The range of a species often extends across a diverse landscape, necessitating that
individuals make different movement and habitat decisions, despite consistent food and
shelter requirements. Great Basin gophersnakes (Pituophis catenifer deserticola) are
threatened in Canada, where they occur at the northern extent of their range in southern
interior river valleys of British Columbia such as the Okanagan Valley. I followed 39
radio-transmittered adult gophersnakes at four sites in the Okanagan, to obtain
information on life history, movement and range patterns, and habitat use. Habitat
selection and movement patterns exhibited by gophersnakes differed between study sites,
sexes, and months, indicating that snake choice varies depending on resources and life
history traits. Despite these fine-grain differences, males moved more than females in the
spring. In addition to this, females moved more than males in the summer and fall.
Differences in movement and range were apparent among the study sites. Habitat
selection differed by study site, however rock-outcrops were consistently selected
overall. Microhabitat selection varied, but retreat sites including logs, rocks, and holes in
the ground, were consistently located closer than random. Hibernation sites in the south
Okanagan were in rock features, while in the north Okanagan a good proportion were in
rodent burrows in hillsides. Hibernation site fidelity was low, and annual reproduction
was common. Oviposition sites were on south-facing slopes of moderate grade with little
to moderate grass cover. Three ecdysis periods were observed when most or all
transmitter-equipped snakes shed their skin.
These findings will be very valuable to species conservation goals in British Columbia
when developing guidelines on the habitats and sizes of areas to protect. With an
iii
understanding of the movement and ranges patterns exhibited by individuals, the area
required to sustain a healthy population of gophersnakes can be determined. Knowledge
of the habitats and microhabitats gophersnakes select makes it possible to identify and
protect important areas at sites known to contain gophersnakes, including the Vaseux,
Ripley, and Vernon study sites. Characterization of hibernation and oviposition sites
allows surveys to identify these areas in locations that may support gophersnakes.
Finally, identification of the timing of various important life history behaviours means
human disturbance can be avoided during mating and oviposition periods, especially on
sites such as Vernon, where land is used for multiple purposes.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/3195 |
| Date | 11 1900 |
| Creators | White, Kathleen Edith |
| Publisher | University of British Columbia |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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