Bibliography: pages 187-191. / The foraging of breeding Jackass Penguins Spheniscus demersus was studied in and around southwestern Cape Province, Saldanha Bay (33⁰ S, 18⁰ E), South Africa. Penguins are difficult to observe at sea. Hence, I devised a number of new techniques for studying the foraging behaviour of Jackass Penguins at sea. I built electronic and autoradiographic remote-sensing devices to measure swimming speed, distance travelled and time spent at each depth by foraging Jackass Penguins. Penguin swimming speed was reduced in proportion to the cross-sectional area of the devices, and results derived from birds wearing the devices had to be interpreted accordingly. Penguins do not regurgitate their stomach contents when handled, so I constructed a wet-offloading stomach pump which extracted 100% of the stomach contents. Using this pump, I determined that the rate of digestion of fish and squid by Jackass Penguins differed. Care is needed in diet interpretations where both fish and squid are major food items.

The ‘landscape of fear’ has been proposed as a unifying concept in ecology by linking population distribution patterns through top-down predator-prey mechanisms. The landscape of fear predicts that prey resource selection patterns are influenced by spatially and temporally predictable patterns of predator risk across a landscape. Although the model has been suggested to predict prey space-use patterns across a variety of systems, it remains unclear if individuals exposed to similarly risky environments (i.e., within the home range) will consistently avoid predator risk. I tested the landscape of fear concept using a natural experiment where moose hunting was introduced to a previously hunter-naïve moose population. I quantified hunting risk by developing risk landscape layers derived from harvest data collected over the first three hunting seasons (2011, 2012 and 2013) in Gros Morne National Park, Newfoundland, Canada. Yearly hunter-risk layers were then used as a continuous variable in moose resource selection analysis to understand if moose respond to hunter risk, and if all individuals respond similarly to risk, as predicted by the landscape of fear. I found moose hunters were generally more likely to harvest moose near landscape features that offered easy access and a wide field of view. Moose generally did not avoid hunting risk until the second hunting season, and only during daylight hours. Conversely, at night, moose were generally found to select hunter-risky areas, with the strength of selection progressively increasing each year. I found considerable individual variation in moose response to hunting risk, however, with some individuals failing to alter selection strategies to avoid hunter risk. The motivation to respond to risk may be based on fitness related trade-offs associated with anti-predatory behavior, personality, and/or an individual’s ability to correctly assess risk on the landscape. My research highlights the importance of incorporating individual patterns in resource selection strategies when attempting to address landscape-level processes, such as the landscape of fear concept.

Predator avoidance behaviors are a critical defense mechanism that can increase the chances of survival for potential prey species. We tested the avoidance behavior of the freshwater amphipod, Gammerus sp., under two different chemical predation cues. The first was the presence of kairomone, which was derived from a species of fish, Gambusia affinis, that was fed a diet exclusively of amphipods. The second predation cue was potential alarm cue derived from macerated conspecific amphipods from the same population as the test species. Response variables included time spent moving after the introduction to the signal as well as the time spent in refuge. Movement of amphipods significantly decreased and time spent in refuge significantly increased when amphipods were exposed to alarm cue as compared to control organisms that received no exposure to predation cues. Exposure to the fish kairomone treatments significantly increased time spent in the refuge but did not significantly influence time spent moving during the trials. These results suggest that amphipods exhibit predator avoidance behavior primarily when there is evidence that an attack has occurred (evidenced by the death of conspecifics within the population), but will also demonstrate avoidance behaviors to a lesser degree when a predator is detected.

Aggregation and species association of 9 species of phytophagous and predaceous mites were studied for 6 yr in an orchard with 100, 2 m tall 'Red Delicious' apple trees. To quantify aggregation, a method was developed that is powerful, and easily interpreted. It relates the proportion of habitat occupied to mean density of the organism, and allows discrimination of aggregation differences between data sets. We found that plant feeders were more aggregated than predators, and active life stages were less aggregated than eggs. Specifically, webspinning spider mites (Tetranychus urticae + Eotetranychus sp.) were the most aggregated. Panonychus ulmi was less aggregated than the webspinning mites, and Bryobia rubrioculus was the least aggregated of the spider mites. Zetzellia mali, the slowest moving predator, had the greatest aggregation of all the predators. The rapid moving phytoseiids were the least aggregated of all the mite species studied, with the specialist predator Metaseiulus occidentalis having the greatest aggregation, the generalist predator Typhlodromus pyri having medium aggregation, and the fast moving Amblyseius andersoni having the least aggregation. Predator-predator, predator-prey, and prey-prey associations were measured using Yule's V association index. Predator-predator associations were the strongest and most consistent, showing a consistent seasonal pattern of neutral-negativeneutral association. Negative associations of T. pyri with other predators were the strongest, which is consistent with evidence that this mite can detect other predators. Predator-prey seasonal associations were weak and mixed, and interactions between prey species were generally weakly positive, probably because of similar habitat preferences. Predaceous mites were generally more aggregated when competing with other predators, possibly allowing the coexistence of 3 predators simultaneously for 6 years via mechanisms proposed by the "aggregation theory of coexistence". G. occidentalis showed the greatest change of aggregation when other predators were present, Z. mali and T. pyri also showed significant changes in aggregation when they were with other predators, but A. andersoni (the largest, fastest predator in our study) showed no changes in aggregation. T. pyri's aggregation increased the most when in the presence of Z. mali, perhaps because of egg predation by the stigmaeid, or because T. pyri could detect the other predator. / Graduation date: 1999

