Browsing by Subject "Key deer"

Now showing 1 - 4 of 4
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    Distribution and abundance of endangered Florida Key deer on outer islands
    (Texas A&M University, 2007-04-25) Watts, Dominque Elijah
    Status assessments are compulsory to efficacious management of large-mammal populations, particularly for endangered species such as the Florida Key deer (Odocoileus virginianus clavium). However, a dearth of data regarding basic demographic parameters has limited status assessment and management of Key deer on outer islands. Traditional survey techniques for Key deer on Big Pine and No Name keys include road-counts, strip-counts, and mark-recapture methods. However, practical limitations render traditional survey techniques impractical for application on outer islands. Thus, assessment of current status and appropriate management is limited by a paucity of information regarding Key deer on outer islands. The purpose of my study was to evaluate the utility of infrared-triggered cameras and forward-looking infrared thermography (FLIR) to monitor occupancy and abundance of Key deer on outer islands, and to obtain baseline information regarding current distribution and abundance of Key deer in these areas. In addition, I wanted to further evaluate the advantages and disadvantages inherent in using baited camera-stations to estimate abundance of large mammal populations. I compared 3 frequently applied methods to estimate abundance from camera-based survey data. All outer islands exhibited estimated abundances considerably below carrying capacities, with larger populations occurring closer to Big Pine Key. Results indicated that other islands and complexes such as Ramrod Key, Water Key, and the Annette complex maintain only small sub-populations (e.g., ??????5 individuals) and other previously inhabited island complexes (i.e., Johnson complex and Summerland Key) no longer maintain sub-populations. Additionally, I compared abundance estimates from FLIR-based surveys to camera-based estimates. Although no test of accuracy was possible, camera-based survey methods consistently produced higher estimates of Key deer abundance on outer islands. Results indicate that aerial FLIR-based survey methods may be unreliable for the survey of large mammals in tropical habitats or areas exhibiting dense vegetation, and camera-based surveys should be the preferred method to survey Key deer abundance on outer islands.
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    Evaluation of the effects of a highway improvement project on Key deer
    (Texas A&M University, 2006-10-30) Braden, Anthony Wayne
    Deer-vehicle collisions (DVCs) along a 5.6-km segment of United States Highway 1 (US 1) on Big Pine Key (BPK), Florida responsible for approximately 26% of endangered Florida Key deer (Odocoileus virginianus clavium) annual mortalities. The Florida Department of Transportation (FDOT) constructed a 2.6-km long system of fencing, 2 underpasses, and 4 experimental deer guards to address DVCs along a portion of the US 1 roadway in 2001??????2002. I evaluated the effectiveness of the project in reducing Key deer mortality by comparing (1) survival of radio-collared deer, (2) deer-vehicle collisions on US 1, and (3) determining the ability of deer to access the fenced segment. I found no significant difference in male or female survival. Key deer-vehicle collisions were reduced by 83??????92% inside the fenced segment. However, overall US 1 Key deer-vehicle collisions did not change. Key deer entry into the fenced segment was minimized to 8 deer during the first-year resulting in 2 deer mortalities. I also assessed the potential impacts of the US 1 corridor project to Key deer movements by comparing (1) radio-collared Key deer annual ranges (2) radio-collared deer corridor movements, and (3) assessing Key deer underpass and corridor use. Female and male ranges and core areas did not change (P > 0.05). Deer movements within the US 1 corridor were comparable pre- (6 of 23 radio-collared deer crossed the corridor) and post-project (4 of 16). Infrared-triggered camera data indicate underpass movements increased over time. Collectively, post-project telemetry and camera data indicates US 1 highway improvements have not restricted Key deer movements. Hourly Key deer movement and US 1 traffic patterns were compared to annual US 1 DVCs. Hourly deer movements showed a positive correlation (P = 0.012, r = 0.505) to hourly DVCs for the full circadian period. Hourly US 1 traffic showed a significant positive relationship (P = 0.012, r = 0.787) with DVCs only during the night period. Evaluation of hourly deer movements and hourly traffic volume on US 1 found hourly DVCs to be the result of a combination between both variables.
