Effects of human‐modified landscapes on taxonomic, functional and phylogenetic dimensions of bat biodiversity

Abstract

Aim To identify characteristics of a human-modified landscape that promote taxonomic (TD), functional (FD) and phylogenetic (PD) dimensions of bat biodiversity.Location Caribbean lowlands of northeastern Costa Rica.Methods During the dry and wet seasons, we quantified TD (Simpson's diversity), as well as FD and PD (Rao's quadratic entropy) of phyllostomid bat assemblages at 15 sites that represented a forest loss and fragmentation gradient. FD was estimated separately for each of seven functional components that reflect particular niche axes (e.g. diet, foraging strategy) and for all functional components combined (FD all ). PD was based on relatedness of species derived from a supertree. We identified the best explanatory landscape characteristics of each dimension using hierarchical partitioning.Results Landscape effects were dimension and season specific. During the dry season, TD and PD increased with increasing proportions of pasture or size of forest patches, whereas FD all decreased with increasing size of forest patches. During the wet season, TD increased with increasing forest patch size, whereas FD all and PD increased with increasing compactness of forest patches and decreasing proximity. Decomposition of FD into separate functional components revealed different landscape effects on ecological aspects of assemblages.Main conclusions One dimension of biodiversity was not a good surrogate for another. Rather, decomposition of biodiversity into different dimensions and functional components facilitated identification of the aspects of assemblages that are most affected by forest conversion and fragmentation. Areas with intermediate amounts of forest and pasture during the dry season harboured highest diversity from taxonomic, functional and phylogenetic perspectives. During the wet season, areas with large, compact forest patches promoted the dimensions of biodiversity. Placement of areas with even amounts of forest and pasture adjacent to large, compact forest patches (e.g. reserves) may maintain high biodiversity of bats and the ecosystem functions that they provide throughout the year.

PRELIMINARY STUDY ON Eidolon helvum (Kerr, 1792) POPULATION DYNAMIC IN CÔTE D’IVOIRE, WEST AFRICA

“…Then, size increasing as regards strawcolored fruit bats population from August to November seems to be linked to the diversity and the abundance of food resource (Cosson et al, 1996;Richter & Cumming, 2006;Durant et al, 2013;Cisneros et al, 2015). Afterwards, food limitation would ensure the upholding of straw-colored fruit bats numbers from November to February (Figure 2).…”

“…Finally, observed reduction as regards straw-colored bats population size for March seems to be dictated and/or associated to the fall of food resource availability (Figures 2). From this on, the individual producers would migrate from March to July, to profit from peaks of food abundance in order to satisfy their high need in energy (Fleming & Eby, 2003;Richter & Cumming, 2006;Durant et al, 2013;Kingston, 2013;Cisneros et al, 2015).…”

“…That could be explained by the fact that the diversity and abundance peaks of food occur in this season, reducing the latter (food) competition. That manna charm the straw-colored fruit bats, since that fruits are produced to attract the frugivorous (Gautier-Hion, 1990;Richter & Cumming, 2006;Fahr & Kalko, 2011;Hagen & Saho, 2011;Cisneros et al, 2015).…”

Ressources Alimentaires De Eidolon helvum (Kerr, 1792), Espece Proche De La Menace (Abidjan, Côte d’Ivoire)

“…La grande consommation des espèces du genre Ficus serait liée à leur abondance et à leur bonne valeur calorifique. En effet, ces ressources alimentaires sont très abondantes, bien distribuées et facilement repérables, d'où la réduction du temps de recherche et de la dépense énergétique associée ainsi que de la compétition alimentaire (Hagen et Sabo, 2011 ;Cisneros et al, 2015). Par ailleurs, ces fruits riches en protéines couvriraient leurs besoins énergétiques journaliers (Thomas, 1982(Thomas, , 1984(Thomas, , 1988Durant et al, 2013 ;Cisneros et al, 2015).…”

“…Ces études permettent également d'apprécier les services écosystémiques joués par ces animaux dans le fonctionnement des écosystèmes (Kunz et al, 2011 ;Meyer et al, 2015 ;Moratelli et Calisher, 2015). En outre, le comportement migratoire et la taille des populations de chauves-souris frugivores, sont liés à la distribution spatio-temporelle des ressources alimentaires (Klingbeil et Willing, 2010 ;Cisneros et al, 2015). Les chauves-souris frugivores consomment plusieurs espèces de plantes dont certaines sont d'importance économique (Kunz et al, 2011 ;Ghanem et Voigt, 2012 ;Mass et al, 2013 ;Herkt et al, 2016 ;Williams-Guillén et al, 2016).…”