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Peter L. F. Fast Marie Fast Anders Mosbech Christian Sonne H. Grant Gilchrist Sébastien Descamps 《The Journal of wildlife management》2011,75(7):1553-1557
Surgically implanted satellite transmitters have been widely used in studies of avian ecology, yet little is known about their potential impacts on birds. We implanted satellite transmitters with percutaneous antennae (approx. 50 g) in 17 female common eiders (Somateria mollissima) at a breeding colony in Arctic Canada. Among females implanted during incubation, 11 of 12 nests were abandoned within 1 week of being radioed. We observed no differences in the proportion of time that implanted female eiders allocated to basic behaviors. Radioed birds were more likely to pick or preen their abdominal (site of surgical incision) and posterior–dorsal (site of antenna exit) regions than unmarked females, although these behaviors were rare (approx. 0.3% of total time budget). Three of 10 females re-observed had a pronounced limp following surgery, but we observed no walking difficulties among these females in subsequent seasons, and we observed some implanted eiders nesting in subsequent years. Mark–resighting models suggest eiders with transmitters had lower apparent survival the year after implantation (67.0%; 85% CI: 47.8–81.9%) than did color-banded eiders (87.5%, 85% CI: 82.5–91.2%), but there was no model support for a survival difference in subsequent years. We conclude that transmitter implantation in common eiders leads to short-term changes in behavior and a decline in first year survival. We encourage researchers to collect similar data on their study subjects where possible and use it to determine the degree to which data are representative of the greater population. © 2011 The Wildlife Society. 相似文献
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Jean-François Giroux Martin Patenaude-Monette Scott G. Gilliland G. Randy Milton Glen J. Parsons Mark L. Gloutney Katherine R. Mehl R. Bradford Allen Daniel G. McAuley Eric T. Reed Nic R. McLellan 《The Journal of wildlife management》2021,85(8):1646-1655
Sound management of bird populations rests upon an adequate understanding of their population dynamics. Our study evaluated recruitment and population growth rates of 14 American common eider (Somateria mollissima dresseri) colonies from Labrador, Nova Scotia, Quebec, Canada, and Maine, USA, during various periods between 1970 and 2019. We used Pradel mark-recapture models to estimate colony-specific growth rates and the relative contributions of survival and recruitment on growth. We also validated this approach using annual nest counts (~8,000 pairs) conducted between 2003 and 2019 during down harvest operations in 3 colonies located in the Saint Lawrence estuary in Quebec. There was generally a good agreement between estimates derived using the 2 approaches. We considered that capture-recapture data were suitable to estimate population trends of common eiders in other colonies, especially for colonies where accurate nest monitoring is impaired by dense vegetation. The breeding abundance declined at major colonies in Maine and Nova Scotia and increased or was stable in Quebec and Labrador. Female survival contributed the most to population growth, but variation in recruitment among colonies was more important than variation in survival to explain population growth. Management measures should thus strive to maximize local recruitment in colonies with declining populations. The assumption that apparent survival probabilities were homogeneous throughout an individual capture history was violated at several colonies in Quebec and Labrador. Using recaptures and band recoveries, we showed that the lower apparent survival for newly marked individuals compared to females that had been recaptured at least once was caused by a difference in site fidelity rather than true survival. But <1% of recaptured females dispersed to another colony for breeding, indicating that the lower site fidelity could be related to heterogeneity in capture probability among individuals. © 2021 The Wildlife Society. 相似文献
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Flemming R. Merkel 《The Journal of wildlife management》2010,74(8):1869-1874
ABSTRACT Severe population declines were reported for common eiders (Somateria mollissima) in western Greenland over the period 1960–2000. A monitoring program, concurrent with more restrictive hunting regulations on common eiders, revealed breeding numbers increasing by 212%, from 2,558 active nests in 2000 to 7,982 nests in 2007. Though it was not possible to directly link harvest reduction and population growth in West Greenland, a similar increase in breeding numbers in Canada was correlated with the harvest reduction in Greenland and linked to increasing adult survival and recruitment of first-time breeders, and a similar explanation is suggested for West Greenland. The study emphasizes that appropriate restrictions in hunting can be efficient in wildlife management and that common eiders can sustain dramatic rates of increase during population regrowth. It also shows that cost-efficient monitoring programs can be established through cooperation with local residents. 相似文献
