansion of seagrass habitat by the exotic Zostera lapontca. and its use by dabbling ducks and brant in Boundary Bay, British Columbia

Baldwin¹

1994

Mar. Ecol. Prog. Ser.

102

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“…have mainly been documented for either wintering (Tamisier 1972;review in Paulus 1982;Miller 1985;Morton et al 1989) or breeding birds (e.g., Seymour 1974;Asplund 1981;Å ström 1992). Time use in staging spring-migrating dabbling ducks remains almost undocumented, even in very common and otherwise well-studied species (but see Arzel and Elmberg 2004).…”

Section: Introductionmentioning

confidence: 99%

A flyway perspective of foraging activity in Eurasian Green-winged Teal,Anas crecca crecca

2007

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Time-activity budgets in the family Anatidae are available for the wintering and breeding periods. We present the first flyway-level study of foraging time in a long-distance migrant, the Eurasian Green-winged Teal, Anas crecca crecca L., 1758 (''Teal''). Behavioral data from early and late spring staging, breeding, and molting sites were collected with standardized protocols to explore differences between the sexes, seasons, and diel patterns. Teal foraging activity was compared with that of the Mallard, Anas platyrhynchos L., 1758 and Northern Shoveler, Anas clypeata L., 1758, and the potential effects of duck density and predator-caused disturbance were explored. In early spring, foraging time was moderate (50.5%) and mostly nocturnal (45%). It increased dramatically in all three species at migration stopovers and during molt, mostly because of increased diurnal foraging, while nocturnal foraging remained fairly constant along the flyway. These patterns adhere to the ''income breeding'' strategy expected for this species. No differences between the sexes were recorded in either species studied. Teal foraging time was positively correlated with density of Teal and all ducks present, but negatively correlated with predator disturbance. Our study suggests that Teal, in addition to being income breeders, may also be considered as income migrants; they find the energy necessary to migrate at staging sites along the flyway.Résumé : Les budgets-temps des Anatidae sont disponibles pour les périodes d'hivernage et de reproduction. Nous pré-sentons la première étude, à l'échelle d'une voie de migration, du temps d'approvisionnement d'un migrateur de longue distance, la sarcelle d'hiver, Anas crecca crecca L., 1758. Les données comportementales de début et fin de migration printanière, reproduction et mue ont été obtenues, avec le même protocole, afin de tester les différences entre sexes, saisons et variations nycthémérales. L'approvisionnement des sarcelles est comparé à celui des canards colverts, Anas platyrhynchos L., 1758, et des canards souchets, Anas clypeata L., 1758; les effets de la densité de canards et du dérangement par les prédateurs sont également testés. Au début du printemps, le temps d'approvisionnement était court (50,5 %), et essentiellement nocturne (45 %). Il augmentait ensuite de façon spectaculaire pour les trois espèces sur les haltes migratoires et durant la mue (principalement à cause de l'approvisionnement diurne, l'approvisionnement nocturne étant constant). Ceci s'accorde avec la stratégie de « reproducteur sur revenu » attendue chez ces espèces. Aucune différence inter-sexe n'a été relevée chez les espèces étudiées. Le temps d'approvisionnement des sarcelles était corrélé positivement avec leur densité et celle de l'ensemble des canards présents et négativement avec le dérangement par les prédateurs. Les sarcelles seraient des reproducteurs mais également des migrateurs sur revenu, trouvant l'énergie nécessaire à leur migration en route.

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“…Feeding of waterfowl in winter is affected by ambient weather conditions (Jorde et al, 1984;Hepp, 1985;Miller, 1985;Morton et al, 1989;Michot et al, 2005). Redheads increase foraging activity in response to increased thermoregulatory demands Michot et al, 1994), as do many other species of waterfowl (Tamisier, 1974;Jorde et al, 1983;Paulus, 1988b;Bergan et al, 1989).…”

Section: Discussionmentioning

confidence: 96%

Foraging behavior of redheads (Aythya americana) wintering in Texas and Louisiana

Woodin

Michot

2006

Hydrobiologia

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Redheads, Aythya americana, concentrate in large numbers annually in traditional wintering areas along the western and northern rim of the Gulf of Mexico. Two of these areas are the Laguna Madre of Texas and Chandeleur Sound of Louisiana. We collected data on 54,340 activities from 103 redhead flocks in Texas and 51,650 activities from 57 redhead flocks in Louisiana. Males and females fed similarly, differing neither in levels of feeding (percent of all birds in flock that were feeding) (p>0.90) nor in percentages of birds feeding by diving, tipping, dipping, or gleaning from the surface (p>0.10). The foraging level of redheads in the upper Laguna Madre region was relatively constant throughout two winters. Foraging of redheads in early winter in Louisiana was significantly greater than redhead foraging in the upper Laguna Madre, but by late winter, foraging by redheads in Louisiana had declined to the same level as that shown by redheads foraging in the upper Laguna Madre. The overall foraging level of redheads from Chandeleur Sound was greater (41%) than that of redheads in the upper Laguna Madre (26%), yet it was quite similar to the 46% foraging level reported for redheads from the lower Laguna Madre. Redheads in the upper Laguna Madre region of Texas fed more by diving than did those in the Chandeleur Sound and the lower Laguna Madre. Diving increased in frequency in late winter. Greater reliance by redheads on diving in January and February indicates that the birds altered their foraging to feed in deeper water, suggesting that the large concentrations of redheads staging at this time for spring migration may have displaced some birds to alternative foraging sites. Our results imply that the most likely period for food resources to become limiting for wintering redheads is when they are staging in late winter.

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Time and Energy Budgets of American Black Ducks in Winter

Cited by 41 publications

References 0 publications

Expansion of seagrass habitat by the exotic Zostera lapontca. and its use by dabbling ducks and brant in Boundary Bay, British Columbia

Expansion of seagrass habitat by the exotic Zostera lapontca. and its use by dabbling ducks and brant in Boundary Bay, British Columbia

A flyway perspective of foraging activity in Eurasian Green-winged Teal,Anas crecca crecca

Foraging behavior of redheads (Aythya americana) wintering in Texas and Louisiana

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