Dispersal is a critical life-history component; it determines gene flow and has profound effects on population structure, demography, social systems, and population viability. To add to our knowledge of dispersal and, in particular, our understanding of the relationship between dispersal and inbreeding, I studied three aspects of the biology of the red-cockaded woodpecker: dispersal of breeding females; the costs, benefits, and frequency of inbreeding; and the effect of inbreeding on natal dispersal. Dispersal of breeding female red-cockaded woodpeckers is strongly associated with inbreeding avoidance and mate choice, weakly associated with site choice, and not found to be associated with social constraints. Estimates of mortality for non-dispersing and dispersing breeding females were 24 and 59 percent per year, respectively-rare evidence of the cost of breeding dispersal. Significant costs of close inbreeding were found. Closely related pairs (kinship coefficient greater than 0.1) had lower hatching success as well as lower survival and recruitment of fledglings than unrelated pairs. Moderately related pairs (kinship coefficient between 0 and 0.1) and moderately inbred individuals had increased hatching success, but did not produce more young. Despite documented costs of close inbreeding and a predictable spatial distribution of closely related males near the natal territory, female fledglings disperse a median of only two territories and a modal distance of one territory. Natal dispersal of females is affected by closely related males on the natal site but unaffected by closely related males or moderately related males that are off the natal site. / Master of Science

No description available.

No description available.

There is a long history in Kiruna of conducting research on the physics of the aurora borealis. There is also a long history of providing tourists with great opportunities to see the auroras. Planning such tourist activities can be challenging since the auroras are hard to predict. Reliable forecasts would be a valuable tool for researchers as well as for tourists and tour guides. One tool that is already available for both researchers and tourists is the all-sky camera in Kiruna, which is operated by the Swedish Institute of Space Physics (IRF). There has been a digital all-sky camera in operation in Kiruna for over 20 years. From the images captured by this camera, the IRF has developed a numerical index - the auroral index.  Forecasting time series with neural network algorithms is a well studies subject. There are many examples from a wide range of felds, including space weather. A type of neural network that has often been successfully used for time series forecasting is the Recurrent Neural Network (RNN), and more specifcally the Long short-term memory (LSTM).  This thesis evaluates the auroral index - in combination with data from the solar wind - as training data for recurrent neural networks. Furthermore, it attempts to fnd a LSTM neural network model capable of making reliable forecasts of the auroral index. The Keras and TensorFlow software libraries are used to build and train the neural network model. Some challenges with the auroral index - when utilized as training data for neural networks - are identifed. The produced LSTM neural network models are not accurate enough for deployment as a production level service. Further development might improve on this. Finally, this thesis suggests future work that may contribute to better forecasting models for auroras in the Kiruna region.

A dual satellite system in a Low Earth Orbit, LEO, would be beneficial to study the electromagnetic occurrences in the magnetosphere and their contributions to the development of the aurora events in the Earth's lower atmosphere. An orbit configuration is sought that would increase the total time that both satellites are inside the auroral oval. Some additional objectives include minimizing the total fuel cost and the average angle between the satellites' radius vectors. This orbit configuration is developed using a series of instantaneous burns applied at each satellite's perigee. An analysis of the optimal solutions generated by a Particle Swarm Optimization method is completed using a cost function with different weights for the time, fuel, and angle terms. Three different scenarios are presented: a single burn case, a double burn case, and a four burn case. The results are calculated using two different orbital mechanics models: an unperturbed two-body simulation and a two-body simulation with added Earth's equatorial bulge effects. It is shown that the added perturbation reduces the total event time in the optimal solutions generated. Specific weights for the cost function are recommended for further studies. / Master of Science

This project had 2 major objectives. The first objective was to assess how well the revised U.S. Fish and Wildlife Service Foraging Habitat Guidelines depict good quality habitat for the red-cockaded woodpecker (Picoides borealis) at Camp Lejeune, NC. To accomplish this, I used multiple linear and logistic regression to examine the relationships between fitness, habitat use, home range size, and habitat characteristics described in the guidelines. I assumed that habitat characteristics that confer quality were related to higher fitness, greater habitat use, and reduced home range size. To a large extent, the guidelines are validated. Red-cockaded woodpeckers responded favorably to habitat that mimics the historical, mature, and fire-maintained pine forests of the southeastern U.S., characterized by high densities of large pines, low densities of small and medium pines, and a lush herbaceous groundcover. Variables positively associated with habitat use and fitness were associated with reduced home range size, and those negatively associated with habitat use and fitness with increased home range size. Percent herbaceous groundcover was a significant regressor indicative of quality in every model. The second objective was to assess how well USFWS foraging partitions represent habitat used by red-cockaded woodpeckers. I conducted home range follows of 23 groups of red-cockaded woodpeckers and estimated the percentage of each home range encompassed by partitions of varying radii. The percentage of the actual home range included in the partition increased as a function of partition radius. The standard 800 m circular partition, on average, included 91% of the home range, but significant variation existed between groups. / Master of Science

