Search

Abstract In many temperate animals, reproductive cycles coincide with seasonal weather changes resulting in behaviour changes such as movement and habitat selection. In social species, these physiological and environmental changes can alter the costs and benefits of social interactions, impacting the structure of animal groups. In little brown myotis (Myotis lucifugus), a gregarious bat occupying much of North America, the pregnancy and lactation phases present different challenges to energy balance and maternal movement, and reduced forage distance has been observed during the lactation period. As such, we hypothesized that differences between reproductive phases alter the roost switching decisions of individual bats and therefore the overall group structure of little brown myotis maternity colonies. We observed that adult females were less likely to switch roosts during the lactation period even when accounting for changing weather conditions. This shift in roost switching behaviour may be the source of observed differences in group structure between reproductive periods. We reported a decline in network cohesiveness, but no meaningful variation in individual roost fidelity and association strengths of dyads between reproductive phases. These results support the contention that reproductive processes in female little brown myotis influence sociality and overall roosting patterns within maternity groups.

Reproductive bats switch frequently among roosts to select the most advantageous microclimates and avoid predation or parasitism. Many bats use human-made structures, such as bat boxes and buildings, in areas where natural structures are less abundant. Artificial structures, which may be warmer and larger than natural structures, may affect bat behavior and roost use. We studied Yuma Myotis (Myotis yumanensis) and Little Brown Myotis (M. lucifugus) in artificial structures at two sites to understand how roost conditions and reproductive pressures influenced roost switching in maternity colonies in the lower mainland of British Columbia, Canada. During summer 2019, we used Passive Integrated Technology (PIT tags and scanners) to track daily roosting locations of individuals. Yuma myotis and little brown myotis used at least five roosts at each site and switched almost daily among roosts. Bats were less likely to switch from roosts that were 25–42°C and switch roosts during lactation, particularly when the young were nonvolant. Our findings suggest that reproductive female myotis that use artificial roosts seek out warm roosts to limit energy expenditure and speed up offspring development. We also found that bats boxes were not thermally stable environments and the behavior of bats reflected temperature variability. Land managers should ensure that multiple nearby roosts are available to maternity colonies, as reproductive bats require a range of temperatures and roost types during summer. [ABSTRACT FROM AUTHOR]

Throughout the Midwest United States, agricultural and urban development have fragmented natural areas, with a disproportionate effect on forests and wetlands. The resulting habitat loss, compounded with the spread of white-nose syndrome (WNS), has caused precipitous population declines in several forest-obligate bat species. In 2019, we discovered a remnant northern long-eared bat (Myotis septentrionalis Trouessart) maternity colony in a small forest fragment adjacent to a restored wetland in northeastern Indiana, USA. We investigated roost selection in this colony during the summers between 2019 and 2021 by attaching radio transmitters to northern long-eared bats and tracking them to day roosts. We measured tree, plot, and landscape-level characteristics for each roost and for a randomly selected available tree in the same landscape, then compared characteristics using paired t-tests. Over 70 net nights, we captured and tracked 4 individuals (1 juvenile male, 1 post-lactating female, and 2 lactating females) to 12 different roosts. There were, on average, 3.5 times more standing dead trees (snags) in plots around roosts compared to available trees (t = −4.17, p = 0.02). Bats in this maternity colony selected roosts near a stretch of flooded forest (which contained 83% of roosts) dominated by solar-exposed, flood-killed snags. These roosts likely provide warm microclimates that facilitate energy retention, fetal development, and milk production. By describing roosts within this landscape, we provide insight into the resources that enable an endangered bat species to persist in urbanized forest fragments. [ABSTRACT FROM AUTHOR]