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    Management strategies for endangered Florida Key deer
    (Texas A&M University, 2004-09-30) Peterson, Markus Nils
    Urban development is of particular concern in the management of endangered Key deer (Odocoileous virginianus clavium) because highway mortality is the greatest single cause of deer mortality (? 50%), and the rural community of Big Pine Key, Florida constitutes the majority of Key deer habitat. Study objectives were to provide and synthesize management strategies useful in the recovery of Key deer. Specifically, I (1) used simulation modeling to evaluate effects of fetal sex ratios (FSR) on Key deer population structure, (2) evaluated the most efficient and socially acceptable urban deer capture methods, (3) evaluated changes in fawn survival, mortality agents, and range size between 1968-2002, and (4) conducted an ethnography of the human population on Big Pine Key to ascertain cultural dynamics within the community and provide guidelines for community based management of Key deer. Key deer were radio-collared (n = 335) as part of 2 separate field studies (1968-1972, 1998-2002), and mortality and survey estimates were collected throughout the entire period (1966-2002). During 1990-2002, I used an ethnographic approach to analyze the conflict surrounding Key deer management and explored how conflict and moral culture applied to this endangered species. These data were used to address my study objectives. I found the most commonly cited FSR (2.67:1, male:female) for Florida Key deer to be inaccurate. A male biased FSR of 1.45:1 was more probable. Modified drop and drive nets were appropriate methods for urban deer capture because they are passive, silent, fast, generally accepted by the public, and yielded low mortality and injury rates. Between 1968-2002 Key deer fawn survival increased in tandem with human development while range sizes decreased. This suggests a positive, but not sustainable, relationship between fawn survival and development. I found disputants on Big Pine Key divided into 2 moral cultures, 1 grounded in stewardship and the other in private property rights. Successful management strategies for the Key deer require understanding and addressing issues at several levels including: Key deer demographics, community perspectives, and cultural norms. Collectively this information can be used by wildlife managers to improve the management and recovery of Key deer.
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    The impacts of urbanization on endangered florida key deer
    (Texas A&M University, 2006-04-12) Harveson, Patricia Moody
    Conservation of native wildlife is becoming increasingly difficult due to continued human population growth and expansion. As the human population continues to increase, so does the rate of consumption of our natural resources. As competition for resources between man and wildlife continues, it is important to understand the effects of urbanization on species. Endangered Key deer (Odocoileus virginianus clavium) are endemic to the Florida Keys archipelago stretching southwest off the southern tip of peninsular Florida. Key deer range is restricted to the Lower Florida Keys with approximately 60% residing on Big Pine Key and 15% residing on No Name Key which have undergone rapid human population growth and development over the past 30 years. Urban development and its associated risk factors (i.e., habitat loss and fragmentation, deer domestication, and deer??vehicle collisions) have been cited as the greatest threat to the Key deer population. For my dissertation research, I evaluated the impacts of 30 years of development on the Key deer population. My results suggest that increased habitat fragmentation and increased road traffic have created areas of varying habitat quality and mortality risk and have resulted in a source-sink system for Key deer on Big Pine Key. In my examination of Key deer metapopulation dynamics, I found a low probability of deer colonizing 2 target outer islands (Sugarloaf and Cudjoe) through dispersal alone in the next 20 years. Further, I examined the impacts of urbanization on changes in Key deer population dynamics, behavior, and morphology. Collectively, my results suggest that over the past 30 years Key deer have become more urbanized, which in turn has influenced Key deer behavior and population viability. Behavioral adaptations due to deer plasticity appear to have provided Key deer with mechanisms to persist in a changing environment due to urbanization. However, the future ability of Key deer to persist in a continuously urbanizing environment cannot be predicted. At some threshold, urban development would become unsustainable, and, unlike other forms of habitat change or environmental disturbances, urban development is in most cases irreversible, requiring careful planning in habitat conservation strategies.