Body condition of Eiders at Danish wintering grounds and at pre-breeding grounds in Åland

2018 ◽  
Vol 160 (1) ◽  
pp. 239-248 ◽  
Author(s):  
Karsten Laursen ◽  
Anders Pape Møller ◽  
Markus Öst
Keyword(s):  
Body Condition ◽  
Wintering Grounds ◽  
Breeding Grounds

scholarly journals Anthropogenic noise affects winter song structure of a long-distance migrant, Gambel’s white-crowned sparrow

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jennifer N Phillips ◽  
Madhusudan Katti
Keyword(s):  
Urban Areas ◽  
Noise Levels ◽  
Long Distance ◽  
Zonotrichia Leucophrys ◽  
Wintering Grounds ◽  
Song Structure ◽  
Habitat Features ◽  
Acoustic Mismatch ◽  
Breeding Grounds ◽  
Zonotrichia Leucophrys Gambelii

Abstract Many animals learn to produce acoustic signals that are used to attract mates and defend territories. The structure of these signals can be influenced by external features of the environment, including the anthropogenic soundscape. In many sedentary species, habitat features and soundscape appears to influence the cultural evolution of songs, often with tradeoffs for better transmission over sexually selected song structure. However, none have investigated whether noise on the wintering grounds affects song structure, which for long-distance migrants may result in an acoustic ‘mismatch’ when returning to a breeding ground. This study investigates urban noise effects on song structure in a long-distance migrant, Zonotrichia leucophrys gambelii, on the wintering grounds in the Fresno Clovis Metropolitan Area and in outlying non-urban areas. Songs and background noise levels were recorded concurrently, and song measurements of frequency and duration were examined differences across noise levels and habitats . We found that the buzz and trill decrease in bandwidth in the presence of noise. The length of the whistle and buzz portion of the song also tends to decreases with noise in urban habitats. This trend toward short, pure tones in noisy areas may transmit better in noisy urban winter habitats, but may not be adaptive on quieter breeding grounds. We suggest that future studies should consider whether winter auditory feedback and song learning environments have consequences for song crystallization and breeding success for long-distance migrants.

Prevalence of heartworm, Sarconema eurycerca, Wehr, 1939 (Nematoda), in whistling swan, Cygnus columbianus columbianus

1979 ◽  
Vol 57 (7) ◽  
pp. 1500-1502 ◽  
Author(s):  
William S. Seegar
Keyword(s):  
North Carolina ◽  
Blood Test ◽  
East Coast ◽  
North Slope ◽  
Wintering Grounds ◽  
Cygnus Columbianus ◽  
The North ◽  
Breeding Grounds

From 1973 to 1976, 795 whistling swans, Cygnus columbianus columbianus, were surveyed for microfilariae of the heartworm, Sarconema eurycerca, by blood test. Swans were captured on their east coast wintering grounds in Maryland and North Carolina, and on their breeding grounds on the North Slope, Alaska. Prevalence of heartworm in winter was 18, 9, 27, and 19% in 1973, 1974, 1975, and 1976, respectively. Prevalence was 32% in adults on the breeding grounds, 1974. Overall prevalence during 4 years was 20%; prevalence was 19% in adults and 24% in juveniles. Microfilariae were not found in cygnets 4 to 6 weeks of age on the breeding grounds.

Winter irruptive Snowy Owls (Bubo scandiacus) in North America are not starving

2018 ◽  
Vol 96 (6) ◽  
pp. 553-558 ◽  
Author(s):  
T. Curk ◽  
T. McDonald ◽  
D. Zazelenchuk ◽  
S. Weidensaul ◽  
D. Brinker ◽  
...  
Keyword(s):  
North America ◽  
Body Condition ◽  
Food Supply ◽  
Eastern North America ◽  
Lower Body ◽  
Age Classes ◽  
Winter Range ◽  
Breeding Grounds ◽  
Output Hypothesis ◽  
Bubo Scandiacus

Winter irruptions, defined as irregular massive movement of individuals over large distances, have been linked to food supply. Two hypotheses have been put forward: the “lack-of-food” suggests that a shortage of food forces individuals to leave their regular winter range and the “breeding output” suggests that unusually large food supplies during the preceding breeding season allows production of a large number of offspring dispersing in winter. According to the breeding output hypothesis, irruptive Snowy Owls (Bubo scandiacus (Linnaeus, 1758)) in eastern North America should not exhibit a lower body condition than individuals in regular wintering regions and individuals on the breeding grounds. Additionally, body condition of irruptive individuals should be unrelated to irruption intensity. Although body condition of juveniles was generally lower than that of adults and improved during the winter, we measured a fair body condition in both juvenile and adult irruptive Snowy Owls across North America. The results showed that Snowy Owls are not in a starving state during winter and that body condition of all age classes was not related to winter irruption intensity. Those results support the breeding output hypothesis suggesting that winter irruptions seem to be primarily the result of a large number of offspring produced when food availability on the breeding grounds is high.

