Roost Surveys Research Articles

Bats and Mayan temples: Bat diversity and the potential for conservation of archeological zones in Yucatan, Mexico

AbstractThe role of archeological zones in biological conservation has been highlighted because of their restrictions over land‐use change, size, and maintenance of upstanding vegetation. The Yucatan Peninsula in Mexico has over 2000 archeological zones amidst biological, ecological, and culturally diverse landscapes. However, due to population centers and tourism growth, the peninsula is experiencing high deforestation and habitat fragmentation rates. To explore the role of archeological zones in biological conservation, we focused on bat species because of their high mobility, use of human structures as refugia, and the ecosystem services they provide. Using mist nets and roost surveys, we compared the bat diversity in four highly visited archeological zones during the dry and wet seasons. In a total effort of 34,560 m2 mist net hours, we found 23 species from six families and seven guilds, representing 53% of all bat species known from the Yucatan state, including two endangered species for Mexico: Mimon cozumelae and Micronycteris schmidtorum. We found between 12 and 19 species in each archeological zone, and the communities were similar between the four sites and between seasons. The Phyllostomidae family was dominant across all sites, accounting for 92% of all the captures. We also recorded 12 species across 52 diurnal and nocturnal roosts, suggesting that Mayan archeological structures could offer several advantages to bats despite the high visitation of tourists. Our results emphasize the need to conduct research beyond natural protected areas to complement conservation policies and incentivize the inclusion of archeological zones in Yucatan's bat conservation plans.Abstract in Spanish is available with online material.

Effects of the environmental conditions and seasonality on a population survey of the Andean condor Vultur gryphus in the tropical Andes.

Among the New World vultures, the Andean condor is considered one of the most culturally and ecologically important species. However, their populations are declining over their entire distributional range. In response, conservation strategies have been implemented in many countries to reverse the increasing extinction risk of this species. The initiatives rely on extensive population surveys to gather basic information necessary to implement policies and to intervene efficiently. Still, there is a need to standardize the surveys based on seasonality and suitable environmental conditions throughout the species distribution. Here, we provide the first assessment of how daily temperature, rainfall, and seasonality influence surveys of Andean condors on a communal roost in the central Peruvian Andes. Using an autoregressive generalized linear model, we associated environmental variables with visual surveys of adult and young condors at three different times of the day and three times a week between June 2014 and March 2015. We found that both adults and young Andean condors showed a threefold reduction in the use of the communal roost after the beginning of the rainy season. Colder and drier days (dry season) are preferable for surveying, as we expect the total number of condors using communal roosts to reduce under rainy (rainfall = -0.53 ± 0.16) and warmer days (temperature = -0.04 ± 0.02) days. Therefore, the significant variation in the use of roosts across seasons and hours should be carefully accounted for in national surveys, at the risk of undermining the full potential of the communal roost surveys. Moreover, we also found a strong bias towards immatures (about 76%) in the adult:immature ratio and a remarkable absence of Andean condors during the wet season. These results suggest that the species might be using other unknown communal roosts hierarchically. Such results provide key information for selecting priority areas for conservation and selecting the best time to survey this species in the tropical Andes. Finally, it may open a fruitful avenue for further research on the protection of the Andean condor.

Predicting habitat suitability for Townsend's big-eared bats across California in relation to climate change.

Effective management decisions depend on knowledge of species distribution and habitat use. Maps generated from species distribution models are important in predicting previously unknown occurrences of protected species. However, if populations are seasonally dynamic or locally adapted, failing to consider population level differences could lead to erroneous determinations of occurrence probability and ineffective management. The study goal was to model the distribution of a species of special concern, Townsend's big-eared bats (Corynorhinus townsendii), in California. We incorporate seasonal and spatial differences to estimate the distribution under current and future climate conditions. We built species distribution models using all records from statewide roost surveys and by subsetting data to seasonal colonies, representing different phenological stages, and to Environmental Protection Agency Level III Ecoregions to understand how environmental needs vary based on these factors. We projected species' distribution for 2061-2080 in response to low and high emissions scenarios and calculated the expected range shifts. The estimated distribution differed between the combined (full dataset) and phenologically explicit models, while ecoregion-specific models were largely congruent with the combined model. Across the majority of models, precipitation was the most important variable predicting the presence of C. townsendii roosts. Under future climate scenarios, distribution of C. townsendii is expected to contract throughout the state, however suitable areas will expand within some ecoregions. Comparison of phenologically explicit models with combined models indicates the combined models better predict the extent of the known range of C. townsendii in California. However, life-history-explicit models aid in understanding of different environmental needs and distribution of their major phenological stages. Differences between ecoregion-specific and statewide predictions of habitat contractions highlight the need to consider regional variation when forecasting species' responses to climate change. These models can aid in directing seasonally explicit surveys and predicting regions most vulnerable under future climate conditions.

