In most birds the dispersal process is usually initiated with a straight emigration from the natal site and the cessation of parental care. Yet for some species, particularly those with extended periods of parental care (such as many large raptors like golden eagles), individuals can carry out prospecting movements prior to dispersing. Prospecting behaviour probably involves individuals searching and evaluating sites, and may influence further decisions made at later stages of the dispersal process. I used long life GPS satellite transmitters fitted to nestling golden eagles to follow them as they dispersed. Young golden eagles emigrated from their natal home ranges from 44 days until 250 days after fledging. The rate at which individuals emigrated increased over time and individuals that developed motility more rapidly also emigrating earlier. Over 90% of individuals made at least one distinct movement away from the natal home range prior to emigrating, with early departing individuals making fewer prospecting trips prior to a definitive departure. Individuals that prospected undertook up to 11 prospecting loops that lasted up to 10 days and with longer duration trips being longer in overall length and maximum distance explored from the natal home range. The direction of prospecting forays was positively correlated with the direction of eventual departure, but the penultimate exploration was no more correlated than less recent explorations indicating a non-random exploration direction. These movements during transience were focussed on a series of temporary settlement areas (TSAs) that varied in number per individual and re-visitation rate. TSAs were used more often during the summer months and locations outside of TSAs occurred much more frequently in the core of known breeding home ranges.

The objectives of this study were to test for the feasibility of satellite radio-tracking of golden eagles (Aquila chrysaetos) breeding in the Grande-Baleine hydro-electric study area, to assess the size of their home-ranges, to determine their food habits during the nesting season, and to describe migration routes and wintering grounds of these birds. / In June and August 1992, six golden eagles, of which 5 adults (4$ rm sp{o}$ + 1 sex unknown), were caught and fixed with transmitters in order to follow their movements over one year. / The golden eagles fed on various animal species, i.e. 8 mammals, 15 birds and one fish, during the breeding season, however Canada geese (Branta canadensis) were the main item in their diet. / Four of the adult eagles undertook their fall migration in October 1992. The other adult eagle died of an unknown cause while the fate of the nestling could not be determined. All the migratory birds moved south to the United States, but they used different migration routes. The four golden eagles reached their wintering grounds in November and December, 1992. / After a three to four month stay in the wintering area, three eagles undertook their spring migration in March 1993. When returning to the breeding area, two of the eagles followed the same migration routes used in fall, while the third one flew off course to the west into Ontario. The first two birds reached their former territories in March and April while the third eagle only arrived in mid-May 1993.

No description available.

This study examines the factors that influence the seasonal movements of Golden Eagles (Aquila chrysaetos), and can thus provide important information that helps to improve the protection of the species. There were two main purposes of this study. First, I wanted to analyze the difference between preferences of juvenile and adult Golden Eagles in their choice of southern or northern hibernation areas. Do younger eagles prefer moving longer distance to southern areas of Sweden? Second, I wanted to investigate how the climate influenced the choice of date of migration in the fall. In other words, does an early winter arrival influence the migration date of Golden Eagles? I also investigated if food availability influenced the migration date in combination with winter arrival? For the statistical analyses, 14 years (1998-2011) of data on snow conditions, temperatures, food availability and records on banded eagles from the counties Ångermanland and Västerbotten were used. I found that young eagles preferred to move further south, while adults tended to move much shorter distances or remained in the nesting area during the winter. How early or late in the fall the eagles moved was mainly affected by the first day when the temperature was -10°C or below combined with the first day when the snow depth reached at least 8 cm. Another factor that seemed to affect the date of migration was the amount of food (smaller prey), which influenced the effects of temperature and snow cover. For example, there were instances when good food availability led to eagles deciding to stay longer despite early snowfall. This important knowledge on how climatic factors and food availability influence the migration of Golden eagles can be useful when developing conservation programs for their future protection.

The attributes of landscapes, abiotic and biotic, influence the behaviour of animals. Understanding the reciprocal effects between the landscape, habitats and the animals are an essential tool in sustainable management of natural resources as well as conservation. A source of information about how the environment shapes the behaviour of animals is movement data. The advent of cheap GPS devices has facilitated data collection. The fine scale spatio-temporal resolution allows the identification of complete home-ranges, even habitat that is only transiently used. Fine-scale movement data can also be used as proxy for behaviour-types; different behaviour states cause different movement tracks. I test, extend and apply the multi-change point analysis (MCPA), developed by Gurarie et al. (2009) for the identification of behavioural change points in irregular movement data. The method relies on conventional time-series analysis methods, rather than a Bayesian framework, such as the state space models. After thorough testing of the MCPA, we apply the method and its extension to the GPS data of four red deer and 27 golden eagles. The red deer data were analysed to detect behavioural changes at a seasonal scale and to serve as a test-bed for our extension of the MCPA. The comparison of movement bouts revealed that the expression of behaviour was on a gradient rather than the discreet states. The study of the golden eagle data highlighted the necessity to choose the appropriate sampling regime of movement. If the intervals between the location-fixes are too big, valuable information about important small scale behaviour will be missed.

