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Estimates first‐year survival of spectacled eiders in the Yukon‐Kuskokwim Delta breeding population in western Alaska. Black circles dashed vertical lines are the annual means and 95% Bayesian credible interval estimates from the integrated population model including environmental covariates
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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 B...
Citations
... Such spatial variations in the effect of environmental changes have generally been documented at large spatial scales (e.g., Descamps et al., 2019;Gaston et al., 2005;Rode et al., 2014;Sandvik et al., 2008) but it has been shown that even populations close to each other may have different responses to sea ice changes (Descamps & Ramírez, 2021). Unfortunately, empirical evidence linking sea ice and Arctic wildlife demography or population dynamics is still relatively scarce (but see Descamps & Ramírez, 2021;Dunham et al., 2021;McGeachy et al., 2024;Regehr et al., 2007;Sauser et al., 2023), and such inter-or intra-population variations in the response to sea ice reduction remain largely unknown. ...
The Arctic is warming four times faster than any other region on Earth, leading to a dramatic reduction in sea ice. Even though sea ice plays a key role in the ecology of many Arctic species, few studies have assessed the consequences of its disappearance on the dynamics of Arctic wildlife populations. Moreover, the potential intra‐population variations in such effects remain largely overlooked. Here, using a 40‐year time series, we assessed how sea ice changes in a High Arctic fjord affected the population dynamics of common eiders Somateria mollissima via changes in their fine‐scale breeding distribution and how these effects varied among breeding sites. More specifically, some islands within the fjord used to be connected by landfast ice to the shore most of the spring and thus to be accessible to one of the main eider predators, the Arctic fox Vulpes lagopus. Following the disappearance of spring sea ice in the fjord, these islands recently became disconnected much earlier in the season and thus inaccessible to foxes. We tested the prediction that these islands now represent favorable nesting grounds for common eiders and that the breeding eider populations on these islands increased following the sea ice retreat. Our results support our prediction and the role played by fox predation in mediating the sea ice effects. Even though the overall eider population in the fjord has slightly declined in the last decades, the recent sea ice reduction has led to a rapid colonization of newly available breeding habitats and to an increasing number of breeding eiders there. Inter‐annual changes in sea ice did not significantly affect the number of eiders breeding on the islands that were historically isolated from fox predation. Ignoring such intra‐population variation between breeding sites in predation risk masks the effects of sea ice reduction on eider dynamics. Our study illustrates the complex and fine‐scale effects of sea ice disappearance on Arctic wildlife and the potential importance of predation in mediating these effects.
... However, the state is not immune to changes that have occurred across the rest of the United States. Alaska is currently experiencing drastic environmental change, and initial signs of habitats and species under pressure are becoming readily apparent [10,11]. For example, Alaska is undergoing climatic warming at more than twice the global rate, resulting in shifting biomes, changing ecological functions, and a redistribution of species [12][13][14]. ...
An examination of the conservation program in the Alaska Regional Office of the U.S. Fish and Wildlife Service revealed that changes in environmental conditions and corresponding changes in the timing and distribution of species were outpacing traditional conservation management methods. This led to a decision to shift the program more toward a proactive and collaborative manner, with less emphasis on utilizing a reactive approach. Efforts to shift the program included reducing staff workloads, increasing capacity, adding new skill sets, providing examples and a framework for proactive conservation, and building support from supervisors. Staff input and feedback was sought throughout the process and used to shift the culture of the program to foster strategic and collaborative conservation. An assessment of the proactive conservation program both provided encouragement and identified areas in need of additional attention. The current proactive conservation program has persisted through shifting agency priorities, declining budgets, and changes in internal leadership. The circumstances that necessitated a paradigm shift toward proactive conservation are not unique to Alaska; we urge others to consider implementation of proactive conservation or another paradigm that better aligns management approaches with the pace and scale of environmental change.
... Direct measurements of demography-environment relationships can be obtained by measuring demographic rates over an environmental gradient, which requires largescale and well-designed monitoring schemes [23]. This has been done for a number of plants [24,25], but only rarely for animal species, for example fish (brown trout, [26]), or birds (North-American forest birds [27] and Arctic sea ducks [28]). As an alternative to direct measurements, Pagel & Schurr [29] suggested an inverse modelling approach that simultaneously estimates the demography-environment relationships and all other process parameters from empirical data. ...
Species respond to climate change with range and abundance dynamics. To better explain and predict them, we need a mechanistic understanding of how the underlying demographic processes are shaped by climatic conditions. Here, we aim to infer demography–climate relationships from distribution and abundance data. For this, we developed spatially explicit, process-based models for eight Swiss breeding bird populations. These jointly consider dispersal, population dynamics and the climate-dependence of three demographic processes—juvenile survival, adult survival and fecundity. The models were calibrated to 267 nationwide abundance time series in a Bayesian framework. The fitted models showed moderate to excellent goodness-of-fit and discriminatory power. The most influential climatic predictors for population performance were the mean breeding-season temperature and the total winter precipitation. Contemporary climate change benefitted the population trends of typical mountain birds leading to lower population losses or even slight increases, whereas lowland birds were adversely affected. Our results emphasize that generic process-based models embedded in a robust statistical framework can improve our predictions of range dynamics and may allow disentangling of the underlying processes. For future research, we advocate a stronger integration of experimental and empirical studies in order to gain more precise insights into the mechanisms by which climate affects populations.
This article is part of the theme issue ‘Detecting and attributing the causes of biodiversity change: needs, gaps and solutions’.
