The Northern Goshawk has been a species of concern since its decline in the early 1990s, which has been attributed in part to loss of critical breeding and wintering habitat. Nest site selection of goshawks has been correlated with certain specific site characteristics including, but not limited to, forest species composition, forest stand size, diameter of nest tree, percent cover, tree height, site slope, and aspect. The goshawk holds the status of a Management Indicator Species (MIS) on all of the six national forests in Utah. This status requires annual monitoring to track goshawk numbers and to address any activities on the forests that may affect nest site activity. Findings from the annual nesting data showed that some territories have been more active than others. We summarized the data from the three national forests in southern Utah in order to understand differences in nesting habitat among the forests. We also analyzed the nesting habitat variables slope, elevation, and nest tree species statistically to determine if they could be used as predictors of nest activity. We found that slope and elevation were not good predictors while nest tree species was significant in its ability to predict nest activity. We concluded the nesting habitat variables we selected were insufficient in their ability to predict nest activity and other variables such as prey species availability, weather conditions in the spring, and forest cover type might be needed to create a model that more accurately predicts nest activity.

Les coûts de remise en forme que les macro et micro parasites imposent aux hôtes peuvent s'expliquer par trois facteurs principaux : (1) Les hôtes utilisent des réponses immunitaires contre les parasites pour prévenir ou contrôler l'infection. Les réponses immunitaires nécessitent de l'énergie et des nutriments pour produire et / ou activer les cellules immunitaires et les immunoglobulines, ce qui est coûteux, provoquant des compromis avec d'autres processus physiologiques comme la croissance ou la reproduction. (2) Le taux métabolique de l'hôte peut être augmenté parce que les dommages aux tissus et la réparation ultérieure de l'infection causée par le parasite peuvent être coûteux. (3) Le taux métabolique des hôtes peut augmenter et donc augmenter également leurs besoins en ressources. La compétition entre macro-parasites et hôtes peut priver les ressources de l'hôte. Les coûts de remise en forme que les macro et micro parasites imposent aux hôtes peuvent s'expliquer par trois facteurs principaux : (1) Les hôtes utilisent des réponses immunitaires contre les parasites pour prévenir ou contrôler l'infection. Les réponses immunitaires nécessitent de l'énergie et des nutriments pour produire et / ou activer les cellules immunitaires et les immunoglobulines, ce qui est coûteux, provoquant des compromis avec d'autres processus physiologiques comme la croissance ou la reproduction. (2) Le taux métabolique de l'hôte peut être augmenté parce que les dommages aux tissus et la réparation ultérieure de l'infection causée par le parasite peuvent être coûteux. (3) Le taux métabolique des hôtes peut augmenter et donc augmenter également leurs besoins en ressources. La compétition entre macro-parasites et hôtes peut priver les ressources de l'hôte. / The fitness costs that macro- and micro-parasites impose on hosts can be explained by three main factors: (1) Hosts use immune responses against parasites to prevent or control infection. Immune responses require energy and nutrients to produce and/or activate immune cells and immunoglobulins, and that is costly, causing trade-offs against other physiological processes like growth or reproduction. (2) The host’s metabolic rate can be increased because tissue damage and subsequent repair from the infection caused by parasite may be costly. (3) The metabolic rate of hosts may increase and hence also increase their resource requirements. Competition between macroparasites and hosts may deprive resources of host. Birds are hosts for many symbionts, some of them parasitic, that could decrease the fitness of their hosts. There is a huge diversity in potential parasites carried in a bird’s plumage and some can cause infection. Nest lining feathers are chosen and transported by adult birds including barn swallows Hirundo rustica to their nests, implying that any heterogeneity in abundance and diversity of microorganisms on feathers in nests must arise from feather preferences. we found that the effects of microorganisms on the behavior of birds may be a combination of positive and negative effects. There may be positive effects of antimicrobial activity on birds through the process of bacterial interference, consisting of certain bacteria impeding the establishment of competing bacterial strains by producing antibiotic substances. Meanwhile, the negative effects may imply that pathogenic or/and feather-degrading microorganisms may reduce fitness components of their hosts. These effects of microorganisms and hence the microbiome can be affected by the behavior of bird hosts.