Rediscovery of the critically endangered Hill's horseshoe bat (Rhinolophushilli) and other new records of bat species in Rwanda.

For forty years, there has been growing uncertainty about whether Hill's horseshoe bat (Rhinolophushilli) still persists in Nyungwe National Park, Rwanda. Only known from one small area within the National Park, R.hilli is listed as Critically Endangered by the International Union for the Conservation of Nature (IUCN), based on its extremely small geographic range and presumed low number of mature individuals. Here, we present and describe bat species occurrence data contributed to the Global Biodiversity Information Facility (GBIF) that we collected as part of a long-term collaborative project to rediscover this lost species. This data paper describes the survey methods and findings resulting from cave roost surveys, capture surveys, and acoustic sampling of bat echolocation activity in Nyungwe National Park and surrounding areas in south-western Rwanda from 2013-2020 and their conservation relevance. We report the discovery of an extant population of Hill's horseshoe bat (Rhinolophushilli) in Nyungwe National Park, Rwanda, 40 years since the last reported observation of the species in 1981. We also report the first record of Lander's horseshoe bat (Rhinolophuslanderi) in Nyungwe National Park and the first record of the Damara woolly bat (Kerivoulaargentata) in Rwanda. The dataset contributed to GBIF and described in this paper includes 278 occurrence records from 10 bat species of five families detected at 71 locations in or near Nyungwe National Park, Rwanda. We include a description of the morphological descriptions of R.hilli and present the first acoustic echolocation signatures and phylogenetic information for this species.

Summer Populations of Northern Long-eared Bat in an Eastern Kentucky Forest Following Arrival of White-nose Syndrome

Myotis bats have experienced significant population losses due to white-nose syndrome (WNS) throughout large portions of their distributions in eastern North America. As closed-space foragers, these species comprise an important feeding guild within eastern forests. An understanding of where summer populations remain and how their ecology has changed following impact from WNS is needed to assess fully the recovery potential of Myotis bats. We used acoustic sampling, capture surveys, radiotelemetry and roost surveys from 2015 to 2018 to evaluate the status of northern long-eared bat (Myotis septentrionalis) in an eastern Kentucky forest following region-wide impacts from WNS to this species. Acoustic activity of Myotis remained unchanged over the 4 y of sampling, with activity of these bats greatest in mid- to late July. Northern long-eared bats represented 97% of the Myotis captured, indicating activity levels likely reflected patterns for this species. We located 18 roost trees of northern long-eared bats in five tree species, including both live and dead trees. All roost trees were on upper slopes within 100 m of ridge top roads. Maximum exit counts, 24 and 21, at two roosts occurred in late May and early June, suggesting these dates represented the summer maternity period of northern long-eared bats in this forest. Our results demonstrated that post-WNS populations of northern long-eared bats on Robinson Forest formed small colonies, day-roosted in trees near roads on forested ridge tops, were reproductively active, and maintained steady levels of activity across the 4 y of sampling. These data suggest that local populations of northern long-eared bats are surviving WNS and continue to persist during summer months in forests of the Appalachian Mountain region. We hypothesize presence of ridge top roads, often associated with forest logging operations, may be important habitat elements for increasing availability of preferred roosting habitat for summer populations of northern long-eared bats in actively managed forests.

