Duke researchers have developed a new way to help endangered species isolated or restricted by deforestation in their natural habitats.

The critically endangered San Martin titi monkey, for instance, inhabits an area no bigger than the size of Connecticut in the lowland forests of north central Peru. This is a problem for a species that travels an average of 663 meters a day for food, socialization and to avoid predators.

Over the last 25 years, an estimated 80 of the monkey's population has decreased due to widespread farming, logging, mining and urbanization. With human activity encroaching on the monkey's habitat, there are not enough well-connected tree canopies for the highly mobile animals to travel as much as they would like.

Using advanced habitat-mapping software and satellite imagery, researchers from Duke University were able to better predict the movements of endangered species in remote or inaccessible regions, so that conservationists can better target their efforts.

"Using these tools, we were able to work with a local conservation organization to rapidly pinpoint areas where reforestation and conservation have the best chance of success," explained Danica Schaffer-Smith, lead author of the study and a doctoral student at Duke's Nicholas School of the Environment. "Comprehensive on-the-ground assessments would have taken much more time and been cost-prohibitive given the inaccessibility of much of the terrain and the fragmented distribution and rare nature of this species."

Known as the Geospatial Habitat Assessment Toolkit (GeoHAT), the Duke team used its technique to identify the 10 percent of remaining forest in the monkeys' range that presents the best opportunity for conservation.

The San Martin titi monkey was recently added to the International Union for Conservation of Nature's list of the 25 most endangered primates in the world. Weighing no more than three pounds, the monkeys mate for life and produce only one offspring a year.

"The images and software, combined with Proyecto Mono Tocón's detailed knowledge of the titi monkey's behaviors and habitats, allowed us to assess which patches and corridors of the remaining forest were the most critical to protect," study researcher Jennifer Swenson added.

Overall, the team found that at least 34 percent of lowland forests in the monkey's northern range, Peru's Alto Mayo Valley, have been lost.

What's worse is nearly 95 percent of remaining habitat fragments are likely too small or poorly connected to support viable populations, and less than 8 percent of all remaining suitable habitats lie within protected areas.

Of the remaining viable forest in the northern range, the team identified a 10-kilometer corridor between Peru's Morro de Calzada and Almendra conservation areas as a high priority for protection.

"For many rare species threatened by active habitat loss, the clock is literally ticking," Schaffer-Smith said. "Software tools like GeoHAT - or similar software such as CircuitScape - can spell the difference between acting in time to save them or waiting till it's too late."

Their findings were recently published in the journal Environmental Conservation.