The global potential for wind power generation is vast, and the number of installations is increasing rapidly. We review case studies from around the world of the effects on raptors of wind-energy development. Collision mortality, displacement, and habitat loss have the potential to cause population-level effects, especially for species that are rare or endangered. The impact on raptors has much to do with their behavior, so careful siting of wind-energy developments to avoid areas suited to raptor breeding, foraging, or migration would reduce these effects. At established wind farms that already conflict with raptors, reduction of fatalities may be feasible by curtailment of turbines as raptors approach, and offset through mitigation of other human causes of mortality such as electrocution and poisoning, provided the relative effects can be quantified. Measurement of raptor mortality at wind farms is the subject of intense effort and study, especially where mitigation is required by law, with novel statistical approaches recently made available to improve the notoriously difficult-to-estimate mortality rates of rare and hard-to-detect species. Global standards for wind farm placement, monitoring, and effects mitigation would be a valuable contribution to raptor conservation worldwide.

Global urbanization is rapidly increasing, specifically within Africa. However, the effects of these processes on Africa's wildlife are largely unexplored. For many species, the effects are detrimental, whereas others are able to colonize these human-altered environments and can even thrive. Raptors are positioned at the top of the food chain and therefore particularly susceptible to environmental changes, and yet they are increasingly associated with urban areas. Given that adaptations to cope with urban stressors may differ from those occurring in more natural habitats, we might expect that directional selection in urban areas could account for phenotypic divergence between urban and rural individuals. This might include selection for different plumage coloration, which could be facilitated in color polymorphic species because no additional mutations are required to create variation. Color polymorphism is common in raptors, with 22% of the Accipitridae family being polymorphic. In this study, we focus on Black Sparrowhawks (Accipiter melanoleucus) in Cape Town, South Africa. We explore whether the morphs are distributed differently along an urban–rural gradient and thus show a local adaptation. Using a long-term study (16 yr), we also investigate whether morph was related to the timing of breeding and breeding performance along the urban gradient. We found no differences of the morph distribution or of their breeding performance in relation to levels of urbanization. Our study represents the first to examine the breeding distribution of a polymorphic raptor in relation to urbanization and one of the first to explore avian productivity in relation to urbanization in Africa.

The endangered Blakiston's Fish-Owl (Bubo blakistoni) has a fragmented distribution in the northeastern Eurasian continent, as well as on Hokkaido, southern Kuril, and Sakhalin islands. To examine the phylogeography of this species, we analyzed mitochondrial sequences. The whole mitochondrial genome, which included duplicated genes, was the largest (>21 kbp) in vertebrates to date. A Bayesian phylogenetic analysis of mitochondrial gene sequences revealed a clear separation between two clades. The insular clade comprised the mitochondrial haplotypes from Hokkaido, southern Kuril, and Sakhalin islands, whereas the continental clade consisted of those from the Eurasian continent, including the Primorye, Amur, and Magadan areas. Analyses based on whole mitochondrial sequences suggested that the level of genetic differentiation between the two subspecies, B. b. blakistoni on the islands and B. b. doerriesi on the continent, was enough to recognize them as separate species. The estimated divergence time between the clades was at least 500,000 yr before present. In contrast, the divergence times within the clades were less than 10,000 yr before present, indicating that the haplotypes within the clades diverged after the last glacial maximum (LGM). Information on the distribution of vegetation suggests that the main areas currently inhabited by B. blakistoni were unsuitable as habitats during the LGM. Lower diversities, higher growth rate, and the pattern of haplotype distribution in the continental population suggest a severe bottleneck and rapid dispersion through the last glacial period. In contrast, the insular population retains a higher haplotype variation. Because southern Hokkaido Island was covered with forests in the LGM, the area could have acted as a refugia for this species.

