Agave distribution and floral display influence foraging rates of an endangered pollinating bat and implications for conservation.

Wildlife conservation involves making management decisions with incomplete knowledge of ecological relationships. Efforts to augment foraging resources for the endangered Mexican long-nosed bat (Leptonycteris nivalis) are progressing despite limited knowledge about the species' foraging behavior and requirements. This study aimed to understand L. nivalis responses to floral resource availability, focusing on individual agave- and local-scale characteristics influencing visitation rates to flowering agaves. We observed bat visitation at 62 flowering agaves around two roosts in northeast Mexico on 46 nights in the summers of 2017 and 2018. We found visitation rate had positive relationships with two agave-scale characteristics: the number of umbels with open flowers and the lower vertical position on the stalk of those umbels (i.e., earlier phenological stages of flowering). However, these factors exhibited strong negative interaction: with few umbels with open flowers, the position of flowering umbels had little effect on visitation rate, but when umbels with open flowers were abundant, visitation rate was more strongly related to the lower flowering umbel position. We also found relationships between visitation rate and two local-scale characteristics: negative for the density of flowering conspecifics within 30 m of the focal agave and positive for the density of dead standing agave stalks within 30 m. Our findings suggest opportunities to augment foraging resources for L. nivalis in ways that are consistent with their foraging behavior, including: increasing the supply of simultaneously blooming flowers by planting agave species that tend to have more umbels with simultaneously open flowers; planting multiple species of agaves with different flowering times to increase the availability of agaves with open flowers on lower-positioned umbels throughout the period when bats are present in the region; planting agaves in clusters; and keeping dead standing agave stalks on the landscape. Our study points to useful management strategies that can be implemented and monitored as part of an adaptive management approach to aid in conservation efforts.

Guild Vertical Stratification and Drivers of Bat Foraging in a Semi-Arid Tropical Region, Kenya.

Africa faces significant challenges in reconciling economic and social development while preserving its natural resources. Little is known about the diverse bat community on the continent, particularly in drier ecosystems. A better understanding of the bat community will help improve and inform the management of these ecosystems. Our study aimed to provide detailed information on the main drivers of bat richness and activity at three different heights above the ground in a semi-arid region of Kenya. We assessed how bat activity varied with space and height using acoustic sampling and complementary methods. We sampled 48 sites at ground level and two sites on meteorological masts at 20 m and 35 m above the ground. We recorded more than 20 bat species, including one species of concern for conservation. Our models showed that the use of space varies with bat guild, creating trade-offs in the variables that affect their activity. Low-flying bat species are mostly associated with habitat variables, whereas high-flying species are more dependent on weather conditions. Our study highlights the richness of bat assemblages in semi-arid environments and emphasizes the need for management measures to protect bat diversity in the face of habitat degradation caused by climate change, land management, and development projects.

Habitat suitability mapping using logistic regression analysis of long-term bioacoustic bat survey dataset in the Cassadaga Creek watershed (USA).

Bat species show global ecological importance, yet their numbers are declining worldwide. Understanding bat-habitat interactions is crucial in terms of developing effective conservation plans. In an effort to model bat habitat suitability in the Cassadaga Creek watershed, long-term bioacoustic bat data (spanning 2009-2020) was compiled, georeferenced and statistically analyzed using logistic regression techniques. In total, 1600 bat occurrence records from five species of bat (559 Eptesicus fuscus, 560 Lasionycteris noctivagans, 143 Lasiurus borealis, 260 Lasiurus cinereus, and 78 Myotis lucifugus) were paired with pseudo-absence points to study the relationship between bat calling behavior and land cover. All bats but Myotis lucifugus had a statistically significant relationship with forested land cover, and all bats had negative interactions with agricultural habitats. Geospatial data was coupled with the statistical output to create maps of habitat suitability and echolocation calling density. This work provides a model that can be employed worldwide to evaluate bat habitat needs or patterns in echolocation behavior. Future research will incorporate a more recently collected dataset that is of greater geographic diversity with a larger number of environmental variables in the species distribution model.

