Landscape genomics of dispersal corridors in NYC

While most people think of corridors as linking patches of pristine habitat, they also play a part in shaping urban landscape connectivity.  Although urban ecosystems typically don’t include large patches of undisturbed or old growth habitat, they do contain a wide variety of green habitats that can support wildlife, from large urban parks (think Central Park in Manhattan) down to the median strips of roadways that contain grass, planted trees and other vegetation.  With increasing urbanization occurring worldwide, understanding how species adapt to and use urban environments is a crucial step in being able to maintain species diversity via individual movement and dispersal between populations.

In his latest paper, Jason Munshi-South looks at connectivity of white-footed mice (Peromyscus leucopus) in one of the largest urban environments in the world – New York City.  He sampled DNA from 15 populations structured in two clusters throughout the city, and tested the prediction that migration rates between urban white-footed mouse populations are associated with landscape connectivity models based on the amount and configuration of tree canopy cover.  He then used the estimated migration rates and connectivity maps to identify the most likely corridors of movement through the urban core for the species.  His results show that tree canopy cover is consistently successful in explaining variation in gene flow, and that even unintended corridors such as bicycle paths, roadsides and cemeteries can potentially provide enough habitat to maintain limited connectivity between white-footed mouse populations. These results have implications for understanding how urbanization may affect population connectivity and individual dispersal, and how urban planning and reforestation efforts might be tailored to account for urban ecosystem processes.