Sexual segregation has been intensely studied across diverse ecosystems and taxa, but studies are often limited to periods when animals occupy distinct seasonal ranges. Some avian and marine studies have revealed that habitat segregation, when sexes differ spatially or temporally in use of the physical landscape, is common during the migratory period and characterized by sex‐specific differences in migratory behaviors. Recent research highlights the importance of understanding movement patterns in the context of the full annual life cycle and highlights the need to extend relevant theories of sexual segregation to the migratory period. We tested predictions from two leading hypotheses of sexual segregation, the forage‐selection hypothesis (FSH) and the reproductive strategy hypothesis (RSH) as applied to the migratory period. We collected global positioning system (GPS) location data for male and female mule deer (
The density and distribution of resources shape animal movement and behavior and have direct implications for population dynamics. Resource availability often is “pulsed” in space and time, and individuals should cue in on resource pulses when the energetic gain of doing so exceeds that of stable resources. Birth pulses of prey represent a profitable but ephemeral resource and should thereby result in shifting functional responses by predators. We evaluated movements and resource selection of coyotes (
- NSF-PAR ID:
- 10438766
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Ecology and Evolution
- Volume:
- 13
- Issue:
- 7
- ISSN:
- 2045-7758
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Odocoileus hemionus ) in south‐central Wyoming and northwest Colorado and tested the main predictions of the FSH and RSH. Both sexes showed high fidelity to their migratory routes, but route fidelity was more variable in males. Males also started spring migrations earlier, ended spring and autumn migrations later, and spent 22% more time on stopover sites during spring migrations. Consequently, males took twice as long in spring and 44% longer in autumn to complete migration. Our results revealed clear sex‐specific migratory behaviors and supported predictions of the RSH that male foraging behaviors optimize body condition for the autumn rut, and females prioritize foraging while balancing reproductive constraints. Specifically, males timed their movements with spring green‐up as optimally as females, and the timing of male migrations and use of stopovers suggested that males prioritized time in areas of high‐quality forage. This refutes predictions of the FSH during the migratory period that males should consistently choose habitats with abundant, low‐quality forage. Our findings provide an important contribution to sexual segregation theory by extending relevant theories to understand male and female movements during the migratory period. -
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Abstract Growing evidence supports the hypothesis that temperate herbivores surf the green wave of emerging plants during spring migration. Despite the importance of autumn migration, few studies have conceptualized resource tracking of temperate herbivores during this critical season. We adapted the frost wave hypothesis (FWH), which posits that animals pace their autumn migration to reduce exposure to snow but increase acquisition of forage. We tested the FWH in a population of mule deer in Wyoming, USA by tracking the autumn migrations of
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Abstract In temperate regions, the annual pattern of spring onset can be envisioned as a ‘green wave’ of emerging vegetation that moves across continents from low to high latitudes, signifying increasing food availability for consumers.
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We hypothesized that four species of ground‐foraging songbirds in eastern North America—two warblers and two thrushes—time their spring migrations to coincide with later phases of vegetation phenology, corresponding to increased arthropod prey, and predicted they would match their migration rate to the green wave but trail behind it rather than surfing its leading edge.
We further hypothesized that the rate at which spring onset progresses across the continent influences bird migration rates, such that individuals adjust migration timing within North America to phenological conditions they experience
en route .To test our hypotheses, we used a continent‐wide automated radio telemetry network to track individual songbirds on spring migration between the U.S. Gulf Coast region and northern locations closer to their breeding grounds.
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All individuals arrived in the southeastern United States well after local spring onset. Counter to our expectations, we found that songbirds exhibited a ‘catching up’ pattern: Individuals migrated faster than the green wave of spring onset, effectively closing in on the start of spring as they approached breeding areas.
While surfing of resource waves is a well‐documented migration strategy for herbivorous waterfowl and ungulates, individual songbirds in our study migrated faster than the green wave and increasingly caught up to its leading edge
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Abstract Large carnivores often exhibit high survival rates in protected areas, whereas intentional and unintentional human‐caused mortality may be greater in adjacent areas. These patterns can result in source‐sink dynamics and limit population expansion beyond protected areas.
We used telemetry data from 438 canids in 141 packs collected from 2002 to 2020 to evaluate mortality risk for wolves, coyotes, and admixed canids in a 3‐species hybrid zone in and adjacent to a large protected area in Ontario, Canada. The hybrid zone is occupied by most of the remaining eastern wolves (
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Our results provide a comprehensive evaluation of factors influencing spatial variation in mortality risk for canids to inform eastern wolf recovery efforts. Additionally, we developed a novel modelling approach for investigating the influence of resource selection on mortality risk, which highlighted that individual‐level responses to risk can strongly influence population‐level mortality patterns.
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