... We were surprised that our index of fox abundance on the Y-K Delta was not related to nest survival of Emperor Geese in our study, as Petersen (1992) reported extreme localized nest failure for Emperor Geese at a different site on the Y-K Delta in years with high fox abundance and Rizzolo et al. (2014) found evidence for a negative relationship between the fox index we used and nest survival of Red-throated Loons (Gavia stellata) on the Y-K Delta. Like this study, Dunham et al. (2021) did not find evidence for a relationship between the fox index we used and nest survival of Spectacled Eiders (Somateria fischeri) on the Y-K Delta. We emphasize that, although we did not find evidence that the index of fox abundance was related to nest survival in our nest survival model, results of our nest count model suggest that the number of nests found in the core study area each year was negatively related to our index of fox abundance. ...
The reproductive ecology of geese that breed in the Arctic and subarctic is likely susceptible to the effects of climate change, which is projected to alter the environmental conditions of northern latitudes. Nest survival is an important component of productivity in geese; however, the effects of regional environmental conditions on nest survival are not well understood for some species, including the Emperor Goose (Anser canagicus), a species of conservation concern that is endemic to the Bering Sea region. We estimated nest survival and examined how indices of regional environmental conditions, nest traits (nest age, initiation date, and maximum number of eggs in the nest), and researcher disturbance influenced daily survival probability (DSP) of Emperor Goose nests using hierarchical models and 24 years of nest monitoring data (1994–2017) from the Yukon–Kuskokwim Delta (Y–K Delta) in western Alaska. Our results indicate that overall nest survival was generally high (µ = 0.766, 95% CRI: 0.655–0.849) and ranged from 0.327 (95% CRI: 0.176–0.482) in 2013 to 0.905 (95% CRI: 0.839–0.953) in 1995. We found that DSPs of nests were influenced by nest traits, negatively influenced by major tidal flooding events and by researcher disturbance, but were not influenced by regional indices of spring timing, temperature and precipitation during nesting, or fox and vole abundance on the Y–K Delta. However, the number of nests found each year was negatively related to our index of fox abundance, suggesting nests that failed as a result of fox predation may have never been discovered due to our limited nest-searching efforts during egg laying. Our results suggest that regional environmental variation had minimal influence on the nest survival of Emperor Geese, although major flooding events were important. Nevertheless, we suspect that within-year variation in local weather conditions and local abundance of predators and alternative prey may be important and should be considered in future studies.
... The need for monitoring Arctic species and ecosystems is growing as northern regions are being disproportionately affected by climate change (Dunham et al., 2021). At the same time, studying Arctic species remains particularly challenging due to extreme weather, remoteness, and limited infrastructure (Høye, 2020). ...
Successful conservation efforts often require novel tactics to achieve the desired goals of protecting species and habitats. One such tactic is to develop an interdisciplinary, collaborative approach to ensure that conservation initiatives are science-based, scalable, and goal-oriented. This approach may be particularly beneficial to wildlife monitoring, as there is often a mismatch between where monitoring is required and where resources are available. We can bridge that gap by bringing together diverse partners, technologies, and global resources to expand monitoring efforts and use tools where they are needed most. Here, we describe a successful interdisciplinary, collaborative approach to long-term monitoring of beluga whales (Delphinapterus leucas) and their marine ecosystem. Our approach includes extracting images from video data collected through partnerships with other organizations who live-stream educational nature content worldwide. This video has resulted in an average of 96,000 underwater images annually. However, due to the frame extraction process, many images show only water. We have therefore incorporated an automated data filtering step using machine learning models to identify frames that include beluga, which filtered out an annual average of 67.9% of frames labelled as “empty” (no beluga) with a classification accuracy of 97%. The final image datasets were then classified by citizen scientists on the Beluga Bits project on Zooniverse (https://www.zooniverse.org). Since 2016, more than 20,000 registered users have provided nearly 5 million classifications on our Zooniverse workflows. Classified images are then used in various researcher-led projects. The benefits of this approach have been multifold. The combination of machine learning tools followed by citizen science participation has increased our analysis capabilities and the utilization of hundreds of hours of video collected each year. Our successes to date include the photo-documentation of a previously tagged beluga and of the common northern comb jellyfish (Bolinopsis infundibulum), an unreported species in Hudson Bay. Given the success of this program, we recommend other conservation initiatives adopt an interdisciplinary, collaborative approach to increase the success of their monitoring programs.
Species responses to climate change are widely detected as range and abundance changes. To better explain and predict them, we need a mechanistic understanding of how the underlying demographic processes are shaped by climatic conditions. We built spatially-explicit, process-based models for eight Swiss breeding bird populations. They jointly consider dispersal, population dynamics and the climate-dependence of three demographic processes - juvenile survival, adult survival and fecundity. The models were calibrated to two-decade abundance time-series in a Bayesian framework. We assessed goodness-of-fit and discriminatory power of the models with different metrics, indicating fair to excellent model fit. The most influential climatic predictors for population performance were the mean breeding-season temperature and the total winter precipitation. Maps of overall growth rate highlighted demographically suitable areas. Further, benefits from contemporary climate change were detected for typical mountain birds, whereas lowland birds were adversely affected. Embedding generic process-based models in a solid statistical framework improves our mechanistic understanding of range dynamics and allows disentangling the underlying abiotic and biotic processes. For future research, we advocate a stronger integration of experimental and empirical measurements and more detailed predictors in order to generate precise insights into the processes by which climate affects populations.