Prevalence of lead exposure among age and sex cohorts of Canada geese

1992 ◽  
Vol 70 (5) ◽  
pp. 901-906 ◽  
Author(s):  
Stephen DeStefano ◽  
Christopher J. Brand ◽  
Donald H. Rusch
Keyword(s):  
Lead Exposure ◽  
Blood Lead ◽  
Threshold Value ◽  
Atomic Absorption Spectrophotometry ◽  
Lead Shot ◽  
Canada Geese ◽  
Wintering Grounds ◽  
Blood Samples ◽  
Breeding Grounds ◽  
Age And Sex

We examined the prevalence of lead exposure from ingestion of waste lead shot among age and sex cohorts of Canada geese (Branta canadensis) on the breeding, migration, and wintering grounds of the Eastern Prairie Population. Blood samples from 6963 geese were assayed for lead concentration by atomic absorption spectrophotometry. On the breeding grounds, no goslings and <1% of adults showed evidence of recent exposure to lead shot (i.e., concentrations in the blood elevated above the threshold value of 0.18 ppm lead). However, median background blood lead concentrations (i.e., blood samples with < 0.18 ppm lead) were higher in adults than goslings, indicating that exposure of adults to lead had occurred during previous seasons. Waste lead shot was available on the migration and wintering grounds, where a larger proportion of the blood samples from immatures (< 1 year old) than adults (> 1 year old) had lead concentrations ≥ 0.18 ppm. Median background lead levels remained higher in adults than in immatures throughout fall and winter. We also found that more immature males than immature females had elevated lead concentrations. Higher rates of intake of food and grit (including shot) probably partially account for the higher prevalence of elevated lead concentrations in immature Canada geese.

scholarly journals The Kill of Wild Geese by the Natives of the Hudson-James Bay Region

ARCTIC ◽  
1957 ◽  
Vol 10 (4) ◽  
pp. 211 ◽  
Author(s):  
Harold C. Hanson ◽  
Campbell Currie
Keyword(s):  
James Bay ◽  
Wintering Grounds ◽  
Bay Area ◽  
Breeding Grounds ◽  
Safe Limit

The economic plight of Indians and Eskimos in the Hudson-James Bay area is partly dependent on the numbers of wild geese nesting in or migrating through their territory. The information presented on kills indicates that the number taken by native hunters is within a safe limit of what the nesting populations of that area can withstand. Expansion of wintering grounds and inaccessibility of breeding grounds assure that wild geese will continue to be an important source of food for the northern natives.

scholarly journals Molt of the Gray Vireo

The Condor ◽  
2000 ◽  
Vol 102 (3) ◽  
pp. 610-618 ◽  
Author(s):  
Gary Voelker
Keyword(s):  
United States ◽  
Late Summer ◽  
Museum Specimens ◽  
Adult Males ◽  
Wintering Grounds ◽  
Dietary Shift ◽  
Breeding Grounds ◽  
Wintering Areas ◽  
Desert Regions ◽  
Northwestern Mexico

AbstractUsing museum specimens, I document the molt cycles and molting grounds of the Gray Vireo (Vireo vicinior). During prebasic molts, adult female Gray Vireos replace their primaries in 57 days, whereas adult males take 70 days; all body plumage is replaced during this molt. Prebasic molts occur almost exclusively on the breeding grounds; just 3 of 41 specimens replacing primaries were collected away from breeding grounds. No molting specimens were collected from wintering areas. Prealternate molt occurs on the wintering grounds, and appears limited to the replacement of innermost secondaries and a limited molt of body plumage. By performing prebasic molt on breeding grounds, the Gray Vireo differs from several other western breeding passerine species that use desert regions of the southwestern United States and northwestern Mexico to exploit late summer food resources. The areas of these southwestern desert regions used by other species form a small portion of the breeding grounds, and encompass the entire wintering grounds, of Gray Vireos. I hypothesize that this contrast in molting regions is not due to differences in the general timing of prebasic molts among these species; rather, the contrast may be due to constraints imposed on Gray Vireos by a dietary shift to fruit during winter and the need to defend winter territories.

