Forest Bats Research Articles

Bat phylogenetic responses to regenerating Amazonian forests

AbstractThroughout the tropics, regenerating secondary forests occupy vast areas previously cleared for agriculture and cattle ranching. However, despite the importance of regenerating forests in mitigating the pervasive negative consequences of forest loss and fragmentation on forest‐associated biodiversity, longitudinal studies on species' phylogenetic responses to matrix regeneration are rare.We surveyed bats in continuous primary forest, primary forest fragments and in the regenerating secondary forest matrix of a whole‐ecosystem Amazonian fragmentation experiment, ~15 and ~30 years after forest clearance, to investigate how changes in matrix quality through forest recovery affect phylogeneticα‐ andβ‐diversity.We found that temporal changes in phylogeneticα‐richness were more marked in the secondary forest matrix than in forest fragments and continuous forest, evidencing a significant increase in total evolutionary history over time. However, when the effects of species richness were accounted for, the phylogenetic structure of each assemblage was reduced close to zero, evincing a random pattern of lineages in all habitat types. Temporal differences in phylogeneticβ‐diversity were driven mainly byβreplacementin secondary forest and continuous forest ~30 years after forest clearance. Both habitats also clustered together in terms ofβrichness, indicating similar levels of evolutionary heritage. Consequently, regenerating secondary forest showed a reduction in the extinction probability of lineages over time.Synthesis and applications. Approximately 30 years of secondary forest regeneration were sufficient for phylogenetic richness to recover to levels similar to those observed in continuous forest. Promoting forest succession on degraded land through a combination of natural and active restoration, while ensuring the long‐term protection of secondary forests regardless of their age, is of key importance for conserving tropical bat diversity and their associated ecosystem services. Such restoration measures would stimulate the recolonization of fragments and matrix habitats by evolutionarily distinct bat species, safeguarding phylogenetically diverse assemblages and ecological functions. Our study suggests that forest restoration in tropical degraded areas should be encouraged and secondary forests be protected by law, especially in countryside ecosystems with high primary forest cover, and in the surroundings of protected areas.

Passive acoustic monitoring reveals the role of habitat affinity in sensitivity of sub‐tropical East Asian bats to fragmentation

AbstractHydropower infrastructure represents a major driver of habitat loss and insular fragmentation worldwide, mostly across the tropics and sub‐tropics. Despite growing evidence of dam‐induced impacts on biodiversity, the effects of insular habitat fragmentation on species assemblages remain poorly understood, particularly for East Asian vertebrates. Here, we assess how insectivorous bats respond to forest fragmentation in Thousand Island Lake, a mega‐hydroelectric dam in East China. Bat assemblages were surveyed across 36 land‐bridge islands of different sizes and degrees of isolation, using AudioMoth recorders. Echolocation calls were classified into sonotypes, each corresponding to either single or multiple species, which were further classified according to their habitat affinities into forest or open‐space foragers. Based on 22 875 five‐min recordings from 108 detector‐nights, we recorded 15 bat sonotypes, eight of which we classified as forest sonotypes (2329 bat passes) and seven as open‐space sonotypes (52 277 bat passes). Overall, sonotype richness increased with island area, but only above a certain threshold (34 ha). Habitat affinity played an important role in ensemble‐level responses to fragmentation; forest sonotype richness increased with island area, whereas open‐space sonotype activity was higher in more isolated islands. Our results highlight the relevance of particularly large fragments (>1000 ha) to maintain area‐sensitive forest bat species. However, islands below 34 ha in size and those more isolated from the mainland are also of conservation value as they, correspondingly, harbour a variable (but substantial) number of species and concentrate higher activity of open‐space foragers. These findings further demonstrate that acoustic sampling methods, as the one presented here, are able to provide key information for evidence‐based policies aimed at halting the ongoing wave of dam‐induced biodiversity loss.

