Seasonal variation and host sex affect bat–bat fly interaction networks in the Amazonian savannahs

Bats are the second-most diverse group of mammals in the world,and bat flies are their main parasites.However,significant knowledge gaps remain regarding these antagonistic interactions,especially since diverse factors such as seasonality and host sex can affect their network structures.Here,we explore the influence of such factors by comparing species richness and composition of bat flies on host bats,as well as specialization and modularity of bat–bat fly interaction networks between seasons and adult host sexes.We captured bats and collected their ectoparasitic flies at 10 sampling sites in the savannahs of AmapáState,northeastern region of the Brazilian Amazon.Despite female bats being more parasitized and recording greater bat fly species richness in the wet season,neither relationship was statistically significant.The pooled network could be divided into 15 compartments with 54 links,and all subnetworks comprised>12 compartments.The total number of links ranged from 27 to 48(for the dry and wet seasons,respectively),and female and male subnetworks had 44 and 41 links,respectively.Connectance values were very low for the pooled network and for all subnetworks.Our results revealed higher bat fly species richness and abundance in the wet season,whereas specialization and modularity were higher in the dry season.Moreover,the subnetwork for female bats displayed higher specialization and modularity than the male subnetwork.Therefore,both seasonality and host sex contribute in different ways to bat–bat fly network structure.Future studies should consider these factors when evaluating bat–bat fly interaction networks.

Modularity and specialization in bat-fly interaction networks are remarkably consistent across patches within urbanized landscapes and spatial scales

Patterns of specialization and the structure of interactions between bats and ectoparasitic flies have been studied mostly on non-urban environments and at local scales.Thus,how anthropogenic disturbances influence species interactions and network structure in this system remain poorly understood.Here,we investigated patterns of interaction between Phyllostomidae bats and ectoparasitic Streblidae flies,and variations in network specialization and structure across Cerrado patches within urbanized landscapes in Brazil and between local and regional scales.We found high similarity in the richness and composition of bat and fly species across communities,associated with low turnover of interactions between networks.The high specialization of bat-streblid interactions resulted in little connected and modular networks,with the emergence of modules containing subsets of species that interact exclusively or primarily with each other.Such similarities in species and interaction composition and network structure across communities and scales suggest that bat-fly interactions within Cerrado patches are little affected by the degree of human modification in the surrounding matrix.This remarkable consistency is likely promoted by specific behaviors,the tolerance of Phyllostomidae bats to surrounding urbanized landscapes as well as by the specificity of the streblid-bat interactions shaped over evolutionary time.