A reported decline in Arctic grayling (Thymallus arcticus) caused the Alaskan State Board of Fisheries to close sport grayling fishing at the Ugashik Narrows, Alaska, in 1990. Sport fishing did not appear to have caused the reported decline; the decline occurred during a period with negligible harvest (Meyer 1990). My objective was to evaluate whether the decline might be an artifact associated with fish movements. I determined locational fidelity between years and persistence of occupation of individual areas and grayling population structure over time. Changes in population structure are circumstantial evidence that movement is occurring. The following factors may effect population parameters: (1) the movement of grayling into and out of the Narrows and (2) periodic displacement of grayling from the Narrows during spawning and migration of sockeye salmon (Oncorhynchus nerka). Therefore, a single sampling effort may seriously underestimate the population.

The Central Arizona Project (CAP) canal system restricts movements of mammals across Avra Valley, Arizona. The Wildlife Mitigation Corridor (WMC) was established to provide access for animals over the Tucson Aqueduct of the CAP, and allow movement across Avra Valley. To determine if animals used the WMC more or less than other canal crossings (i.e., bridges), we recorded tracks of desert mule deer (Odocoileus hemionus crooki), collared peccary (Pecari tajacu), and coyote (Canis latrans) in and out of the WMC from August 1996 through July 1997. We also monitored two water catchments adjacent to crossings within the WMC with cameras to determine if catchments were used by wildlife. Deer and collared peccaries used crossings in the WMC more than those outside of the WMC. There was no significant difference between use of crossings by coyotes. Coyotes used all crossings throughout the year regardless of the availability of water sources.

<p>Eastern Kingbirds (<i>Tyrannus tyrannus</i>) breed from coast to coast in North America and build open-cup nests in trees. They have been extensively studied across most of their range and have only on occasion been documented to reuse a nest from a previous season. However, at Malheur National Wildlife Refuge (MNWR), located in southeastern Oregon, ~10 % of female Eastern Kingbirds reuse old nests of mainly American Robins (<i>Turdus migratorius </i>). In an attempt to address why nest reuse is so common at MNWR, I used artificial nests to evaluate two hypotheses as to why nest reuse is common in this breeding population. The first hypothesis states that Eastern Kingbirds reuse nests to save time and/or energy (TES) and the second one states nest reuse occurs because there is a shortage of suitable nest sites (NSS). I was able to reject the TES hypothesis because artificial nests provided no apparent reproductive benefits to Eastern Kingbirds, except that if a nest had failed it took less time to lay a replacement clutch after an initial failure if an artificial nest was used instead of building a new nest. A more reasonable explanation is that Eastern Kingbirds face a limited availability of suitable nest sites. With this in mind, I took vegetation measurements to address the hypothesis that Eastern Kingbirds make adaptive choices when selecting a nest site, in which case they would choose sites that increase their probability of breeding successfully. Successful nests, both natural and artificial, were placed higher in a tree and on a steeper angled nest branch than their failed counterparts. Those findings suggest that Eastern Kingbirds make adaptive choices when selecting a nest site. </p>

<p> South Florida's loggerhead (<i>Caretta caretta</i>), green (<i>Chelonia mydas</i>) and leatherback (<i>Dermochelys coriacea </i>) sea turtles hatchling have environmentally determined sex. The <i> in situ</i> nest mean hatchling sex ratios (SR) were highly femalebiased: loggerhead <i>F</i>=0.89) and green turtle <i>F</i>=0.81; leatherback's SR was nearly balanced (0.55<i>F</i>). Nest temperatures and SRs differed between leatherbacks and loggerhead and green turtles. The latter two did not differ. The loggerhead response parameters were estimated within biological limitations by both 50-65% of incubation and mean middle 1/3 temperature. The maximum middle 1/3 temperature was the best-fit predictor for green turtles. No best-fit sex ratio-temperature response could be identified for leatherbacks. Clutches incubating under natural conditions can vary greatly in SR; TRT differences may account for differences among species' sex ratios.</p>

Abstract Not Available.