Diversity and activity rate of a bat communities in a voluntary nature reserve in the Agneby-Tiassa region (South-East, Côte d’Ivoire)

In order to provide basic data on the specific diversity of bats in a private forest of fifty hectares, located in the Agnéby-Tiassa region (South-eastern Côte d'Ivoire), a study was carried out there from August 26 to October 15, 2018. This was conducted in three types of habitats represented by a forest, a wetland and an edge zone. Sixty-three individuals were captured using mist nets during 38 days, from 18h00 to midnight. Twelve species of bats belonging to nine genera and five families have been inventoried. This community is dominated by Epomops buettikoferi, Scotonycteris zenkeri, Nanonycteris veldkampi, Macronycteris gigas, Hipposideros caffer and Mops thersites. The activity study has shown that Microchiroptera are most active from 18h30 to 20h while bats' activity is most intense from 21h30 to 23h00. The forest, the wetland and the edge zone are respectively the most diversified in species of bats. Epomops buettikoferi, Nanonycteris veldkampi and Hipposideros caffer activities are positively correlated with forest and edge zone while Macronycteris gigas, Mops thersites, Scotophilus nux and Eidolon helvum have a greater affinity for the wetland.

Diversity and Abundance of Roadkilled Bats in the Brazilian Atlantic Forest

Faunal mortality from roadkill has a negative impact on global biodiversity, and bats are among the roadkilled animals. In South America, the Atlantic Forest covers southeastern Brazil, a region which sustains a large bat diversity. In this biome, the Sooretama reserves are crossed by the federal highway BR-101, one of the busiest in Brazil. We analyzed bats roadkilled along the 25 km stretch of highway that crosses the Sooretama reserves. Data were collected between the years 2010 and 2015. In total, 773 individuals distributed among 47 bat species were roadkilled during this period. The insectivorous feeding guild was the most affected, accounting for 25 species and 74% of the recorded roadkill, and those flying in the open area were the most frequently roadkilled (41.9%). Bat mortality rates did not differ between months of the year. However, the relation between rainy days and roadkill was negative. Monitoring by foot was more efficient than by car for detection of bat carcasses. Radars with a speed limit below 60 km/h reduced the rates of roadkill. The diversity of deceased bats found in this study represents 40% of the known species in the Atlantic Forest, and is the largest among current studies of species killed on highways globally. The present study raises concerns about the high diversity and abundance of roadkilled insectivorous bats and the conservation of these animals in the Neotropical region.

Diet and trophic structure of frugivorous bats (Phyllostomidae) in forests and chagras of the Andean–Amazon piedmont, Ecuador

Diet and trophic structure of frugivorous bats (Phyllostomidae) in forests and chagras of the Andean–Amazon piedmont, Ecuador

Bat responses to silviculture treatments: Activity over 13 years of regeneration

Using silviculture treatments as a tool to create habitat for wildlife is a common practice in wildlife conservation and natural resource management. Although diverse forest age structures and composition benefit many wildlife species, relatively little is known about bat response to young forest habitat. Understanding how the activity of bats changes as young forests age, and the influence of landscape level, stand level, and biologically relevant variables on bat activity, can improve effectiveness of forest management actions designed to benefit bat populations. We measured activity of bats in young forests regenerating from harvests implemented 2007–2018. We selected 26 sites, each of which consisted of a regenerating stand and paired control stand in adjacent interior forest, and used acoustic monitors to record bat activity from 5 May – 9 September 2019 and 2020, with a break from 1 July – 14 July so that monitoring fell into pre- or post-volant timeframes. We used an information theoretic approach to assess support for landscape level, stand level, and biologically relevant variables on bat activity in regenerating stands. Through our research we found (i) bats were more active in young forest stands than natural canopy gaps in interior forests, (ii) bat activity was highest in the first few years post treatment and decreased as young forests continued to age, and (iii) bat activity was highly dependent on biological factors, not landscape or stand level factors. Collectively, these findings suggest that forest management for young forest habitat may benefit forest-associated bats, at least in predominantly forested landscapes where young forest habitat is under-represented.

Corrigendum to: Dietary patterns of phyllostomid bats in interior Atlantic Forest of eastern Paraguay

Corrigendum to: Dietary patterns of phyllostomid bats in interior Atlantic Forest of eastern Paraguay

Dietary patterns of phyllostomid bats in interior Atlantic Forest of eastern Paraguay

Abstract We examined patterns of dietary overlap of phyllostomid bats in interior Atlantic Forest of Paraguay. In addition, we examined microgeographic, seasonal, and species-specific, differences in dietary patterns. We obtained 4,519 dietary records for bats from two sites in eastern Paraguay representing 26 different kinds of resources. The three most abundant resources made up 85% of all dietary records. No significant difference in diets of phyllostomid bats existed between sites. Overlap was high and significantly greater than random. Overlap at both sites was higher in winter than in summer. Consumption of dietary items was different between seasons and reflected changes in consumption primarily of the three most consumed items. Resource breadth was narrower in winter than summer. Sites, season, and species together accounted for 71% of the variation in dietary items. Unique effects, after controlling for variation shared with other factors, of species and season were significant, whereas that of site was not. While much dietary variation in interior Atlantic Forest falls along phylogenetic lines, such patterns are weak and resource utilization appears to be substantively influenced by generalist ecology of bats and seasonal nature of the environment in this system.

