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The Arctic is undergoing rapid and accelerating change in response to global warming, altering biodiversity patterns, and ecosystem function across the region. For Arctic endemic species, our understanding of the consequences of such change remains limited. Spectacled eiders (Somateria fischeri), a large Arctic sea duck, use remote regions in the Bering Sea, Arctic Russia, and Alaska throughout the annual cycle making it difficult to conduct comprehensive surveys or demographic studies. Listed as Threatened under the U.S. Endangered Species Act, understanding the species response to climate change is critical for effective conservation policy and planning. Here, we developed an integrated population model to describe spectacled eider population dynamics using capture–mark–recapture, breeding population survey, nest survey, and environmental data collected between 1992 and 2014. Our intent was to estimate abundance, population growth, and demographic rates, and quantify how changes in the environment influenced population dynamics. Abundance of spectacled eiders breeding in western Alaska has increased since listing in 1993 and responded more strongly to annual variation in first‐year survival than adult survival or productivity. We found both adult survival and nest success were highest in years following intermediate sea ice conditions during the wintering period, and both demographic rates declined when sea ice conditions were above or below average. In recent years, sea ice extent has reached new record lows and has remained below average throughout the winter for multiple years in a row. Sea ice persistence is expected to further decline in the Bering Sea. Our results indicate spectacled eiders may be vulnerable to climate change and the increasingly variable sea ice conditions throughout their wintering range with potentially deleterious effects on population dynamics. Importantly, we identified that different demographic rates responded similarly to changes in sea ice conditions, emphasizing the need for integrated analyses to understand population dynamics., Our understanding of the consequences of climate change for Arctic endemic species is limited. We developed an integrated population model to describe the population dynamics of spectacled eiders, a threatened Arctic sea duck. Our analysis revealed abundance has increased since listing under the Endangered Species Act in 1993, however, spectacled eiders are vulnerable to climate change and the increasingly variable sea ice conditions experienced throughout their core wintering range.

Conspecific presence can indicate the location or quality of resources, and animals settling near conspecifics often gain fitness benefits. This can result in adaptive conspecific attraction during breeding habitat selection as demonstrated in numerous terrestrial, territorial birds. There is growing interest in using simulated conspecific social cues (e.g., decoys, broadcasted vocalizations) to manage bird distributions, yet it remains unclear when this approach is likely to succeed. We reviewed published studies to evaluate whether the strength of conspecific attraction in terrestrial birds is mediated by characteristics of species (life history traits), simulated cues (e.g., timing and duration), sites (e.g., quality), and how conspecific attraction was measured. We identified 31 experiments that simulated social cues and compared conspecific settlement between treatment and control sites. We then used phylogenetically controlled meta-regression to assess the impacts of 19 moderators on settlement. Nearly all species included in these experiments were migratory passerines, and social cues generally had a strong, positive influence on their settlement decisions, as the odds of site occupancy were 3.12× (95% CI: 0.81–11.69) greater in treatment sites relative to control sites. Within this group, conspecific attraction was evolutionarily conserved with ≥25.5% (95% CI: 5.1%–65.4%) of the variance in treatment effects explained by phylogenetic relatedness. However, we found no evidence that any covariates influenced the response to social cues, and we posit this stems from limited research specifically designed to identify the mechanisms mediating conspecific attraction. We therefore developed a research agenda that provides a framework for testing mechanistic hypotheses regarding how cue characteristics, species traits, and spatial contexts may mediate attraction to conspecifics. Evaluating these hypotheses will greatly advance the field by helping managers understand when, where, and why simulating social cues can be used to enhance populations of species that are of conservation concern.LAY SUMMARYSimulating the presence of terrestrial birds often attracts breeders of the same species, though how this varies among species, simulated cues, or locations remains unknown.We reviewed 31 experiments that examined conspecific attraction to simulated social cues in terrestrial breeding birds and tested the effects of 19 variables on attraction.These experiments, which focused primarily on migratory songbirds, revealed strong effects of simulated presence on settlement rates, but no strong evidence that any other variables affected settlement rate.Simulating social cues such as vocalizations could be useful for managers interested in attracting migratory songbirds, although whether this extends to other terrestrial species remains unknown.A greater understanding of how and where to use this technique will improve its utility as a tool for enhancing populations of species of conservation concern.

