<p> The Pacific Coast population of the western snowy plover (<i>Charadrius nivosus</i> nivosus; plover) is listed as a federally threatened species under the U.S. Endangered Species Act due to poor reproductive success from anthropogenic habitat loss, and high predation pressure. Plovers in the South San Francisco Bay use dry salt evaporation ponds, and wildlife-managed ponds, to breed and winter. However, the South Bay Salt Pond Restoration Project aims to restore up to 6,110 hectares of this habitat back to native tidal marsh, which will force plovers to breed in smaller areas and in higher densities. In order to recover plovers in these unique conditions, remaining habitat can be enhanced using oyster shells, which may camouflage breeding plovers, and decrease predation. This study evaluated the effect of oyster shell enhancement on plover breeding success by comparing nesting density, success, and brood behavior between enhanced and unenhanced areas. Plovers did select to nest in enhanced areas; however, nest survival did not increase relative to unenhanced areas. Brood behavior was also affected by enhancement, though highly correlated with the location of optimal foraging habitat. It is likely that enhancement will only improve nesting success if predators are concurrently controlled. Ultimately, plovers may benefit from the application of oyster shells as it attracts nesting effort, and may be strategically used by resource managers.</p><p>

<p>Billions of dollars have been invested in land protection as a strategy to conserve biodiversity based on the assumption that protected areas buffer species from processes that drive extinction. Increasingly, protected area expansion and connectivity are being incorporated into climate change adaptation strategies to facilitate anticipated shifts in species ranges in response to predicted changes in temperature and precipitation. However, the effectiveness of protected areas at maintaining biodiversity, either by reducing the risk of extinction or facilitating colonization into new areas, has not been well established. In addition, the growing reliance on multiple-use protected areas that allow resource extraction, such as timber harvest and mineral mining, has raised questions about whether multiple-use protected areas are equally beneficial for long-term biodiversity conservation as more strictly protected areas that limit active resource management. In order to address these questions using repeated Breeding Bird Atlas data, I first had to confront the limitations of existing approaches to account for imperfect detection by developing a novel modelling approach to addresses the gap between requirements of other multi-season occupancy models (i.e. repeated sampling) and existing datasets. I then applied that single-visit dynamic occupancy modelling approach to Atlas data in New York and Pennsylvania for 97 species to quantify drivers of colonization and extinction while accounting for imperfect detection in landscapes that varied by type and amount of land cover and area under protection. In general, protected areas increased colonization and lowered extinction probabilities to an increasing degree as both forest cover and neighborhood protection decreased, with particular benefits for forest breeding birds. Both strict and multiple-use protected areas increased colonization and reduced extinction more for mature forest species than early forest species, with the greatest benefits accruing when forest cover was relatively low. These results provided the most comprehensive evidence to date that protected areas can facilitate species persistence by both reducing the risk of extinction and providing attractive colonization sites as species? ranges shift and that biodiversity conservation can be compatible with renewable resource extraction.

No description available.

Although the unprotected lands of northern Tanzania support large numbers of elephants, and provide critical linkages for wildlife movements across the region, there is little information on the dispersal patterns of elephants in these unprotected lands. Our home range measures (100% MCP) of 21 elephants with satellite collars in four study regions were highly variable (191 to 3,698 km2). Home range sizes (95% fixed kernel) of bulls were typically larger than those of females, and wet season ranges were typically larger than dry season ranges. There were large differences in average home range sizes reflected varying strategies for obtaining food and water and avoiding humans. All eight radio-collared elephants (3 bulls, 5 females) in the West Kilimanjaro study region crossed the Tanzania-Kenya border, but typically elephants crossed more frequently in the wet than the dry season, and bulls crossed 47% more frequently than females. These extensive transboundary movements indicate that the elephant populations of West Kilimanjaro and Amboseli NP constitute a single transboundary population. Based upon 14,287 fixes from eight collared elephants, the vast majority of time was spent in unprotected (X¯ =91.5%) versus protected (X¯ =8.5%) areas. Amboseli NP was visited by all eight elephants and was the protected area most utilized (X¯ =8%, range 2-24%). Based upon the movements of 15 GPS-collared elephants in northern Tanzania, we identified eight areas that we considered important for wildlife conservation corridors/linkages for elephants. Our conservation priorities for these corridors were based upon the levels of threats and conservation potential. Community interviews and hilltop surveys were used in two Maasai villages to determine the extent of wildlife conflict, community attitudes towards elephants, and if elephants were using a vegetation corridor to move between Tanzania and southern Kenya. Elephants were the most problematic wildlife species and were considered a nuisance. However, they believed they attracted tourists, and generally did not believe elephant numbers should be reduced. Based upon elephant conflict and use and the communities' need to maintain areas for cattle grazing and medicinal plant collection, the two communities established the first wildlife conservation corridor in Tanzania.

