Identifying best conservation areas for an endangered and endemic raptor in Cuba through abundance spatial modeling: A niche-centroid distances approach

Abstract

Several rare species of the island of Cuba are facing local extinction risk and threats. The endemic Cuban Black-Hawk ( Buteogallus gundlachii ) is threatened by habitat loss as ~50% of its original habitat has been fragmented by tourism activity. Despite this situation, little information on its population size is available and its abundance patterns in relation to environmental variables are largely unknown. Such information is urgently needed to understand its geographic distribution and population abundance trends. We modeled the spatial patterns of abundance of the hawk in central Cuba and then assessed the effectiveness of protected areas for conserving this species. We fitted an ecological niche model to occurrence data of the Cuban Black-Hawk. The centroid of the predicted distribution range was calculated in ecological space and the multidimensional Euclidean distance to the niche centroid (DNC) was estimated. A function describing the relationship between the species abundance and the distance to the niche centroid was used to construct a map depicting the distribution of the Cuban Black-Hawk abundance. The potential distribution range of the raptor encompasses a 703.4 km 2 area and represents 12.5% of the total study area. Results show an inverse relationship between DNC and abundance (R 2 = 0.37): the sites closer to the centroid of the ecological niche of the species contain more individuals. The model shows that a shorter distance to the coastline and larger distance to urban zones increase the probability of occurrence of the hawk. Based on these results, we estimated that only 24% of the area where a high hawk abundance is expected is currently included in protected areas. We suggest establishing priority survey sites and strengthening protection of the Cuban Black-Hawk in the zones we identified as most valuable in the archipelago. This approach could also be used for other rare and endemic species in other ecosystems.