Autonomous sound recording is a promising sampling method for birds and other vocalizing terrestrial wildlife. However, while there are clear advantages of passive acoustic monitoring methods over classical point counts conducted by humans, it has been difficult to quantitatively assess how they compare in their sampling performance. Quantitative comparisons of species richness between acoustic recorders and human point counts in bird surveys have previously been hampered by the differing and often unknown detection ranges or sound detection spaces among sampling methods. We performed two meta‐analyses based on 28 studies where bird point counts were paired with sound recordings at the same sampling sites. We compared alpha and gamma richness estimated by both survey methods after equalizing their effective detection ranges. We further assessed the influence of technical sound recording specifications (microphone signal‐to‐noise ratio, height and number) on the bird sampling performance of sound recorders compared to unlimited radius point counts. We show that after standardizing detection ranges, alpha and gamma richness from both methods are statistically indistinguishable, while there might be an avoidance effect in point counts. Furthermore, we show that microphone signal‐to‐noise ratio (a measure of its quality), height and number positively affect performance through increasing the detection range, allowing sound recorders to match the performance of human point counts. Synthesis and applications. We demonstrate that when used properly, high‐end sound recording systems can sample terrestrial wildlife just as well as human observers conducting point counts. Correspondingly, we suggest a first standard methodology for sampling birds with autonomous sound recorders to obtain results comparable to point counts and enable practical sampling. We also give recommendations for carrying out effective surveys and making the most out of autonomous sound recorders.

H data from known-origin tissues of two migratory organisms in North America and Europe, we compared the accuracy, precision and similarity of assigned origins using both short-and long-term d 2 H p isoscapes. 3. Relative to long-term d 2 H p isoscapes, using short-term isoscapes for assignment often resulted in dissimilar regions of likely origin but did not significantly improve accuracy or precision. This was likely due to reduced spatial coverage in the data used to generate the short-term d 2 H p isoscapes. 4. We suggest that continued efforts to collect precipitation isotope data with a large spatiotemporal range will benefit future research on incorporating temporal variation in the amount and isotopic composition of precipitation into geospatial assignment models.

Distributions of landbirds in Canadian northern forests are expected to be affected by climate change, but it remains unclear which pathways are responsible for projected climate effects. Determining whether climate change acts indirectly through changing fire regimes and/or vegetation dynamics, or directly through changes in climatic suitability may allow land managers to address negative trajectories via forest management. We used SpaDES, a novel toolkit built in R that facilitates the implementation of simulation models from different areas of knowledge to develop a simulation experiment for a study area comprising 50 million ha in the Northwest Territories, Canada. Our factorial experiment was designed to contrast climate effects pathways on 64 landbird species using climate-sensitive and non-climate sensitive models for tree growth and mortality, wildfire, and landbirds. Climate-change effects were predicted to increase suitable habitat for 73% of species, resulting in average net gain of 7.49 million ha across species. We observed higher species turnover in the northeastern, south-central (species loss), and western regions (species gain). Importantly, we found that most of the predicted differences in net area of occupancy across models were attributed to direct climate effects rather than simulated vegetation change, despite a similar relative importance of vegetation and climate variables in landbird models. Even with close to a doubling of annual area burned by 2100, and a 600 kg/ha increase in aboveground tree biomass predicted in this region, differences in landbird net occupancy across models attributed to climate-driven forest growth were very small, likely resulting from differences in the pace of vegetation and climate changes, or vegetation lags. The effect of vegetation lags (i.e., differences from climatic equilibrium) varied across species, resulting in a wide range of changes in landbird distribution, and consequently predicted occupancy, due to climate effects. These findings suggest that hybrid approaches using statistical models and landscape simulation tools could improve wildlife forecasts when future uncoupling of vegetation and climate is anticipated. This study lays some of the methodological groundwork for ecological adaptive management using the new platform SpaDES, which allows for iterative forecasting, mixing of modeling paradigms, and tightening connections between data, parameterization, and simulation.

Understanding migratory connectivity is critical for interpreting population dynamics, seasonal interactions, and for the implementation of conservation strategies of migratory species. We evaluated the migratory connectivity of a Neotropical migratory songbird, the Ovenbird (Seiurus aurocapilla) using archival light-level geolocators deployed at two breeding and four nonbreeding locations while incorporating Ovenbird abundance as prior information using Bayes' Rule. We also included band recoveries submitted to the United States Geological Survey's Bird Banding Laboratory to assess connectivity of areas where geolocators were not deployed. We created a probabilistic map of origin for each capture site and mapped spring migration routes between nonbreeding and breeding locations. We found a complete separation of eastern and western populations of Ovenbirds throughout the annual cycle. Breeding Ovenbirds from western Canada spent the nonbreeding season throughout Central America and migrated through central North America during spring migration. Birds breeding in the northeastern United States were distributed throughout the central Greater Antilles in the Caribbean and migrated through eastern North America during spring migration. Fall migration routes were not included because the timing of migration coincided with fall equinox when latitudinal estimates are unreliable. However, longitudinal estimates suggest no overlap between eastern and western populations during fall migration. Ovenbirds with geolocators attached in Jamaica bred in the northeastern United States with the highest posterior probability of origin found in Massachusetts, while Ovenbirds captured in Florida and Puerto Rico bred primarily in the mid-Atlantic. Incorporating Ovenbird abundance as a prior into geolocator estimates decreased the area of origin by 90.37% ± 1.05% (mean ± SE) for the breeding season and 62.30% ± 1.69% for the nonbreeding season, compared to geolocator estimates alone. Ovenbirds exhibited strong migratory connectivity between breeding and nonbreeding season, which has important implications for various aspects of the ecology, evolution, and conservation.