Overheating turns a bat box into a death trap

Thirty juvenile large forest bats (Vespadelus darlingtoni) were found dead in a plywood bat box. This is the first example in Australia of an overheating event in a bat box resulting in multiple mortalities. It confirms that extreme heat in poorly insulated bat boxes can result in acute hyperthermia.

Bats of Eastern Cape and Southern Kwazulu-Natal Forests, South Africa: Diversity, Call Library and Range Extensions

Bats are a highly diverse order with substantial economic and ecological value. Similarly, forests in South Africa form a valuable biome supporting unique biotic diversity, yet forest bat communities have not previously been surveyed. We sampled 17 forests, of seven forest types and three forest groups, in the Eastern Cape and southern KwaZulu-Natal provinces, located within the Maputaland-Pondoland-Albany global biodiversity hotspot. We utilized capture and acoustic survey methods to compile the first bat species inventory for these forests. Species identification was performed with a combined approach of morphology, echolocation, and DNA barcodes. With this we contributed novel DNA barcodes to the Barcode of Life Data System. A total of 25 species was recorded, with range extensions southward into the Eastern Cape for six species, indicating the region to be more diverse than previously thought. Updated modelled distribution maps for these species are presented. We compiled the first reference call library of hand released bats for South African forest habitats, and the southeast region of the country. We compared species richness, diversity, and dissimilarity of the forest types and found that Scarp forests host the highest species richness and diversity. Patterns of species assemblage similarities between forest groups are attributed to forest biogeographical history and historical dispersal routes of forest fauna. A comprehensive survey, such as this, may assist in the compilation and implementation of forest conservation management plans and future monitoring programs.

A relict tropical forest bat assemblage from the early Miocene of the Ribesalbes-Alcora Basin (Castelló, Spain)

ABSTRACTWe present the bat assemblage from the early Miocene (MN4, 16.9–15.95 MY) basin of Ribesalbes-Alcora, which has yielded the remains of ten chiropteran taxa. Bat assemblages are rarely recovered in the fluvio-lacustrine fossil record. A bat species described in this work,Cuvierimops penalverisp. nov., is a new form of a typically Oligocene free-tailed bat. In addition, the other molossidsHydromops helveticus,Rhizomops cf.brasiliensis,Chaerephonsp.,Tadaridasp., and the vespertilionidsMyotis cf.intermediusandMiostrellusaff.petersbuchensis, as well as undetermined fossils ascribed to the generaSubmyotodon,Plecotus, andRhinolophusare described. This is the first record of the genusRhizomopsin the early Miocene; the genusCuvierimopsis the first recording from the Neogene, while the ‘Lazarus taxon’Chaerephonis the first fossil record of this genus, registered previously only in Holocene deposits. This bat assemblage with a high abundance of molossids is typical from the early Oligocene of western Europe, while in the early Miocene from Europe the molossids are scarce. The abundance of these bats is consistent with the presence of a tropical forest surrounding a paleolake. The fossils from the Ribesalbes-Alcora Basin represent the most complete bat assemblage of the Iberian Peninsula during this age, and significantly increase our knowledge about the early Miocene bats of Europe.

Temperature preference by bats in the montane forests of Machu Picchu, Peru

Information on the thermal preference of bats goes back to studies carried out since the middle of the 20th century, mainly in NorthAmerica and Europe. Here we present information on the thermal preference of six bat species in the cloud forests of the HistoricSanctuary of Machu Picchu (Cusco, Peru). The data were obtained in field using a thermographic camera and an infrared thermometer.Our results show the intervals and averages of the selected temperatures, as well as the differences between sexes of each species. Thisinformation constitutes the first effort in Peru to understand the temperature ranges that natural and artificial bat refuges should have.

