<p> As growing human populations put an increasing demand on finite ocean resources, fisheries management tools rely ever more on high quality inputs and a comprehensive understanding of model factors. Stock assessment modeling for South Atlantic (SA) King Mackerel, <i>Scomberomorus cavalla </i>, uses inputs such as abundance indices, growth parameters, and fisheries landings. However, one underlying assumption in this modeling system is there are measurable connections among life stages. A juvenile abundance index developed from the SEAMAP-SA Coastal Trawl Survey (CTS) is presumed to represent ecological recruitment. Very weak correlations to other life stage proxies suggested a deficiency with the juvenile abundance index accuracy and indicated data exploration into the index formulation was needed. Examination of CTS juvenile length frequencies support that the smallest juveniles appear in the summer and spring juveniles are from overwintering of the previous year class. Juvenile abundance indices developed using year class (year in which a fish is spawned) rather than year of sampling (as done for previous assessments) showed substantial differences, in particular lowering AIC values indicating an improvement in model accuracy. Evidence of seasonal and regional variation with CTS juveniles prompted the development of separate age 0 and age 1 indices. Correlations of these indices to fisheries-derived year class strength suggested the age 0 index to be the best indicator of initial juvenile king mackerel abundance while the age 1 index reflects abundance after high early life stage mortality. Data exploration also was conducted for potential environmental variables impacting age 0 and age 1 abundance. Relationships were found between age 0 abundance and freshwater input, the Gulf Stream, hurricane activity, and predator abundance and between age 1 abundance and freshwater input and hurricane activity. This research provides not only valuable baseline knowledge for SA king mackerel juveniles, but also findings pertinent for their management. </p><p>

<p> Conservation of endangered Indiana bats (<i>Myotis sodalis</i>) requires knowledge of regional habitat use patterns. I radio-tracked Indiana bats to roosts and foraging areas to document summer habitat use. Sexes selected different roost trees: reproductive females selected maples, whereas males selected elms and other species, but did not use maples. Distribution models based on environmental correlates revealed that soil series was the strongest contributor to niche models. Females selected roosts in silt loams; males selected roosts in muck, silt loam and fine sandy loams. All bats foraged in habitats over fine sandy and gravelly loams. Male roosts and female foraging areas were found near local water body elevations, though males foraged at higher elevations. The niche models suggest that sexes roost and forage separately, but that ranges for these activities overlap. My findings identify habitats selected by Indiana bats thereby enabling more effective conservation for this endangered species.</p><p>

<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>

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).

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.

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No description available.

<p> Each fall hunters kill hundreds of thousands of White-tailed Deer (<i> Odocoileus virginianus</i>) in Missouri and Illinois. Field dressing these deer provides a large influx of nutrient rich offal into the ecosystem. To date, little research has examined the effects of this resource on wildlife. We used trail cameras positioned over offal piles to examine species richness and diversity in a range of habitats during the 2011-2013 hunting seasons in Missouri and Illinois. There were a total of 17 different sampling sites, resulting in over 4 thousand photographs. Images were analyzed and organized into timed feeding events. Sites were categorized into one of three habitat types: field, edge, or forest. We documented 10 different scavenger species feeding on the offal. There was no significant difference in scavenger diversity (<i>F</i>=2.95; <i>d.f.</i>= 2,14; <i> p</i>=0.085), richness (<i>F</i>=2.25; <i>d.f.</i>2, 14; <i>p</i>=0.14;), nor habitat preference (<i>F</i>=0.51; <i> d.f.</i>2,14; <i>p</i>= 0.61) among habitat types. We also found no significant difference in the community structure of scavengers among the three habitat types (<i>R</i>= -0.049; <i>p</i>=0.64). However, there was a difference in the preferred mean feeding times of avian vs. mammalian scavengers (<i>U</i>=1,215.5; <i>Z</i>=11.24; <i> p</i>=0). The presence of offal piles does not appear to repel deer, as they were frequently observed in close proximity. The apparent similarity of the scavenger guild among habitat types can be attributable to the mosaic of fragmented habitat that characterizes the Midwest, as well as the generalized behavior of the species.</p>

MAYA is a prototype computerized population dynamics model designed to enhance decision making in wildlife management. Initially, the basis of scientific and philosophical design and implementation of enhanced computer modeling are discussed. This discussion forms the foundation for the development of the actual model. The model is a general population model, utilizing previously known data on seasonally migratory mule deer (Odocoileus hemionus) as both an example and a test of the model's capabilities. By combining detailed sub-models at the single species level, the behavior of a larger system is mimicked. The mathematical parameters of this system are restricted to those which correspond to known biological processes. Feedback control is utilized to regulate the dynamic interplay of processes related to specific recognizable structures or physiological functions. The model maintains the identity of the individual organism as the mediator of all transactions within the system. The primary focus of these transactions is energy; specifically consumer energy budgets and their mechanisms of regulation. Equations are presented in finite difference form for digital computer implementation, utilizing a time step of unit length. The result is a Fortran program, MAYA, and a description and discussion of a number of simulation trials. This model was created with an eye not only for computer simulation, but also to raise issues, both philosophic and scientific, as to the reason for, and purpose of, computer management in our society. Thus, it is not until Chapter 4 that an actual discussion of MAYA is to be found. Logic dictates that one should understand the philosophic and theoretic approach of the person creating a model to best understand, question and, hopefully, improve upon the final product. These issues are discussed in Chapters 1 and 2. The greatest value of this model is to provide, based on the ensuing sets of assumptions in Chapter 3, the logical consequences that would otherwise take a great deal of tedious arithmetic--it is a tool to assist the imagination.