Research666 the probability that our method missed peaks (spatial: 0.12, temporal: 0.18) or detected false peaks (spatial: 0.11, temporal: 0.37) due to data gaps and showed that our approach remains useful even for sparse and/or sporadic location data. Our study presents a generalizable approach to evaluating migratory connectivity across the full annual cycle that can be used to focus migratory bird conservation towards places and times of the annual cycle where populations are more likely to be limited.

Establishing links between breeding and wintering populations of longdistance migratory birds and other animals is fundamental to several aspects of migration research. However, severe limitations in our ability to track small-bodied migratory species still limits this field despite several recent technological breakthroughs. The measurement of naturally occurring stable isotopes of several elements in the tissues of migrants that travel across isotopic gradients or isoscapes has the potential to identify large scale migratory connectivity without some of the biases associated with the use of extrinsic markers. We investigated migratory connectivity between European breeding and African wintering populations of barn swallow (Hirundo rustica) by comparing feather isotope (δ 13 C, δ 15 N, δ 2 H) values with those expected from previously established feather isotopic clusters for Africa. We used a likelihood approach to assigning individuals to molt origins that also made use of prior information provided by ring recoveries as part of the EURING and SAFRING ringing efforts. We found evidence for strong isotopic spatial structure in the dataset, supporting the notion of a migratory divide in Europe with birds breeding in the Netherlands, Denmark, Germany and Eastern Europe wintering in southern Africa and virtually all samples from Switzerland westward being assigned to clusters in the northern portion of the species' winter range. Individuals from the United Kingdom were assigned to areas including Namibia, Botswana, northern South Africa, and along the coast of Mozambique and Tanzania. Birds wintering in the northernmost region of the wintering grounds tended to breed in the southernmost region of the breeding grounds, providing some evidence of leap-frog migration. We detected a strong latitudinal threshold in feather δ 13 C in Europe for African-grown feathers, suggesting that birds breeding in southern Europe (< 50° Latitude) primarily used C3-dominated habitats in Africa, whereas birds in northern Europe (> 53° Latitude) primarily used C4-dominated habitats. Our results emphasize the power in using a multi-isotope approach to assign individuals and populations to known continental-scale isoscapes and the advantages of combining isotopic and conventional (ring recovery) information within a Bayesian assignment framework. breeding grounds where they subsequently raise more offspring [8]. Other factors influencing overwinter survival and arrival phenology of birds on the breeding grounds involve large-scale climatic events or trends experienced on the wintering grounds, or en route, and there is considerable evidence for differential vulnerability to such factors among species and subpopulations within species depending on degree of migratory connectivity [9,10].Establishing migratory connectivity has benefited from several recent technological advances involving both extrinsic and intrinsic markers that can augment the more conventional but valuable long-term ring recovery programs [11]. Notably, the 3 U...

Conservation of migratory wildlife requires knowledge of migratory connectivity between breeding and non-breeding locations. Stable isotopes in combination with geographical isotopic patterns (isoscapes) can provide inferences about migratory connectivity. This study examines whether such an approach can be used to infer wintering areas in sub-Saharan Africa, where we lack such knowledge for many species, but where this method has not been used widely. We measured δ (2)H, δ (13)C and δ (15)N in winter-grown feathers of a breeding Swiss and Spanish population of European hoopoe Upupa epops--a typical Palaearctic-Afrotropical migrant. δ (2)H values predicted that ~70 % of the hoopoes spent the non-breeding season in the western portion of their potential winter range. This was corroborated by a shallow east-west gradient in feather-δ (2)H values of museum specimens from known African origin across the potential winter range and by the recovery of Swiss hoopoes marked with geolocators. Hoopoes categorized as from eastern versus western regions of the wintering range were further delineated spatially using feather δ (13)C and δ (15)N. δ (15)N showed no trend, whereas adults were more enriched in (13)C in the western portion of the range, with eastern adults being in addition more depleted in (13)C than eastern juveniles. This suggests that eastern juveniles may have occupied more xeric habitats than sympatric adults. We demonstrated that stable isotopes, especially δ (2)H, could only very roughly delineate the winter distribution of a trans-Saharan Palaearctic migrant restricted primarily to the Sahelian and savanna belt south of the Sahara. Further refinements of precipitation isoscapes for Africa as well the development of isoscapes for δ (13)C and δ (15)N may improve assignment of this and other migrants.

Rusty Blackbird is listed as a species of "special concern" by the Committee On the Status of Endangered Wildlife In Canada, and has shown steep population declines in recent decades. Forty-five locations with historical survey data from the 1970s in the Mackenzie Valley, Northwest Territories, Canada were revisited in 2006 to check for changes in the occurrence or abundance of Rusty Blackbird. Our retrospective analysis revealed a number of analytical challenges for such comparisons that we describe. The number of lakes on which this species occurred does not appear to have declined significantly in the past three decades when a correction for survey duration was applied. The range-wide decline of 5.1%/yr based on Christmas Bird Count data would have resulted in 2006 occupancy at ≈5 lakes. We estimate that with correction this would have increased to ≈26. However, naive or unadjusted analyses with a Chi-squared test showed a significant decline. A simulated resampling of the historical data was performed using a repeatability factor of 62% that was derived from a subset of historical lakes that was visited twice in the 1970s. Only 8 of 13 lakes resurveyed had the same results on both historical visits. Our unadjusted 2006 results are a likely outcome, i.e., a 14.9% chance of finding this result, when this repeatability factor is considered, and the likelihood of no change is higher when our corrected data are considered. The possibility of double counting in the historical data further reduced the likelihood of a large decline in relative abundance. Therefore, Rusty Blackbird occurrence does not appear to have changed significantly in the past 33 yr in the Mackenzie Valley. We conclude with a qualitative discussion that supports the notion that declines in the southern parts of their range may be a large factor in the observed rates of population decline.