Natural and anthropogenic factors influencing the bat community in commercial tree stands in a temperate lowland forest of natural origin (Białowieża Forest)

In 2011–2017, we examined the ecology of bat assemblages in the commercially used stands of the Białowieża Forest, Poland. The species composition was analyzed, as well as the relationship between bat activity and distance to buildings and to open waters. The relationship between bat activity and stand age, type of stand (coniferous vs. deciduous), and tree canopy closure (open vs. dense) was also examined. Bat activity was recorded using full-spectrum ultrasound detectors, with subsequent analysis using specialized software. Bats were recorded on eight linear transects. The following species of bats were found: western barbastelle (Barbastella barbastellus), serotine (Eptesicus serotinus), northern bat (Eptesicus nilssoni), common noctule (Nyctalus noctula), lesser noctule (Nyctalus leisleri), soprano pipistrelle (Pipistrellus pygmaeus), Nathusius’ pipistrelle (Pipistrellus nathusii), common pipistrelle (Pipistrellus pipistrellus), parti-coloured bat (Vespertilio murinus), and bats from the genus Myotis. Bat activity was affected mainly by the canopy structure along a transect, the number of dead trees, and the age of tree stands. The activity of three from five studied open space aerial foraging bat species (serotine bat, northern bat, and parti-coloured bat) was negatively affected by canopy closure along a transect. Canopy cover was not the most important factor for the other two open space bat species - the common noctule and lesser noctule. Canopy closure was also not a primary factor affecting the edge space foragers like species from this genus Pipistrellus. The activity of Nathusius’ pipistrelle was positively correlated with the number of nearby dead trees, whereas the activity of the common pipistrelle was negatively correlated with the upper quartile of trees age. There was no good single environmental variable for the activity of western barbastelle, bats of the genus Myotis and the soprano pipistrelle. However, we found that the activity of western barbastelle and soprano pipistrelle clearly increased among years. The results suggest that commercial forests with limited economic activity are still a suitable environment for forest bats, including rare and endangered species. They also show that the transformation of stands, resulting in anthropogenic open areas, as well as forest roads, allows synanthropic species to penetrate deep into compact stands. We still do not fully know the impact of such a transformation of the fauna on the forest ecosystem, including the impact on vulnerable bat species closely related to forests.

No room to move: bat response to rainforest expansion into long-unburnt eucalypt forest

The expansion of rainforest trees into long-unburnt open forests is widespread globally, including in high-rainfall regions of eastern Australia. Increased tree density can reduce insectivorous bat activity and species richness by constraining echolocation and foraging success. Yet it is unknown whether sclerophyll and rainforest trees differ in their effects on open forest bat communities. We sampled insectivorous bats and nocturnal flying insects at two heights (understorey, canopy) in dry sclerophyll forest of eastern Australia with contrasting fire histories and levels of rainforest pioneer invasion. We found that both time since fire and functional identity of midstorey trees influenced the local bat community, whereas insect biomass had little effect. Long-unburnt forests with a rainforest pioneer midstorey had lower bat activity (63% lower) and species richness (35% lower) than recently burnt forests with a more open midstorey. Bat species richness also declined beneath the dense sclerophyll midstorey in long-unburnt forests, although was unaffected in the canopy above. Strong negative correlations between rainforest tree density and bat community activity and richness indicate that rainforest trees, in contrast with sclerophyll trees, exert additional negative control over open forest bat communities. Our results show that habitat suitability for clutter-intolerant bats declined well before the often-recommended maximum fire-intervals for dry open forest, providing evidence of an upper threshold for fauna conservation in rainforest-invaded open forests. To conserve bat communities in dry open forests vulnerable to rainforest invasion, fire should occur with sufficient frequency to prevent rainforest pioneers developing a dense midstorey that displaces clutter-intolerant bats.