Diversity and Distribution of Bats in Triyuga and Chaudandi Municipality, Udayapur, Nepal

Eastern Nepal is rich in bats diversity, 34 species of bats have been recorded from 11 eastern districts and three districts remain till now. Even most of the districts surveyed including Udayapur have been focused only at some sites. Most of the area in the previously surveyed district has yet to be conducted. There is a lack of public awareness of the importance and values of bats. Many people have a negative attitude towards bats and there exist some prevailing threats to bats in Nepal. Study area includes 17 sites Churia range and Inner-Terai of Udayapur district. Roost survey and mist netting were conducted during six days of 2015 and 2016. In total four species of bats were recorded. 14 individuals of bats were captured from the roosts by gloved hands. However, bat could not be captured in mist nets. Previously, bat surveys were conducted at Katari in Udayapur District. Pipistrellus sp. from 12 sites, Cynopterus sphinx from three sites, Megaderma lyra from two sites Taphozous longimanus was recorded from one site. Similar, most of the people had no idea on the importance and value of bats. No direct threats on bats were observed in the study area during the survey.

Record of bats and their echolocation calls from southern Dolakha, central Nepal

Abstract With 52 species, bats make up almost a quarter of all the mammal species in Nepal, and yet remains the least understudied group of mammals. Owing to its diverse geography and climate, more species of bats potentially occur in the country, and acoustic surveys could improve the knowledge of their ecology. So, a study was conducted in Sailung and Melung Rural Municipalities of Dolakha district of Nepal, with the objectives of assessing bat species richness and preparing digital records of their echolocation calls. Using mist-netting and roost survey during three periods in 2018 (late March, late May to early June and mid-November), 10 species of bats were recorded: Cynopterus sphinx, Lyroderma lyra, Rhinolophus ferrumequinum, Rhinolophus luctus, Rhinolophus pearsonii, Rhinolophus sinicus, Hipposideros armiger, Myotis formosus, Myotis sp. and Nyctalus noctula. Ten roosts (mostly caves) were located. Echolocation calls of six of these species were documented, including signals of three species described for the first time in Nepal. This study also reports the fifth record of Myotis formosus in Nepal and new locality record of the species after two decades. The echolocation calls documented hereafter may serve as a reference for species identification for non-invasive studies of bats.

New bat records in south-eastern Bosnia and Herzegovina with additional confirmation of Myotis alcathoe and Myotis brandtii

The Balkans represent one of the regions with the highest bat diversity in Europe. Thus far, 31 bat species have been recorded in Bosnia and Herzegovina (BiH). The bat fauna of this Balkan country is one of the least studied in Europe. In order to reduce this knowledge gap, bat research was carried out during a ten-day inventory in the vicinity of Čajniče in south-eastern BiH (Republic of Srpska). Mist net surveys resulted in the capture of 15 bat species: Rhinolophus ferrumequinum, R. hipposideros, Myotis brandtii, M. mystacinus sensu lato, M. alcathoe, M. emarginatus, M. nattereri, M. bechsteinii, M. blythii, Nyctalus leisleri, Eptesicus serotinus, Vespertilio murinus, Pipistrellus pipistrellus, P. pygmaeus, and Plecotus auritus. Acoustic surveys resulted in recording one additional species: Barbastella barbastellus. Roost surveys yielded in the finding of three maternity colonies of R. hipposideros. The genetic analysis resulted in the first molecularly confirmed M. brandtii and M. alcathoe records for BiH. Capture of several post-lactating females, sexually active males and multiple juveniles is proof for reproducing populations of these species in the country. During this brief study, we found more than half of all known bat species in BiH in an area of circa 75 km2 .

Conservation status of the recently described Ecuadorian Amazon parrot Amazona lilacina

SummaryAmazona lilacina is a threatened species endemic to Ecuador, existing across a patchwork of mangroves, lowland coastal forests, agricultural and community owned land. The species was described in 2014 and listed as ‘Endangered’ on the IUCN Red List, however, full assessment of the population was lacking. Using a combination of field observations, roost surveys and community questionnaires, conducted over the last 20 years, we provide up-to-date information on the species’ Extent of Occurrence, estimate its global population size, and evaluate its level of threat. Our results suggest the species occurs across an area of 19,890 km2 in three distinct geographically isolated subpopulations. Roost surveys across the range estimate the minimum remaining population at 741–1,090 individuals and we present evidence to suggest a 60% decline over the past 19 years in one part of the species’ range. We conducted community questionnaires with 427 people from 52 communities. The presence of pet parrots was reported in 37 communities, including 17 communities which reported pet A. lilacina. From this we predict that over half of all communities within our study area keep parrots as pets and at least 96 communities keep A. lilacina. Our findings justify an IUCN Red Listing of at least ‘Endangered’ for this species and highlight the need for conservation support. In order to assess population health in more detail, further research is required to assess genetic diversity and roost dynamics, and to identify areas that may be important for feeding and nesting throughout the range. As many of these areas are likely to overlap with community owned land, we suggest that future conservation actions should revolve around, and be led by, these communities.