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REBECCA L. BENTZEN ABBY N. POWELL ROBERT S. SUYDAM 《The Journal of wildlife management》2008,72(8):1781-1789
Abstract: King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2 sites, Teshekpuk and Kuparuk, Alaska, USA, 2002–2005. We evaluated both a priori and exploratory competing models of nest survival that considered importance of nest concealment, seclusion, and incubation constancy as strategies to avoid 2 primary egg predators, avian (Larus spp., Stercorarius spp., and Corvus corax) and fox (Alopex lagopus). We used generalized nonlinear techniques to examine factors affecting nest survival rates and information-theoretic approaches to select among competing models. Estimated nest survival, accounting for a nest visitation effect, varied considerably across sites and years (0.21–0.57); however, given our small sample size, much of this variation may be attributable to sampling variation (s̀2process = 0.007, 95% CI: 0.003–0.070). Nest survival was higher at Kuparuk than Teshekpuk in all years; however, due to the correlative nature of our data, we cannot determine the underlying causes with any certainty. We found mixed support for the concealed breeding strategy; females derived no benefit from nesting in areas with more willow (Salix spp.; measure of concealment) except that the observer effect diminished as willow cover increased. We suggest these patterns are due to conflicting predation pressures. Nest survival was not higher on islands (measure of seclusion) or with increased incubation constancy but was higher post-fox removal, indicating that predator control on breeding grounds could be a viable management option. Nest survival was negatively affected by our nest visitations, most likely by exposing the nest to avian scavengers. We recommend precautions be taken to limit the effects of nest visits in future studies and to consider them as a possible negative bias in estimated nest survival. Future models of the impacts of development within the breeding grounds of king eider should consider the influence of humans in the vicinity of nests. 相似文献
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Abstract The population of emperor geese (Chen canagica) in western Alaska, USA, declined by >50% from the 1960s to the mid-1980s and has increased only slightly since. Rates of population increase among arctic geese are especially sensitive to changes in adult survival. Improving adult survival in seasons or geographic areas where survival is low may be the best means of increasing the emperor goose population. We monitored fates of 133 adult female emperor geese that were radiomarked with surgically implanted very high frequency or satellite radiotransmitters from 1999 to 2004 to assess whether monthly survival varied among years, seasons, or geographic areas. Because of uncertainties in determining whether a bird had died based on the radio signal, we analyzed 2 versions of the data. One version used conservative criteria to identify which birds had died based on radio signals and the other used more liberal criteria. In the conservative version of the data we detected 12 mortalities of emperor geese, whereas in the liberal interpretation there were 18 mortalities. In both versions, the models with greatest support indicated that monthly survival varied seasonally and that compared to most seasons estimated monthly survival was lower (φ = 0.95–0.98) in May and August when emperor geese were mainly on the Yukon-Kuskokwim Delta. From 44% to 47% of annual mortality occurred in those months. Estimated monthly survival was higher (φ = 0.98–1.0) from September through March when emperor geese were at autumn staging or wintering areas and in June and July when birds were nesting, rearing broods, or molting. Estimated annual survival was 0.85 (95% CI = 0.77–0.92) in the best-supported model when we used conservative criteria to identify mortalities and 0.79 (95% CI = 0.74–0.85) under the best model using liberal mortality criteria. Lower survival in August and May corresponded to periods when subsistence harvest of emperor geese was likely highest. Managers may be able to most effectively influence population growth rate of emperor geese by reducing subsistence harvest on the Yukon-Kuskokwim Delta in May and August. 相似文献
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SARAH A. SONSTHAGEN SANDY L. TALBOT RICHARD B. LANCTOT KEVIN G. MCCRACKEN 《Molecular ecology》2010,19(4):647-657