Genetic diversity, structure, and effective population size of an endangered, endemic hoary bat, 'ope'ape'a, across the Hawaiian Islands.

Island bat species are disproportionately at risk of extinction, and Hawai'i's only native terrestrial land mammal, the Hawaiian hoary bat (Lasiurus semotus) locally known as 'ope'ape'a, is no exception. To effectively manage this bat species with an archipelago-wide distribution, it is important to determine the population size on each island and connectivity between islands. We used 18 nuclear microsatellite loci and one mitochondrial gene from 339 individuals collected from 1988-2020 to evaluate genetic diversity, population structure and estimate effective population size on the Islands of Hawai'i, Maui, O'ahu, and Kaua'i. Genetic differentiation occurred between Hawai'i and Maui, both of which were differentiated from O'ahu and Kaua'i. The population on Maui presents the greatest per-island genetic diversity, consistent with their hypothesized status as the original founding population. A signature of isolation by distance was detected between islands, with contemporary migration analyses indicating limited gene flow in recent generations, and male-biased sex dispersal within Maui. Historical and long-term estimates of genetic effective population sizes were generally larger than contemporary estimates, although estimates of contemporary genetic effective population size lacked upper bounds in confidence intervals for Hawai'i and Kaua'i. Contemporary genetic effective population sizes were smaller on O'ahu and Maui. We also detected evidence of past bottlenecks on all islands with the exception of Hawai'i. Our study provides population-level estimates for the genetic diversity and geographic structure of 'ope'ape'a, that could be used by agencies tasked with wildlife conservation in Hawai'i.

Metabarcoding dietary analysis in the insectivorous bat Nyctalusleisleri and implications for conservation.

In this study, we aim to uncover diet preferences for the insectivorous bat Nyctalusleisleri (Leisler's bat, the lesser noctule) and to provide recommendations for conservation of the species, based on the analysis of prey source habitats. Using a novel guano trap, we sampled bat faeces at selected roosts in a forest in Germany and tested two mitochondrial markers (COI and 16S) and three primer pairs for the metabarcoding of bat faecal pellets. We found a total of 17 arthropod prey orders comprising 358 species in N.leisleri guano. The most diverse orders were Lepidoptera (126 species), Diptera (86 species) and Coleoptera (48 species), followed by Hemiptera (28 species), Trichoptera (16 species), Neuroptera (15 species) and Ephemeroptera (10 species), with Lepidoptera species dominating in spring and Diptera in summer. Based on the ecological requirements of the most abundant arthropod species found in the bat guano, we propose some recommendations for the conservation of N.leisleri that are relevant for other insectivorous bat species.

Analysis of Genomic Sequence Data Reveals the Origin and Evolutionary Separation of Hawaiian Hoary Bat Populations.

We examine the genetic history and population status of Hawaiian hoary bats (Lasiurus semotus), the most isolated bats on Earth, and their relationship to northern hoary bats (Lasiurus cinereus), through whole-genome analysis of single-nucleotide polymorphisms mapped to a de novo-assembled reference genome. Profiles of genomic diversity and divergence indicate that Hawaiian hoary bats are distinct from northern hoary bats, and form a monophyletic group, indicating a single ancestral colonization event 1.34 Ma, followed by substantial divergence between islands beginning 0.51 Ma. Phylogenetic analysis indicates Maui is central to the radiation across the archipelago, with the southward expansion to Hawai'i and westward to O'ahu and Kaua'i. Because this endangered species is of conservation concern, a clearer understanding of the population genetic structure of this bat in the Hawaiian Islands is of timely importance.

The taxonomic reassessment of a reportedly extinct bat, Pipistrellus sturdeei (Chiroptera: Vespertilionidae).

Insular bats are among the most vulnerable mammal species whose survival are threatened by several human-mediated factors, frequently paralleled by the paucity of information and lack of adequate management plans. Pipistrellus sturdeei is known only by the holotype collected from the remote Bonin Islands more than a hundred years ago and is declared to be extinct by the Japanese authorities. However, its taxonomic validity and collection locality is regarded ambiguous by some scholars. Here we report details about its collection circumstances and provide evidence that it morphologically differs from all other pipistrelles. We would like to raise attention on the species and the importance of a detailed study on its possible survival.