One unresolved issue in the study of cooperative breeding is why individuals that delay their own reproduction assist others in raising young. Red-cockaded woodpecker helpers may again future indirect fitness benefits by increasing survival of breeders, who produce offspring related to the helper in the future. Breeder survival may be enhanced because of general benefits of group living, either because of the helper's own presence or because helping increases the production of fledglings. I demonstrate that breeder survival increases in the presence of helpers and additional young. Helpers may also reduce the workload of the breeder, and this may increase breeder survival as well. I show that breeders spend less time incubating and provisioning young when a helper is present. Helpers may also gain fitness benefits if once they become breeders, they are assisted by young they previously helped raise. Expected frequencies of reciprocal exchange of helping are low (2%). Slightly higher observed frequencies may be accounted for by preferential helping of kin and effects of territory quality. Reciprocity occurs no more often than expected among helpers unrelated to the young they help raise suggesting that young males do not preferentially helper former care-givers. i conclude that helpers do not gain fitness benefits from reciprocity. I examined the proximate causes of delayed breeding and helping behavior by measuring plasma testosterone (T) and prolactin (PRL) concentrations in female breeders, male breeders, and male helpers during different stages of the reproductive cycle. Among male breeders and helpers, T is low during the nonbreeding stage, peaks during copulation and declines during the incubation and nestling-provisioning stages. Helpers appear physiologically capable of reproducing: their T concentrations are equal those of breeders. Helpers unrelated to the breeding female have higher T than helper related to her. Sexual inactivity by male helpers is best explained by behavioral suppression. Female breeder, male breeder, and male helper PRL was equal and increased from the nonbreeding stage through the copulation and incubation stages. During the nestling provisioning stage, male breeder and male helper PRL declined, while female PRL continued to increase. I conclude that the physiological bases of helping behavior and parental behavior are the same. / Ph. D.

No description available.

Cavity-excavating birds, such as woodpeckers, are ecosystem engineers and are often assumed to rely upon wood decay fungi to assist in softening the wood of potential excavation sites. Endangered red-cockaded woodpeckers (Picoides borealis; RCWs) are the only birds known to solely excavate through the sapwood and into the heartwood of living pine trees and generally take many years to complete their excavations. These birds may have developed a partnership with wood-inhabiting fungi to facilitate the excavation process. Past attempts to understand the complex relationships between cavity excavators and fungi relied on visual surveys of fruiting bodies, or evidence of decay, resulting in a one bird, one fungus paradigm. Using molecular methods, I investigated the relationships between RCWs and fungi, and found that the relationships between cavity-excavators and fungi involve multiple fungal species and are far more complex than previously imagined. Through a field survey, I showed that RCW excavations contain distinct communities of fungi, and propose two hypotheses to explain this result, (1) RCWs select trees with distinct fungal communities (tree selection hypothesis), or (2) RCWs promote distinct fungal communities via their excavations (bird facilitation hypothesis). By swabbing the birds, I found that RCWs carry fungal communities similar to those found in their completed excavations, demonstrating that RCWs may directly facilitate fungal dispersal during the excavation process. Through a test of the bird introduction hypothesis which implemented human-made experimental drilled cavity starts (incomplete excavations), half of which were inaccessible to the birds, I showed that RCW accessibility influences fungal community development in excavations. This experimental evidence demonstrates that the relationship between RCWs and fungal communities is a multipartite symbiosis may be mutualistic. Finally, by tracking fungal community development in experimental cavity starts through time, I also demonstrated that the fungal communities found in RCW excavations undergo succession, and that this process is influenced by the birds. The relationships described in this body of work provide the basis for future studies on cavity excavators and fungi, and also have implications for a diverse community of secondary cavity nesters, wood-inhabiting fungi, forest ecology, and the conservation of biodiversity. / Ph. D.

About 70% of the plant species in the temperate zone are characterised by clonal growth, clonal species are also in majority in the Arctic and Subarctic where they affect the structure and composition of the vegetation. It is therefore of great importance to increase our knowledge about clonal plants and their growth and life histories. I have investigated how ramets of the stoloniferous plant Linnaea borealis are affected by the naturally occurring variation in environmental factors, such as: light, nutrient and water availability. Moreover, I examined the seed set and how supplemental hand pollination affects seed set in L. borealis, and also investigated the significance of the apical meristem for shoot population fitness. All studies were performed under field conditions in northern Sweden in a Subarctic environment and most are experimental. The results show that nutrient resorption from senescing leaves is not significantly affecting the growth and nutrient pools of the ramet. This implies that the growth of L. borealis ramets is not governed by micro-site resource availability. However, removal of light competition resulted in increased branching and number of lateral meristems produced, reduced growth, and decreased root:shoot ratio on a per ramet basis. Thus, ramets of L. borealis can efficiently exploit favourable light patches through plastic growth. Apical dominance exerts a significant effect on shoot population fitness and can be lost through rodent grazing. However, loss of apical dominance is dependent on the timing of grazing, if the apical meristem is removed early in the autumn the ramet can repair the loss until the next summer. If grazing occur during spring the dry weight and leaf area production is affected negatively. Seed production in L. borealis in the Abisko area varies between years and sites, and was unaffected by supplemental hand pollination treatment, implying that there is no lack of pollinator activity.