Does Spatial Structure Persist Despite Resource and Population Changes? Effects of Experimental Manipulations on Coyotes

We tested the influence of a change in food resource distribution on space use and diet of coyotes (Canis latrans). We focused on 2 facets of space use: maintenance of home ranges by residents, and establishment of home ranges by immigrants after a coyote removal program. The study was conducted on 2 populations of coyotes in southern Texas. In both populations, a clumped, high-quality food source was added to randomly selected feeding stations to measure the influence of food distribution and abundance on home-range patterns, trespassing rates, and consumption of native prey. In established home ranges, coyotes visited and foraged at stations regularly and were found closer to stations during the treatment period. Although there was no overall treatment effect on home-range size (F = 1.66, d.f. = 5, P = 0.15), home ranges without supplemental food remained stable in size, whereas home ranges that had received supplemental food increased during the posttreatment period (t = 2.09, d.f. = 1, P = 0.04). Core areas showed a similar trend; there was no overall treatment effect (F = 1.51, d.f. = 2, P = 0.24); however, core areas of home ranges that received supplemental food were smaller than those of controls during the treatment period (t = 2.71, d.f. = 1, P \u3c 0.01). There were no statistical differences in occurrence of any species, such as small mammals or white-tailed deer (Odocoileus virginianus), in scats of treatment versus control coyotes. Coyotes within the study site after removals were located closer to feeding stations during treatment than posttreatment (F = 8.83, d.f. = 1, P \u3c 0.02,n = 897) periods, yet home-range size with supplemental food was larger than home-range size during the posttreatment period. Our findings suggest that a resource other than food influences coyote spatial patterns

A Networked Telerobotic Observatory for Collaborative Remote Observation of Avian Activity and Range Change ⋆

The scientific field study of wildlife often requires vigilant observation of detailed animal behavior over extended periods. In remote and inhospitable locations, observation can be an arduous, expensive, and dangerous experience for field scientists. We are developing a new class of networked teleoperated robotic “observatories ” that allows “citizen scientists ” and professional scientists to remotely observe, record, and index animal activity and behaviors via the internet. This paper describes CONE-Welder, installed at the Rob & Bessie Welder Wildlife Foundation in Texas to gather photographic and quantitative data for a biological study of avian activity and hypothesized range change for selected subtropical bird species. Since the system was deployed on 12 May 2008, over 600 users (“players”) have participated online. Players have requested over 2.2 million camera frames and captured over 29,000 photographs. Within these photos, citizen scientists have classified 74 unique species, including eight avian species previously unknown to have breeding populations within the region. The collected dataset quantifies seasonal presence of birds of particular interest, e.g., the Green Jay (Cyanocorax incas). This paper describes the system architecture, the game interface that provides incentives for player participation, and initial data collected. CONE-Welder is available online at

Spatial ecology and habitat utilization of American alligators in an urban-influenced ecosystem

Previous studies have explored spatial ecology and habitat use of alligators and other crocodilian species. However, few studies have explored these characteristics in urban environments. We studied an alligator population that occurred in an urban-influenced ecosystem, a habitat that has received little scientific attention. Our objectives were to determine spatial ecology and habitat use of American alligators within this urban system and to provide a template of methodology and analytical techniques that can be used by urban biologists, planners and researchers in order to assess and study urban crocodilian populations.We recorded 653 observations of alligators and their locations during 19 alligator surveys at an encounter rate of 0.6 alligators per km/survey. Results indicated that alligators exhibited clustering patterns of distribution. Thirteen different wetland types occurred within our survey area, but alligators were only observed in 10 of the 13. We found few differences in habitat use among size classes. We observed little segregation between adult and subadult size classes. However, there was spatial segregation between hatchlings and all other size classes, presumably due to female nest site selection. Alligators of all size classes seemingly avoided areas of high human activity; therefore, urbanization can influence alligator distribution and habitat use within wetland ecosystems. We provide methods and information that can be incorporated into future research and management of urban crocodilian populations. Utilizing this information, biologists can identify potential target areas for implementing management strategies, identify habitat and nesting areas, and mitigate human-alligator conflict