During the spring of 1969 and 1970, 28 Golden Eagle eyries in four locales in central Utah were observed to determine the prey utilized during the nesting season. Visits were made every two weeks to the eyries. Prey were removed from the nests upon counting to avoid recounting at the next visit. Sixteen species of vertebrates were found as prey for nesting Golden Eagles. Mammals comprised 96 per cent of the prey, and lagomorphs alone accounted for 92 per cent. The blacktail jackrabbit occurred as 77.8 per cent of all prey items. Avian species constituted 3.9 per cent of prey items brought to the nests. Game animals utilized as prey were exclusively birds, and accounted for 2.7 per cent of all prey. No remains of domestic animals were found in the nests.

The availability of water is a limiting resource for many wildlife species in arid and semi- arid environments. Free water is essential for critical life stages for numerous species, including migration, reproduction, survival, and habitat selection. Riparian areas in the desert occur relatively infrequently, but support a disproportionally large percentage of plant and wildlife species found in arid environments. Our study covered two aspects of water use in the west desert of Utah. The first was assessing the impacts of nonnative ungulates (specifically feral horses and cattle) on natural springs, and how they influenced water quality, vegetation, and wildlife diversity at those springs. We found that these ungulates reduced plant cover and plant species richness at our sites. Additionally, we found that the number of plant species positively correlated with wildlife diversity. This indicates that further management of these nonnative ungulates may be warranted. In our second chapter we investigate how Golden Eagles (Aquila chrysaetos) use water by quantifying seasonal use, behavior, and testing a hypothesis that a ‘runway’ with drop in elevation is needed for eagles to have a quick exit. We found that eagle use of water resources was strongly concentrated in the summer months during the hottest temperatures. Adult birds used water features more often than younger birds. The most common behavior exhibited at water features was drinking, followed by bathing and preening. We found that there was a positive relationship between the number of visits and the maximum slope at each site, supporting the idea that the ‘runway’ is not required but is preferred at water sources. Overall, our results indicated that Golden Eagles use water regularly in arid environments, particularly during summer months. This research provides insight into how species are using desert riparian areas and how these species and habitats should be managed in future decades.

Development and climate change in the sagebrush habitats are causing population declines of North American hawks and eagles. For these species, understanding the landscape features that are preferred for nesting and the prey they consume in sagebrush habitats are important in developing conservation plans. Specifically, we know little of the preferred nest-sites and diet of Ferruginous Hawks (Buteo regalis) and Golden Eagles (Aquila chrysaetos) many locales. In our study, we determined the landscape characteristics associated with nest sites for these two raptor species in the Uintah Basin, UT to predict where nests may occur in our study area. We found that slope, elevation, distance to nearest oil and gas wells, geology, and facing south were the most important variables in characterizing Golden Eagle nest-sites. Elevation, slope, vegetation type, and distance to nearest oil and gas wells were the most important variables in characterizing Ferruginous Hawk nest-sites. In addition, we looked at the diets of Golden Eagles, Ferruginous Hawks, and Northern Goshawks in the Uinta Basin, UT using a genetic analysis method novel to raptors. We found species consistent with previous diet studies and detected prey items not previously reported, including the Western Whiptail (Aspidocelis tigris), Domestic Cow (Bos Taurus), Domestic Pig (Sus scrofa), and Rock Bass (Amboplites rupestris) within Ferruginous Hawk samples. Results from our study can provide managers with tools to better survey for nest-sites and to provide an alternative method of diet analysis to provide insight into prey species important to these raptors.

The aim in this study was to develop a model for the probability of finding active golden eagle nests during their breeding season. It was done by using environmental variables derived from expert models which were tested against empirical data. This resulted in a habitat suitability index (HSI), which in this case is assumed to indicate the probability of active nests of golden eagles. The study was conducted together with the County Administrative Board of Västernorrland with the purpose to improve golden eagle’s ecological status.To develop the model, different combinations of several explanatory variables were tested in a model selection process, where the most optimal and parsimonious model was chosen. The tested variables have earlier been shown to affect golden eagles, as slope, aspect, forest age, foraging habitat, suitable flight routes, human population density, roads, railways, power lines, wind power plants, hiking trails and clear cuts. The variables where applied in in ArcMAP at three different scales: nest scale (25 x 25 meter), proximate scale (a circle with the radius of 500 meter) and home range scale (a circle with the radius of 8253 meter). A preliminary test of the variables showed that all golden eagle nests were found in slopes with at least 5֯ degreesas well as in home ranges with human population density not more than 8 people/km2. Due to that a stratified analysis wasperformed. The variables where analysed by multiple logistic regression in R, where the occurrence of golden eagles’ nestswas compared towards random points in the landscape. All variables were also tested one by one by logistic regression. Afterperforming the multiple logistic regression, it was possible to apply its equation into ArcMap to obtain suitability maps withHSI values over Västernorrland’s county.The comparisons of different models show that it is better to combine different spatial scales in the model than only using one spatial scale. The result indicate that three different models might be the best, which all had different combinations of slope and aspect at nest scale and power lines at the proximate scale. Two of these models also include hiking trails and human population density, both at home range scale, in their equation. Since it was some unclarity about the causality between hiking trails and human population density, the conclusion was not to choose any of these as the final model. The final model was more parsimonious and had an additive effect from slope and southern aspect at the nest scale and an antagonistic effect from power lines at the proximate scale.This study clarifies that golden eagles’ habitat preferences for nesting sites during their breeding period is steep slopes (at minimum 5֯ degrees) in more southern aspects with few power lines in the proximate area surrounding the nest. Their homeranges are also situated in areas with less than 8 people/km2. The study also pinpoints a potential conflict between golden eagleand wind power planning, as golden eagles prefer steep slopes and remote areas, which also are valuable areas for wind powerplants. Golden eagles’ preference of remote areas also indicate that they might be affected by human persecution, why certainconservation effort should be focused into this issue. Out from the final model, you can find cluster in the landscape where youcan focus conservation management and restrict exploitation. Due to low number of wind power plants in the landscape, nothingcould be concluded about their effect on golden eagle in this study. An advice from the golden eagle’s perspective is to use theprecautionary principle and further plan wind power plants in areas which already have high disturbance, as for example closeto power lines or roads. The result also indicates that forest age from SLU Forest Map is not suitable for telling where to findgolden eagle nests. GIS-data over forest age would facilitate conservation management for plenty of species connected to theforest.Although good statistical results for the final model, cautions need to be taken in general, since neither population viability analysis have been included, nor changes over time in the landscape. Another issue is the low sample size, where a larger sample size would make it possible to perform profound calibration and validation of the data. To develop a more robust model, the advice is to include these into the model and use a larger sample size.

