Hundreds of species of birds in South America require tree-cavities for nesting, and many of these species are threatened by selective logging and clearing of forest for farms. Our objectives were to examine variation in cavity supply among bird species and habitats, and to encourage conservation of tree cavities for nesting birds.
Our field research in the Atlantic forest of Argentina showed that five sympatric parrot species partitioned their nest niche, overlapping little in cavity characteristics. However, cavity supply declined for all species with increasing human impact, from primary forest, through logged forest, to farms. Globally endangered Vinaceous-breasted Parrot was the only parrot species found more often nesting in logged forest and farms than in primary forest, but we found no suitable cavities in 14.8 ha of farmland. Our field research in the Amazon forest of Brazil showed that second-growth forest recovered a similar number of cavities to primary forest after ~30 years; though probably suitable for small birds, these cavities did not include large high cavities required by larger birds such as forest-falcons or parrots. Given the slow time to recover cavities suitable for parrots in secondary forest, it is critical to promote conservation of large trees currently providing such cavities, including remnant trees on farms.
Patches of Atlantic forest on farms provide critical wildlife habitat and several ecosystem services, yet they are under pressure from farmers. These farmers need wood and cropland, and do not think of habitat loss as an important threat to endangered species. In our outreach efforts, we aimed to encourage farmers to value forest patches for their services to both humans and wildlife, and to strengthen their commitment to conserving habitat. Using interactive story-telling in 12 rural schools, we learned that most children had entered the forest to gather fruits, water, firewood or honey, and most had eaten wild forest animals; however, they did not consider these to be important reasons why someone would protect forest on their farm. We conducted two annual rounds of age-appropriate educational activities with grades K-12 at 17 rural schools in the Atlantic forest, to promote forest conservation. One year after the first round of activities (but before the second round), 93% of Grade 7 students included forest clearing and/or cutting trees among the top three activities that threaten endangered species in our province. To conserve forest and endangered species, high school students proposed to (1) take better care of the soil to avoid clearing new areas of forest (e.g., using winter cover like oats to prevent erosion on existing cropland), (2) plant native trees, and (3) not hunt endangered species. Twenty-one farmers planted a total of 321 native tree seedlings on their farms, to provide a future source of food and refuge for Vinaceous-breasted Parrots. ($7,840)