Nest site selection and nesting success of plains sharp-tailed grouse were examined on the Grand River National Grassland in South Dakota during the nesting season from 2009-2012. We used conditional logistic regression to assess vegetation production, ecological site description, and landscape position on nest site selection. Two competing models regarding nest site selection: top model consisted of non-native forbs and native cool-season grasses, second best model included all grass and forb. Nine ESDs were used for nesting; loamy and clayey ecological sites most frequently used and produced the highest standing crop. Most frequent observed nest site State were Annual/Pioneer Perennial and Introduced and Invaded Grass. Top model for nest daily survival rates included litter, second-best model included ESD; second-best model showed negative effect for nests initiated in thin claypan, limy backslope, and sandy ecological sites. Based on daily survival estimate and 23-day incubation period, nests were 59% successful.

Wood ducks are thought to depend on mature hardwood forests juxtaposed with palustrine wetlands but these habitats have been continuously degraded or destroyed since European settlement. Wood ducks are adaptable and the use of marginal habitats and nest boxes has extended their range and probably was important to the recovery of wood duck populations. Until now no study has analyzed the contribution of upland nesting to local population growth and maintenance. I investigated predation effects on nest site selection using wood duck nests and simulated nests placed in natural cavities. Using demographic data collected on wood ducks in southern Illinois, I created a population model to compare growth rates of population segments that nested in upland and floodplain habitats. During 1993-1998, 179 of 244 radiomarked hens remained on the study area as resident hens. One hundred-four nests were located by following radiomarked hens and 66% of nests were found in upland forests. Nests in the floodplain were initiated earlier than nests in the upland. Thirty-six percent of known nest cavities were used in subsequent years but <10% were used by the same hen. Nest success was greater in upland habitats (0.78 ± 0.10) than in floodplain habitats (0.54 ± 0.18). Hen survival through the nesting season was 0.80 ± 0.03 and did not differ between habitats or age classes. Sixty-five percent (n = 43) of simulated floodplain nests were destroyed compared to 33% (n = 45) in the upland. Logistic regression models of simulated nest data indicated cavity security could be important in the fragmented floodplain forests of Union County Conservation Area (UCCA). No physical characteristics of wood duck nest cavities differentiated successful and unsuccessful nesting attempts. The growth rate of the local population was positive and estimated to be about 3%. Lambda was most sensitive to upland nesting parameters and floodplain parameters appeared to have little impact on lambda. Hens nesting in the area appear to have adapted to predation pressure by nesting in more secure floodplain cavities at UCCA or by nesting in the upland habitats. Floodplain and upland habitats are ecologically intertwined and the local wood duck population would not survive if either habitat were destroyed or severely degraded.

In aquatic turtles, females select nest sites that have a high degree of solar exposure, and exploit recently tilled agricultural fields for nesting, presumably because of increased solar exposure and/or easier nest excavation, and the importance of incubation temperature on survival and offspring phenotype. These same disturbed sites are often contaminated by pollutants and turtles can incorporate high levels of pollutants into their eggs which negatively impact hatch success. For my M.S. research, I investigated turtle nest site selection in a system dominated by agricultural and industrial land use, the impact of crop growth on the thermal and hydric dynamics of turtle nests, and I used paired field and laboratory experiments to examine the individual and interactive impacts of agricultural land use and Hg contamination on hatch success and offspring phenotype in Chelydra serpentina. Of the 150 turtle nests found during this research, 84% were located in human-disturbed soils. Nest site characteristics were similar among nests found in Hg contaminated and reference areas. Agriculture and control nests did not differ in temperature at the time of nesting, but temperatures diverged as crops grew, with temperatures in nests in agricultural fields averaging 2.5 °C lower than control nests over the course of incubation. Similarly, despite no initial difference, nest moisture levels diverged throughout incubation and moisture averaged 107 kPa lower in agricultural than control soils throughout incubation. In my field and laboratory experiments, I found that in comparison to turtles from control incubation conditions (i.e., warmer), turtles incubated under agricultural thermal regimens (i.e., colder) took longer to hatch, hatched at smaller structural body sizes, lost more mass after hatching, had lower post-hatching structural growth rates, and were more likely to be male. Additionally, thermal conditions associated with agricultural land use interacted with high levels of mercury to impact hatching success and offspring sex ratios. My thesis research provides one of the first documentations of negative interactive effects of mercury pollution and habitat quality on early vertebrate development and highlights the importance of examining the combined influence of multiple global changes on biological systems. / Master of Science / In aquatic turtles, females select nest sites that have a high degree of solar exposure, and exploit recently tilled agricultural fields for nesting, presumably because of increased solar exposure and/or easier nest excavation, and the importance of incubation temperature on survival and offspring phenotype. These same disturbed sites are often contaminated by pollutants and turtles can incorporate high levels of pollutants into their eggs which negatively impact hatch success. For my M.S. research, I investigated turtle nest site selection in a system dominated by agricultural and industrial land use, the impact of crop growth on the thermal and hydric dynamics of turtle nests, and I used paired field and laboratory experiments to examine the individual and interactive impacts of agricultural land use and Hg contamination on hatch success and offspring phenotype in Chelydra serpentina. Of the 150 turtle nests found during this research, 84% were located in human-disturbed soils. Nest site characteristics were similar among nests found in Hg contaminated and reference areas. Agriculture and control nests did not differ in temperature at the time of nesting, but temperatures diverged as crops grew, with temperatures in nests in agricultural fields averaging 2.5 °C lower than control nests over the course of incubation. Similarly, despite no initial difference, nest moisture levels diverged throughout incubation and moisture averaged 107 kPa lower in agricultural than control soils throughout incubation. In my field and laboratory experiments, I found that in comparison to turtles from control incubation conditions (i.e., warmer), turtles incubated under agricultural thermal regimens (i.e., colder) took longer to hatch, hatched at smaller structural body sizes, lost more mass after hatching, had lower post-hatching structural growth rates, and were more likely to be male. Additionally, thermal conditions associated with agricultural land use interacted with high levels of mercury to impact hatching success and offspring sex ratios. My thesis research provides one of the first documentations of negative interactive effects of mercury pollution and habitat quality on early vertebrate development and highlights the importance of examining the combined influence of multiple global changes on biological systems.

