Populations of many species are decreasing, but the underlying causes are often poorly understood, impeding effective conservation action. One useful approach is to determine which demographic rates drive variation in population growth rate () and identify ecological and environmental causes. I identified key demographic rates driving the decrease in Ring Ouzel (Turdus torquatus) population size, a species of high conservation concern in the UK, and explored underlying ecological and environmental causes. The number of breeding pairs decreased by 44-100% during 1979-2009 across 13 study areas throughout the UK. The population in my study area in Glen Clunie, Aberdeenshire, Scotland, decreased by 67%, from 39 to 13 breeding pairs, during 1998-2009. Mean  calculated from annual censuses was 0.91. I recorded reproductive success, and used re-sightings of marked individuals to estimate survival rates in each year, thus measuring the mean, variance and covariance among key demographic rates. Prospective elasticity analysis indicated that  was most sensitive to adult survival. However, integrated elasticity analysis, accounting for estimated demographic covariance, indicated that  was most sensitive to first-year survival. Retrospective decomposition of variance indicated that first-year survival contributed most to observed variation in . However, adult survival was low compared with species with similar life histories. Juveniles fledged from early-season broods had higher survival probability during each four-day period post fledging (0.952 ± 0.011) than juveniles fledged from late-season broods (0.837 ± 0.021). Predation was the main apparent cause of mortality. Juveniles foraged on invertebrates in grass-rich areas during June to mid-July, but then switched to feed mainly on moorland berries in higher-altitude, heather-rich, areas during mid-July to early-September. Thus, a variety of habitats providing different food types is required during the late summer. This thesis illustrates the value of integrating demographic and ecological studies to understand population change in species of conservation concern.

No description available.

Fire scar analysis to identify fire events and stand age structure analysis to identify fire effects on survivorship of trees were used to reconstruct surface and crown fire regimes in upper elevation forests of the Gila Wilderness, NM. Fire regimes varied across forest type, but not necessarily across elevation. Prior to the twentieth century, (from 1706 to 1904), the mean return interval for large fires was 8 years. During the twentieth century, (from 1904 to 1995), the mean fire return interval for large fires was 46 years. The virtual end of historically frequent fire regimes due to livestock grazing and fire suppression since the turn of the century has affected successional pathways of forest types across elevations, favoring later successional forest species and structures.

<p> The bog turtle (<i>Glyptemys muhlenbergii</i>) is listed as threatened under the U.S. Endangered Species Act primarily because of the loss and degradation of its specialized wetland habitat. Adequate nesting habitat may be a limiting factor for bog turtle recovery, and nesting habitat creation or expansion may be an effective conservation tool but only if managers understand nesting behaviors, habitat requirements, and threats to nest success. The objective of this study was to understand the nesting ecology of the bog turtle and to use this information to suggest improvements to bog turtle management. I used radio telemetry to locate nesting females. I then used nest location and maternal genetic microsatellite data to investigate nest-site fidelity and natal homing. I collected microhabitat data at each nest and random points in both spring and fall at three spatial scales to understand nest-site selection. I also studied nest success with and without predator excluder cages to determine if predator excluders reduced predation or altered nest conditions. I found evidence that females display nest-site fidelity to nest-site areas but no evidence for natal homing. Bog turtles nested in relatively small patches of habitat in close proximity to water or saturated soil with low densities of woody stems and low percent cover of woody vegetation, forbs, and ferns. Predator excluders reduced predation by &sim;40% while having no effect on nest temperatures, incubation periods, or underlying (disregarding predation) nest success. Given the results of this research, I conclude that the creation of new nesting areas could be a viable conservation tool, as females do not always return to the same nest-site area. Managers should create or maintain small patches of open-canopy habitat with reduced woody vegetation in areas that have consistent moisture from spring to fall. Increasing the availability of nesting areas may eventually lead to increases in recruitment, but if predation pressures are high, managers should also deploy predator excluders. This is the first study to examine the behavioral drivers of bog turtle nest-site selection and the efficacy of predator excluders on bog turtle nests.</p>

The problem addressed is the public's lack of awareness of the contributions of landscape architects and other natural resource professionals to the practices of land stewardship. One solution is a travel guide to be developed using marketing and interpretive principles. The research question is: what should be the content of the travel guide such that it would increase public awareness about landscape architecture and related natural resource professions and their role in land stewardship? The scope included research for planning the guide: it excluded collection of specific project information. A questionnaire was administered to landscape architects at two professional meetings. The major findings include which topics best explain the profession, and the types of projects that should be selected. These findings are valuable to natural resource professional societies and to publishing industry marketers, and for use in pursuing grant funding to continue the guide's development.