For four decades, there have been changes in the ranges of many bat species in Europe, particularly shifts in their northern limits. This phenomenon is more spectacular for migratory species than sedentary ones, especially for representatives of the genera Pipistrellus and Hypsugo. Kuhl’s pipistrelle Pipistrellus kuhlii (Kuhl, 1817) is the one of western Palaearctic bat species with conspicuous range expansion—in the last three decades, the species has rapidly expanded and colonised new territories both northwards and westwards. In Central Europe, two genetic lineages occur that are also quite different morphologically: P. kuhlii kuhlii (hereafter P. kuhlii) and P. kuhlii lepidus (hereafter P. lepidus). The contact zone between these two lineages passes through Hungary and Slovakia, although the real range of distinct lineages and/or morphotypes are still unclear. The first records of P. kuhlii from Poland (probably belonging to P. lepidus) come from Warszawa, central Poland (2004) and Zawiercie, southern Poland (2005): both specimens were males, found in December in buildings. Since then, there have been further reports of the presence of this species in Poland—occurring mostly in large cities along the valleys of large rivers such as the Wisla and Bug, from both periods of activity and hibernation. In subsequent years in Poland the occurrence of only P. lepidus has been confirmed, while P. kuhlii has been recorded from southern locations in the Carpathian Mountains in Slovakia. This paper describes the first record of this species from Poland, further indicating the existence of a maternity colony. In mid-July of 2020, a non-volant juvenile male was found in Krakow, Krowodrza district (50°04'11.7" N, 19°54'55.9" E). Initially poorly visible diagnostic features have become unambiguous with development and similar to those in P. kuhlii: narrow pale wing margin and orange penis colouration. After about two months in captivity, a mature individual capable of flying was released at the site where it was found. The presence of a maternity colony indicates that this species (i) has been part of the Polish fauna for several years, and (ii) its range in Poland possibly expands much further north.

The free-tailed bat (Tadarida brasiliensis) likely migrates from the southwestern USA and northern Mexico to the south of Mexico to spend the winter in the Cueva San Francisco (CSF), which is the southernmost known roost of the species. In this study, we examined colony size and composition of the free-tailed bats at the CSF for two annual cycles to know if these parameters fluctuate throughout the year and whether these fluctuations indicate that the CSF is a winter roost. From February 2018 to November 2019, we conducted monthly observations and captured bats with a mist net of 12 × 2.6 m to determine sex, age, reproductive status, and relative abundance. The duration of the emergence flight (DEF) was also recorded. We detected significant fluctuations in colony size that were caused by the movement of pregnant females in spring, lactating and post-lactating females and males in summer, and by females and males in autumn and winter. The CSF was occupied all year-round by females and males. Our results indicate that the cave is a winter roost for females and males, a transitional roost for pregnant females that form their maternity colony elsewhere in summer, and a temporary roost for males in summer. We suggest that the CSF is crucial for the conservation of the free-tailed bat. [ABSTRACT FROM AUTHOR]

Two lactating females of Brandt’s bat were radio-tracked during 26–28 June 2016 and 14–20 June 2017 in the Polesie State Radiation-Ecological Reserve (Khoiniki district, Gomel region). Four tree roosts of nursery colonies of Brandt’s bat were found. The roosts were detected at the dead oak trees in an old oak forest at a distance of 142–870 m from each other. Roosts were located in trunk cracks and behind peeling bark at a height of 4–16 m above the ground. Visual inspection during the evening revealed that the maternity colony consisted of 8–10 individuals of Brandt’s bat. In 2016, there was a mixed colony of Brandt’s bat and the soprano pipistrelle (Pipistrellus pygmaeus). This is the first documented record of maternity colonies of Brandt’s bat and the easternmost finding localities of this species in Belarus.