Visits at artificial RFID flowers demonstrate that juvenile flower-visiting bats perform foraging flights apart from their mothers

During the transition from parental care to independent life, the development of adequate foraging skills is a major challenge for many juvenile mammals. However, participating in their parents’ knowledge by applying social learning strategies might facilitate this task. For several mammals, communal foraging of adults and offspring is suggested to be an important mechanism in mediating foraging-related information. For the large mammalian taxon of bats, only little is known about foraging-related social learning processes during ontogeny. It is often suggested that following their mothers during foraging flights would represent a valuable option for juveniles to socially learn about foraging, e.g., where to find resource-rich foraging patches, but explicit tests are scarce. In the present study, we investigated the foraging behavior of juvenile flower-visiting bats (Glossophaga soricina) in a dry forest in Costa Rica. We tested whether recently volant, but still nursed pups perform foraging flights alone, or whether pups follow their mothers, which would enable pups to socially learn where to feed. For that, we trained mothers and pups to feed from artificial flowers with a RFID reading system and, subsequently, conducted a field experiment to test whether RFID-tagged mothers and pups visit these flowers communally or independently. Unexpectedly, pups often encountered and visited artificial flowers near the day roost, while mothers rarely did, suggesting that they foraged somewhere further away. Our results demonstrate that still nursed juveniles perform foraging flights apart from their mothers and might learn about the spatial distribution of food without participating in their mother’s knowledge, for instance, by following other conspecifics or applying individual learning strategies. An initial potential lack of foraging success in this period is likely compensated by the ongoing maternal provisioning with breast milk and regurgitated nectar during daytime. Our results contribute to the growing body of research on the ontogeny of mammalian foraging behavior in general.

Murciélagos (Chiroptera) del departamento del Tolima, Colombia: diversidad en un bosque húmedo tropical y actualizacion de la lista de especies del departamento

Los murciélagos (Chiroptera) representan el orden de mamíferos con mayor número de especies en Colombia, sin embargo, aún son escasos los estudios sobre la diversidad de este grupo taxonómico en algunas regiones del país. Objetivo. Describir la diversidad taxonómica de murciélagos en un bosque húmedo tropical (Reserva Agroecológica Santa Librada: RASL) en el departamento del Tolima, Colombia, y actualizar la lista de especies de los murciélagos en el departamento. Metodología. Se realizaron muestreos sistemáticos utilizando cinco redes de niebla y capturas manuales entre el 2016 y 2018 en la RASL, así como una revisión exhaustiva de registros sobre murciélagos del Tolima, a partir de fuentes literarias y especímenes en museos. Resultados. Para la RASL se registraron 19 especies pertenecientes a 13 géneros y 4 familias. Phyllostomidae fue la familia más representativa con 191 registros. Para el departamento se confirma la presencia de 99 especies de murciélagos. Conclusiones. La diversidad de murciélagos en el departamento del Tolima es mayor de lo que se ha considerado. Se adicionan 18 registros a la lista departamental y se identifican algunos vacíos de información y errores que pueden ser fuente de malas interpretaciones sobre la diversidad de murciélagos del Tolima reportada en la literatura. Finalmente, se reconoce la importancia de los parches de bosque húmedo tropical al norte del Tolima como sitios que albergan una alta diversidad de murciélagos, en su mayoría inexplorada.

Mind the gap: Effects of canopy clearings on temperate forest bat assemblages

Gaps in the forest canopy appear to play a major role in local species richness as they increase habitat heterogeneity and border effects. In the case of bats, these small clearings seem to play an important role as foraging and commuting sites. However, further research is required to set the actual role of forest gaps on bat biology in order to consider them as conservation targets in forest management. In this study, we test whether bat species richness and activity are higher in gaps within a large Scot pine (Pinus sylvestris) forest than in the adjacent tree covered control sites. We also test these differences in the forest specialists since this group is particularly sensitive to forest management. To investigate this, we used bat detectors in 9 gaps and their adjacent control points during ten nights in July - August 2016 and 2017. The trends resulting from the analysis of 228,108 bat calls support that species richness and activity of bat assemblages were higher in gaps than in the adjacent control points. A similar pattern was detected in the most sensitive tree dwelling bat species. These results stress the importance of gaps as useable areas for the forest bat assemblages and suggest the interest of managing gaps for bat conservation within large areas of continuous tree cover.

Spatial patterns of bat diversity overlap with woodpecker abundance.