The reproductive success of American kestrels (Falco sparverius) infected with Trichinella pseudospiralis was significantly reduced when compared with uninfected controls. Egg laying was delayed, and infected females produced fewer eggs than uninfected controls. Infected females were more aggressive and copulated less frequently. Egg breakage among infected birds was greater than among controls. Infected females tended to lay eggs outside the nest box. Infected females did not incubate as frequently as the controls, thus accounting for the higher prevalence of embryo mortality among these birds. The above effects translated into a mean production of 2.1 hatchlings per control pair and 0.6 per infected pair of kestrel. Both in breeding and non-breeding kestrel, T. pseudospiralis infections gave rise to a general decline in mobility. Behavioural effects are primarily attributable to the presence of muscle larvae. The parasite showed no predilection for specific muscle groups.

No description available.

<p> Limited survey data and numerous anecdotal accounts indicate that the Common Nighthawk <i>(Chordeiles minor)</i> is experiencing population declines in Wisconsin. However, the magnitude of the decline is unclear because current avian monitoring efforts are not conducted at dusk when Common Nighthawks are most active nor do they specifically target urban areas such as cities and villages where Common Nighthawks are known to nest on flat graveled rooftops. New urban, crepuscular monitoring methods are needed in order to gain a better understanding of current Common Nighthawk demographics in Wisconsin. </p><p> The goal of this thesis was to conduct a baseline study using citizen science &ndash; based methodology to determine where Common Nighthawks persist in cities and villages in southeastern Wisconsin. The objectives of the study were to collect information on environmental factors, landscape features, and land cover types of potential importance to Common Nighthawks during the breeding season and then analyze the data collected to investigate correlations between each variable and Common Nighthawk occurrence at each survey point. The aim was to use the findings of the baseline study to inform current avian monitoring efforts such as the Wisconsin Nightjar Survey so that adjustments allowing for more effective monitoring of Common Nighthawks could be implemented in survey route placement and survey protocol. </p><p> Between June 7th and July 18th 2013, volunteers conducted 1,412 surveys at 494 points in 82 cities and villages within the Southeast Glacial Plains and Southern Lake Michigan Coastal ecological landscapes of Wisconsin. Common Nighthawks were detected in 98 surveys at 68 points in 32 cities and villages. On three different evenings at each point, volunteers conducted 10 &ndash; minute point counts in which they counted Common Nighthawks and described their behavior. During surveys, volunteers recorded the temperature ( &deg; F), estimated the moon phase, rated the sky condition, wind speed, noise, light pollution, and insect activity, and counted the number of potential Common Nighthawk predators (e.g. crows, gulls, raptors, and cats), and the number of Chimney Swifts. Volunteers also counted sources of artificial ambient light (e.g. street lights and stadium lights) and flat rooftops surrounding (100 meter buffer) the survey point. </p><p> The land cover surrounding each survey point (500 meter buffer) was analyzed from the National Land Cover Database (NLCD) 2011 using Geographic Information Systems (GIS). The number and total area of flat graveled rooftops surrounding each point (500 meter buffer) were estimated from aerial photos taken in 2011 using GIS. Results from statistical analysis of land cover classes suggests that in cities and villages, Common Nighthawks are more likely to be found in areas with higher percentages of impervious or built-up land cover. Agricultural land cover was the only land cover class that demonstrated a statistically significant negative correlation with Common Nighthawk presence. Strong, statistically significant positive correlations were found between Common Nighthawk presence and both the number of flat graveled rooftops and the total area of flat graveled rooftops. </p><p> Mann -Whitney U analysis of environmental variables recorded by volunteers suggests a statistically significant negative correlation between Common Nighthawk presence and percent moon illumination. A statistically significant positive correlation was also found between Chimney Swift <i>(Chaetura pelagica) </i>, counts and Common Nighthawk presence. A statistically significant positive correlation was also found between Common Nighthawk presence and the two landscape features measured by volunteers (100 meter buffer) &ndash; the number of flat rooftops, and the number of sources of artificial ambient light. </p>

Thèses (M.Sc.)--Université de Sherbrooke (Canada), 1998. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2008. / Title from PDF t.p. (viewed on Jul 27, 2009). Source: Dissertation Abstracts International, Volume: 69-11, Section: B, page: 6633. Adviser: Curtis M. Lively.