A Proximity to the nearest neighbour

B Adjacent neighbour of each age-sex class Figure 10.6 Exploration of patterns of spatial proximity can reveal some unexpected structure to what appears superficially to be a random gathering. In the case of farm cats, these graphs, based on G. Kerby's field study in Macdonald et al. (in press), reveal (A) that different age-sex classes of individuals positioned themselves at significantly different distances to their nearest neighbors and (B) that these positionings differed significantly...

Utility Distributions

From location data such as those shown in figure 3.2, most home range estimators produce a utility distribution describing the intensity of use of different areas by an animal. The utility distribution is a concept borrowed from economics. A function, the utility function, assigns a value (the utility, which can be some measure of importance) to each possible outcome (the outcome of a decision, such as the inclusion of a place within an animal's home range Ellner and Real 1989). If the utility...

Feeding Site Surveys

Feeding site surveys are among the earliest approaches used to investigate food habits and were initially developed to determine the foods of livestock. This method relies on an inventory of plants consumed or identification of prey remains. Because of the limitations imposed by cover or nocturnal activity, the food habits of many species cannot be observed directly. As a result, some investigators have relied on an examination of feeding sites. This technique obviously depends on the ability...

Investigating Food Habits of Terrestrial Vertebrates

Why study food habits Probably one of the most fundamental questions that ecologists attempt to answer is, What resources does a particular species require to exist Indeed, the first principle among wildlife ecologists is to have a thorough understanding of the food, cover, and water requirements of an animal before initiating any effort to alter the factors that may be limiting it. Information on food habits is therefore an important introduction to the natural history of any species. This has...

Advantages and Problems of the Demographic Response Design

The best measure of habitat quality would be a test of its effects on demographic parameters such as population growth and carrying capacity. Such tests are extraordinarily difficult in most situations, as evidenced by the scant published studies of this nature. Most demographic response studies I reviewed examined potential relationships between habitat and animal density. Because habitat-specific density is actually a reflection of differential habitat use, investigations of habitat-related...

Info

Stubbendieck. 1986. Methods of measuring herbage and browse utilization. In C. W. Cook and J. Stubbendieck, eds., Range research Basic problems and techniques, 120-121. Denver, Colo. Society of Range Management. Cooperrider, A. Y. 1986. Food habits. In A. Y. Cooperrider, R. J. Boyd, and H. R. Stuart, eds., Inventory and monitoring of wildlife habitat, 699 710. Denver, Colo. U.S. Bureau of Land Management. Corbett, L. K. 1989. Assessing the diet of dingoes from feces A...

Marker Evaluation Studies

We recommend increased efforts to test for effects of markers, changes in existing protocols and recommendations, and more publication of the results of marker evaluation studies. Evaluation studies are a critical step in the marker validation process, but many commonly used markers have been evaluated for only a few species. Our review highlighted several specific deficiencies in our understanding of marker effects, such as effects of radiotransmitters in fish, efficacy of internally versus...

Modeling Species Distribution with GIS

Fabio Corsi, Jan de Leeuw, and Andrew Skidmore From the variety of checklists, atlases, and field guides available around the world it is easy to understand that distribution ranges are pieces of information that are seldom absent in a comprehensive description of species. Their uses range from a better understanding of the species biology, to simple inventory assessment of a geographic region, to the definition of specific management actions. In the latter case, knowledge of the area in which...

Critical Review of the Effects of Marking on the Biology of Vertebrates

Vertebrates often are marked to facilitate identification of free-ranging individual animals or groups for studies of behavior, population biology, and physiology. Marked animals provided data for many of the topics discussed in this volume, including home range use, resource selection, social behavior, and population estimation. Markers can be classified into three general categories mutilations, tags and bands, and radiotransmitters. The appropriate marking technique for a study depends on...

Useavailability Design

Among studies of birds and mammals, the use availability design is the most popular. I reviewed habitat-related papers dealing with birds and mammals published in the Journal of Wildlife Management during 1985-1995 and found that most 90 of 156, or 58 percent relied on a use-availability study design to assess habitat selection, preference, or quality. Thomas and Taylor 1990 further categorized use-availability studies into three approaches one in which habitat-use data are collected on animals...

Methods for Evaluating Habitat Selection Preference and Quality

Three general study designs have been used to infer habitat quality. The first, generally called the use availability design, compares the proportion of time that an animal spends in each available habitat type generally judged by the number of locations, or less commonly, by the distance traveled e.g., Salas 1996 to the relative area of each type. The second, which I call the site attribute design, compares habitat characteristics of sites used by an animal to unused or random sites. These two...

The Ethogram

Early in any study a researcher must classify the behavior patterns to be documented. This classification is an ethogram, and constitutes a dictionary of the researcher's language without an ethogram, meaning is not fixed. Ethograms have become unpopular because like dictionaries they take up large amounts of space and are dull to read. However, they are vital reference material for those wishing to assess a study's conclusions critically. As a corollary, it is not uncommon for the brunt of...