Presence or abundance of owls is frequently assessed using call-broadcast surveys to elicit responses and increase detection rates, but can draw owls in from a distance and could affect conclusions about fine-scale habitat associations. Passive acoustic surveys with field personnel or autonomous recording units (ARUs) may be a less biased method for surveying owls. Automated recognition techniques have proven useful to process large volumes of acoustic recordings from ARUs, and we sought to test the utility of automated recognition for three owl species. We built templates or “recognizers” for the territorial calls of the Barred Owl (Strix varia), the Boreal Owl (Aegolius funereus), and the Great Horned Owl (Bubo virginianus). We assessed the performance of each recognizer by evaluating precision, processing time, and false negatives. We used ARUs to survey for owls in northeastern Alberta, Canada, and compared the results from the recognizers to results from researchers listening to a subsample of the recordings. We verified the results to filter out false positives, but verification time was substantially lower than time spent listening. We processed more recordings and obtained a larger dataset of owl detections than would have been possible with either listening to the recordings only or conducting traditional field surveys without ARUs, suggesting a significant benefit of automated recognition. Precision was quite variable, but false negatives were relatively low and did not affect results of owl habitat associations. Given the relatively low detection rates of owls by listening to recordings, an automated recognition approach is likely to be highly useful for monitoring owls.

Weather conditions influence flight performance of soaring raptors, which take advantage of the strength of rising air currents to travel and forage. Most studies on soaring raptors are not conducted when precipitation and fog are present or during the hottest times of the day, when it is expected that these factors reduce species' detectability. The effect of weather on the movement of migratory birds has been studied extensively, but few studies have addressed these effects on nonmigratory tropical raptors. We described the richness, composition, and activity patterns of a diurnal soaring raptor community and we identified how daily weather conditions affected the probability of observing a species. For 11 mo, we surveyed five fixed points in an Important Bird and Biodiversity Area consisting mainly of montane Atlantic Forest in northeastern Brazil, for a total of 98 point counts. We recorded 12 species of soaring raptors, of which five made up 88% of all sightings. We added new records for three soaring raptor species, updating the previous richness list for the study region to 26 species. Daily wind velocity positively influenced the probability of observing Short-tailed Hawks (Buteo brachyurus). Daily relative humidity positively influenced the probability of observing Mantled Hawks (Pseudastur polionotus) and negatively influenced that of Roadside Hawks (Rupornis magnirostris). Six species would not have been recorded if afternoon samplings were not made. We demonstrated the need to consider weather conditions and time of day to increase the chance of observing diurnal soaring raptors.

We compared two color-marking techniques, celluloid color leg bands and colored dye on the feathers, for individual identification of American Kestrels (Falco sparverius). We trapped and color-marked 65 kestrels in October through December of 2014 and 2015. We searched for kestrels once a week with binoculars and a spotting scope and each time, recorded how kestrels were marked, either by bands, dye, or both. We confirmed that seven of the 195 color bands were lost during the study. The longest time that dye was still visible was 149 d after marking. We saw color bands from a maximum distance of 245 m and color dye from a maximum distance of 428 m. Of kestrels we were able to identify at least 10 times (n = 39) within the season that markings were applied, we saw only dye 17.3% of the time and only bands 19.4% of the time. We saw both markers (dye and at least one band) 63.3% of the time. Both methods can be used for successful identification of wintering kestrels, but a combination of the two techniques can increase the chance of seeing an identifiable mark. Color bands are long-term markers and allow identification of kestrels whose dye has faded or those that return in following years. Color dye makes it easier to identify kestrels that are difficult to approach, as well as those with territories extending away from accessible roadways.

Hematological and biochemical parameters are used to assess the health of birds and to support conservation plans for threatened species, such as the Andean Condor (Vultur gryphus). We studied 22 captive Andean Condors from the Rehabilitation Center for Raptors of the Unión de Ornitólogos of Chile to determine reference values. We measured packed cell volume, total plasma solids, and total and differential leukocyte counts; we analyzed aspartate aminotransferase, gamma-glutamyl transpeptidase, lactate dehydrogenase, alkaline phosphatase, creatine kinase, creatinine, calcium, inorganic phosphorus, and uric acid. We found no blood parasites and no significant differences between sexes (P > 0.05). Our results establish a baseline for hematological and serum biochemistry parameters for the Andean Condor.