Evaluating survey methods for bat roost detection in ecological impact assessment.

The disturbance, damage and destruction of roosts are key drivers of bat population declines worldwide. In countries where bats are protected by law, bat roost surveys are often required to inform ecological impact assessments. Yet, evidence‐based information on survey methodology to detect bat roosts is crucially lacking, and failing to detect a roost can lead to serious errors during decision‐making processes. Here, we assess the efficacy of bat roost surveys in buildings as implemented in the UK. These consist of a daytime inspection of buildings, followed by a series of acoustic surveys at dusk/dawn if during the daytime inspection evidence of bats is found, or if the absence of bats cannot be verified. We reviewed 155 ecological consultants’ reports to (1) compare survey outcome between daytime inspection and acoustic surveys and (2) determine the minimum sampling effort required during acoustic surveys to be confident that no bats are roosting within a building. We focused on two genera of bats most frequently found in buildings in Europe – Pipistrellus (crevice roosting species with high‐intensity echolocation calls that can be easily detected by ultrasound detectors) and Plecotus (species that roost in open spaces and which emit faint echolocation calls that are difficult to detect). Daytime inspections were efficient in detecting open‐roosting species such as Plecotus species but were likely to miss the presence of crevice‐dwelling ones (here Pipistrellus species) which may lead to erroneous conclusions if no acoustic surveys are subsequently prescribed to confirm their absence. A minimum of three and four acoustic surveys are required to be 95% confident that a building does not host a roost of Pipistrellus species and Plecotus species, respectively, thus exceeding current recommendations. Overall, we demonstrated that reports submitted as part of an ecological impact assessment provide suitable data to test and improve survey methods.

Chiropteran diversity and the key determinants of their distribution in Eastern Ghats, India

Understanding the patterns of biodiversity is central to species conservation planning. Here we illustrate chiropteran diversity and distribution pattern of the hill ranges of the Eastern Ghats of Odisha state, India using roost survey and mist net survey techniques. The present study recorded 23 bat species including two newly recorded species for the study site i.e., Hipposideros galeritus and Megaderma spasma. The bat capture rate was the highest in the moist deciduous forest describing higher bat populations compared with the places of human habitation. Utilities of 21 climate, three physiographic and two disturbance variables and species distribution modelling could reveal that the north-eastern part was more suitable for bat distributions than the southern part of the region. The climate, physiographic and disturbance variables were crucial in their distributions, where elevation and potential evapotranspiration were highly significant. Unlike other species, Taphozous melanopogon showed negative correlation with these variables. The mean diurnal temperature and precipitation seasonality have positive influence on bat distributions, indicating their resilience to seasonal precipitation changes and day time temperature fluctuations. The negative effect of temperature seasonality on the distribution of Pteropus giganteus could attribute to its vulnerability to climate change effects. The study provides inputs for monitoring the future spatio-temporal changes, suggesting long term conservation measures. It could generate basic information on the impacts of climate change on bat distribution in the future climate change scenario.

An Inventory of Chiropteran Fauna in Bhubaneswar City, Eastern India

An inventory of chiropteran fauna was carried out in Bhubaneswar city, Odisha, eastern India during October 2015 and March 2016 following roost survey and mist net survey techniques. During the study a total 19 species of bats belonging to seven families including the nationally threatened Rhinolophus rouxii were recorded of which family Vespertilionidae was the most diverse one, represented by five species. Majority of 11 species are found roosting and breeding in old temples and caves and are vulnerable from renovation activities, persecution and tourism. Therefore, long term monitoring of these sites are essential to understand the population trend over time and derive appropriate conservation implications.

Communal roosts of the Blue-fronted Amazons (Amazona aestiva) in a large tropical wetland: Are they of different types?

