No abstract

A temporal separation of energetically costly life history events like reproduction and maintenance of the integumentary system is thought to be promoted by selection to avoid trade-offs and maximize fitness. It has therefore remained somewhat of a paradox that certain vertebrate species can undergo both events simultaneously. Identifying potential costs of overlapping two demanding life history stages will further our understanding of the selection pressures that shape the temporal regulation of life history events in vertebrates. We studied free-living tropical Slaty brush-finches (Atlapetes schistaceus), in which individuals spontaneously overlap reproduction and moult or undergo both events in separation. To assess possible costs of such an overlap we quantified feather quality and flight performance of individuals in different states. We determined individual’s life history state by measuring gonad size and scoring moult stage, and collected a newly grown 7th primary wing feather for later analysis of feather quality. Finally, we quantified flight performance for each individual in the wild. Overlapping individuals produced lighter and shorter wing feathers than individuals just moulting, with females decreasing feather quality more strongly during the overlap than males. Moreover, overlapping individuals had a reduced flight speed during escape flights, while their foraging flight speed was unaffected. Despite overlappers being larger and having a smaller wing area, their lower body mass resulted in a similar wing load as in breeders or moulters. Individuals measured repeatedly in different states also showed significant decreases in feather quality and escape flight speed during the overlap. Reduced escape flight speed may represent a major consequence of the overlap by increasing predation risk. Our data document costs to undergoing two life history stages simultaneously, which likely arise from energetic trade-offs. Impairments in individual quality and performance may represent important factors that select for temporal separation of life history stages in other species.

In human-transformed landscapes, predators may feed on domesticated animals, and thus affect human well-being, creating negative perceptions and leading to conflict with people that can result in the persecution of the predator. We studied the factors that influence the perception of the Black-and-chestnut Eagle (Spizaetus isidori) in four rural Andean communities in Colombia and compiled historical and recent evidence on the persecution and other causes of mortality of this species in the country. We applied 267 questionnaires and conducted 16 interviews with local inhabitants, via visits to homes and schools in the surroundings of S. isidori nests. The perception of S. isidori by the inhabitants was largely negative and influenced by different socio-demographic factors such as gender, chicken (Gallus gallus) ownership, and chicken management. The records we obtained indicate that 47 eagles were shot, 16 were captured (three for illegal trafficking) and two were electrocuted on hightension wires. The persecution of S. isidori occurs as retaliation or as a preventative measure against chicken predation, and is a significant cause of mortality of this species in Colombia. Effective conservation planning for S. isidori in Colombia needs to go further than the protected areas system, and include a socioecological perspective in conservation practices applied at landscapes scales that are dominated by people. Education programs and socioecological research, along with participatory work in local communities are key to the conservation of S. isidori in breeding territories. This approach can also prevent conflict over food resources-G. gallus and other poultry-that are shared by humans and S. isidori in rural landscapes.

Habitat use and movement patterns in animals are usually determined by the availability of food, morphological and physiological traits, social systems, and safe sites to complete vital cycles. The objective of this study was to estimate the home-range area, daily traveled distance, and patterns of space use by Oilbirds (Steatornis caripensis), and the factors that can affect them in Cueva de Los Guacharos National Park (Huila, Colombia). We attached GPS devices to five individuals and recovered information from three. Home ranges were estimated by minimum convex polygon (MCP), 95 and 50% kernel methods. Traveled distances were estimated as the sum of the linear distances between sampling points (every 30 min), and patterns of habitat use were evaluated through ecologicalniche factor analysis (ENFA), including forest cover, altitude, and degree of fragmentation. Analysis of habitat preference was done using 25 vegetation plots established in frequently used areas and species richness, and the proportion of consumed plants was compared with other locations within their distribution range. Home-range area was estimated to be 4517 km², possibly an underestimation due to reduced sample size. The average traveled distance per night was 55 km (range: 0-112 km). Analyses of habitat use showed a clear preference for areas with higher forest cover. Height above sea level was also largely associated with frequencies of habitat use, indicating a low use of areas above 3000 m, while the degree of fragmentation was not a strong predictor of habitat use. Finally, vegetation plots in frequently used areas showed a higher abundance of fruiting trees consumed by Oilbirds than control plots. Overall, Oilbirds have amazing movement capacity, being able to use distant landscape elements, and showing a clear preference for areas with forest cover, lower altitude, and areas with a high representation of the plant species they consume.

In anthropogenically transformed habitats, some birds of prey feed on domestic animals, triggering conflict between people and predators. To manage this conflict, it is important to understand the ecological circumstances associated with the predation of domestic animals. We studied variation in the diet of the endangered Black-and-chestnut Eagle (Spizaetus isidori) in four different Andean landscapes in Colombia. We analyzed 261 prey items brought to five S. isidori nests during the period when the nestlings were being raised. Domestic fowl are relatively frequent prey in the diet of S. isidori in three of the four localities studied (frequency: 9.3%-36%), representing 12.2% to 37.1% of the total biomass of prey consumed. In terms of biomass, in Ciudad Bol ıvar, Jard ın, and Campohermoso, the sites with the greatest forest cover, mammals were the most important prey in the diet of S. isidori, while in Gachalá, the most deforested site, domestic fowl were the most important prey. We recommend that forest cover be maintained and increased to provide habitat for wild prey in the breeding territories of S. isidori using the landscape management tools best suited to the specific socioecological contexts of this eagle's territories. We also suggest that the management of domestic fowl under controlled conditions or the use of some deterrent be examined as strategies to mitigate or prevent conflict between people and S. isidori. Socioecological research and educational programs should be carried out to increase the public's understanding of this eagle and its benefits to the ecosystem.