Virtually any person exposed to American movies or television has likely heard the call of a common loon (Gavia immer). Its use as a sound prop has become ubiquitous in any scene related to the outdoors or the wilderness, even if the area filmed is in no way related to true loon habitat. The reason behind this is that the common loon and its haunting cries have come to symbolize the great outdoors. The sound of their call is meant to make the audience feel like the scene they are watching is in a remote area, far from the trappings of civilization, and, in our experience, it works. Hollywood has picked up on a sentiment held by many outdoor enthusiasts and is using it successfully. Unfortunately the southern range of the common loon is contracting and concern has been expressed over disturbance to breeding pairs by human activities, such as shoreline development, boating, and water-skiing, as well as possible contamination with lead, mercury, and other pollutants. If this alarming trend continues it may be that Hollywood movies will be the last place where a loon call can be heard in the United States. In the following chapters I will explore various threats to common loon populations. I will start in Chapter 1 with an evaluation of the potential effects of global warming on common loons within the North American breeding range. In Chapter 2 I review the available literature on wildlife disturbance and discuss some of the shortcomings and future research needs. I then go to a finer scale of study in Chapter 3 with a spatial analysis of disturbance factors and the effects on breeding common loons at Lake Umbagog National Wildlife Refuge. From there, in Chapter 4, I proceed to an analysis of specific behavioral responses exhibited by common loons in response to observed and experimentally imposed disturbance events. Finally, in Chapters 5 and 6, I briefly describe two natural disturbance events observed during our research, an immature bald eagle (Haliaeetus leucocephalus) predating a loon nest, and a loon nest defense of an aggressive American mink ( Nevison vison).

Mole salamanders (Ambystoma) and woodfrogs ( Lithobates sylvaticus) are abundant in New England and depend on ephemeral wetlands for breeding. Their aquatic habitats have been well studied and are protected by several local and regional regulations. State endangered species laws also protect mabled salamanders (A. opacum), Jefferson salamanders (A. jeffersonianum), and blue-spotted salamanders (A. laterale). However, these amphibians spend most of their adult lives in terrestrial habitats that remain poorly protected and elusive to researchers. In chapter 1, I developed a novel technique using passive integrated transponders for tracking small animals. I used this technique to track marbled salamanders walking up to 200 m from their breeding pond during post-breeding migrations. In Chapter 2, I examined the importance of multiple habitat variables for controlling the distributions of woodfrogs and spotted salamanders at 455 ponds in western Massachusetts. Based on a variable-comparison technique I developed, the best predictor for either species of amphibian was the amount of forest in the surrounding landscape. Both species were found more frequently in upland forests where the ponds are least protected by state and federal wetland regulations. In chapter 3, I used my data from chapter 2 and three other similar data sets to conduct an analysis of spatial scale and to parameterize a recently published resistant kernel model. The complex model parameterized by an expert panel did significantly worse than the null model. The distributions of both amphibians were best predicted by measuring the landscape at very large scales (over 1000 m). The most effective scales for conservation may be largest for organisms of intermediate dispersal capability. In chapter 4, I explored the evolution and genetics of the Jefferson/blue-spotted/unisexual salamander complex. I framed research into the fascinating unisexual reproductive system with a model that relates nuclear genome replacement, positive selection on hybrids, and biogeography of the species complex. I parameterized this model using genetic data taken from salamanders spanning Massachusetts and an individual-based breeding simulation. If paternal genomes are transmitted to offspring with the frequencies reported from laboratory experiments, then my model suggests that there must be strong selection favoring unisexuals with hybrid nuclei.

