Richard B. Lanctot

In bird species with precocial development, i.e. chicks acquire abilities to leave the nest soon after hatching, the nestling period during which parents warm their young in the nest by brooding them is short but critical to breeding success. The duration of the nestling period (DNP) depends on the hatching synchrony of eggs and the speed at which chicks acquire these abilities but may be indirectly affected by parental behaviour and temporal variations in temperature and predation. We assessed the effects of incubation strategy (bi- or uniparental), hatching start time, incubation initiation date and predation risk on the DNP in Arctic-breeding sandpipers. We found that the DNP was longer in biparental species (29.75 ± 8.95 h) compared with uniparental ones (25.82 ± 6.87 h) and was extended in nests where chicks began hatching during the colder ‘night’ hours. No effect of incubation initiation date or predation pressure was found on the DNP. We suggest that parental investment strategies and constraints related to circadian variations in temperature in chicks drive the DNP in Arctic-breeding sandpipers. These results help us better understand how different species may exhibit different behavioural responses during nesting to impending climate change.

Addressing urgent conservation issues, such as the drastic declines of North American migratory birds, requires creative, evidence‐based, efficient, and collaborative approaches. The abundance of over 50% of monitored North American shorebird populations has declined by over 50% since 1980. To address these declines, we developed a partnership of scientists and practitioners called the Shorebird Science and Conservation Collective (hereafter the collective ). The collective was founded to translate the combined findings of shorebird tracking data into on‐the‐ground conservation action. With advice from an advisory group, the collective acts as an intermediary whereby dedicated staff collate and analyze data contributions from scientists to support knowledge requests from conservation practitioners. In its first three years, data contributions from 75 organizations include over 7.1 million shorebird observations forming movement paths of 3420 individuals representing 36 species tracked across the Americas and have informed 18 conservation projects spanning education, land and species management, land conservation, and policy requests. Others engaged in translational science from big data could consider similar knowledge‐sharing models that prioritize usable data products, foster collaborative engagement between science experts and practitioners, build focused communities around topics or taxonomic groups, and employ a proof‐of‐concept phase to develop scalable solutions while making progress toward long‐term funding to sustain impact. As the volume of scientific data continues to grow, intermediaries, such as the collective, can be vital liaisons to rapidly integrate and interpret research to support conservation action. Dedicated to the memory of Shiloh Schulte and his conservation achievements for shorebirds.

Aim: Site network approaches to waterbird conservation are easily biased towards species that occur in high densities and locations and periods of the annual cycle with dense concentrations of birds, thereby potentially failing to address underlying factors driving certain population declines. Here, for shorebird populations that migrate along the East Asian–Australasian Flyway, we examine the extent to which recent conservation efforts at key sites in the Yellow Sea—that is, sites that are vital for stabilising densely concentrated , rapidly declining shorebird species—might address factors underlying low adult survival and steep population declines in shorebird species that migrate and winter along a broad front (i.e., the East China Sea, Yellow Sea and Japan). Location: East Asia. Methods and Results: Using geolocator‐derived migration tracks, an integrated survival model and a population matrix model to estimate winter‐population‐specific survival rates and population trends in a quintessential East Asian shorebird population—the arcticola subspecies of the Dunlin ( Calidris alpina )—we show that in 2010–2014 differences between arcticola winter populations in the intensity of their declines were most likely linked to conditions on their wintering grounds, with individuals that wintered in the East China Sea or Japan showing the steepest population declines (mean: −12% year ⁻¹ [50% credible interval: −3%, −22%] and −17% year ⁻¹ [−6%, −30%], respectively) and individuals that wintered in the Yellow Sea surprisingly stable (+4% year ⁻¹ [−5%, +14%]). Main Conclusions: For shorebird populations that winter in East Asia and migrate along a broad front, additional conservation efforts in the East China Sea and Japan are likely necessary to reverse population declines.

Amplitude, or intensity, of sound is a fundamental characteristic of inter acoustic communication, with relevance in many scientific fields. The amplitude of an animal’s acoustic signal at its source (“source amplitude”) may be particularly relevant in the field of acoustic allometry, where relationships between species’ physical and acoustic features (e.g., dominant frequency) have been well-established across taxa. However, despite their potential scientific value, records and studies of source amplitudes remain remarkably scarce for avian species. Here we present novel estimates of source amplitude (range, mean, and median) for 17 species of Arctic-breeding birds, derived from measurements made in Utqiaġvik, Alaska during June 2024. We found a strong positive correlation between body mass and source amplitude in this data via a Markov Chain Monte Carlo multivariate generalized linear mixed model (MCMCglmm). Both phylogeny and individual identity were important random effects in this model. In contrast, random effects from environmental factors and measurement characteristics were minimal. Our work represents the first model describing the relationship between source amplitude and allometry across avian genera. We hope that this study will spur other investigations into avian source amplitude and its relationship to morphological and life history features for species in the Arctic and elsewhere.

