AVIS-IBIS

Birds of Indian Subcontinent

Repeated Human Intrusion and the Potential for Nest Predation by Gray Jays

Publication Type:Journal Article
Year of Publication:2002
Authors:GUTZWILLER, KEVINJ, Riffell, SK, Anderson, SH
Journal:The Journal of Wildlife Management
Volume:66
Issue:2
Date Published:2002
ISBN Number:0022541X
Keywords:Corvidae, Garrulus, Garrulus glandarius, Perisoreus, Perisoreus canadensis
Abstract:Through attraction of avian nest predators, human activity near nests is known to cause lower nesting success or nest failure in some species. This is a significant conservation issue because many wildlands are subjected to repeated intrusion by recreationists, ecotourists, and other user groups during avian breeding seasons. Yet, wildlife scientists still have limited knowledge about the extent to which repeated human intrusion attracts avian nest predators. We studied this topic in subalpine forest in Wyoming, USA, and experimented with the gray jay (Perisoreus canadensis), a nest predator that is known to approach recreationists. During 1989-1993, we implemented intrusions within 20 circular 1-ha (113-m-diam) sites for 1 or 2 hr each week during a 10-week period when potential passerine prey were breeding. Simultaneously, 10 circular 1-ha control sites did not receive experimental intrusions. The average number of gray jays on intruded sites was higher than that on control sites by 156% (1989), 225% (1990), 59% (1991), 13% (1992), and 29% (1993). The probability of gray jay recurrence on intruded sites was higher than that on control sites by 125% (1989), 300% (1990), 20% (1991), 33% (1992), and 20% (1993). By increasing the number and recurrence of gray jays, relatively low levels of repeated intrusion can increase the potential for nest predation by gray jays. We caution that additional work is necessary to assess whether attraction of gray jays actually leads to increased nest predation. Knowledge of when intrusion does and does not attract gray jays is important because information about both events is necessary to define the levels and circumstances of intrusion that are influential. Wildlife managers can use knowledge about intrusion-induced attraction of avian nest predators to help decide whether or how recreational activity in wildlands should be managed.
URL:http://www.jstor.org/stable/3803170
Short Title:The Journal of Wildlife Management
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith