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ELK REPRODUCTIVE RESPONSE TO REMOVAL OF CALVING SEASON DISTURBANCE BY HUMANS
Author(s) -
SHIVELY KIRK J.,
ALLDREDGE A. WILLIAM,
PHILLIPS GREGORY E.
Publication year - 2005
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.2193/0022-541x(2005)069[1073:errtro]2.0.co;2
Subject(s) - disturbance (geology) , ice calving , wildlife , productivity , ecology , seasonal breeder , biology , environmental science , pregnancy , paleontology , genetics , macroeconomics , lactation , economics
We evaluated elk ( Cervus elaphus ) reproductive success following removal of human disturbance during calving season, by comparing data from 2 segregated groups of free‐ranging elk (control and treatment) from 1 pre‐disturbance year, 2 disturbance years, and 2 post‐disturbance years. Treatment‐group elk were subjected to simulated recreational activity during calving season in disturbance years but not in pre‐ or post‐disturbance years. Control animals experienced only ambient levels of disturbance throughout the study, and their calf/cow proportions (proportion of marked adult female elk maintaining a calf in Jul and Aug) were similar throughout the 5 years. We observed reduced productivity of treatment‐group elk compared to controls during disturbance years after adjusting for nontreatment year differences. We hypothesized that productivity would return to, or potentially exceed, pre‐disturbance levels following removal of disturbance. Productivity rebounded following release from disturbance, and full recovery was achieved by the second post‐disturbance year. However, we did not observe productivity in excess of pre‐disturbance years, as might be expected if release from energetic demands of maintaining a calf in 1 year increases probability of maintaining a calf in the following year. Our results are consistent with hypotheses that human‐induced disturbance during parturition periods can reduce reproductive success and that removal of disturbance can allow productivity to recover to pre‐disturbance levels. Managers of wildlife and wildlife habitat should consider potential impacts of human‐induced disturbance on wildlife populations. Wildlife populations, depressed by human‐induced disturbance during the neonatal period, may have the ability to rebound if the disturbance is removed.