We investigated local genetic associations among female Pacific common eiders (Somateria mollissima v‐nigrum) nesting in a stochastic Arctic environment within two groups of barrier islands (Simpson Lagoon and Mikkelsen Bay) in the Beaufort Sea, Alaska. Nonrandom genetic associations were observed among nesting females using regional spatial autocorrelation analyses for distance classes up to 1000 m in Simpson Lagoon. Nearest‐neighbour analyses identified clusters of genetically related females with positive lr values observed for 0–13% and 0–7% of the comparisons in Simpson Lagoon and Mikkelsen Bay, respectively, across years. These results indicate that a proportion of females are nesting in close proximity to more genetically related individuals, albeit at low frequency. Such kin groupings may form through active association between relatives or through natal philopatry and breeding site fidelity. Eiders nest in close association with driftwood, which is redistributed annually by seasonal storms. Yet, genetic associations were still observed. Microgeographic structure may thus be more attributable to kin association than natal philopatry and site fidelity. However, habitat availability may also influence the level of structure observed. Regional structure was present only within Simpson Lagoon and this island group includes at least three islands with sufficient driftwood for colonies, whereas only one island at Mikkelsen Bay has these features. A long‐term demographic study is needed to understand more fully the mechanisms that lead to fine‐scale genetic structure observed in common eiders breeding in the Beaufort Sea. 相似文献
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Sarah A. Sonsthagen Sandra L. Talbot Kim T. Scribner Kevin G. McCracken 《Journal of Biogeography》2011,38(7):1368-1380
Aim Glacial refugia during the Pleistocene had major impacts on the levels and spatial apportionment of genetic diversity of species in northern latitude ecosystems. We characterized patterns of population subdivision, and tested hypotheses associated with locations of potential Pleistocene refugia and the relative contribution of these refugia to the post‐glacial colonization of North America and Scandinavia by common eiders (Somateria mollissima). Specifically, we evaluated localities hypothesized as ice‐free areas or glacial refugia for other Arctic vertebrates, including Beringia, the High Arctic Canadian Archipelago, Newfoundland Bank, Spitsbergen Bank and north‐west Norway. Location Alaska, Canada, Norway and Sweden. Methods Molecular data from 12 microsatellite loci, the mitochondrial DNA (mtDNA) control region, and two nuclear introns were collected and analysed for 15 populations of common eiders (n = 716) breeding throughout North America and Scandinavia. Population genetic structure, historical population fluctuations and gene flow were inferred using F‐statistics, analyses of molecular variance, and multilocus coalescent analyses. Results Significant inter‐population variation in allelic and haplotypic frequencies were observed (nuclear DNA FST = 0.004–0.290; mtDNA ΦST = 0.051–0.927). Whereas spatial differentiation in nuclear genes was concordant with subspecific designations, geographic proximity was more predictive of inter‐population variance in mitochondrial DNA haplotype frequency. Inferences of historical population demography were consistent with restriction of common eiders to four geographic areas during the Last Glacial Maximum: Belcher Islands, Newfoundland Bank, northern Alaska and Svalbard. Three of these areas coincide with previously identified glacial refugia: Newfoundland Bank, Beringia and Spitsbergen Bank. Gene‐flow and clustering analyses indicated that the Beringian refugium contributed little to common eider post‐glacial colonization of North America, whereas Canadian, Scandinavian and southern Alaskan post‐glacial colonization is likely to have occurred in a stepwise fashion from the same glacial refugium. Main conclusions Concordance of proposed glacial refugia used by common eiders and other Arctic species indicates that Arctic and subarctic refugia were important reservoirs of genetic diversity during the Pleistocene. Furthermore, suture zones identified at MacKenzie River, western Alaska/Aleutians and Scandinavia coincide with those identified for other Arctic vertebrates, suggesting that these regions were strong geographic barriers limiting dispersal from Pleistocene refugia. 相似文献
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Tiedemann R Paulus KB Havenstein K Thorstensen S Petersen A Lyngs P Milinkovitch MC 《Molecular ecology》2011,20(15):3237-3250
Intraspecific brood parasitism (IBP) is a remarkable phenomenon by which parasitic females can increase their reproductive output by laying eggs in conspecific females' nests in addition to incubating eggs in their own nest. Kin selection could explain the tolerance, or even the selective advantage, of IBP, but different models of IBP based on game theory yield contradicting predictions. Our analyses of seven polymorphic autosomal microsatellites in two eider duck colonies indicate that relatedness between host and parasitizing females is significantly higher than the background relatedness within the colony. This result is unlikely to be a by-product of relatives nesting in close vicinity, as nest distance and genetic identity are not correlated. For eider females that had been ring-marked during the decades prior to our study, our analyses indicate that (i) the average age of parasitized females is higher than the age of nonparasitized females, (ii) the percentage of nests with alien eggs increases with the age of nesting females, (iii) the level of IBP increases with the host females' age, and (iv) the number of own eggs in the nest of parasitized females significantly decreases with age. IBP may allow those older females unable to produce as many eggs as they can incubate to gain indirect fitness without impairing their direct fitness: genetically related females specialize in their energy allocation, with young females producing more eggs than they can incubate and entrusting these to their older relatives. Intraspecific brood parasitism in ducks may constitute cooperation among generations of closely related females. 相似文献
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The southeast Beaufort Sea is a critical spring staging area for common and king eiders (Somateria mollissima v-nigrum, S. spectabilis), and is for many the final stop before they reach their breeding grounds throughout the western Canadian Arctic. The region also has significant oil and gas potential, and the recent approval of a pipeline through the Mackenzie Valley may make development of these resources economically viable. We used satellite telemetry to determine the distribution and habitat use of eiders staging in the southeast Beaufort Sea in spring, and the overlap of eiders with oil and gas exploration. From 2004 to 2009, we monitored 51 eiders equipped with platform terminal transmitters (PTTs) throughout spring migration (May–June). We compared the marine habitats used by each species, and evaluated habitat preferences using resource selection functions. The location and extent of the flaw lead (open water along the interface between mobile pack ice and stationary landfast ice) at the time when eiders were staging varied among years, but both species showed a strong preference for use of flaw lead habitats. This preference was stronger for common eiders than for king eiders, which also used pack ice extensively. Common eiders generally occurred near the landfast ice edge, whereas king eiders were just as often nearer to the pack ice edge of the flaw lead. Average water depth (±SE) for common eiders was 22 ± 2 m compared to 30 ± 1 m for king eiders. Kernel density estimators showed that eiders generally occurred in lower densities in areas of otherwise suitable habitat off the Mackenzie River delta. We suggest that this is a result of the highly turbid water discharged by the Mackenzie River, which limits visibility. Oil and gas exploration overlapped significantly with the areas used by eiders. The high density of birds using the restricted and ice-rich flaw lead habitats indicates that an accidental spill in the region could be catastrophic for Canada's western Arctic eider populations. © 2013 The Wildlife Society. 相似文献
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Partner choice is important in nature, and partnerships or coalitionswithin which reproduction is shared are the subject of growinginterest. However, little attention has been given to questionsof which individuals are suitable partners and why. Common eider(Somateria mollissima) females sometimes pool their broods andshare brood-rearing duties, and body condition affects caredecisions. We constructed a model in which females, based ontheir body condition and the structure of the joint brood, assessthe fitness consequences of joining a coalition versus tendingfor young alone. We tested the model's predictions by comparingdata on the condition of females in enduring and transient coalitions.Our model showed that the range of acceptable brood arrays ina female coalition decreases with increasing condition of thefemale, so females tending alone should be in better conditionthan multifemale tenders. This prediction is in agreement withprevious data. The model also predicts that females in goodcondition should join coalitions with females in poor conditionand not with other females in good condition. This predictionwas also supported by data: in enduring two-female coalitions,the positive correlation between the better female's conditionand the difference in condition between the two females wasstronger than would be expected by random grouping of females.In contrast, in transient coalitions of females, this correlationdid not differ from the correlation expected under random grouping.Model assumptions seem to fit with eider natural history, andthe model may prove to be a useful way to study brood amalgamationbehavior of waterfowl in general. 相似文献
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LAURA M. PHILLIPS ABBY N. POWELL ERIC J. TAYLOR ERIC A. REXSTAD 《The Journal of wildlife management》2007,71(6):1892-1898
