<p> Mottled ducks (<i>Anas fulvigula</i>) are a non-migratory waterfowl species endemic to the western Gulf Coast, with a separate, genetically distinct subspecies (<i>A. fulvigula fulvigula</i>) occurring in peninsular Florida. Birds from Texas, Louisiana, and Florida were released in coastal South Carolina from 1975-1983, and banding data suggest an expanding population. I monitored 72 mottled duck nests and captured and radio-marked 196 pre-breeding and nesting females between 2010 and 2014 to study breeding ecology of these birds in the Ashepoo, Combahee, Edisto Rivers Basin. Nest success averaged 12% and varied with vegetation height and year. Indicated breeding pair surveys revealed breeding mottled ducks select managed wetland impoundments, predominately influenced by water depth. Future research should investigate ecology of nest predators of mottled ducks to devise successful habitat management strategies for breeding birds. Preliminary evidence suggests that managed wetland impoundments are important to breeding and brood rearing mottled ducks in coastal South Carolina.</p>

<p>Coyote distribution and habitat use, diet and foraging behavior, and space use patterns were investigated in the greater Detroit area of southeastern Michigan. We found evidence of coyotes on 24 of 30 (80%) suburban and 7 of 11 (64%) urban plots. Overall fifty-eight percent of coyote evidence was found within edge habitats, with den sites and tracks the only types of evidence found strictly in interior habitats. Land cover around evidence points included more wooded land cover than expected in suburban areas, suggesting the importance of tree cover for coyote occupancy, and more open space and wooded land cover than expected in urban areas, highlighting their avoidance of heavily populated areas. Coyote diet was assessed through identification of remains of food items recovered in coyote scat. White-tailed deer, eastern cottontail rabbit, and small rodents were the most consumed prey in both urban and suburban areas. Coyote consumption of white-tailed deer biomass was 7.2% greater than expected in suburban areas and 10.0% less than expected in urban areas and the difference was significant (<i>P</i> &lt; 0.004). More white-tailed deer, raccoon, and woodchuck biomass was consumed compared to other studies, likely due to high use of road-kill. In suburban areas, coyote selection for road-killed white-tailed deer was positive regardless of white-tailed deer or rabbit abundance. Coyotes in urban areas used a foraging strategy that incorporated both prey selection and switching, with no strong discernable pattern. Radio-telemetry technology was used to gather relocations of coyotes for analysis of home range and cores areas frequented by coyotes. Smaller home ranges were made up of greater proportions of urban land than natural land cover, although there was variation. Core areas were dominated by relatively large patches of natural land cover and had greater connectivity compared to home range areas. Radio-telemetry data suggested that coyotes were selective in their use of space, avoiding urban land in favor of natural land cover. </p>

<p> Western Screech-Owls (<i>Megascops kennicottii</i>) are small, nocturnal owls that occur year-round throughout most of the Trans-Pecos region in West Texas, and are associated with deciduous woodlands and riparian habitats. Roadside nocturnal callback surveys, were established along well-defined trails within the Davis Mountains Preserve, and took place from May until August for two years to ascertain the relative abundance of Western Screech-Owls within the property. Abundance indices (birds detected/visit/station) were calculated for both survey seasons. Radiotelemetry was incorporated to determine certain life-history information, while habitat was characterized from both survey and telemetry sites. Occupancy models with detection probabilities were created using Program PRESENCE based on collected presence-absence data. Based on criteria for suitable screech-owl habitat previously defined in the literature, several models were also generated within ArcGIS to compare with the field data and to help predict areas of occupancy within the property. Owl abundance averaged 1.05 owls/point in 2013 and 0.82 owls/point in 2014. Six owls were marked during the study, and 3 of 6 locations were confirmed as daytime roosting sites. Statistically, there were no significant differences between occupied survey sites and telemetry sites, with only the percentage of canopy being significantly different with a mean difference of 9.32, <i> t</i>₄₂ = -2.36, <i>p</i> = 0.023. Both owls and transmitters were discovered in dense juniper-oak mottes on north-facing slopes, indicating a preference for dense, short, closed canopy areas for roosting. Overall vegetative ground cover for the two seasons averaged 54% and 48%, respectively. It was concluded that none of the included covariates in the models influenced either occupancy or detection probabilities, though detectability demonstrated an overall trend based on time of night. GIS models did not reveal any variable that strongly influenced owl occupancy but did correspond with results from previous literature.</p>

