Tailoring Wildlife Corridors for Maximum Effectiveness
Environments around the world are becoming increasingly fragmented, with human development being the leading cause. In response, wildlife advocates are striving to either retain precious links between increasingly sparse patches of habitat, or are trying to re-create links where they have been broken. Many studies have confirmed just how important “habitat connectivity” is to maintaining healthy species and ecosystems. To that end, wildlife habitat corridors have become a vital way that species can maintain “their fundamental niches in geographic space as climate changes.” Unfortunately, most habitat corridor plans focus on a single species.
This study was undertaken with the recognition that developing habitat corridors “may more effectively protect regional biodiversity if they are developed to support the movement of multiple species simultaneously, rather than movement of one single species.” The researchers note that this is different from the more common approach of protecting patches or corridors that support one or several wide-ranging, large-bodied species and “assuming that conservation of these umbrella species will also facilitate conservation of smaller or less mobile organisms.” The researchers here stress that, although their idea may make better sense intuitively, it hasn’t been tested empirically. To evaluate the approach, they looked at connectivity scenarios for a range of threatened mammals in Borneo.
What they found was that the “all-species-combined corridor scenario generally led to larger increases in total landscape cost for each species than the single-species-optimized scenarios. However, the multispecies scenarios that grouped ecologically similar species were generally more effective.” In other words, though the multi-species approach costs more, it works better. The authors suggest that the umbrella species approach generally fails to conserve community connectivity for threatened species; they also note that the multi-species scenarios are more effective when they focus on a combinations of “ecologically similar species (e.g., carnivores or herbivores), rather than a collection of taxa with very different habitats.” Overall, the study stresses that, in any case possible, there should be a focus on species that are sensitive to human disturbance, and the study may suggest interesting opportunities for wildlife advocates to also group species together in their advocacy and habitat protection efforts.