Effects of aggression on breeding, affiliation, and reproductive success of lsland Foxes (Urocyon littoralis) on Santa Rosa Island, CA
Loading...
Authors
Karslake, Elizabeth B.
Issue Date
2012
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
The island fox (Urocyon littoralis) is found on the Channel Islands off the coast of
Los Angeles, Califomia, and six islands each support a different subspecies. Recently,
three subspecies underwent dramatic population declines due to golden eagle predation.
The National Park Service began a very successful captive breeding program, and now all
captive foxes have been released back into the wild. For several years, video cameras
were placed in fox pens on Santa Cruz, Santa Rosa, and San Miguel Islands to monitor
fox pairs during the breeding season. From these videos, I assessed the relationship
between aggressive, affiliative, and sexual behaviors of fox pairs on Santa Rosa. While
research has been done on factors effecting reproductive success of the island fox, none
have looked specifically at effects of these behaviors. In my project, I observed no
correlations between aggressive, affiliative, or sexual behaviors. The only correlations
were between sexual behaviors and between aggressive behaviors. Interestingly male
aggression levels in some pens increased slightly, but not statistically significant, around
the copulatory tie date. As island foxes and their mainland counterparts, gray foxes, are
closely related to the ancestral canid form, it may be that island foxes are induced
ovulators like most other camivores.
Also, I compiled the age of each fox, previous reproductive history, size of litter,
and fate of pups into a table to analyze how intra-pair aggression levels for a pair affected
their reproductive successes. Intra-pair aggression did not affect reproductive success, but
none of the pens experienced extreme levels of aggression. It is possible that reproductive
success of foxes is instead affected by other factors such as the age of the male or female
or social compatibility between the pair. Although all the captive foxes on Santa Rosa
were released back into the wild in 2008, these findings are still relevant. Each of the
Channel Islands is very susceptible to change, and it is possible that foxes will need to be
brought back into a captive breeding program. Therefore, relevant findings can be
potentially beneficial to future island fox captive breeding programs.
Description
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.