by Marina de Castro Deus
The great increase of species extinctions due to human-related habitat destruction, pollution, overharvesting and global climate change, often force conservationists to choose which species to help. Usually species that are poor dispersers, with few populations, low reproduction rates, or very specific environmental requirements, reproductive site or feeding habits, are most vulnerable to extinction. Endemic species, limited to a specific habitat, fall under the list of vulnerable species, small changes in their niche, including temperature, can be enough to destabilize the population to the point of extinction.
Jackson et al. (2015) conducted a study on the Vancouver Island White-tailed Ptarmigan (Lagopus leucura saxatilis), an endemic bird from North America’s coastal mountains considered to be threatened by the effect of climate fluctuations. The research consisted in analyzing data from scientific research, field surveys and used a Random Forest Model in order to predict the possible habitats that this alpine bird can occupy in a future global warming scenario. They predicted the decline of natural habitat for the years 2020s, 2050s and 2080s under two greenhouse gas scenarios, one with low and one with high greenhouse gas levels in the atmosphere. They analyzed future climate changes in mean summer temperature, mean summer precipitation and precipitation as snow to determine the probability of presence-absence of the bird. The results obtained showed that available habitat patches became smaller and increasingly fragmented. In both low and high greenhouse gas future scenarios the available habitat decreased greatly. In the 2080s the prediction for habitat decrease is 56% for low greenhouse gases scenario and 74% for high greenhouse gas scenario. The authors claim that not only these results will cause the bird to be confined to mountaintops, but also habitat quality is likely to decrease owing to possible thermal stress, increase competition and habitat confinement of other similar alpine species.
Jackson M.M., Gergel S.E., Martin K., 2015 Effects of Climate Change on Habitat Availability and Configuration for an Endemic Coastal Alpine Bird. PLoS ONE, e0142110, doi 10.1371/journal.pone.0142110