Unveiling the factors shaping the distribution of widely distributed alpine vertebrates, using multi-scale ecological niche modelling of the bat Plecotus macrobullaris

Several alpine vertebrates share a distribution pattern that extends across the South-western Palearctic but is limited to the main mountain massifs. Although they are usually regarded as cold-adapted species, the range of many alpine vertebrates also includes relatively warm areas, suggesting that factors beyond climatic conditions may be driving their distribution. In this work we first recognize the species belonging to the mentioned biogeographic group and, based on the environmental niche analysis of Plecotus macrobullaris, we identify and characterize the environmental factors constraining their ranges. Distribution overlap analysis of 504 European vertebrates was done using the Sorensen Similarity Index, and we identified four birds and one mammal that share the distribution with P. macrobullaris. We generated 135 environmental niche models including different variable combinations and regularization values for P. macrobullaris at two different scales and resolutions. After selecting the best models, we observed that topographic variables outperformed climatic predictors, and the abruptness of the landscape showed better predictive ability than elevation. The best explanatory climatic variable was mean summer temperature, which showed that P. macrobullaris is able to cope with mean temperature ranges spanning up to 16 degrees C. The models showed that the distribution of P. macrobullaris is mainly shaped by topographic factors that provide rock-abundant and open-space habitats rather than climatic determinants, and that the species is not a cold-adapted, but rather a cold-tolerant eurithermic organism. P. macrobullaris shares its distribution pattern as well as several ecological features with five other alpine vertebrates, suggesting that the conclusions obtained from this study might be extensible to them. We concluded that rock-dwelling and open-space foraging vertebrates with broad temperature tolerance are the best candidates to show wide alpine distribution in the Western Palearctic.We wish to thank Orly Razgour for her insightful comments on the manuscript and for proofreading the text. The Basque Government (research projects IT385-07, IT301-10 and IT754-13, and predoctoral grants BFI-2010-190 and BFI-2009-252) and the University of the Basque Country UPV/EHU supported this work

Insight on how fishing bats discern prey and adjust their mechanic and sensorial features during the attack sequence

Several insectivorous bats have included fish in their diet, yet little is known about the processes underlying this trophic shift. We performed three field experiments with wild fishing bats to address how they manage to discern fish from insects and adapt their hunting technique to capture fish. We show that bats react only to targets protruding above the water and discern fish from insects based on prey disappearance patterns. Stationary fish trigger short and shallow dips and a terminal echolocation pattern with an important component of the narrowband and low frequency calls. When the fish disappears during the attack process, bats regulate their attack increasing the number of broadband and high frequency calls in the last phase of the echolocation as well as by lengthening and deepening their dips. These adjustments may allow bats to obtain more valuable sensorial information and to perform dips adjusted to the level of uncertainty on the location of the submerged prey. The observed ultrafast regulation may be essential for enabling fishing to become cost-effective in bats, and demonstrates the ability of bats to rapidly modify and synchronise their sensorial and motor features as a response to last minute stimulus variations.This study was part of the Ministerio de Ciencia e Innovacion (MICINN) project CGL2009-12393. The University of The Basque Country (UPV/EHU) (INF09/15) and the Basque Government (IT385-07 and IT301-10) funded this study and provided grant support to O.A. and A.A (BFI-2009-252, BFI-2010-190, Doktore berriak eta Ikertzaile doktoreak espezializatzeko kontratatzeko laguntzak)

What mechanism of niche segregation allows the coexistence of sympatric sibling rhinolophid bats?

Introduction: Our purpose was to assess how pairs of sibling horseshoe bats coexists when their morphology and echolocation are almost identical. We collected data on echolocation, wing morphology, diet, and habitat use of sympatric Rhinolophus mehelyi and R. euryale. We compared our results with literature data collected in allopatry with similar protocols and at the same time of the year (breeding season). Results:Echolocation frequencies recorded in sympatry for R. mehelyi (mean = 106.8 kHz) and R. euryale (105.1 kHz) were similar to those reported in allopatry (R. mehelyi 105–111 kHz; R. euryale 101–109 kHz). Wing parameters were larger in R. mehelyi than R. euryale for both sympatric and allopatric conditions. Moths constitute the bulk of the diet of both species in sympatry and allopatry, with minor variation in the amounts of other prey. There were no inter-specific differences in the use of foraging habitats in allopatry in terms of structural complexity, however we found inter-specific differences between sympatric populations: R. mehelyi foraged in less complex habitats. The subtle inter-specific differences in echolocation frequency seems to be unlikely to facilitate dietary niche partitioning; overall divergences observed in diet may be explained as a consequence of differential prey availability among foraging habitats. Inter-specific differences in the use of foraging habitats in sympatry seems to be the main dimension for niche partitioning between R. mehelyi and R. euryale, probably due to letter differences in wing morphology. Conclusions: Coexistence between sympatric sibling horseshoe bats is likely allowed by a displacement in spatial niche dimension, presumably due to the wing morphology of each species, and shifts the niche domains that minimise competition. Effective measures for conservation of sibling/similar horseshoe bats should guarantee structural diversity of foraging habitats