Investigation of the geographic origin of burrowing owl fleas with implications for the ecology of plague

The Auk ◽  
2019 ◽  
Vol 136 (1) ◽  
Author(s):  
Kara A Navock ◽  
David H Johnson ◽  
Samantha Evans ◽  
Matthew J Kohn ◽  
James R Belthoff
Keyword(s):  
Isotope Analysis ◽  
Geographic Origin ◽  
Breeding Ground ◽  
Athene Cunicularia ◽  
Wintering Grounds ◽  
Burrowing Owls ◽  
Burrowing Owl ◽  
Isotopic Compositions ◽  
Breeding Grounds ◽  
Host Parasite

ABSTRACT Host-parasite relationships between Western Burrowing Owls (Athene cunicularia hypugaea) and the fleas (Pulex irritans, Siphonaptera:Pulicidae) they harbor were studied to understand the extent to which migratory Burrowing Owls translocated fleas from wintering grounds to breeding grounds. This has implications for host-parasite relationships in Burrowing Owls and also potentially for the dynamics of plague, as Burrowing Owl distributions overlap plague foci, owls inhabit fossorial mammal colonies where epizootic outbreaks of plague occur, and owls may harbor species of flea that are competent plague vectors. We used hydrogen stable isotope analysis to help elucidate geographic origins of fleas collected from adults and nestlings in 2 migratory populations of Burrowing Owls in Idaho and Oregon, USA. For adults, we posited that bird-mediated dispersal would impart flea isotopic compositions representative of southern latitudes and be similar to owl toenail tissue recently grown on wintering grounds, but they would differ from contour feathers presumably grown on breeding grounds the previous year. We assumed nestling feathers and toenails would have isotopic compositions representative of the breeding grounds. We analyzed contour feathers and toenails from adults collected shortly after they arrived in breeding grounds following spring migration and from nestlings later in the breeding season, to which we compared isotopic compositions in fleas collected from individuals of both age classes. Fleas on nestlings in both populations had isotopic compositions that did not differ from nestling feathers and toenails, suggesting that nestling fleas had breeding ground origins. Fleas on adults in one population (Oregon) had breeding ground isotopic signatures, as flea compositions did not differ from nestling feathers or toenails. Adult owls in Idaho had fleas that similarly did not express a wintering ground signature, but they were enriched in the heavy isotope (deuterium) relative to nestling feathers and toenails. Therefore, we discuss the possibility that adult owls in Idaho acquired fleas at migratory stopover sites. While the latter indicates that Burrowing Owls have the potential to disperse fleas, there was no evidence of continent-wide movement of fleas by owls from wintering grounds to breeding grounds.

Cross-seasonal dynamics in body mass of male Harlequin Ducks: a strategy for meeting costs of reproduction

2010 ◽  
Vol 88 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Daniel Esler ◽  
Jeanine C. Bond
Keyword(s):  
Body Mass ◽  
Spring Migration ◽  
Feeding Time ◽  
Energy Reserves ◽  
Costs Of Reproduction ◽  
Wintering Grounds ◽  
Energy Stores ◽  
Harlequin Ducks ◽  
Breeding Grounds ◽  
Wintering Areas

Considerations of acquisition of energy for reproduction by waterfowl have disproportionately focused on females, although males also require energy for reproduction. We quantified variation in body mass of male Harlequin Ducks ( Histrionicus histrionicus (L., 1758)) on coastal wintering areas prior to spring migration, as well as on breeding grounds, to determine when and where nutrients were acquired to meet costs of reproduction. Male mass on wintering grounds increased, on average, by 45 g (7%) in the weeks prior to migration. On breeding streams, we inferred that body mass of paired males decreased with the length of time on breeding grounds. Also, on average, male mass was considerably lower on breeding streams than when they departed coastal wintering sites. We conclude that males store nutrients on marine wintering grounds for subsequent use during the breeding season. Male Harlequin Ducks are highly vigilant while on breeding streams and the associated reduction in feeding time presumably requires energy stores. We suggest that males have evolved a strategy that is at least partially “capital” for meeting costs of reproduction, in which they acquire an optimal amount of energy reserves prior to spring migration and subsequently invest them in behaviours that can enhance reproductive success.

Sign in / Sign up

Export Citation Format

Share Document