Analysis of animal movement has been integrated into a framework of four components: internal state, motion capacity, navigation capacity, and external factors (Nathan et al., 2008). We used this framework to enhance understanding of movement behavior in the 15 West Indian rock iguana (Cyclura) taxa and to inform conservation management. Our review found that adult female Cyclura large-scale movement is primarily driven by nesting and migrations. Nest site selection also influences hatchling dispersal, but few studies identify preferred habitats for nesting females. Anthropogenic impacts on nesting ecology are largely unexplored, especially in Cyclura carinata. We studied C. carinata nesting ecology in a threatened population, aiming to identify habitat preferences and assess human impact on nesting success. This research fills gaps by addressing both proximate causes of movement and ultimate outcomes of movement decisions, essential for developing effective conservation strategies. Understanding both aspects is crucial for mitigating threats to Cyclura populations.

<p>This thesis focuses on a black-tailed godwit (<i>Limosa limosa</i>) population, consisting of 35-40 pairs, that breeds on a grazed shore meadow on SE Gotland, Sweden. The small size of the population makes it more prone to extinction due to chance events, than a larger population.</p><p>The godwits showed microhabitat preferences when choosing nest sites. Godwit nests had higher vegetation over the nest cup, lower surrounding (1-3 m) vegetation and different plant species composition, as compared to random sites. Breeding near conspecifics or other wader species, especially lapwings (<i>Vanellus vanellus</i>) and further away from potential predator perches were the most important factors in decreasing nest predation. A comparison between different shore meadows along the east coast of the island revealed that large, open areas suffered less from nest predation. Thus, shore meadows suitable for breeding godwits should be large and without trees or other predator perches and have a grazing regime that favours variation in vegetation height.</p><p>Over 80% of previously ringed adults returned each year, but very few birds ringed as chicks were recovered. Hatching success was 55-60% for all observed nests. To predict the future of the current population, demographic data were used in an ecological risk analysis. The simulations showed that the Gotlandic population will not survive the coming 40 years without immigration.</p><p>Black-tailed godwits are divided into three subspecies. Genetic analyses (mtDNA) revealed that all subspecies had unique haplotypes and there was a clear geographic structure among subspecies. Within the <i>limosa</i> subspecies, godwits on Gotland and Öland showed a high proportion of rare haplotypes, but no genetic variation was found in Dutch birds. These results imply that black-tailed godwits on Gotland and Öland have high conservation value.</p>

This thesis focuses on a black-tailed godwit (Limosa limosa) population, consisting of 35-40 pairs, that breeds on a grazed shore meadow on SE Gotland, Sweden. The small size of the population makes it more prone to extinction due to chance events, than a larger population. The godwits showed microhabitat preferences when choosing nest sites. Godwit nests had higher vegetation over the nest cup, lower surrounding (1-3 m) vegetation and different plant species composition, as compared to random sites. Breeding near conspecifics or other wader species, especially lapwings (Vanellus vanellus) and further away from potential predator perches were the most important factors in decreasing nest predation. A comparison between different shore meadows along the east coast of the island revealed that large, open areas suffered less from nest predation. Thus, shore meadows suitable for breeding godwits should be large and without trees or other predator perches and have a grazing regime that favours variation in vegetation height. Over 80% of previously ringed adults returned each year, but very few birds ringed as chicks were recovered. Hatching success was 55-60% for all observed nests. To predict the future of the current population, demographic data were used in an ecological risk analysis. The simulations showed that the Gotlandic population will not survive the coming 40 years without immigration. Black-tailed godwits are divided into three subspecies. Genetic analyses (mtDNA) revealed that all subspecies had unique haplotypes and there was a clear geographic structure among subspecies. Within the limosa subspecies, godwits on Gotland and Öland showed a high proportion of rare haplotypes, but no genetic variation was found in Dutch birds. These results imply that black-tailed godwits on Gotland and Öland have high conservation value.