<p> Unregulated hunting and habitat loss led to a near extirpation of moose (Alces alces) in New Hampshire in the 1800s. After state protection in 1901, the estimated population increased slowly to &sim;500 moose in 1977, then increased rapidly in the next 2 decades to &sim;7500 following an increase in browse habitat created by spruce budworm (<i>Choristoneura fumiferana </i>) and related timber salvage operations, and then halved from 1998-2016 despite highly available optimal habitat. The declining population was partially related to the specific management objective to reduce moose-vehicle collisions, and a possible change in deer hunter and moose behavior that influence population estimates. But given the substantial decline in productivity and condition of cows, and frequent episodes of high calf mortality in April, the primary cause of decline was presumed to be is an increase in winter tick abundance. </p><p> This study examined the relationships among moose density, optimal habitat, weather/ground conditions, winter tick abundance, and natal dispersal in northern New England. Comparing movement data from the previous (2002-2006) and current (2014-2016) productivity studies in New Hampshire and Maine, the distance of natal dispersal, home and core range size, and home and core range overlap did not significantly (<i>P</i> > 0.05) change despite an increase in optimal habitat and a decrease in moose density.</p><p> Geographic changes in tick abundance were related to an interaction between moose density, and the onset and length of winter. Annual changes in tick abundance in northern New Hampshire are driven by desiccating late summer conditions, as well as the length of the fall questing season. Lower precipitation (6.4 cm) and higher minimum temperatures (9.8 &deg;C) specifically concentrated during larval quiescence from mid-August through mid-September reduces winter tick abundance and the likelihood of an epizootic event. The onset of winter, defined by the first snowfall event (> 2.54 cm), influenced the length of the questing season relative to the date of long-term first snowfall event (14 November). In the epizootic region, average winter tick abundance on moose harvested in mid-October indicated a threshold of 36.9 ticks, above which an epizootic is like to occur unless an early snowfall event shortened the fall questing season. Optimal habitat created by forest harvesting was produced at an annual rate of 1.3% (1999-2011) and is not considered limiting in northern New Hampshire, but likely concentrates moose density locally (&sim;4 moose/km²) facilitating the exchange of winter ticks. In northern New Hampshire, snow cover late into April did not reduce tick abundance in the following year and cold temperatures (&lt; 17 &deg;C) that induced replete adult female mortality are extremely rare in April.</p><p> Given a continuation of warming climate and conservative moose harvest weather conditions and high local moose densities will continue to favor the life cycle of winter ticks, increasing the frequency of winter tick epizootics and shift the epizootic region slowly northward. Conversely, temporary reduction of moose density may substantially reduce parasite abundance and support a healthier and more productive moose population.</p><p>

<p> The Rusty Blackbird (Euphagus carolinus) is a migratory songbird that breeds in and near the boreal wetlands of northern New England and Canada. Although the Rusty Blackbird was once common, the species has declined by an estimated 90% since the 1960&rsquo;s (Greenberg et al. 2010). I used single-season occupancy analysis to model breeding Rusty Blackbirds&rsquo; use of 60 beaver (Castor canadensis) influenced wetlands in Coos County, New Hampshire and Oxford County, Maine. I conducted three 30 minute detected/ not detected surveys, surveyed food availability and foraging habitat, and digitized each survey wetland. Rusty Blackbirds&rsquo; use of wetlands was best predicted by the site covariates mud and invertebrate abundance and detectability was best predicted by survey period. Probability of wetland use decreased with increasing mud cover and increased with increasing aquatic invertebrate abundance. I recommend that future researchers survey for Rusty Blackbirds for 30 minute periods to maximize survey coverage.</p><p>

