Frogs released into man-made habitats may not breed as successfully as their wild counterparts because of disease and lower food availability, according to a recently published PLOS ONE study. These findings could help improve strategies to counter the impact of land development, which often involves building new habitats for displaced species.
Previous research has found that captive-bred animals may not reproduce successfully when they are released into a created environment. Researchers from the University of Newcastle set out to investigate the factors that contribute to breeding problems in man-made habitats.
The scientists monitored endangered green and golden bell frogs, Litoria aurea, that had been released into created ponds on Kooragang Island in the New South Wales region of Australia. They compared the frogs’ health and habitat to those of populations in natural breeding ponds, as well as in natural ponds where breeding did not occur.
The researchers found that plant and invertebrate species were less diverse in the created habitat than in natural ponds, which may have reduced the nutritional resources available to the frogs for breeding. Also, compared to the wild populations, a greater proportion of frogs in the created habitat carried the chytrid fungus, a pathogen previously shown to reduce reproductive functioning in male L. aurea.
“This study shows the benefit of monitoring released populations alongside a wild population so that we can understand how to improve conservation efforts,” says Kaya Kloptoker, one of the lead researchers.
While the study was limited to one area in Australia, the researchers say their findings point to certain methods that could improve the likelihood of success when reintroducing frogs into any created habitat. Their recommendations include planting a diversity of plant species to attract invertebrates and following guidelines to reduce disease within the frog population.
Research Article: Klop-Toker K, Valdez J, Stockwell M, Fardell L, Clulow S, Clulow J, et al. (2016) We Made Your Bed, Why Won’t You Lie in It? Food Availability and Disease May Affect Reproductive Output of Reintroduced Frogs. PLoS ONE 11(7): e0159143. doi:10.1371/journal.pone.0159143
Image Credit: An endangered green and golden bell frog courtesy of Evan Pickett