Ecological niche modelling of two cryptic bat species calls for a reassessment of their conservation status

• Published in: The Journal of applied ecology Vol. 44; no. 6; pp. 1188 - 1199
• Main Authors: SATTLER, THOMAS, BONTADINA, FABIO, HIRZEL, ALEXANDRE H, ARLETTAZ, RAPHAËL
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.12.2007; Blackwell Science Ltd; Blackwell Publishing Ltd; Blackwell Science
• Subjects: Animal communication; Animal, plant and microbial ecology; Applied ecology; Bats; Biological and medical sciences; Biological taxonomies; Boyce Index; Chiroptera; Conservation; Conservation biology; Conservation status; Cryptic species; Discriminant analysis; Ecological modeling; Ecological Niche Factor Analysis (ENFA); Ecological niches; Factor analysis; Fundamental and applied biological sciences. Psychology; General aspects; General aspects. Techniques; Genetics; Genotype & phenotype; Habitat conservation; habitat suitability; Habitats; Human settlements; Mammalian Populations: Demography, Resources and Impacts; Methods and techniques (sampling, tagging, trapping, modelling...); niche differentiation; Niches; P. pygmaeus; Pipistrellus; Pipistrellus pipistrellus; Pipistrellus pygmaeus; population ecology; Rare species; red list status; riparian forests; Riverine habitats; Species; Switzerland; Taxa; threatened species; wildlife habitats; wildlife management; Woodlands; Switzerland; Europe; Status; niche differentiation; Boyce Index; Endangered species; Ecological Niche Factor Analysis (ENFA); Conservation; Environmental factor; Habitat suitability; red list status; Modeling; P. pygmaeus; Switzerland; Vertebrata; Mammalia; IUCN Red List; Ecological niche; Cryptic species; Pipistrellus pipistrellus; Differentiation; Chiroptera
• ISSN: 0021-8901; 1365-2664
• DOI: 10.1111/j.1365-2664.2007.01328.x

1. It is difficult to establish conservation priorities for cryptic species when their ecological requirements are confounded by problems with species identification. In some cases, such as Chiroptera, cryptic taxa may actually consist of both widespread, abundant species and localized, rare species. Discrimination between these species may be facilitated by phenotypic, species-specific traits such as echolocation calls. Echolocation studies supported by genetic data have revealed that one of the most abundant bat species in Europe actually consists of two cryptic species: Pipistrellus pipistrellus and P. pygmaeus. 2. We recorded echolocation calls from both species along road transects in Switzerland to study their distribution and abundance. Using Ecological Niche Factor Analysis and discriminant analysis, we characterized species-specific habitat requirements, built habitat suitability maps and examined interspecific differences in niche parameters. 3. The presence of P. pygmaeus was associated with landscape matrices comprising large rivers and lakes, human settlements and open woodland. P. pipistrellus utilized similar habitat matrices but was far more tolerant to deviations from its optimal habitat. P. pygmaeus occupied a much narrower ecological niche, encompassed mainly within that of its sister taxon. 4. Synthesis and applications. P. pipistrellus is ranked as 'not threatened' in Switzerland. The results from this study indicate an abundance approximately 30 times higher than that of P. pygmaeus. In contrast, P. pygmaeus is distributed patchily and occurs at comparatively low densities. We recommend reclassification of P. pygmaeus as 'rare and potentially threatened'. Conservation of P. pygmaeus should focus on the management of riparian woodland in areas with a high probability of occurrence. This study emphasizes the need to recognize the potential existence of cryptic taxa so that effective conservation management of rare species can be put into place before they are seriously endangered.