Nesting distributions of animals vary from isolated individuals to large colonies of breeding individuals and they can be influenced by numerous factors, including environmental conditions, relatedness and social interactions. Parrots are one of the most threatened orders of birds. Factors that influence their nesting success in natural habitat have been the focus of previous research. However, these past studies operated in systems limited in nest sites, which may also have influenced population dynamics. In contrast, the Bahama Parrot nests underground in abundant limestone solution cavities in the karst pine forest of Abaco Island, The Bahamas. This situation allows exploration of environmental and social factors that may influence nest success and breeding productivity without the limitation of the availability of nesting site resources. The objective of this study is to investigate the causes and consequences of semi-colonial nesting aggregations in the Bahama Parrot, addressing the influence of local habitat, relatedness of nesting neighbors, social behavior, and success of neighboring nests. The results of this information can be used in the management of habitat and parrot populations on Abaco Island, The Bahamas. The research was carried out on Great Abaco Island during the parrot breeding season (April - September) in 2010 – 2013. Nests were found by traversing logging roads. A number of ecological features were measured around nesting cavities and unused limestone cavities with the same dimensions as parrot cavities to identify favored characteristics. Nearest neighbors were identified for a subset of nests. Behavioral observations included time budgets of vocalization and movement to and from nests at focal and comparison nests (nearest neighbors and more distant nests) to determine if parrots were synchronizing behavior with close-nesting individuals. Predator simulations were conducted to elicit defense responses from focal and nearest neighbor nesting pairs. Using DNA collected from adults and chicks, I assessed whether spatially aggregated nests reflected kin clusters. Bahama Parrots on Abaco were distributed in aggregated spatial patterns in the nesting area. They nested in cavities found in more open areas. One contributing factor for the nest distribution was the uneven distribution of limestone cavities. Greater numbers of nests were found in areas with higher cavity concentrations. However, areas with high cavity concentrations but no parrot nests indicated that additional factors also were involved in concentrating nests in an area. Relatedness did not influence the aggregated nesting pattern. Close nesting neighbors were not more closely related than nesting individuals at other nest sites. No evidence of extra pair paternity was found within the small sample of nests that had full families sampled. However, genotypes of chicks raised in the same cavity in different years did provide support for the general belief that monogamous parrot pairs often reused the same nesting cavities over multiple years. Distances between neighbors had no effect on vocal synchrony. When a predator was introduced to a nest, the vocal response by the nesting pair and the nearest neighbor nesting pair increased, however no other behaviors provided nest defense. An effective defense against feral cats as predators was the predator control program carried out by the Bahamas National Trust. Nest success was higher in years with the predator control program underway. I did detect a relationships between nest success at a focal nest and its neighbor. Finally, I reviewed the taxonomic status of the Cuban parrot (Amazona leucocephala) complex. My review suggested that the two Bahama populations of the Cuban parrot (Amazona leucocephala bahamensis) should be classified as separate species (Amazona abaconensis and Amazona inaguanensis) and that the two Cuban populations should be a single subspecies (Amazona leucocephala leucocephala). These parrots use limestone cavities in the ground in open pine woodland as nest sites, and areas with higher densities of these cavities are used to a greater extent. As populations are expected to increase due to the success of a predator control program, sites with high cavity density are expected to be prime habitat for new nesting individuals. I therefore recommend the continuation of the prescribed burning to maintain the open understory that these parrots select. Furthermore, given the effectiveness of a current feral cat removal program in increasing nesting success, I recommend that predator control continue. / A Dissertation submitted to the Department of Biological Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2016. / June 23, 2016. / Amazona leucocephala, Bahama Parrot, Group Nesting, Nesting Neighbors, Predator Impact, Relatedness / Includes bibliographical references. / Emily H. DuVal, Professor Directing Dissertation; Peter Beerli, University Representative; Kimberly A. Hughes, Committee Member; Brian Inouye, Committee Member; Frances C. James, Committee Member; Thomas E. Miller, Committee Member.

