title: Application of large-scale parentage analysis for investigating natal dispersal in highly vagile vertebrates: a case study of American black bears (Ursus americanus).
abstract: Understanding the factors that affect dispersal is a fundamental question in ecology and conservation biology, particularly as populations are faced with increasing anthropogenic impacts. Here we collected georeferenced genetic samples (n = 2,540) from three generations of black bears (Ursus americanus) harvested in a large (47,739 km2), geographically isolated population and used parentage analysis to identify mother-offspring dyads (n = 337). We quantified the effects of sex, age, habitat type and suitability, and local harvest density at the natal and settlement sites on the probability of natal dispersal, and on dispersal distances. Dispersal was male-biased (76% of males dispersed) but a small proportion (21%) of females also dispersed, and female dispersal distances (mean ± SE  =  48.9±7.7 km) were comparable to male dispersal distances (59.0±3.2 km). Dispersal probabilities and dispersal distances were greatest for bears in areas with high habitat suitability and low harvest density. The inverse relationship between dispersal and harvest density in black bears suggests that 1) intensive harvest promotes restricted dispersal, or 2) high black bear population density decreases the propensity to disperse. Multigenerational genetic data collected over large landscape scales can be a powerful means of characterizing dispersal patterns and causal associations with demographic and landscape features in wild populations of elusive and wide-ranging species.
authors.affiliation: Biology Department, Grand Valley State University, Allendale, Michigan, United States of America; Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Moore
authors.affiliation: Department of Zoology, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Hope M
authors.initials: HM
authors.lastname: Draheim
authors.affiliation: Wildlife Division, Michigan Department of Natural Resources, East Lansing, Michigan, United States of America.
authors.forename: Dwayne
authors.initials: D
authors.lastname: Etter
authors.affiliation: Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Scott
authors.initials: S
authors.lastname: Winterstein
authors.affiliation: Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, United States of America.
authors.forename: Kim T
authors.initials: KT
authors.lastname: Scribner
mesh_terms: D063147:Animal Distribution; D000818:Animals; D005260:Female; D060005:Genotyping Techniques; D008297:Male; D011156:Population Density; D011336:Probability; D012737:Sex Factors; D001503:Ursidae / Q000235:genetics / Q000502:physiology*