Abstract: We estimated areas used by king eiders (Somateria spectabilis) in the Alaskan Beaufort Sea, how distributions of used areas varied, and characteristics that explained variation in the number of days spent at sea, to provide regulatory agencies with baseline data needed to minimize impacts of potential offshore oil development. We implanted sixty king eiders with satellite transmitters at nesting areas on the North Slope of Alaska, USA, in 2002-2004. More than 80% of marked eiders spent >2 weeks staging offshore prior to beginning a postbreeding molt migration. During postbreeding staging and migration, male king eiders had much broader distributions in the Alaskan Beaufort Sea than female eiders, which were concentrated in Harrison and Smith Bays. Distribution did not vary by sex during spring migration in the year after marking. Shorter residence times of eiders and deeper water at locations used during spring migration suggest the Alaskan Beaufort Sea might not be as critical a staging area for king eiders during prebreeding as it is postbreeding. Residence time in the Beaufort Sea varied by sex, with female king eiders spending more days at sea than males in spring and during postbreeding. We conclude the Alaskan Beaufort Sea is an important staging area for king eiders during postbreeding, and eider distribution should be considered by managers when mitigating for future offshore development. We recommend future studies examine the importance of spring staging areas outside the Alaskan Beaufort Sea. 相似文献
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Jordan M. Thompson Thomas V. Riecke Bryan L. Daniels Kyle A. Spragens Melissa L. Gabrielson Christopher A. Nicolai Benjamin S. Sedinger 《The Journal of wildlife management》2022,86(5):e22223
Despite the importance of green-winged teal (Anas crecca) as a harvested species in North America, recent information on variation in vital rates among regions is lacking. We used band recovery data and hierarchical autoregressive models to examine temporal and age-sex-class variation in survival, hunting mortality, and nonhunting mortality probabilities of green-winged teal banded at Kgun Lake on the Yukon-Kuskokwim Delta, Alaska, USA, from 1997–2019. We used data from 10,554 adult and juvenile green-winged teal of known sex and age banded and released at Kgun Lake, and 1,245 hunter recoveries. Estimates of annual survival probability for adult females and males ranged from 0.44 (95% CI = 0.29–0.54) to 0.49 (95% CI = 0.37–0.68) and 0.56 (95% CI = 0.50–0.61) to 0.58 (95% CI = 0.50–0.64), respectively, during our study period. Estimates of annual survival probability for juvenile females and males ranged from 0.36 (95% CI = 0.18–0.56) to 0.46 (95% CI = 0.31–0.71) and 0.51 (95% CI = 0.38–0.61) to 0.56 (95% CI = 0.44–0.71), respectively. Hunting mortality probability was greatest for juvenile males and least for adult females. Hunting mortality probability of juvenile males increased from 0.09 (95% CI = 0.05–0.13) in 1997 to 0.14 (95% CI = 0.11–0.18) in 2015. Nonhunting mortality probability was greater and more variable than hunting mortality probability for all age-sex classes, indicating nonhunting mortality contributed most to total mortality of green-winged teal banded at Kgun Lake during our study. Additionally, survival probability of female green-winged teal banded at Kgun Lake is less than published estimates for green-winged teal banded in the boreal forest of Alaska. We recommend continuing consistent banding operations for green-winged teal on the Yukon-Kuskokwim Delta and other important breeding areas to further understand factors influencing nonhunting mortality and how they may vary seasonally and geographically. 相似文献
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E. Isabel Buttler H. Grant Gilchrist Sébastien Descamps Mark R. Forbes Catherine Soos 《The Journal of wildlife management》2011,75(2):283-288
Researchers often consider the importance of minimizing holding time during research activities; however, the long-term costs of such handling stress is rarely measured explicitly. As part of an ongoing study of common eiders (Somateria mollissima) at a breeding colony in East Bay, Southampton Island, Nunavut, we recorded duration of restraint for females captured during avian cholera epizootics (2007 and 2008) and monitored female fates (breeding probability, onset of laying, and survival) relative to holding time. Probability of death increased with holding time in 2007 from an estimated 0.05 for females held 20 min to 0.33 for females held for 150 min. In 2008, we responded by limiting holding time to <90 min and mortality was no longer positively correlated with holding time, although total mortality was greater due to increased severity of avian cholera. In both years, longer restraint durations delayed onset of egg-laying after capture by 0.5 days for each 10 min of additional restraint but did not prevent breeding. This delay of nest initiation did not enhance survival probability. Our results show that prolonged holding time can exacerbate mortality during epizootics and emphasize the importance of minimizing restraint time in wild birds, especially in the presence of diseases. © 2011 The Wildlife Society. 相似文献