I conducted this study to better understand the greater roadrunner’s (Geococcyx californianus) spatial use, nest site selection, and sexual morphometrics. Data were first collected from a roadrunner population in Fisher County, Texas. I trapped, measured, and removed feathers for sex confirmation through DNA PCR analysis. I then fit the roadrunners with a radio transmitter and released them at the capture site. I captured a total of 10 birds (1 male and 9 females) and triangulated the location of each bird 2-4 times per week from February to August 2011 during the roadrunner nesting season. The data produced a mean minimum convex polygon nesting range of 43.01-ha, a 50% core utilization distributions of 11.88-ha, and an overlap index of 33.05 percent. Habitat selection ratios showed a preference for ridge as well as grassland habitat and avoidance of bare ground and flatland habitats. The location data from west Texas was further analyzed to build a predictive logistic regression model to understand the significant site characteristics in roadrunner land use during the nesting season. It was determined that percent rock (-0.12, P = 0.0001) and percent litter (-0.05, P = 0.0052) were the best predictors in determining actual from random locations. Rock references open area for hunting, transportation as well as ridge habitat. Litter alludes to region below dense stands of shrubs and is used by roadrunners for evasion from threats and as shade for thermoregulation. The measurements from the roadrunners in west Texas as well as museum specimens from across their natural range were combined to develop an easy, inexpensive, and field-relevant sex identification model. The strongest model consisted of bill depth (0.79, P< 0.0001) and bill tip to the back of the head (0.05, P = 0.1573) which were both found to be larger in males. The final portion of this study concerned roadrunner nest site selection. Data were collected in Wilbarger County, Texas from May 2006 to October 2009. A predictive logistic regression model of nesting locations determined that mesquite nesting tree (-0.89, P = 0.0064), oval tree shape (1.58, P = 0.0118), mesquite density (-0.004, P = 0.0080), and topographic edge (1.37, P = 0.0027) were the best predictors in determining actual nest sites from random locations.

Artificial beach nourishment, the most common method to mitigate coastal erosion in the United States, is also considered the most ecologically friendly alternative for shoreline stabilization. However, this habitat alteration has the potential to impact nesting marine turtles and developing hatchlings. The first objective of this study was to determine how nourishing beaches with two different design templates affects loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting success, the ratio of nests to the total number of nests and non-nesting emergences, and reproductive success, the ratio of hatched and emerged hatchlings to the total number of eggs deposited. Two types of restoration designs exist along the southern Brevard County, FL coastline, which supports some of the highest density loggerhead and green turtle nesting worldwide. Since 2005, approximately 35 kilometers of beach have undergone 1) fullscale restoration (typically called nourishment), where sand was added above and below the mean high tide line (2005, 2010) or 2) dune restoration, where sand was placed on the dune (2005, 2006, 2008, 2009). To quantify the effects of these restoration types, we used a Before-After-ControlImpact-Paired Series (BACIPS) model, which tests for significance between the difference in nesting success rates at the impact (engineered) and control sites (natural beach) before and after restoration ( ). For loggerheads, there was a significant difference in after dune restoration during the years of construction (2005, 2006, 2008, and 2009; p

No description available.

Insular fauna face disproportionate risks of extinction owing to direct human perturbation and intrinsic factors that are enhanced at small population sizes. Currently, our understanding of the processes that promote long-term persistence of naturally small populations and the cryptic processes that may contribute to accelerating their decline is limited by lack of empirical investigations across the range of natural conditions. Implementing effective protections for rare and understudied taxa requires the identification and examination of factors that limit recruitment at critical life stages. Predicting population health outcomes of future perturbations further necessitates an understanding a taxon’s behavioral ecology. Finally, cryptic threats to viability, such as inbreeding depression, must be investigated with an appreciation for taxon-specific life history, as these attributes can alter the context in which severe fitness reductions are expressed. In this project I enlist integrative and cross-disciplinary approaches to study the behavioral ecology and conservation genetics of a critically endangered West Indian Rock Iguana, Cyclura nubila caymanensis, on Little Cayman Island. I demonstrate how coastal communal nesting areas, a critical limiting resource on the island, serve a diverse population demographic and contribute to significantly enhanced nesting outcomes. These data emphasize the importance of expanding protections for major sites, as aggregative nesting appears to be perpetuated by both habitat suitability and adaptive fitness benefits. I next evaluate the possibility of evolved inbreeding avoidance strategies, including natal dispersal, non-assortative mate choice, and genetic bet-hedging. I conclude that the contribution of pre-reproductive dispersal to inbreeding avoidance likely outweighs that of active mate choice. Importantly, observed patterns of siring success imply constrained female choice and sexual conflict over genetic mating outcomes – a pattern that may extend to many territorial, male-driven mating systems and therefore should be an important consideration in genetic management. Finally, I investigate age-dependent inbreeding effects and the degree to which inbreeding depression may limit recruitment to the breeding population. I fail to reveal significant correlations of multi-locus heterozygosity with hatchling fitness; however, negative effects of parental inbreeding on fecundity and hatching success imply fitness consequences of inbreeding depression could be felt at other life stages.