Using the case of the Osceola Parkway Extension in Orange and Osceola Counties, this research examines how the legal geographies of expressway development and property rights claims intersect with gopher tortoise (Gopherus polyphemus) conservation efforts in Central Florida. Proposed and existing road infrastructure projects, such as the proposed Osceola Parkway Extension, continue to fragment gopher tortoise habitat in Florida. The Central Florida Expressway Authority rationalizes the road as a necessity, justifying appropriation of land for the parkway extension’s development. Thus, determining the route of the Osceola Parkway Extension has become the focus of road governance. The majority of the proposed road alignments for the extension transect Split Oak Forest and Wildlife Management Area, threatening the security of both the gopher tortoise population and gopher tortoise mitigation property within the forest. However, while the Central Florida Expressway Authority has jurisdiction over the governance of the road, it does not own the land needed to build it. This creates a relation between road governance and competing property rights, which then poses the question: what property rights must be ceded for right-of-way acquisition? Competing property rights holders have become enmeshed in the road governance process, as environmentalists seeking to protect conservation easements conflict with residential property owners. Thus, the mobilization of competing property rights claims structure the dialogue around road infrastructure encroachment onto conservation lands. How the competing values of suburban family homes and conservation easements, and the human and animal lives they support, are balanced will ultimately shape the road’s alignment. This suggests that legal and political conservation strategies need to be understood in dialogue with the governing rationalities of expressway and suburban development that continue to constitute enduring threats to the gopher tortoise and their local environments. / A Thesis submitted to the Department of Geography in partial fulfillment of the requirements for the degree of Master of Science. / 2019 / November 8, 2019. / Circulation, Conservation, Expressway, Gopher Tortoise, Governance, Property / Includes bibliographical references. / Tyler McCreary, Professor Directing Thesis; Mabel Gergan, Committee Member; Ronald E. Doel, Committee Member.

No description available.

The world’s biodiversity is concentrated in tropical ecosystems, yet tropical forests are being converted for agriculture at a rapid rate. I evaluated the potential of an alternative coffee production system known as Integrated Open Canopy (IOC) to contribute to avian conservation. This study was conducted from 2005–2010 in the Cordillera de Tilarán, Costa Rica. My results indicate that species richness of forest-dependent birds was significantly higher in IOC farms than in shade coffee farms, and was comparable to secondary forest sites. There was no difference in species richness of Neotropical-Nearctic migrants between IOC and shade coffee farms. Overall similarity was higher between IOC farms and primary forest than between shade coffee farms and primary forest. The golden-winged warbler (Vermivora chrysoptera) is a declining Neotropical-Nearctic migrant bird, yet little is known about its non-breeding season ecology and demographics. I found that golden-winged warbler abundance was highest at intermediate precipitation levels found at middle elevations (1000–1200 m) of the Pacific slope, but they were absent from the dry forests at lower elevations on the Pacific slope. Abundance peaked in forests with canopy heights of 22 m, and was positively related to the quantity of hanging dead leaves. Radio-telemetry data indicated that golden-winged warblers used microhabitat features characteristic of disturbance more frequently than expected by chance. Selection of these microhabitat features was related to their highly specialized dead-leaf foraging behavior, which may also have contributed to their high degrees of site fidelity, mixed-species flock attendance, and territoriality. These behaviors have important conservation implications because they constrain density, and thus could affect carrying capacity. Population dynamics were characterized by estimating plot-level and individual-level apparent survival and recruitment rates within and among non-breeding seasons. Both levels of analysis suggested that recruitment was too low to offset mortalities within this study area. This study indicates that increasing forest cover in tropical agricultural landscapes may be the most effective way of providing habitat for bird species of high conservation concern, including the golden-winged warbler. Integrated open canopy coffee production is one option for achieving this goal because it provides a financial incentive to protect or restore forest.