Seasonally abundant arthropods are a crucial food source for many migratory birds that breed in the Arctic. In cold environments, the growth and emergence of arthropods are particularly tied to temperature. Thus, the phenology of arthropods is anticipated to undergo a rapid change in response to a warming climate, potentially leading to a trophic mismatch between migratory insectivorous birds and their prey. Using data from 19 sites spanning a wide temperature gradient from the Subarctic to the High Arctic, we investigated the effects of temperature on the phenology and biomass of arthropods available to shorebirds during their short breeding season at high latitudes. We hypothesized that prolonged exposure to warmer summer temperatures would generate earlier peaks in arthropod biomass, as well as higher peak and seasonal biomass. Across the temperature gradient encompassed by our study sites (>10°C in average summer temperatures), we found a 3‐day shift in average peak date for every increment of 80 cumulative thawing degree‐days. Interestingly, we found a linear relationship between temperature and arthropod biomass only below temperature thresholds. Higher temperatures were associated with higher peak and seasonal biomass below 106 and 177 cumulative thawing degree‐days, respectively, between June 5 and July 15. Beyond these thresholds, no relationship was observed between temperature and arthropod biomass. Our results suggest that prolonged exposure to elevated temperatures can positively influence prey availability for some arctic birds. This positive effect could, in part, stem from changes in arthropod assemblages and may reduce the risk of trophic mismatch.

Global climate change has altered the timing of seasonal events (i.e., phenology) for a diverse range of biota. Within and among species, however, the degree to which alterations in phenology match climate variability differ substantially. To better understand factors driving these differences, we evaluated variation in timing of nesting of eight Arctic‐breeding shorebird species at 18 sites over a 23‐year period. We used the Normalized Difference Vegetation Index as a proxy to determine the start of spring (SOS) growing season and quantified relationships between SOS and nest initiation dates as a measure of phenological responsiveness. Among species, we tested four life history traits (migration distance, seasonal timing of breeding, female body mass, expected female reproductive effort) as species‐level predictors of responsiveness. For one species (Semipalmated Sandpiper), we also evaluated whether responsiveness varied across sites. Although no species in our study completely tracked annual variation in SOS, phenological responses were strongest for Western Sandpipers, Pectoral Sandpipers, and Red Phalaropes. Migration distance was the strongest additional predictor of responsiveness, with longer‐distance migrant species generally tracking variation in SOS more closely than species that migrate shorter distances. Semipalmated Sandpipers are a widely distributed species, but adjustments in timing of nesting relative to variability in SOS did not vary across sites, suggesting that different breeding populations of this species were equally responsive to climate cues despite differing migration strategies. Our results unexpectedly show that long‐distance migrants are more sensitive to local environmental conditions, which may help them to adapt to ongoing changes in climate.

Addressing urgent conservation issues, like the drastic declines of North American migratory birds, requires creative, evidence-based, efficient, and collaborative approaches. Over 50% of monitored North American shorebird populations have lost over 50% of their abundance since 1980. To address these declines, we developed a partnership of scientists and practitioners called the Shorebird Science and Conservation Collective (hereinafter “the Collective”). Here, we present this successful case study as an example for others engaged in translational science. The Collective acts as an intermediary whereby dedicated staff collate and analyze data contributions from scientists to support knowledge requests from conservation practitioners. Data contributions from 74 organizations include over 6.7 million shorebird locations forming movement paths of 3,345 individuals representing 36 species tracked across the Americas. We describe the founding and structure of the Collective and conservation activities we supported in our first two years. As the volume of scientific data on animal movements continues to grow, groups like the Collective can be vital liaisons to rapidly integrate and interpret research to support conservation action.

Baseline information about declining North American shorebird populations is essential to determine the effects of global warming at low-lying coastal areas of the Arctic and subarctic, where numerous taxa breed, and to assess population recovery throughout their range. We estimated population sizes on the Yukon-Kuskokwim Delta in western Alaska on the eastern edge of the Bering Sea. We conducted ground-based surveys during 2015 and 2016 at 589 randomly selected plots from an area of 35,769 km². We used stratified random sampling in 8 physiographic strata and corrected population estimates using detection ratios derived from double sampling on a subset of plots. We detected 11,110 breeding individuals of 21 taxa. Western Sandpiper (Calidris mauri), Red-necked Phalarope (Phalaropus lobatus), Dunlin (subspecies C. alpina pacifica), and Wilson’s Snipe (Gallinago delicata) were the most abundant taxa. We estimated that ~6.9 million individual shorebirds were breeding on the entire Yukon-Kuskokwim Delta in 2015 and 2016. Our surveys of this region provided robust population estimates (CVs ≤ 0.35) for 14 species. Our results indicate that the Yukon-Kuskokwim Delta supports a large proportion of North America’s breeding populations of the Pacific Golden-Plover (Pluvialis fulva), the western population of a Whimbrel subspecies (Numenius phaeopus hudsonicus), a Bar-tailed Godwit subspecies (Limosa lapponica baueri), Black Turnstone (Arenaria melanocephala), a Dunlin subspecies (Calidris alpina pacifica), and Western Sandpiper. Our study highlights the importance to breeding shorebirds of this relatively pristine but climatically sensitive deltaic system. Estuaries and deltaic systems worldwide are rapidly being degraded by anthropogenic activities. Our population estimates can be used to refine prior North American population estimates, determine effects of global warming, and evaluate conservation success by measuring population change over time.