Bats Actively Track and Prey on Grape Pest Populations

There is growing evidence about the role of insectivorous bats against agricultural pests in various crops. Nevertheless, little research addressed the aggregational and functional responses of bat assemblages to changes in pest availability across a spatio-temporal scale. Therefore, we examined the activity and diet habits of different bat species using DNA metabarcoding by simultaneously monitoring the relative abundance of two major pests (the European grapevine moth, Lobesia botrana, and the leaf rolling tortrix, Sparganothis pilleriana) through the grape growing season, in a vineyard region of the Iberian Peninsula. During pest major irruptions, we found the highest bat activity levels and frequencies of grape pests in the diet of bats, although not all bat species contributed equally to pest suppression. Bats of different foraging guilds positively responded to pest abundances, indicating distinct bat species may synergistically play a role at suppressing agricultural pests at broad scales of the aerospace. For instance, narrow space foragers exploiting major irruptions in grape interior, edge space foragers hampering pest dispersion at local scale, and open space foragers preventing infestations of new grapevine patches at broader scales. Yet, our study exposed the current methodological constraints regarding pest dispersion dynamics, acoustic monitoring of bats? foraging activity or the unfeasibility of metabarcoding to reliably quantify prey abundance in bats diet, and thus further improvement in these issues is required in order to gain insight on the agroecological interactions between bats and pests.We are grateful to owners of the winery cellars (Artadi, Berarte, Laukote, Puelles, Ramon Saenz, Granja Nuestra Senora de Remelluri and R. Lopez de Heredia Vina Tondonia) for facilitating the collection of faeces and for allowing us to conduct the experiments on their estates. We also thank Ana Maria Diez Navajas and NEIKER-Tecnalia workers for sending data on the phenology of L. botrana during the sampling period. Special gratitude to Gonzalo Garcia Baquero for his valuable help with statistical analysis and Vanessa A. Mata for her priceless advice on modeling and the Sequencing and Genotyping Unit-Genomic Facilities-SGIker (UPV/EHU/ERDF, EU) for the technical support provided. This project was funded by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (CGL-2015-69069P), as well as the Government of the Basque Country (IT75413 and IT1163-19). The Basque Government granted UB (PRE_2019_2_0186)

Pest consumption in a vineyard system by the lesser horseshoe bat (Rhinolophus hipposideros)

Herbivorous arthropods cause immense damage in crop production annually. Consumption of these pests by insectivorous animals is of significant importance to counteract their adverse effects. Insectivorous bats are considered amongst the most voracious predators of arthropods, some of which are known crop pests. In vineyard-dominated Mediterranean agroecosystems, several crops are damaged by the attack of insect pests. In this study we aimed 1) to explore the diet and pest consumption of the lesser horseshoe bat Rhinolophus hipposideros and 2) analyse whether the composition of pest species in its diet changes throughout the season. We employed a dual-primer DNA metabarcoding analysis of DNA extracted from faeces collected in three bat colonies of a wine region in Southwestern Europe during the whole active period of most pest species. Overall, 395 arthropod prey species belonging to 11 orders were detected; lepidopterans and dipterans were the most diverse orders in terms of species. Altogether, 55 pest species were identified, 25 of which are known to cause significant agricultural damage and 8 are regarded as pests affecting grapevines. The composition of pest species in faeces changed significantly with the season, thus suggesting several periods should be sampled to assess the pest consumption by bats. As a whole, the results imply that R. hipposideros acts as a suppressor of a wide array of agricultural pests in Mediterranean agroecosystems. Therefore, management measures favouring the growth of R. hipposideros populations should be considered.The research was supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (CGL-2015-69069P), as well as the Government of the Basque Country (IT754-13). The Basque Government granted UB (PRE_2016_1_0139). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

New Adenovirus Groups in Western Palaearctic Bats

In the context of long-term screening for viruses on Western Palaearctic bats, we tested for the presence of adenovirus 1392 oropharyngeal swabs and 325 stool samples taken from 27 bat species. Adenoviruses were detected in 12 species of the Vespertilionidae and the Rhinolophidae families. Fifty positive respiratory and 26 positive stool samples were studied. Phylogenetic analyses of partial hexon protein and partial DNA-dependent DNA polymerase genes indicate that all these bat adenoviruses belong to the genus Mastadenovirus but without constituting a monophyletic cluster. According to genetic identities, the new groups are distinct to the previously described Bat mastadenovirus A and B species and contribute with potentially new members. Our data support that diversity of bat mastadenovirus is host-dependent and increase the knowledge of potentially pathogenic virus from bats. Due to the active role of bats as viral reservoirs, the characterization of these viruses is relevant for Public Health.This project was financially supported by an agreement between the Public Health Department of the Spanish Ministry of Health and the Instituto de Salud Carlos III for the development of "Rabies Surveillance in Spain" and by projects SAF 2006-12784-C02-01, SAF 2006-12784-C02-02, SAF 2009-09172 and SAF2013-47194-P of the General Research Programme of the Spanish Ministry of Science and Education

