Theses and Dissertations

Permanent URI for this collection

https://hdl.handle.net/10217/100425

Of special note are theses cited in James R. Meiman's Little South Poudre Watershed and Pingree Park Campus (Colorado State University, College of Forestry and Natural Resources, 1971).

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Open Access
Home range, site fidelity, reproductive ecology, and den site characteristics of the San Clemente Island fox
(Colorado State University. Libraries, 2012) Resnik, Jessica Ruth, author; Andelt, William F., advisor; Savidge, Julie A., committee member; Stanley, Thomas R., committee member; Theobald, David M., committee member
Since 2004, the endangered status of 4 island fox (Urocyon littoralis) subspecies has prompted increased efforts to understand and manage island foxes on all 6 islands where they occur. High rates of vehicle-related mortalities and potential for exposure to pathogens are of particular concern on San Clemente Island, California. Basic spatial ecology of the San Clemente Island fox (U. l. clementae) is needed for effective management but is currently inferred from home range studies on other island fox populations. Additionally, little is known about reproduction and denning of this subspecies, and island foxes in general. To better inform management strategies, I studied the spatial and reproductive ecology of this subspecies. During 2006-2007, I collected telemetry locations throughout the diel period for a random sample of foxes (n = 29), a sample with home ranges that included roads (n = 18) and a sample with home ranges that excluded roads (n = 19). I also monitored the movements of females in the random sample during 2007 to determine the proportion producing litters, number of kits in weaned litters, chronology of reproduction, and den site characteristics. I found that San Clemente Island foxes had home ranges (mean = 0.75 km2, SE = 0.9) and core areas (mean = 0.19 km2, SE = 0.03) 36-116% larger than reported in published studies for other island fox subspecies. Home ranges were largest during the pup-independence season (mean = 0.76 km2, SE = 0.07), but did not vary between pup-dependence (mean = 0.68 km2, SE = 0.11) and breeding (mean = 0.66 km2, SE = 0.10) seasons. Core area sizes were similar among all seasons. Annual home ranges and core areas for foxes living near roads were 77% and 82% larger compared to non-road foxes. Seasonal home ranges were larger for road foxes than for non-road foxes during the pup-independence and breeding seasons, but were similar in size during the pup-dependence season. Site fidelity between seasons ranged from 18-50%, was greater for home ranges of males than females, and was not different between genders for core areas. I did not detect dispersal during the home range study. Only 3 or 4 of 23 females produced a total of 6 pups. Of 13 females recaptured and examined for reproductive status, most had lactated in previous years (n = 7), or had some evidence of lactating but not weaning pups (n = 4); two females had never lactated. Breeding and parturition occurred two months earlier than reported for other island fox subspecies in wild-born or captive breeding populations since the 1970s. Females used two or three dens in succession and dens were almost exclusively found in rock crevices. Five of 23 foxes had home ranges that included supplemental food sources and human habitation, including all four females observed with pups, suggesting this could be a factor in reproductive success. I recommend caution when generalizing findings from other island fox subspecies and suggest managers establish subspecies-specific information to better inform conservation strategies on the different islands.
Open Access
Reproduction, denning ecology, and behavior of the San Clemente Island fox (Urocyon littoralis clemente)
(Colorado State University. Libraries, 2010) Gould, Nicholas Paul, author; Andelt, William F., advisor; Clements, William, committee member; Ghalambor, Cameron, committee member; Stanley, Thomas R., committee member
Island foxes (Urocyon littoralis) have experienced severe reductions in populations on 4 of 6 California Channel Islands. While numbers of San Clemente Island (SCLI) foxes (Urocyon littoralis clemente) have remained relatively stable, additional data on reproductive success in urban and rural areas is necessary so that we can better manage the population if it sustains declines. We also need to know locations and characteristics of den sites in order to minimize possible impacts of military training activities on foxes. I found that 5 of 6 urban females and 5 of 11 rural females produced at least 19 kits on the northern 2/3 of SCLI during 2008. Although foxes in urban areas may be reproducing more successfully than foxes in rural areas, urban foxes often selected den sites near roads which may expose them to increased mortalities. I located 23 den sites, on an average of 17-18° slopes with 40% having westerly-facing aspects. I recommend redirecting ground-disturbing military training maneuvers away from these areas during February through June which may minimize impacts of training activities on foxes. Collisions with vehicles have created concern for the welfare of the endemic San Clemente Island fox. The small population on the northern 2/3 of SCLl has sustained an estimated annual mortality rate of 3-8% due to collisions with vehicles from 2000 through 2007. To identify potential management solutions for minimizing these mortalities, I examined behavioral responses of SCLI foxes to approaching vehicles on roads. 