Woodpecker diversity is usually higher in natural forests rich in dead wood and old trees than in managed ones, thus this group of birds is regarded as an indicator of forest biodiversity. Woodpeckers excavate cavities which can be subsequently used by several bird species. As a consequence, their abundance indicates high avian abundance and diversity in forests. However, woodpecker-made holes may be also important for other animals, for example, mammals but it has seldom been investigated so far. Here, we examine how well one species, the Great Spotted Woodpecker, predicts species richness, occurrence and acoustic activity of bats in Polish pine forests. In 2011 we conducted woodpecker and bat surveys at 63 point-count sites in forests that varied in terms of stand age, structure and amount of dead wood. From zero to five Great Spotted Woodpeckers at a point-count site were recorded. The total duration of the echolocation calls during a 10-min visit varied from 0 to 542 s and the number of bat species/species groups recorded during a visit ranged between zero to five. The local abundance of the woodpecker was positively correlated with bat species richness (on the verge of significance), bat occurrence and pooled bat activity. The occurrence of Eptesicus and Vespertilio bats and Nyctalus species was positively related with the abundance of the Great Spotted Woodpecker. The activity of Pipistrellus pygmaeus, Eptesicus and Vespertilio bats and a group of Myotis species was not associated with the woodpecker abundance, but echolocation calls of Nyctalus species, P. nathusii and P.pipistrellus were more often at sites with many Great Spotted Woodpeckers. Moreover, the probability of bat presence and the activity of bats was generally higher shortly after dusk and in middle of the summer than in late spring. We suggest that the observed correlations can be driven by similar roosting habitats (e.g., woodpeckers can provide breeding cavities for bats) or possibly by associated invertebrate food resources of woodpeckers and bats. The abundance of Great Spotted Woodpecker seems to be a good positive indicator of bat species richness, occurrence and activity, thus adding a group of relatively cryptic forest species that are indicated by the presence of the Great Spotted Woodpecker.

Systematic Review of the Roost-Site Characteristics of North American Forest Bats: Implications for Conservation

Continued declines in North American bat populations can be largely attributed to habitat loss, disease, and wind turbines. These declines can be partially mitigated through actions that boost reproductive success; therefore, management aimed at promoting availability of high-quality roosting habitat is an important conservation goal. Following the principles of the umbrella species concept, if co-occurring species share similar roost-tree preferences, then management practices targeting one species may confer conservation benefits to another. We conducted a systematic review of roost-site characteristics of thirteen species inhabiting eastern temperate forests to: (1) synthesize existing knowledge across species; (2) assess niche overlap among co-occurring species; and (3) evaluate the potential for currently protected species to serve as conservation umbrellas. We performed multivariate ordination techniques to group species based on the seven most-reported roost-site characteristics, including tree species, diameter at breast height, tree health, roost type, tree height, canopy closure, and roost height. Species sorted into three roosting guilds: (1) southern wetland inhabitants; (2) foliage specialists; and (3) dead tree generalists. Myotis septentrionalis and Perimyotis subflavus had significant roost-niche overlap with five and four other species respectively, and their existing protections make them suitable umbrellas for other bats in the North American eastern temperate forests.

Effects of land‐use change on functional and taxonomic diversity of Neotropical bats

AbstractHuman land‐use changes are particularly extensive in tropical regions, representing one of the greatest threats to terrestrial biodiversity and a key research topic in conservation. However, studies considering the effects of different types of anthropogenic disturbance on the functional dimension of biodiversity in human‐modified landscapes are rare. Here, we obtained data through an extensive review of peer‐reviewed articles and compared 30 Neotropical bat assemblages in well‐preserved primary forest and four different human‐disturbed habitats in terms of their functional and taxonomic diversity. We found that disturbed habitats that are structurally less similar to primary forest (pasture, cropland, and early‐stage secondary forest) were characterized by a lower functional and taxonomic diversity, as well as community‐level functional uniqueness. These habitats generally retained fewer species that perform different ecological functions compared to higher‐quality landscape matrices, such as agroforestry. According to functional trait composition, different bat ensembles respond differently to landscape change, negatively affecting mainly gleaning insectivorous bats in pasture, narrow‐range species in cropland, and heavier animalivorous bats in secondary forest. Although our results highlight the importance of higher‐quality matrix habitats to support elevated functional and taxonomic bat diversity, the conservation of bat species that perform different ecological functions in the mosaic of human‐modified habitats also depends on the irreplaceable conservation value of well‐preserved primary forests. Our study based on a pooled analysis of individual studies provides novel insights into the effects of different human‐modified habitats on Neotropical bat assemblages.