From a bat's perspective, protected riparian areas should be wider than defined by Brazilian laws.

Riparian areas around streams are those areas in which biological communites are directly influenced by the stream. The size of protected riparian areas and their conservation has become a controversial topic after changes implemented in the Brazilian Forest Code (BFC): a set of laws that regulates the size of Permanent Protection Areas (PPA). Here, we investigate the influence of distance from water bodies on bat-species and guild composition in a lowland Amazonian rainforest. Our hypotheses were that bat assemblages would change depending on the distance to the water body and that the abundance of herbivorous bats (frugivorous and nectarivorous) would be greater in areas close to water. Bats were captured with mist-nets in 24 riparian and 25 non-riparian plots within a trail grid in an old-growth terra-firme forest, northeast of Manaus, Amazonas, Brazil. Each plot was sampled three times in a total of 7056 net-hours. We captured 1191 bats, comprising 51 species. We used model selection based on AIC (Akaike Information Criterion) to compare linear and piecewise regressions to estimate the ecological thresholds for different bat assemblages. Piecewise models with one breakpoint were more parsimonious than linear models for abundance data, and the species and guild composition of animalivorous and frugivorous bats. Animalivorous-bat abundance increased from the stream to about 181 m, and frugivorous-bat abundance decreased within 50 m of the stream. The patterns of guild abundance suggest that frugivorous bats may need greater access to streams than animalivorous bats. The most conservative model suggests that most of the variation in bat composition occurs close to the stream and extends to up 114 m from the banks. Therefore, the 30 m wide strip of riparian forest protected by Brazilian law would maintain a relatively small fraction of bat-species assemblages in Ducke Reserve, and is insufficient to represent most of the assemblage-composition variation within the riparian zone. The suggestion to reduce the width of the protected riparian zone from 30 to 15 m for streams smaller than 10 m wide, as is under discussion, would likely be prejudicial for bat assemblages.

Increasing evidence that bats actively forage at wind turbines.

Although the ultimate causes of high bat fatalities at wind farms are not well understood, several lines of evidence suggest that bats are attracted to wind turbines. One hypothesis is that bats would be attracted to turbines as a foraging resource if the insects that bats prey upon are commonly present on and around the turbine towers. To investigate the role that foraging activity may play in bat fatalities, we conducted a series of surveys at a wind farm in the southern Great Plains of the US from 2011-2016. From acoustic monitoring we recorded foraging activity, including feeding buzzes indicative of prey capture, in the immediate vicinity of turbine towers from all six bat species known to be present at this site. From insect surveys we found Lepidoptera, Coleoptera, and Orthoptera in consistently high proportions over several years suggesting that food resources for bats were consistently available at wind turbines. We used DNA barcoding techniques to assess bat diet composition of (1) stomach contents from 47 eastern red bat (Lasiurus borealis) and 24 hoary bat (Lasiurus cinereus) carcasses collected in fatality searches, and (2) fecal pellets from 23 eastern red bats that were found on turbine towers, transformers, and tower doors. We found that the majority of the eastern red bat and hoary bat stomachs, the two bat species most commonly found in fatality searches at this site, were full or partially full, indicating that the bats were likely killed while foraging. Although Lepidoptera and Orthoptera dominated the diets of these two bat species, both consumed a range of prey items with individual bats having from one to six insect species in their stomachs at the time of death. The prey items identified from eastern red bat fecal pellets showed similar results. A comparison of the turbine insect community to the diet analysis results revealed that the most abundant insects at wind turbines, including terrestrial insects such as crickets and several important crop pests, were also commonly eaten by eastern red and hoary bats. Collectively, these findings suggest that bats are actively foraging around wind turbines and that measures to minimize bat fatalities should be broadly implemented at wind facilities.