<p> This study investigates the population dynamics, movements, and habitat use of a population of western pond turtles in Orange County, California from 2008-2012 using radio telemetry and mark-recapture data. Western pond turtles have been thought to be declining throughout their range. However, few studies have documented their status in southern California, where urbanization has changed the landscape drastically in recent decades. I individually marked 236 pond turtles using hoop-net funnel traps and estimated the population size at 308 individuals, which is the largest estimate reported in southern California. Mean capture per unit effort was 5.03&plusmn;0.87. Mean female carapace length (CL) (142&plusmn;14mm) was not significantly larger than males (139&plusmn;14 mm). I also documented 20 nest and 9 estivation locations. Mean distances included 176 &plusmn;130.80 meters (m) and 91&plusmn;58.6 m. These data identify the population demography, which can be a metric of population stability. Other known populations need to be estimated to determine their regional status.</p>

<p> Conserving bird populations in urban landscapes often depends on interactions between extinction, recolonization, and survival in remnant habitat patches such as small nature preserves. Thus, determining the ecological value of small nature preserves to birds is a necessary step towards an informed conservation strategy. As such, I conducted a year round capture-mark-recapture study from April 2010 to March 2014 to examine population dynamics of Northern Cardinals (<i>Cardinalis cardinalis</i>) and Carolina Wrens (<i> Thryothorus ludovicianus</i>) in a 41.7-ha nature preserve embedded in an urban matrix. More specifically, we examined variation in survival, recruitment, and realized population growth rates relative to year, season, sex, age, and wing length (as a proxy for body size) to investigate attributes that affect individual survival and to assess whether the reserve served as a population source or sink. The overall annual apparent survival rate of Northern Cardinals (0.520 &plusmn; SE 0.050) was higher than that of the Carolina Wrens (0.349 &plusmn; 0.050), and estimates in both species were similar to regional baseline estimates. The survival rates for adults were significantly higher than for immatures in both species, with body size having a positive influence on survival. Seasonal variation in survivorship was evident only in Northern Cardinals, being highest in the winter and lowest during the breeding season. Average annual population growth rate was slightly greater than 1.0 for both species, indicating stable or perhaps modestly increasing populations. These results represent the first published full annual cycle estimates of survival and population growth relative to age, sex, and body size for non-migratory passerines. Our results suggest that urban forests can provide the necessary resources to sustain growing populations of locally common birds. Furthermore, our demographic estimates derived from two healthy bird populations can serve as target values for other species of conservation concern within human-modified landscapes. </p>

<p> The coastal temperate rainforest is one of the rarest ecosystems in the world, and a major portion of the global total is found in Southeast Alaska. In this ecosystem, Sitka black-tailed deer are the dominant large herbivore, influencing large carnivores that prey on deer such as wolves and bears, as well as plant species and communities through browsing. In addition, deer play an important economic and cultural role for humans in Southeast Alaska, making up the large majority of terrestrial subsistence protein harvested each year as well as providing the backbone of a thriving tourism industry built around sport hunting. Given the importance of deer in this system, there remain a surprisingly large number of key gaps in our knowledge of deer ecology in Southeast Alaska. </p><p> These knowledge gaps are potentially troubling in light of ongoing industrial timber-harvest across the region, which greatly alters habitat characteristics and value to wildlife. This dissertation research project was undertaken with the aim of filling several connected needs for further understanding deer ecology, specifically 1) patterns of reproduction and fawn survival, 2) population dynamics in response to environmental variability, and the underlying drivers of spatial selection during 3) reproduction and 4) winter. To fill these knowledge gaps, I developed robust statistical tools for estimating rates of fawn survival, and found that fawns must be captured at birth, rather than within several days of birth, in order to produce unbiased estimates because highly vulnerable individuals died quickly and were thus absent from the latter sample. I then use this robust approach to estimate vital rates, including fawn survival in winter and summer, and developed a model of population dynamics for deer. I found that winter weather had the strongest influence on population dynamics, via reduced over-winter fawn survival, with mass at birth and gender ratio of fawns important secondary drivers. </p><p> To better understand deer-habitat relationships, I examined both summer and winter habitat selection patterns by female deer. Using summer-only data, I asked how reproductive female deer balance wolf and bear predation risk against access to forage over time. Predation risks and forage were strong drivers of deer spatial selection during summer, but reproductive period and time within reproductive period determined deer reaction to these drivers. To ensure adequate reproductive habitat for deer, areas with low predation risk and high forage should be conserved. Focusing on winter, I evaluated deer spatial selection during winter as a response to snow depth, vegetation classes, forage, and landscape features. I allowed daily snow depth measures to interact with selection of other covariates, and found strong support for deer avoidance of deep snow, as well as changes in deer selection of old-growth and second-growth habitats and landscape features with increasing snow depth. Collectively, this dissertation greatly improves our understanding of deer ecology in Alaska, and suggests habitat management actions that will help ensure resilient deer populations in the future.</p>