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ABSTRACT We seeded experimental plots with number 4 lead pellets and sampled these plots for 10 years to assess the settlement rate of pellets in tundra wetland types commonly used by foraging waterfowl. After 10 years, about 10% of pellets remained within 6 cm of the surface, but >50% remained within 10 cm. We predict that spent lead pellets will eventually become unavailable to waterfowl; however, it will likely require >25 years for all pellets to exceed depths at which waterfowl species may forage. 相似文献
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KELLY K. HASTINGS TOM S. GELATT JAMES C. KING 《The Journal of wildlife management》2009,73(7):1040-1051
ABSTRACT Steller sea lion (Eumetopias jubatus) pups (n = 366) were hot-branded at Lowrie Island, Southeast Alaska, USA, in June 2001 and 2002 for vital-rates studies. To assess potential mortality following branding, we estimated weekly survival to 12 weeks postbranding using mark-recapture models. Survival estimates ranged from 0.984/week to 0.988/week, or 0.868 over the 12-week period; varied little with sex, year, and capture area; and were higher for larger than smaller male pups and unexpectedly lower for larger than smaller female pups. Inclusion of resights at 1–3 years of age prevented a −4.5% bias in cumulative survival to 12 weeks postbranding by accounting for pups that survived but permanently emigrated from Lowrie Island during the 12-week survey. Data from double-marked pups (i.e., branded and flipper-tagged) indicated the low brand-misreading probability of 3.1% did not bias survival estimates. Assuming survival differences between the first 2 weeks postbranding and later weeks were due entirely to the branding event, potential postbranding mortality of branded pups attributable to the branding event was 0.5–0.7%, or one pup for every 200 marked. Weekly survival of branded pups was nearly identical to estimates from a control group of undisturbed, unbranded pups born to 10–11-year-old branded adult females in 2005 (0.987–0.988/week) and similar to pup survival estimates from other otariid studies. Available data did not indicate substantial mortality to 12 weeks postbranding resulting from the branding disturbance, suggesting branding of Steller sea lion pups can be used effectively for investigations of population declines without significantly affecting population health or study goals. 相似文献
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ABSTRACT Population parameters of American martens (Martes Americana) are often monitored to guide management actions. In order to better understand changing marten population demographics, we estimated marten abundance and several population parameters on a portion of northeast Chichagof Island (NCI), Southeast Alaska, USA, using capture-mark–recapture methods in combination with radiotelemetry and compared these data with demographic estimates derived from the trapper catch from the larger NCI area. We found that capture probability remained relatively high across trapping sessions by using a standard live-trapping protocol, and we found no evidence of capture probability being consistently affected by population or environmental factors. Estimated marten numbers varied greatly over the period, ranging from a low of 14.1 martens (0.17/km2) during winter 1997–1998 to a high of 45.6 martens (0.55/km2) during winter 1995–1996. The annual trend was for decreasing numbers from winter 1990–1991 to winter 1992–1993, then increasing numbers through winter 1995–1996. By winter 1996–1997, numbers had dropped substantially and remained low through 1997–1998. All population parameters varied temporally, including annual survival (0.34–1.00), sex ratio (1.0–3.5), mean age (0.5–2.9), body condition (-0.08–1.35), and fecundity (0.44–2.70). Yearly trapper catches on NCI varied greatly from 19 to 354 martens (0.02 martens/km2 to 0.31 martens/km2) because of changing trapper effort and marten abundance. We found mean ages of carcasses a good predictor of population mean age, but sex ratios were highly variable. Marten numbers and fecundity were strongly correlated with rodent abundance, especially long-tailed voles (Microtus longicaudus). By monitoring demographic parameters of the population or trapper-caught carcasses, managers can gain insight into temporal population dynamics. Also, total captures of individuals may provide a useful estimate of marten numbers without the expense of radiocollaring and tracking individuals because population estimates were highly correlated with number of individuals captured during a standard survey. Because of their high vulnerability to trapping, close monitoring of marten populations is important for the conservation and sustained-yield management of the species. A tracking strategy developed with input data on preseason abundance and age structure may be the best management approach, especially for small populations with limited immigration. 相似文献