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Understanding natal emigration in group-living carnivores
Kathleen M Petersen1, Joel M Tebbenkamp2, Matthew A Mumma3
1Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho, Moscow, Idaho, USA.
The Journal of Animal Ecology
|July 30, 2026
Summary
Ecological factors like prey availability and wolf density, not human hunting, drive grey wolf emigration. This study reveals key drivers of dispersal in cooperative breeders, informing wildlife management strategies.
Area of Science:
- Ecology
- Evolutionary Biology
- Conservation Genetics
Background:
- Dispersal is a fundamental ecological process influencing population dynamics and evolution.
- Understanding individual variation in emigration, especially in human-modified landscapes, is crucial but understudied.
- Cooperative breeders, like grey wolves, exhibit complex social structures that can influence dispersal patterns.
Purpose of the Study:
- To investigate the drivers and patterns of natal emigration in a managed grey wolf population.
- To evaluate the influence of prey biomass, wolf density, human-caused mortality, and sex on emigration.
- To apply a novel genetic approach to identify emigrants in a wild, social carnivore population.
Main Methods:
- Utilized sibship analyses of DNA from harvested grey wolves (Canis lupus) to identify natal emigration.
- Analyzed data from 224 individuals across 182 sibling groups in Idaho, USA (2017-2023).
- Assessed the impact of covariates (prey biomass, wolf density, human-caused mortality, sex) on emigration probability and dispersal distance.
Main Results:
- No significant sex differences were found in emigration propensity or dispersal distance.
- Emigrants dispersed an average of 81.8 km from their natal territories.
- Emigration probability increased with higher prey biomass and decreased with higher wolf density; human-caused mortality had no detectable effect.
Conclusions:
- Ecological factors, specifically resource availability and population density, are stronger drivers of emigration than human-caused mortality in this grey wolf population.
- The findings highlight the importance of landscape-scale conditions in shaping dispersal patterns for cooperative breeders.
- The novel genetic framework is applicable to studying dispersal in other social systems with traceable kin structures, aiding wildlife management.
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