Browsing by Subject "Animal behavior"
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Item Behavior, demography, and competition in Microtus longicadus and M. mexicanus(Texas Tech University, 1971-08) Conley, Walter H,Not availableItem Discrimination of foraging paths produced by different search tactics(Texas Tech University, 2001-05) Higgins, Christopher L.Search tactics are cognitive processes, or decision mechanisms, that organisms utilize to elicit a group of related and sequential behaviors that allow them to locate available resources such as food, mates, refugia, and habitats. However, our knowledge of the actual tactics that animals utilize while searching for resources is limited, and very little empirical evidence has been gathered. As a result, a suite of models of theoretical search tactics was developed to emulate the searching behaviors of mobile individuals so that inferences might be made about their decision mechanisms, and to determine whether individuals are capable of searching with a globally optimal solution. The theoretical tactics included four deterministic tactics (maximum-distance search, minimum-distance search, nearest-neighbor search, and trajectory-directed search) and five probabilistic tactics (reciprocal-distance search, inverse-squared-distance search, uniformly random search, Pearson random walk, and Levy random walk). These tactics included variations of random walks and systematic searches in an attempt to characterize biologically realistic searching behaviors. The theoretical search tactics were simulated with hypothetical predators finding and consuming the same sets of resources, assuming no satiation or learning, so that comparisons among the resulting search paths could be made. Correlated measures of path length, consistency of movement, path linearity and turn rate were used to characterize the geometry of the resulting search paths. Classieal multivariate analysis, including discriminant function analysis (DFA) and non-linear artificial neural networks (ANN), were used to discriminate among the theoretical tactics and to classify "unknown" search paths into one of the underlying search tactics, both based on the geometry of the resulting paths. Both linear and non-linear discriminatory anah ses revealed a strong overlap between the nearest-neighbor search and the minimum-distance search tactics. This overlap implies that it is possible for animals to utilize search tactics that mirror the globally optimal solution without having complete knowledge of the specific location of available resources. Furthermore, both methods of analyses demonstrated that inferences could be made about the actual tactics that animals utilize while searching for resources based on the geometry of the search paths, but with varying degrees of reliability.Item Raptors associated with Black-tailed prairie dog colonies and directional manipulation of prairie dog colony expansion using visual barriers in shortgrass prairie(Texas Tech University, 2003-12) Merriman, Joel WhitcombNot availableItem Relationship of lesser prairie-chicken density to landscape characteristics in Texas(2012-05) Timmer, Jennifer; Boal, Clint W.; Butler, Matthew J.; Ballard, Warren B.; Whitlaw, Heather A.Ground-based lek surveys have traditionally been used to index trends in prairie grouse populations (Centrocercus and Tympanuchus spp.). However, indices of abundance or density can be fundamentally flawed and techniques that account for incomplete detection should be used. Distance sampling is a common technique used to estimate the density and abundance of animal populations and has been used with aerial surveys to monitor avian populations. With an increase in renewable energy development in native prairies and sagebrush steppe, there is a greater need to effectively monitor prairie grouse populations. One such species, the lesser prairie-chicken (LPC; T. pallidicinctus), has faced significant population declines and is thus, a species of conservation concern. In addition, much of the current and proposed wind energy development in the Great Plains overlaps some of the extant LPC distribution and few peer-reviewed studies have been conducted to investigate this potential threat to LPCs. Hierarchical distance sampling models can relate LPC lek density to landscape features and help predict the potential impact from wind and other energy development on lek density. Thus, the main objectives of our study were to estimate lek density in the LPC range in Texas and model anthropogenic and landscape features associated with lek density. We accomplished this by flying helicopter lek surveys for 2 field seasons and employing a line-transect method developed at Texas Tech University. We inventoried 208, 7.2 km × 7.2 km survey blocks and detected 71 new leks, 25 known leks, and observed 5 detections outside the current LPC range. We estimated 2.0 leks/100 km2 (90% CI = 1.5–2.8 leks/100 km2) and 12.3 LPCs/100 km2 (90% CI = 8.5– 17.9 LPCs/100 km2) for our sampling frame. Our state-wide abundance estimates were Texas Tech University, Jennifer M. Timmer, May 2012 vii 301.9 leks (90% CI = 219.4–415.4 leks) and 1,822.4 LPCs (90% CI = 1,253.7–2,649.1 LPCs). Our best model indicated lek size and lek type (wi = 0.360) influenced lek detectability. Lek detectability was greater for larger leks and natural leks rather than man-made leks. We used hierarchical distance sampling to build spatially-explicit models of lek density and landscape features. The 2 most competitive models included percent shrubland + transmission line (>69kv) density and only percent shrubland (AIC= 943.817, wi = 0.486; AIC = 945.098, wi = 0.256, respectively). We model-averaged our most competitive models and estimated the number of leks in our sampling frame at 245.7 leks (cv = 0.137). Lek density peaked at lower levels of transmission line density and where ≈60% of the landscape was composed of shrubland patches (shrubs <5 m tall comprising ≥20% of the total vegetation). Our state-wide survey efforts provide wildlife managers and biologists with population estimates, new lek locations, and identified spatially-explicit predictions of lek density. Our spatially-explicit models predicted lek density based on percent shrubland and transmission line density, which can be used to predict how lek density may change in response to transmission line development and changes in habitat conditions. This copy has been corrected.Item Stereotypic behavior in pregnant swine(Texas Tech University, 1995-12) Dailey, Jeffery WilliamIn Exp. 1, behavior of three genotypes were compared for gilts in outdoor or indoor production systems. The genotypes investigated were PIC Camborough-15, (C-15), PIC Camborough-Blue, and York X Landrace. No significant main effects of genotype were found. The oral/nasal/facial chewing observed in indoors pigs was lower in frequency than similar environment-directed oral/nasal/facial behaviors outdoors. Exp.2 compared behavior over 24-h for individually-kept C-15 sows in three systems: pasture, soil or gestation crates. Each treatment group performed statistically similar amounts of total oral/nasal/&cial behaviors for the 24-h sait5)le period. Frequency, duration and sequential analyses of sow behaviors for an intensive 2-h period starting 30 min post-feeding were investigated. While the precise substrate may differ depending upon availability, sows in each treatment showed similar overall duration and frequency of oral/nasal/facial behaviors. Sequential analyses showed stereotyped behaviors may be natural pre- and post-feeding appetitive and consolatory chewing and rooting activities modified in sequence and form by the available substrates.