Psittacidae species are among the most threatened birds in the world. Approximately one-half of the 390 parrot species are experiencing population declines. The Blue-fronted Amazon (Amazona aestiva) is the most traded parrot worldwide and suffers from poaching and habitat loss. Many species of parrots, including the Blue-fronted Amazon, form communal roosts where they spend the night. Under certain circumstances, roost surveys can be a rapid and cost-effective way to obtain information about the demography of parrots or the consequences of threats. We surveyed an area of 2,700 km2 in a large wetland in mid-western of Brazil and located five Blue-fronted Amazon roosts. We conducted monthly counts of the birds arriving at these roosts for 28–61 months and stratified the counts into flock sizes. We used this information to estimate the number of parrots using these roosts to determine whether the roosts follow seasonal patterns and whether they have different flock-size structures and different dynamics throughout the year, as well as to determine the trends of the roosting parrots, which are stratified by flock size. The roosts were different, as they followed different seasonal patterns and had different flock-size structures, which could be interpreted in relation to the parrot breeding cycle. The trends of singletons, which index the number of reproductive couples each year, and the number of pairs parrots increased or fluctuated around a baseline, but the number of fledged young in the year declined throughout the study. This is of concern, as it indicates problems in population recruitment, which could have been unnoticed by the management authorities, as the total numbers were not decreasing. Although every monitored roost had birds of each age or reproductive condition strata, the fact that the roosts were different could be important in terms of management, as it will be more effective for the conservation of the Blue-fronted Amazon to protect a carefully chosen set of complementary roosts.

Bat Fauna (Mammalia: Chiroptera) of Southern Odisha Along the Eastern Ghats, India

Bats have not received adequate attention in biodiversity research and conservation activities in India despite their ecological values. In the present study, we carried out an inventory of bat fauna in southern Odisha region during September 2014 to August 2016 and recorded a total 16 species of bats in seven families, of which the insectivorous bats were represented by maximum 12 species over frugivores and carnivores. During the study 76 roosting sites were recorded from exposed branches, foliage and cavities of trees, caves, crevices in large rocks and abandoned buildings and caves were significantly preferred by maximum 11 species. Gupteswar cave tourism site in Koraput district was found to be the most diverse and important bat roosting and breeding site in southern Odisha region. Cave tourism, hunting for ethno-zoological practices and cutting down of roosting trees were observed as major threats to bats. As the inventory was primarily based on roost survey, more systematic survey using mist nets and acoustic monitoring can further strengthen the bat fauna database of southern Odisha.

Identification of Southeastern Bat Species Using Noninvasive Genetic Sampling of Individual Guano Pellets

Abstract The impact of white-nose syndrome on North American bat populations may limit the effectiveness of traditional monitoring methods, including roost surveys, mist netting, and acoustic monitoring, and, in turn, determination of bat species occurrence. Genetic markers from deoxyribonucleic acid (DNA) extracted from feces (i.e., guano pellets) may provide an effective alternative method for assessing occurrence. We used an existing genetic marker from the 16S ribosomal subunit, mitochondrial DNA, to create a DNA sequence database for the 16 species of bats known to occur in Tennessee. We used our database to identify bat species from DNA extracted from 68 guano pellets collected from accumulations found in buildings of Great Smoky Mountains National Park from May to August 2015. No bats were directly observed at 19 roost buildings (55.9% of all identified roost buildings), where genetic analysis of guano was the only method available to determine species occurrence. Two of the species we detected roosting in buildings using DNA from guano, the little brown myotis Myotis lucifugus and northern long-eared myotis M. septentrionalis, are of special concern as a result of declines from white-nose syndrome. There are no records of the northern long-eared myotis roosting in Great Smoky Mountains National Park buildings, and no records of the little brown myotis roosting in buildings since white-nose syndrome became established in Great Smoky Mountains National Park. Our findings emphasize the utility of these genetic techniques for detecting bat species when visual or acoustic methods may be compromised by species rarity, elusive behavior, or similarities in species morphology and call characteristics.

Small in Size But Rich in Bats — Species Diversity and Abandoned Man-Made Structures Put Asinara Island (Sardinia) into Conservation Focus for Bats in the Mediterranean Region

During the last decades, the important role of bats in ecosystems and the threats to many bat species were increasingly recognized, and bats were integrated into several conservation acts. Protected areas like national parks may play a major role in bat conservation if species requirements are included in management plans. With its high bat diversity and many unexplored off-shore islands, Sardinia has a high potential for the protection of European bats and for research on their ecology. We conducted the first survey of the bat fauna on the Sardinian off-shore island and National Park Asinara, a formerly inhabited island. We applied a multi-method approach over two years to create a proper species inventory and to obtain data on the use of man-made structures by the bats. We recorded bat calls at different sites in summer and winter, captured bats via mist-netting, and performed roost surveys of man-made structures. Ten species were identified, three of them are highly protected, namely Rhinolophus hippos...