Thesis (M.S.) in Marine Biology--University of Maine, 2002. / Includes vita. Bibliography: leaves 61-69.

Predatory gastropods (Neogastropoda) feed with a proboscis (elongate snout) and complex foregut. The presence of developmental modules (semi-autonomous components) in foregut development may have facilitated emergence of predatory feeding. In species with indirect development (feeding larval stage) physical and temporal separation of developing foregut modules (dorsal=larval esophagus; ventral=juvenile feeding structures) allows larval feeding and rapid switch to carnivory. However, previous studies on neogastropods with direct development (no feeding larval stage) did not identify foregut developmental modules. Thus, I investigated foregut development in two predatory, direct developing neogastropods: Nucella lamellosa and N. ostrina (Muricoidea), using histological sectioning, 3D reconstructions, TEM, and SEM. In both species, I showed evidence for dissociable dorsal and ventral foregut developmental modules. In N. lamellosa, the two modules were physically separate, although they were not separate in N. ostrina. My results reconcile differences in previous descriptions of foregut development between neogastropods with indirect and direct development. / Graduate

Coyotes fed upon agricultural carrion at feedlots operated by the Farmer's Investment Company (FICO) and Roisland Farms. Agricultural carrion was not available in the Whetstone area. The FICO feedlot stopped operating in May 1976, and carrion was not available there after that time. Coyotes were trapped and shot at the FICO feedlot from November 1975 through March 1976, from June through August 1976, and from May through August 1977. Coyotes were trapped at Roisland Farms in July and August 1976 and January and February 1977. A trapper collected coyotes in the Whetstone area from January through March 1976 and from November 1976 through February 1977. I operated a scent station line on the Santa Rita Experimental Range on a monthly basis from October 1975 through June 1976, from September 1976 through June 1977, and in December 1977. From data on the visitation of scent stations by coyotes, lagomorphs, and small mammals I calculated indices of monthly relative abundance for each animal group. There were no differences among the age distributions, weights, ovulation rates, and litter sizes of coyotes from the 3 study areas. The mean weights of all adult-sized male and female coyotes collected during this study were 11.1 and 9.3 kg, respectively. The overall mean ovulation rate and mean litter size were 4.1 and 3.4, respectively. At FICO and Roisland, 70 to 90% of yearling and adult females bred, but only 20% bred in the Whetstone area. There were more male than female coyotes at FICO, but sex ratios were not different from 1:1 at Roisland and Whetstone. The visitation rates of coyotes, lagomorphs, and small mammals fluctuated greatly during this study. Monthly visitation rates of coyotes differed significantly, but annual and daily rates did not. The visitation rates of both lagomorphs and small mammals were significantly different between years and among months, but not among days. Lagomorph and small mammal visitation increased significantly after the trapping of coyotes and the end of the FICO carrion supply in the summer of 1976. Coyote visitation appeared to decrease after the summer of 1976. Prior to the summer of 1976, the visitation rates of coyotes and lagomorphs were positively correlated, but the rates of coyotes and small mammals were not correlated. After the summer of 1976, coyote visitation was negatively correlated with both lagomorph and small mammal visitation. The distribution of coyote and lagomorph visits along the scent station line did not change after the summer of 1976. Small mammal visitation, however, increased in the distant section of the line after the summer of 1976. Coyotes visited stations located on the upwind side of the road more frequently than they stopped at stations on the downwind side. Lagomorphs showed no preference for either side of the road, but small mammals visited more stations on the downwind side of the road than on the upwind side. The breeding rate at FICO did not decrease after the carrion supply ended. It seems unlikely, therefore, that the high breeding rate at FICO was caused by feeding on carrion. The scent station technique has potential as a means of monitoring the monthly relative abundance of coyotes and certain prey groups. Unfortunately, visitation is a function of animal numbers and activity. Further research is required to quantify the relationship between visitation and abundance for each animal group.

Diss. (sammanfattning) Umeå : Univ., 2008. / Härtill 4 uppsatser.

Thesis (M. Sc.), Memorial University of Newfoundland, 1999. / Bibliography: p. 17-32.

Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.