Sensitivity of populations of bats (Mammalia: Chiroptera) in relation to human development in northern Paraná, southern Brazil / Sensibilidade das populações de morcegos (Mammalia: Chiroptera) frente ao desenvolvimento humano no norte do Paraná, sul do Brasil

Most natural forests have been converted for human use, restricting biological life to small forest fragments. Many animals, including some species of bats are disappearing and the list of these species grows every day. It seems that the destruction of the habitat is one of its major causes. This study aimed to analyze how this community of bats was made up in environments with different sizes and quality of habitat. Data from studies conducted in the region of Londrina, Parana, Brazil, from 1982 to 2000 were used. Originally, this area was covered by a semi deciduous forest, especially Aspidosperma polyneuron (Apocynaceae), Ficus insipida (Moraceae), Euterpe edulis (Arecaceae), Croton floribundus (Euforbiaceae), and currently, only small remnants of the original vegetation still exist. The results showed a decline in the number of species caught in smaller areas compared to the largest remnant. In about 18 years of sampling, 42 species of bats were found in the region, representing 67% of the species that occur in Paraná and 24.4% in Brazil. There were two species of Noctilionidae; 21 of Phyllostoma; 11 Vespertilionidae and eight Molossidae. Eight of these were captured only in the largest fragment, Mata dos Godoy State Park (680 ha). Ten species had a low capture rate in the smaller areas with less than three individuals. Of the total sampled, 14 species were found in human buildings, and were able to tolerate modified environments, foraging and even using them as shelter. As the size of the forest area increases, there is a greater variety of ecological opportunities and their physical conditions become more stable, i.e., conditions favorable for growth and survival of a greater number of species. Forest fragmentation limits and creates subpopulations, preserving only long-lived K-strategist animals for some time, where the supporting capacity of the environment is a limiting factor. The reduction of habitats, species and genetic diversity resulting from human activities are endangering the future adaptability in natural ecosystems, which promotes the disappearance of low adaptive potential species.

A maior parte das florestas naturais foi convertida para uso humano, confinando a vida biológica a pequenos fragmentos florestais. Muitos animais, dentre os quais algumas espécies de morcegos, encontram-se em vias de desaparecimento e a lista dessas espécies aumenta a cada dia, sendo a destruição dos habitats um dos principais responsáveis por esse quadro. O objetivo deste trabalho foi analisar a composição da comunidade de morcegos em ambientes com diferentes tamanhos e qualidade de habitat; para isso, foram utilizados dados de trabalhos realizados na região de Londrina - Paraná, Brasil, entre os anos de 1982 e 2000. Originalmente, essa área era coberta por floresta estacional semidecidual, com destaque para Aspidosperma polyneuron (Apocynaceae), Ficus insipida (Moraceae), Euterpe edulis (Arecaceae) e Croton floribundus (Euforbiaceae); nota-se que, atualmente, restam apenas pequenos remanescentes da vegetação original. Os resultados mostraram um declínio no número de espécies capturadas nas áreas de menor tamanho em relação ao maior remanescente. Em aproximadamente 18 anos de amostragens, 42 espécies de morcegos foram encontradas na região, o que representa 67% das espécies que ocorrem no Paraná e 24,4% no Brasil, sendo duas espécies de Noctilionidae, 21 de Phyllostomidade, 11 de Vespertilionidae e oito de Molossidae. Destas, oito foram capturadas apenas no maior fragmento, o Parque Estadual Mata dos Godoy (680 ha). Dez espécies apresentaram baixo índice de captura nas menores áreas, com menos de três indivíduos. Do total amostrado, 14 espécies foram encontradas em edificações humanas, sendo capazes de tolerar ambientes modificados, forrageando e até mesmo utilizando-os como abrigo. Conforme o tamanho da área de floresta aumenta, há uma maior variedade de oportunidades ecológicas e suas condições físicas tornam-se mais estáveis, ou seja, há condições favoráveis para o crescimento e a sobrevivência de um maior número de espécies. A fragmentação florestal limita e cria subpopulações, preservando somente por algum tempo um animal de vida longa, K-estrategista, em que a capacidade suporte do meio é um fator restritivo. A redução dos habitats, das espécies e da diversidade genética resultante das atividades humanas está pondo em risco a adaptabilidade futura nos ecossistemas naturais, o que promove o desaparecimento de espécies de baixo potencial adaptativo.