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

Abstract

Summary1. 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.

Bosque Mesófilo De Montaña Y Escenarios De Cambio Climático: Una Evaluación en Hidalgo, México

“…En la Figura 2 se muestra la distribución espacial de los hábitats para cada especie en condiciones base o actuales, así como aquellas al considerar cambio climático y, en el Cuadro 3 se presentan las superficies ocupadas para las condiciones actuales. Los mapas representan la idoneidad del hábitat e indican cómo la combinación de las variables ambientales satisfacen los requerimientos de dichas especies (Sattler, Bontadina, Hirzel, & Arlettaz, 2007 ambientales disponibles en la zona de estudio, siendo el valor encontrado el máximo posible para una especie. Por su parte, la especialización mide qué tan amplio es el nicho ecológico de una especie, refiriéndose a que tan restringida se encuentra dentro de la región estudiada.…”

“…Al aplicar cambio climáti-co se observó una tendencia irregular y extremista, difícil de corroborar únicamente con datos estadísticos. Los dos modelos sugieren que el hábitat óptimo aumentará a 13.5 % variables satisfies the requirements of these species (Sattler, Bontadina, Hirzel, & Arlettaz, 2007). It should be noted that it was decided to group habitat into four classes of equal representativeness: unsuitable (0-25), marginal (26-50), suitable (51-75) and optimal (76-100) habitat.…”

Habitat preferences of bats in anthropogenically altered, mosaic landscapes of northern Poland

“…They indicated rather more eurytopic habits in P. pipistrellus and some specialization in P. pygmaeus, but the most preferred habitats are almost the same. In Switzerland, stenotopic P. pygmaeus uses a much narrower habitat niche than eurytopic P. pipistrellus but completely overlaps with the niche of the latter (Sattler et al 2007). On the contrary, a principal component analysis, performed by Nichols and Racey (2006) on the proportion of time spent in each habitat, showed a distinct clustering of radiotracked individuals of the two species, with no overlap, providing clear evidence for habitat partitioning.…”

“…Moreover, regional differences in species' habitat use might be modified by the presence or absence of potential competitors and the resulting differences in patterns of resource partitioning. Several studies focused on the habitat use of two sibling bat species, Pipistrellus pipistrellus and P. pygmaeus in Western Europe (Vaughan et al 1997a;Russ and Montgomery 2002;Davidson-Watts et al 2006;Nichols and Racey 2006;Sattler et al 2007). However, they rarely included the third member of the Pipistrellus genus, Pipistrellus nathusii, i.e.…”

Integrating population size analysis into habitat suitability assessment: implications for giant panda conservation in the Minshan Mountains, China

“…With the advances in computer tools such as the geographic information system (GIS), remote sensing (RS), and statistical modeling techniques, predictions of species geographic distribution based on environmental conditions have gained much attention in ecology, and have been widely applied to habitat prediction (Li et al 1997;Hirzel et al 2002;Reutter et al 2003) and habitat evaluation (Liu et al 1999(Liu et al , 2001Hirzel et al 2004;Xu et al 2006a;Sattler et al 2007;Wang et al 2008). Among some commonly employed statistical techniques, multiple regression models (e.g., generalized linear model [GLM] and generalized addictive model [GAM]), which require both ''presence'' and ''absence'' data of species for model calculation, showed robust performances for interpreting species distributions (Hirzel et al 2001(Hirzel et al , 2002.…”