Natal Dispersal and Recruitment of Juvenile White-Tailed Ptarmigan in Colorado
Giesen KM and Braun CE. 1993. Natal Dispersal and Recruitment of Juvenile White-Tailed Ptarmigan in Colorado. The Journal of Wildlife Management. 57(1):72-77
Dispersal may affect survival and recruitment of yearlings into the breeding population and, thus, be a factor regulating population density. Therefore, we documented natal dispersal and recruitment of white-tailed ptarmigan (Lagopus leucurus) from 2 populations in northcentral Colorado between 1966 and 1990. Recoveries and returns of 1,437 birds banded as juveniles totaled 326 (22.7%); 258 (79.1%) were males and 68 (20.9%) were females. We calculated natal dispersal distances of 126 males and 40 females banded prior to brood breakup (15 Sep) and relocated during subsequent breeding seasons. Males had high philopatry to natal areas (median dispersal distance = 1.25 km); whereas females dispersed farther (median dispersal distance = 4.00 km). More than half (51.1%) of yearling males, but only 12.9% of yearling females, recruited into the breeding population at the Rocky Mountain National Park study area, had originally been banded as juveniles. The higher return rate of banded juvenile males was due to their high natal philopatry because there was no difference in total numbers of yearling males and females recruited. The minimum September-June survival rate of banded juvenile males was 35.0% in an unhunted population and 34.3% in a hunted population. Short natal dispersal distances of male white-tailed ptarmigan affected colonization of vacant habitats and should be considered in transplant programs.
- Type
- Journal Article
- Authors
- Giesen, Kenneth; Braun, Clait
- Units
- ROMO
- Keywords
- Animal Behavior, Animal Studies, Birds, Migration, white-tailed ptarmigan (Lagopus leucurus)