Bats of Alpi Marittime Nature Park (North West Italy) and Site of Community Importance IT1160056: distribution and status

A survey of bats was carried out at Alpi Marittime Nature Park and more generally within Site of Community Importance (SIC) IT1160056 from April 1991 to January 2015, using different techniques such as: mist-netting, acoustic sampling and roost surveys. Twenty-one species of bats were detected (<em>Rhinolophus ferrumequinum, Rhinolophus hipposideros, Myotis bechsteinii, Myotis daubentonii, Myotis emarginatus, Myotis myotis, Myotis mystacinus, Myotis nattereri, Myotis oxygnathus, Pipistrellus kuhlii, Pipistrellus nathusii, Pipistrellus pipistrellus, Pipistrellus pygmaeus, Nyctalus leisleri, Hypsugo savii, Eptesicus nilssonii, Eptesicus serotinus, Barbastella barbastellus, Plecotus auritus, Plecotus macrobullaris, Tadarida teniotis</em>). Species diversity is higher in this area than in other Alpine protected areas of a similar size. Records of <em>E. nilssonii</em>, <em>P. pygmaeu</em>s and <em>P.</em> <em>macrobullaris</em> in the study area contribute to the knowledge of the distribution of these species in Piedmont and more generally in Italy. In particular, thanks to records of <em>E.</em> <em>nilssonii</em>, its geographic range could be extended to the western part of the Alps whereas it previously seemed to be only present in the Central-Eastern Alps.

Current status of communal crow roost survey in Yokohama

Current status of communal crow roost survey in Yokohama

Species and Acoustic Diversity of Bats in a Palaeotropical Wet Evergreen forest in Southern India

The Western Ghats of India is among the top 25 biodiversity hotspots in the world. About 43% of the reported 117 bat species in India are found in this region, but few quantitative studies of bat echolocation calls and diversity have been carried out here thus far. A quantitative study of bat diversity was therefore conducted using standard techniques, including mist-netting, acoustical and roost surveys in the wet evergreen forests of Kudremukh National Park in the Western Ghats of Karnataka. A total of 106 bats were caught over 108 sampling nights, representing 17 species, 3 belonging to Megachiroptera and 14 to Microchiroptera. Acoustical and roost surveys added three more species, two from Microchiroptera and one from Megachiroptera. Of these 20 species, 4 belonged to the family Pteropodidae, 10 to Vespertilionidae, 3 to Rhinolophidae, 2 to Megadermatidae and 1 to Hipposideridae. We recorded the echolocation calls of 13 of the 16 microchiropteran species, of which the calls of 4 species (Pipistrellus coromandra, Pipistrellus affinis, Pipistrellus ceylonicus and Harpiocephalus harpia) have been recorded for the first time. Discriminant function analyses of the calls of 11 species provided 91.7% correct classification of individuals to their respective species, indicating that the echolocation calls could be used successfully for non-invasive acoustic surveys and monitoring of bat species in the future.

Findings on the Chiropteran Status in Rautahat and Sarlahi, Nepal

Bats are the second most diverse mammals found in earth with around 1250 species in a single Chiropteran order. In Nepal, authentic list of 53 bat species have been prepared so far. This research was conducted in 10 VDCs of Rautahat and Sarlahi with the main objectives being assessing the status, diversity and threats. Key-informant survey, direct observation, roost survey and mist netting were done for assessing the primary data. A total of five species were identified. Deforestation, poaching, destruction of old houses, concrete constructions, use of chemical fertilizers in agricultural and fruit lands, change in the agricultural pattern and deliberate killing were identified as major. People’s attitude was satisfactory, though awareness level was found to be low. Diversity was found to be very high, but the respondents argued that the bats’ frequency was in continuous decrease from past few years. DOI: http://dx.doi.org/10.3126/init.v5i0.10253 The Initiation 2013 Vol.5; 50-54