Remnant forest in Costa Rican working landscapes fosters bird communities that are indistinguishable from protected areas

Effects of agriculture and nature reserves on avian behavior in northwestern Costa Rica

Behavioral changes are often animals' first responses to environmental change and may act as a bellwether for population viability. Nonetheless, most studies of habitat conversion focus on changes in species occurrences or abundances. We analyzed >14,000 behavioral observations across 55 bird species in communities in northwestern Costa Rica to determine how land use affects reproductive, foraging, and other passive kinds of behaviors not associated with either foraging or reproduction. Specifically, we quantified differences in behaviors between farms, privately owned forests, and protected areas and implemented a novel modeling framework to account for variation in detection among behaviors. This framework entailed estimating abundances of birds performing different behaviors while allowing detection probabilities of individuals to vary by behavior. Birds were 1.2 times more likely to exhibit reproductive behaviors in forest than in agriculture and 1.5 times more likely to exhibit reproductive behaviors in protected areas than in private forests. Species were not always most abundant in the habitats where they were most likely to exhibit foraging or reproductive behaviors. Finally, species of higher conservation concern were less abundant in agriculture than in forest. Together, our results highlight the importance of behavioral analyses for elucidating the conservation value of different land uses.

Sensitivity of tropical montane birds to anthropogenic disturbance and management strategies for their conservation in agricultural landscapes

Tropical montane bird communities are hypothesized to be highly sensitive to anthropogenic disturbance because species are adapted to a narrow range of environmental conditions and display high rates of endemism. We assessed avian sensitivity at regional and continental scales for a global epicenter of montane bird biodiversity, the tropical Andes. Using data from an intensive field study of cloud forest bird communities across 7 landscapes undergoing agricultural conversion in northern Peru (1800-3100 m, 2016-2017) and a pan-Andean synthesis of forest bird sensitivity, we developed management strategies for maintaining avian biodiversity in tropical countrysides and examined how environmental specialization predicts species-specific sensitivity to disturbance. In Peru, bird communities occupying countryside habitats contained 29-93% fewer species compared with those in forests and were compositionally distinct due to high levels of species turnover. Fragments of mature forest acted as reservoirs for forest bird diversity, especially when large or surrounded by mixed successional vegetation. In high-intensity agricultural plots, an addition of 10 silvopasture trees or 10% more fencerows per hectare increased species richness by 18-20%. Insectivores and frugivores were most sensitive to disturbance: abundance of 40-70% of species declined in early successional vegetation and silvopasture. These results were supported by our synthesis of 816 montane bird species studied across the Andes. At least 25% of the species declined due to all forms of disturbance, and the percentage rose to 60% in agricultural landscapes. The most sensitive species were those with narrow elevational ranges and small global range sizes, insectivores and carnivores, and species with specialized trophic niches. We recommend protecting forest fragments, especially large ones, and increasing connectivity through the maintenance of early successional vegetation and silvopastoral trees that increase avian diversity in pastures. We provide lists of species-specific sensitivities to anthropogenic disturbance to inform conservation status assessments of Andean birds.

Landscape Conservation Assessment in the Latin American Tropics: Application and Insights from Costa Rica

Landscape quality is an important aspect of conservation and sustainable development, yet holistic assessments of landscapes in the Latin American tropics are scarce. Here we employ an onsite survey across Costa Rica using the Landscape Assessment Protocol (LAP), a rapid assessment method, to assess the conservation condition of landscape views. In a survey of 50 landscape view sites in different parts of the country, LAP’s 15 metrics (evaluation criteria) were effective in providing an index for landscape quality showing a gradient of degradation in response to various modern anthropogenic pressures. The response of the index over a variety of landscape types correlates well with the Human Footprint anthropogenic pressure assessment, an independent land degradation index. Urban and peri-urban landscape types showed the most degraded conditions relative to flatland, coastal, and upland types on all metrics. Despite certain subjective attributes, the assessment method seems effective in providing a quality condition index that may assist in quality characterization and in promoting participation in landscape interpretation, landscape literacy, and landscape-scale conservation initiatives, especially in a region where landscape views (scenic resources) are threatened by widespread land-use changes. Finally, recommendations are made for the further application and testing of LAP, specifically for use in the neotropics.