Red-tailed hawks (Buteo jamaicensis), Swainson's hawks (Buteo swainsoni), great horned owls (Bubo virginiaus), and ravens (Covus corax and C. cryptoleucus) occur sympatrically in desert grasslands in Arizona. Desert grasslands have been invaded by trees since Anglo-American settlement. They may also be subject to greater human disturbance than historically, because of recent increases in illegal immigration along the U.S.-Mexico border. These changes may affect the abundance, diversity, competitive interactions, and reproductive success of raptors and corvids in desert grasslands. I studied raptors and corvids on the Santa Rita Experimental Range (SRER) and Buenos Aires National Wildlife Refuge (BANWR) in southern Arizona. My objectives were to (1) assess how spatial relationships among nesting raptors and corvids affect reproductive success, (2) identify characteristics of the environment selected by members of the assemblage for nest sites and home ranges, (3) identify similarities and differences in nest site and home-range characteristics among species, and (4) investigate how anthropogenic changes in desert grasslands have affected raptors and corvids. Productivity (x̄ [95% CI]) was high for red-tailed hawks on the SRER (1.82 [1.41, 2.23] young per breeding pair [YPB]), but low for all species on the BANWR (great horned owls: 0.96 [0.54, 1.38] YPB; ravens: 1.75 [1.39, 2.10]; red-tailed hawks: 1.04[0.83, 1.24]; Swainson's hawks: 0.91 [0.67, 1.16]) relative to range-wide averages (great horned owls: 1.42 [1.27, 1.56]; ravens: 2.39 [2.70, 3.07]; red-tailed hawks: 1.35 [1.20, 1.50]; Swainson's hawks: 1.34 [1.23, 1.45]). All species on both sites selected nest sites with taller nest trees and greater tree volume than available at random. Swainson's hawks selected home ranges with greater grass volume than available on BANWR. Overlap in habitat use was high among all species, exceeding 54% for nest trees, 80% for nest sites, and 90% for home ranges. Mesquite-dominated desert grasslands seemed to provide high quality habitat for red-tailed hawks on the SRER, but reproductive success for assemblage members on BANWR was poor. We suggest that competition, resulting from high habitat overlap, and human disturbance by illegal immigrants, has depressed raptor and corvid reproductive success on the BANWR.

I used archives of wildfire perimeters (fire atlases) within a geographic information system (GIS) to describe and evaluate fire frequency patterns for the 20th century in the 486,673-ha Gila/Aldo Leopold Wilderness Complex (GALWC), New Mexico and the 785,090-ha Selway-Bitterroot Wilderness Complex (SBWC) in Idaho and Montana. I addressed questions about changing 20th century fire frequencies and landscape-scale controls of fire frequency by analyzing fire atlases along with data for topography, vegetation, and climate. Similarities and differences in comparisons between study areas highlight important aspects of fire regimes and strengthen my interpretation and inference. In the GALWC, fire rotations were shortest during the recent wildfire use period (1975-1993) and longest during the pre-modern suppression period (1909-1946). In the SBWC, fire rotations were shortest during the pre-modern suppression period (1880-1934) and longest during the modern suppression period (1935-1975). Elevations with the highest fire frequencies differed between study areas. However, forest types found at these elevations are characterized by similar overstory tree species. Steeper northeastern slopes in the GALWC and southwestern slopes in the SBWC burned most frequently. I assert that, in the GALWC, horizontal fuel continuity is a main factor determining fire frequency. In the SBWC, fuel moisture status limits fire frequency. Fires are most frequent in areas where ignitions occur and neither fuel continuity nor fuel moisture are likely to limit fire spread. Three statistical modeling approaches were used to produce maps of reburn probabilities. Log-likelihood modeling provided the most satisfactory results, while logistic regression and classification and regression trees yielded statistically insignificant models. Empirical models contributed to the assertion that fuel continuity limits fire frequency in the GALWC while fuel moisture limits fire frequency in the SBWC. Mapped fire perimeters provide a valuable source of spatial historical information for describing the role of large fires over broad areas. This dissertation enhances scientific knowledge about broad scale changes in fire regimes. Comparisons between areas facilitate identification of unique versus general patterns. Results provide a contemporary baseline for comparison with estimates of Pre-EuroAmerican fire frequencies, and a historical, spatial context for modeling and managing future fire regimes.