Golden eagles (Aquila chrysaetos canadensis Linnaeus 1758) are declining in some areas throughout their Nearctic range (Sauer et al. 2011). This reduction is linked to changes in their habitat caused by human activities. Golden eagles inhabit an extensive range of environments (Watson 1997, Kochert et al. 2002). In the American Continent, the golden eagle's range encompasses Alaska, Canada, the United States and the Northern and Central portions of Mexico. Northern golden eagle populations migrate during winter to southern grounds, crossing international boundaries of Canada, the US and Mexico and therefore, their conservation is of trilateral concern. Golden eagles are protected by domestic laws in the three North American countries where they occur (FWCA 1997, BGEPA 1940, MBTA 1918, Lacey Act 1900, DOF 2002) and although the IUCN list the species as Least Concern, the A. c. canadensis subspecies has been protected by CITES since 1975 (Birdlife International 2012). While intensively studied in the United States, very little is known in Mexico about golden eagle ecology and their populations. As the national bird of Mexico, its conservation has been a priority for the Mexican government since its inclusion in the Endangered Species List in 1994 (SEDESOL 1994). Several threats jeopardize golden eagle populations throughout their range in North America: habitat alteration and fragmentation, electrocution, collisions with vehicles, collision with windmills and wires, poisoning from lead ingestion, drowning, shooting and trapping, and poaching for illegal wildlife trade. Mexican experts believe that a dramatic decline occurred over recent decades and that the remaining pairs have been restricted to remnant suitable habitat patches (SEMARNAP-INE 1999). Long-term survival of golden eagles largely depends on the effectiveness of current conservation efforts of habitat at a landscape level. Successful conservation and management requires accurate information on ecology of the species upon which decisions can be based. This study investigated habitat characteristics of the areas occupied by golden eagles and developed strategies for habitat management and protection to improve golden eagle viability in Chihuahua State. I surveyed a portion of Chihuahuan Desert Ecoregion in Mexico to locate golden eagle territories during 2009 and 2010. I located 30 golden eagle nesting territories and found similar composition of cover type, vegetation structure and prey indices between the territory cores and their buffer zones. Distance to most anthropogenic disturbance sources was similar between golden eagle sites and random areas (n=60). Grassland was the most common cover type, occurring in 100% of the nesting territories, and comprising 58% of the territories' area, suggesting a disproportionate use of this cover type compared to its overall availability (25% of the state area). I used landscape attributes such as topographic characteristics and human disturbances to model the probability of occurrence of golden eagles across the landscape. I used logistic regression to model the occurrence of golden eagles at two different landscape scales and selected the best model at a home range scale based on AIC values to develop a predictive map of golden eagle distribution in Chihuahua, Mexico. I found that at a home range scale, golden eagles' occurrence was positively related to open areas and terrain ruggedness and negatively to human settlements, while at a larger scale it was positively related to open areas and negatively related to forested areas. The results confirm that golden eagles are dependent on grasslands and rugged terrain. I developed predictive maps of golden eagle occurrence using a logistic regression and a Mahalanobis distance approach using the variables from the model chosen to compare the performance and output with logistic regression modeling. I analyzed the Mexican National Plan for Golden Eagle Recovery (PACE - Ã guila Real) and proposed a conservation strategy oriented to protect golden eagle populations and their habitat in Chihuahua, Mexico. This strategy integrates ecologic knowledge developed in the first two chapters and incorporates social participation of all stakeholders. The strategy recognizes the potential limitations of conservation implementation programs in Mexico and explores the potential opportunities to protect golden eagles populations and their habitat. / Ph. D.