The Foraging Ecology of the Mountain Long-Eared Bat Plecotus macrobullaris Revealed with DNA Mini-Barcodes

10 p.Molecular analysis of diet overcomes the considerable limitations of traditional techniques for identifying prey remains in bat faeces. We collected faeces from individual Mountain Long-eared Bats Plecotus macrobullaris trapped using mist nets during the summers of 2009 and 2010 in the Pyrenees. We analysed their diet using DNA mini-barcodes to identify prey species. In addition, we inferred some basic features of the bat's foraging ecology that had not yet been addressed. P. macrobullaris fed almost exclusively on moths (97.8%). As prey we detected one dipteran genus (Tipulidae) and 29 moth taxa: 28 were identified at species level (23 Noctuidae, 1 Crambidae, 1 Geometridae, 1 Pyralidae, 1 Sphingidae, 1 Tortricidae), and one at genus level (Rhyacia sp., Noctuidae). Known ecological information about the prey species allowed us to determine that bats had foraged at elevations between 1,500 and 2,500 m amsl (above mean sea level), mostly in subalpine meadows, followed by other open habitats such as orophilous grasslands and alpine meadows. No forest prey species were identified in the diet. As 96.4% of identified prey species were tympanate moths and no evidence of gleaning behaviour was revealed, we suggest P. macrobullaris probably forages by aerial hawking using faint echolocation pulses to avoid detection by hearing moths. As we could identify 87.8% of the analysed sequences (64.1% of the MOTUs, Molecular Operational Taxonomic Units) at species level, we conclude that DNA mini-barcodes are a very useful tool to analyse the diet of moth-specialist bats.This work was supported by Hezkuntza, Unibertsitate eta Ikerketa Saila, Eusko Jaurlaritza – The Basque Government (research projects GIC07/05 and IT301-10, and grants BFI-2010-190, and BFI-2009-252) and the University of The Basque Country, Euskal Herriko Uniberstiatatea UPV/EHU. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Bats from different foraging guilds prey upon the pine processionary moth

Outbreaks of the processionary moth Thaumetopoea pityocampa (Denis & Schiffer-mailer, 1775), a forest pest from the Palearctic, are thought to induce a behavioral response of bats, but up to now the moth has been seldom identified as bats' prey. Studies on bat diets suggest moths with cyclical outbreaks attract a wide array of bat species from different foraging guilds. We test whether bats feed upon T. pityocampa in the Iberian Peninsula irrespective of the predator's ecological and morphological features. We found that seven out of ten bat species belonging to different foraging guilds contained T. pityocampa DNA in their faeces and no difference was found in the foraging frequency among foraging guilds. A different size of the typical prey or the lack of fondness for moths can explain the absence of the pest in some bat species. Moreover, the intraspecific foraging frequency of T. pityocampa also changed with the sampling site likely representing differential availability of the moth. Lack of information on flight and dispersal behavior or the tympanate nature of the adult moth complicates understanding how different foraging guilds of bats prey upon the same prey. Our data suggests that T. pityocampa is a remarkable food source for many thousands of individual bats in the study area and we anticipate that more bats besides the species studied here are consuming this moth.The Basque Government (project IT754-13) and the Spanish Government (MINECO project CGL2012-38610) funded this work. Logistical support was provided by the Laboratorio de Ecologia Molecular, Estacion Biologica de Donana, CSIC (LEM-EBD). The Government of the Basque Country (Grant BFI-2011-245) and the University of the Basque Country, UPV/EHU provided grant support to AAE. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Novel Papillomaviruses in Free-Ranging Iberian Bats: No Virus-Host Co-evolution, No Strict Host Specificity, and Hints for Recombination

Papillomaviruses (PVs) are widespread pathogens. However, the extent of PV infections in bats remains largely unknown. This work represents the first comprehensive study of PVs in Iberian bats. We identified four novel PVs in the mucosa of free-ranging Eptesicus serotinus (EserPV1, EserPV2, and EserPV3) and Rhinolophus ferrumequinum (RferPV1) individuals and analyzed their phylogenetic relationships within the viral family. We further assessed their prevalence in different populations of E. serotinus and its close relative E. isabellinus. Although it is frequent to read that PVs co-evolve with their host, that PVs are highly species-specific, and that PVs do not usually recombine, our results suggest otherwise. First, strict virus-host co-evolution is rejected by the existence of five, distantly related bat PV lineages and by the lack of congruence between bats and bat PVs phylogenies. Second, the ability of EserPV2 and EserPV3 to infect two different bat species (E. serotinus and E. isabellinus) argues against strict host specificity. Finally, the description of a second noncoding region in the RferPV1 genome reinforces the view of an increased susceptibility to recombination in the E2-L2 genomic region. These findings prompt the question of whether the prevailing paradigms regarding PVs evolution should be reconsidered.Supported by the disappeared Spanish Ministry for Science and Innovation (MICINN) grants CGL2010-16713, SAF2006-12784-CO2, and SAF2009-09172