Thirty years of research has made carotenoid coloration a textbook example of an honest signal of individual quality, but tests of this idea are surprisingly inconsistent. Here, to investigate sources of this heterogeneity, we perform meta-analyses of published studies on the relationship between carotenoid-based feather coloration and measures of individual quality. To create color displays, animals use either carotenoids unchanged from dietary components or carotenoids that they biochemically convert before deposition. We hypothesize that converted carotenoids better reflect individual quality because of the physiological links between cellular function and carotenoid metabolism. We show that feather coloration is an honest signal of some, but not all, measures of quality. Where these relationships exist, we show that converted, but not dietary, carotenoid coloration drives the relationship. Our results have broad implications for understanding the evolutionary role of carotenoid coloration and the physiological mechanisms that maintain signal honesty of animal ornamental traits., Studies of honest signaling have found an inconsistent relationship between carotenoid coloration and individual quality. Here, Weaver et al. compare dietary and biochemically converted carotenoid coloration using meta-analyses and show that converted carotenoids drive relationships with quality measures.

Species that provide intensive parental care could suffer fitness costs associated with conspecific brood parasitism. Here we evaluate the effect of conspecific brood parasitism on apparent annual survival probability of female Prothonotary Warblers Protonotaria citrea using a multistate model with imperfect state assignment analysed in a hierarchical Bayesian framework. We found no difference in annual survival probability between host and non-host females. These findings agree with previous work in that there seems to be little apparent cost of conspecific brood parasitism to female warblers in this system. This article is protected by copyright. All rights reserved.

All ecological measurements are subject to error; the effects of missed detection (false negatives) are well known, but the effects of mistaken detection (false positives) are less understood. Long-term capture–recapture datasets provide valuable ecological insights and baselines for conservation and management, but where such studies rely on noninvasive re-encounters, such as field-readable color bands, there is the potential to accumulate detection errors as the length of the study and number of tags deployed increases. We investigated the prevalence and effects of misreads in a 10-yr dataset of Red Knots (Calidris canutus rufa) marked with field-readable leg flags in Delaware, USA. We quantified the effects of misreads on survival estimation via a simulation study and evaluated whether removal of individuals only reported once in a year (potential misreads) influenced survival estimation from both simulated datasets and our case study data. We found overall apparent error rates of 0.31% (minimum) to 6.6% (maximum). Observer-specific error rates and the variation among observers both decreased with the number of flags an observer recorded. Our simulation study showed that misreads lead to spurious negative trends in survival over time, particularly for long-term studies. Removing all records in which a flag was only recorded once in a sampling occasion reduced bias and eliminated spurious negative trends in survival but also reduced precision in survival estimates. Without data filtering, we found a slight decrease in Red Knot annual survival probability from 2008 to 2018 (β = −0.043 ± 0.03), but removing all single-observation records resulted in no apparent trend (β = −0.0074 ± 0.02). Spurious trends in demographic rates could influence inference about population trajectories and resultant conservation decision-making. Data filtering could eliminate errors, but researchers should carefully consider the tradeoff between precision obtained by larger sample sizes and potential bias due to misreads in their data.

Conspecific brood parasitism (CBP), although prevalent in some avian taxa, is easily overlooked when it occurs in low frequencies, and therefore the ecology of this behavior has only occasionally been described in passerines. We describe the occurrence of CBP in a population of Prothonotary Warblers (Protonotaria citrea) breeding in nest boxes, demonstrate associated fitness costs, and investigate parasite strategy. We genotyped individuals at 6 microsatellite loci and used Cervus software to determine log-likelihood of maternity (LOD scores) for offspring and social mothers. We set critical cutoff LOD scores at 95% confidence for exclusion of the social mother and assignment of a parasite mother from the breeding population. Of 805 nestlings (233 family groups during 2009–2013), we found that 12.7% had genotypes that were incompatible with their social mother. Females with unrelated nestlings (hosts) fledged fewer biological offspring within the host year than nonhost females despite fledging mo...