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Biodiversity conservation requires decisions about how to efficiently allocate limited resources among management strategies, locations and species. In their latest research, Wilson et al. demonstrate how novel, high-resolution information on species distributions and risk of forest loss can be integrated to identify priority areas for the two groups at regional and landscape scales.
Each year, millions of migratory birds leave their breeding grounds in the temperate forests of Canada and the United States and migrate to the tropical forests of Latin America, where they will spend the next 6 to 9 months on the wintering grounds among a rich diversity of Neotropical resident species.
Many of these migratory birds are in decline, with recent studies showing that those declines are often steepest for species that migrate further, especially those going as far as South America. For several of these species, the declines appear linked to the loss of forest habitat on the overwintering grounds in places like the northern Andes.
One such species where this is known to be the case is the Canada Warbler (Cardellina canadensis), a migrant that breeds in boreal forests of Canada and the eastern United States, and overwinters in mid-elevation forests of Colombia, Venezuela and, northern Ecuador and Peru.
Conservation efforts for migratory species require international collaboration. In the case of migrants like the Canada Warbler, the recognition of threats on the overwintering grounds means that Canada and the United States are working with partners in Latin America to provide funding and effort to help their recovery.
Because these migratory species share habitat with numerous resident species, many of which are also threatened, these conservation efforts have the potential for a win-win solution for migrants and residents if we strategically allocate conservation effort and resources to areas that benefit both groups.
In our study, we used novel high resolution distribution maps from the eBird citizen science program for migrants and Terrestrial Area of Habitat maps for residents to identify regions and landscapes that can provide shared benefits for the two groups. We also integrated projections of forest loss to 2050 to identify those areas that are important to both groups and are most at risk of losing forest habitat in the coming decades.
We first identified a focal area for 23 migratory species that would be a high priority for conservation in Canada and the United States. The species richness for this group was greatest along a corridor from the Yucatan peninsula south to the northern Andes but also included southwest Mexico and Hispaniola.
Within this migrant focal area, threatened resident mammals, amphibians, reptiles and birds all showed hotspots of species richness along the west and east Andean slopes. Taxa-specific hotspots included montane areas of southern Mexico and central Guatemala for amphibians and reptiles, and the entire east slope of the Colombian East Andes for mammals.
Our prioritization identified several areas of high projected forest loss within areas of importance for migrants and residents including the Pacific dry forests of southwest Mexico, montane regions of northern Central America and the west Andean slope of Colombia and Ecuador.
Conservation funds are often limited and therefore by aligning multiple priorities we have an opportunity to leverage greater returns on conservation investments. Here we showed how novel high resolution information on species distributions can be used to do this for migratory and resident species.
Our approach could be extended to align this information with other initiatives such as forest restoration projects and sustainable development programs to benefit human well being and biodiversity.
Read the full paper Opportunities for the conservation of migratory birds to benefit threatened resident vertebrates in the Neotropics in Journal of Applied Ecology.