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Long-term population dynamics of a managed burrowing owl colony

Journal of Wildlife Management

By:
, , and
https://doi.org/10.1002/jwmg.170

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Abstract

We analyzed the population dynamics of a burrowing owl (Athene cunicularia) colony at Mineta San Jose International Airport in San Jose, California, USA from 1990-2007. This colony was managed by using artificial burrows to reduce the occurrence of nesting owls along runways and within major airport improvement projects during the study period. We estimated annual reproduction in natural and artificial burrows and age-specific survival rates with mark-recapture techniques, and we estimated the relative contribution of these vital rates to population dynamics using a life table response experiment. The breeding colony showed 2 distinct periods of change: high population growth from 7 nesting pairs in 1991 to 40 pairs in 2002 and population decline to 17 pairs in 2007. Reproduction was highly variable: annual nesting success (pairs that raised =1 young) averaged 79% and ranged from 36% to 100%, whereas fecundity averaged 3.36 juveniles/pair and ranged from 1.43 juveniles/pair to 4.54 juveniles/pair. We estimated annual adult survival at 0.710 during the period of colony increase from 1996 to 2001 and 0.465 during decline from 2002 to 2007, but there was no change in annual survival of juveniles between the 2 time periods. Long-term population growth rate (lambda) estimated from average vital rates was lambdaa=1.072 with lambdai=1.288 during colony increase and lambdad=0.921 (DELTA lambda=0.368) during decline. A life table response experiment showed that change in adult survival rate during increasing and declining phases explained more than twice the variation in growth rate than other vital rates. Our findings suggest that management and conservation of declining burrowing owl populations should address factors that influence adult survival.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Long-term population dynamics of a managed burrowing owl colony
Series title:
Journal of Wildlife Management
DOI:
10.1002/jwmg.170
Volume:
75
Issue:
6
Year Published:
2011
Language:
English
Publisher:
Wiley
Publisher location:
Hoboken, NJ
Description:
12 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Wildlife Management
First page:
1295
Last page:
1306
Time Range Start:
1990-01-01
Time Range End:
2007-12-31
Country:
United States
State:
California
City:
San Jose
Other Geospatial:
Mineta San Jose International Airport
Online Only (Y/N):
N
Additional Online Files (Y/N):
N