1 found that during 67% of 541 observations, foxes remained within 5 m of an approaching vehicle, and during 26% of 258 observations, foxes remained on the road as the vehicle passed suggesting many foxes were naive toward vehicles. During 8% of 258 observations, foxes remained in the center of the road; thus, we were required to stop our vehicle to avoid hitting the fox. I examined 5 main behaviors (running, walking, sitting, standing, and foraging) of foxes as a vehicle approached to ascertain if behaviors of foxes changed with distance. Foxes showed no trend towards avoidance behaviors (running or walking away) at closer distances (0, 5, 25 m) to the approaching vehicle. During 49 of 150 observations where foxes exhibited directional movements in response to our vehicle at 0, 5, 25, 50 and 100 m, foxes approached our on-coming vehicle, further suggesting SCLI foxes exhibit naive behaviors toward vehicles. I found no significant effects of road surface, biological season, day versus night, and foxes in urban versus rural areas on behaviors. I recommend educating drivers on SCLI about the general lack of vehicle avoidance behaviors of foxes, and recommend reducing the speed limit to minimize impacts of vehicles on island foxes.
Open Access
Reproduction, denning, and spatial ecology of juvenile, yearling, and adult San Clemente Island foxes (Urocyon littoralis clementae)
(Colorado State University. Libraries, 2015) Hamblen, Emily Elizabeth, author; Andelt, William F., advisor; Coleman, Robert O., committee member; Stanley, Tom R., committee member; Noon, Barry R., committee member
The endemic California Channel Island fox (Urocyon littoralis) declined substantially on four of the six islands that it occupies between 1994 and 2002. One subspecies, the San Clemente Island fox (SCLI; Urocyon littoralis clementae) has maintained a relatively stable population compared to the subspecies that declined. The San Clemente Island fox is listed as threatened by the state of California, thus, increased information on reproductive behavior and success as well as home range area and dispersal is essential for understanding the population dynamics of this species. I used a spatially balanced random sampling design to capture and radio-collar 30 foxes from 31 December 2008 to 10 January 2009. I then captured juvenile island foxes from 20 June to 8 October 2009. I determined reproductive status of 28 island foxes through observations of collared yearlings and adults with or without juveniles between 25 February and fall 2009. A greater proportion of adults (11/20) than yearlings (1/8), and a greater proportion of females (9/12) than males (3/16) were observed interacting with juveniles. Litter sizes averaged 2.0 juveniles. Only one of 28 collared foxes exhibited either polygamous or "helper" behaviors. Parturition started approximately two months earlier than historically recorded on other islands. I observed four dens located in shrubs and one den in a hole without surrounding vegetation. The average slope of terrain next to dens was 6o, average aspect was 148o, and orientation of the most worn entrance to the den averaged 152o. If monetary resources are limited, I suggest focusing on females to monitor and estimate reproductive success because males were infrequently found with juveniles. If emergence from dens continues to occur earlier than previously recorded, then the current recommended time period for trapping (20 June–January) may need to exclude January to reduce stress during pregnancy of females. Our results should help inform future population modeling for the San Clemente Island fox population. Home range sizes varied by age class, whereas sex and type of telemetry (vehicle vs walk-in) did not affect home range size. I did not observe overlap often enough to evaluate differences by age classes, but the largest percentage of overlap occurred between an adult male and yearling male (57.8%) and an adult male with an adult female (47.4%). Five of 17 juveniles, one of nine yearlings, and 0 of 21 adults dispersed. I documented the largest average (3.49 km) and maximum dispersal (10.0 km) of any Channel Island fox study. The presence of dispersal in SCLI foxes suggests that 1) juveniles, and particularly males, should be targeted for vaccination because they are more likely to disperse and possibly transmit diseases than older age classes, and 2) if populations are reduced, island foxes may be able to repopulate areas through dispersal.

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Browsing Theses and Dissertations by Author "Andelt, William F., advisor"

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