I studied Gray Hawks (Asturina nitida) nesting along the upper San Pedro River in southeastern Arizona from 1995 to 1997. I identified 27 territories within the study area with a mean of 24.3 territories occupied per year. Productivity averaged 1.32 young per occupied nest during the study. Years did not differ in number of successful nests or in number of young produced. Mean size of home ranges (n = 10 males), based on the 90% adaptive kernel method, was 59.2 ha (range 21.4-91.2). Gray Hawk diet was composed of 68.6% reptiles, the majority being whiptail lizards ( Cnemidophorus spp). Daily foraging patterns were bimodal with peaks during mid-morning and late afternoon. Almost all Gray Hawk nests were located in cottonwoods (Populus fremontii). Nest trees tended to be dominant trees in the area. Gray Hawks did not use vegetation randomly within their home ranges. Mesquite (Prosopis juliflora) and cottonwood were used more than expected based on availability. Nearly 80% of all foraging locations were in mesquite. Within mesquite, Gray Hawks used areas of taller trees and lower horizontal cover than found at random sites. Trees used as foraging perches were taller than the surrounding canopy. Foraging and random sites did not differ in prey abundance indicating that prey availability is more important than prey abundance in determining where Gray Hawks forage. I developed a method of predicting home ranges for all 27 territories utilizing telemetry information from a sample of male hawks, a geographic information system, and logistic regression. This model produced estimates of vegetative composition within home ranges that were correlated strongly with vegetation composition in home ranges based on telemetry. The models I developed performed better than circular buffers around nest sites. Using the predicted home ranges, I developed an ordinal logistic model to identify what vegetative components influence Gray Hawk productivity. Area of mesquite was the primary determinant of habitat quality in Gray Hawks. Cottonwood-willow (Salix gooddingii) vegetation also can increase quality of home ranges when mesquite is present in low amounts.

Coyotes (Canis latrans) are common in many urban areas in North America, but little is known about how they adapt to urbanization. I studied the way they use the urban landscape by determining the patch types chosen for foraging, travelling, and resting. Home ranges encompassed a smaller proportion of natural areas and a greater proportion of parks and residential areas than were available in Tucson. Rates of nocturnal movement by coyotes peaked at midnight and at dawn. Natural areas, parks, and residential areas were used most by coyotes throughout the night, but rates of movement did not differ among these patch types. I created a GIS (geographic information system) model to predict the presence or absence of coyotes in all patch types throughout Tucson. The model indicates that most areas in Tucson are likely to be used by coyotes; it may be refined by adding new variables and by examining these variables at a finer spatial scale. Studies have not documented the health of coyotes in urban areas, where they may be reservoirs of disease for domestic canids. I determined the prevalence of pathogens, estimated survival rates, and identified sources of mortality. The prevalence of canine distemper virus was 27%, the prevalence of infectious canine hepatitis was 50%, the prevalence of canine parvovirus was 100%, and the prevalence of leptospirosis was 27%. The annual survival rate of coyotes was 0.72. Most necropsied coyotes were killed by humans. Coyotes in urban areas come into conflict with humans. Few humans have been attacked by coyotes, but small pets are susceptible to attack. The primary means of deterring coyotes from areas where their presence is unwanted is by eliminating all sources of food and water. The urban-dwelling public must become better educated about coyotes to minimize human-coyote conflicts.

In the states of Tabasco and Chiapas, Mexico there is a lack of long-term harvest scheduling models that consider the effects of the harvest activities on the surrounding areas. Additionally, these problems are combinatorial in nature, which makes them hard to solve. Consequently, only harvest scheduling for small areas can be solved to optimality using traditional approaches such as integer programming (IP). In this study, a genetic algorithms (GA) model was used to generate multiple viable solutions for long-term spatially constrained problems on large areas with a great number of management units. This model enables consideration of regeneration and reharvest in forest planning. The flexibility of the model allows it to handle a different set of time periods, database sizes, different species and diverse tree growth models. The data set employed corresponds to a eucalyptus plantation with a cutting cycle seven years and a planning horizon of 10 rotation periods. Total plantation area is 300,000 ha, divided in 5,388 harvest units. IP was used as a standard to validate the efficiency and accuracy of the GA method. The GA performance with different combinations of genetic operators was tested. Scheduled volume flow for simulated communities was computed. Additionally, three different volume assignment scenarios (low, medium and high) were compared to estimate the effect of volume assignment on the spatial optimization output. The significant findings of this research are: (1) a long-term spatially constrained robust solution was found through the use of genetic algorithms for a large area with more harvest units than those reported elsewhere, (2) the solution allowed re-harvest in the same planning horizon, (3) most of the genetic algorithms runs performed better than the integer programming, and (4) on average the volume scheduled for every simulated community was comparable for the two methods used in the work. In both cases, the percentages of the potential volume ranged between 7 and 29%.