<p> Size-at-age of Pacific Halibut (<i>Hippoglossus stenolepis</i>) has declined significantly since the 1980s. For instance, the average weight of a 20-year-old female declined from 55 kg in 1988 to 20 kg in 2014. The decline in size-at-age corresponds to a period of declining Pacific Halibut recruitment, spawning biomass, and reductions in catch limits for the directed commercial Pacific Halibut longline fishery. The causes of changes in Pacific Halibut size-at-age are poorly understood. Our project investigates several hypotheses related to declines in size-at-age, including the effects of environmental and ecological variability on growth, and the cumulative effects of harvest and size-selective fishing. Specific potential environmental covariates include the Pacific Decadal Oscillation, which is an index of basin-wide sea surface temperatures, and summer sea surface temperatures along the continental shelf of the Gulf of Alaska. Specific ecological variables include annual biomass estimates of Arrowtooth Flounder (<i>Atheresthes stomias</i>) and Pacific Halibut to investigate the potential role of inter- and intraspecific competition, respectively. We used a population modeling approach to simulate the effects of fishing on size-at-age. We found that the large increase in Arrowtooth Flounder biomass since the 1970s corresponds to declines in Pacific Halibut size-at-age. Our results also suggest that periods of high Pacific Halibut biomass relates to poor growth and low size-at-age. Finally, we found that harvest and size-selective fishing explains between 30 and 65% of observed declines since the 1980s in the Gulf of Alaska, and up to 100% of the declines in Southeast Alaska and British Columbia where harvest rates were high in the 1990s and 2000s. Our findings have implications for fisheries management, including balancing tradeoffs associated with size limits, and understanding how changes in environmental and ecological conditions can shift management reference points such as maximum sustainable yield.</p>

<p>Recreational activities have been shown repeatedly to have negative effects on wildlife. Appropriate management to minimize the effects of such activities, especially to species of conservation concern, is therefore a goal of utmost importance. This study characterized the visual ecology and anti-predator behaviors of the California Towhee, <i>Melazone crissalis</i>, in the context of parameterizing models for estimating the size and shape of wildlife buffer areas. Contrary to expectation, explicitly incorporating species-specific data on the towhee's visual system and individual-level data on physiological condition and life history traits did not significantly alter estimated buffer area requirements relative to models based solely on behavior. Similarly, towhees exhibited no differences in average alert or flight initiation distances with respect to direct versus tangential approaches. In contrast, data collected across a variety of habitat types in the field suggest that minimum approaching distances for the birds were highly dependent upon local vegetation parameters that included percent cover, density, and height. In general, more vegetative cover was associated with smaller alert and flight initiation distances. Together, these results suggest that a simple management solution (e.g., calculating buffer areas based on mean alert distance alone) may be adequate for this species, but that local habitat conditions will need to be taken into consideration for optimal management solutions. </p>