Among mammals, bats present the greatest diversity in reproductive strategies. In this study we analyzed reproductive and population characteristics of Myotis nigricans over one year in a temperate region in Brazil. We carried out the samplings in an anthropic roost, in Pedras Grandes municipality, Santa Catarina state. We captured bats monthly with mist nets installed at the roosts exits and identified the captured individuals according to sex, reproductive condition and age. There was greatest number of females than males. Population size was estimated from 569 to 1050 individuals. Births occurred mainly from September to January, with more than one pregnancy event along the year, evidencing a seasonal and bimodal polyester pattern. The reproductive period of M. nigricans in southern Brazil is similar to the records made in other regions. Despite of it, there is no pattern along its distribution range. [ABSTRACT FROM AUTHOR]

Abstract: The consequences of different management strategies following natural disturbances are a matter of global concern. In former production forests around the Northern Hemisphere, the abandonment of intervention, such as removal of dead wood, after outbreaks of bark beetles has been increasingly promoted to regain more natural conditions. However, many focal species of conservation, such as the barbastelle bat Barbastella barbastellus, do not primarily depend on dead wood but might respond indirectly to disturbance‐induced changes of forest structural attributes. We investigated the response of B. barbastellus foraging activity and roost selection by combining acoustic surveys, radio telemetry, and airborne light detection and ranging (LiDAR) to characterize B. barbastellus habitat use on different scales. B. barbastellus foraging activity increased with increasing canopy opening. Maternity colonies were recorded exclusively in trees killed by bark beetles. Bats preferred roost trees with a higher volume (m3 ha−1) of live trees in the surrounding, and trees with on average larger diameters than nearby control trees. Our results revealed that outbreaks of bark beetles result in forest structural attributes that are suitable habitat for B. barbastellus. Salvage logging, i.e., the removal of beetle‐affected trees, generally deteriorates the positive effects of bark‐beetle outbreaks on the foraging and roosting habitat of B. barbastellus. We recommend maintaining snags of large diameter if salvage logging is mandatory. [ABSTRACT FROM AUTHOR]

Many temperate-climate bats migrate tens to hundreds of kilometers from hibernacula to summer habitat each spring and in the opposite direction each fall. Understanding the timing of migration can help reduce the risk of disturbance via anthropogenic activities, guide effective management and determine future impacts of a changing climate. We examined the influence of weather and day of year on the arrival and departure of Indiana bats (Myotis sodalis) monitored at a summer maternity colony site in central Indiana from 1998 to 2014, using emergence count data to track the timing of bat presence during the spring and fall migration seasons. We used an information theoretic approach to compare 23 models that predicted bat presence as a function of weather, climate and lunar illumination; these models predicted arrival of the first Indiana bat and the first observation of a colony in spring, and the last observation of a colony and the last bat observed in fall. Bats embarked on spring and fall migrations to the maternity colony area at approximately the same time each year (arriving ∼3 April and departing ∼7 October) and variation was accounted for by changes in weather. Spring arrival and colony formation were predicted by higher temperatures (x = 22.5°C for colony formation) and precipitation and lower wind speeds, whereas lower temperatures (x = 25.9°C for colony breakup) and precipitation and higher wind predicted colony breakup and departure in fall. Spring migration coincided with periods of increased winds and thus, we advocate for higher cut-in speeds for wind turbines during bat migration seasons. Resource managers should consider the entire time that bats are on the summer landscape when defining regulations and implementing conservation measures. [ABSTRACT FROM AUTHOR]

Copyright of Fire Ecology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In an attempt to fill knowledge gaps relating to genetic structure in the endangered gray bat (Myotis grisescens), we investigated geographic patterns in multilocus microsatellite DNA (msDNA) genotypes and mitochondrial DNA (mtDNA) haplotype frequencies across eight primary hibernacula. Isolation-by-distance (IBD) was absent in the msDNA data and no bottlenecks were detected, with genotypic diversity (AR = 6.52, Ho = 0.64) and overall genetic differentiation (FST = 0.024, P < 0.001) being comparable to other Myotis and North American vespertilionids. Genetic structure (ΦCT = 0.063, P < 0.001) among groups of populations (K = 2) was observed. We also identified a pattern of slight east-west regional genetic structure, likely attributable to the natural barrier of the Mississippi River Alluvial Plain, in the haplotype data (ΦCT = 0.086, P < 0.05), along with moderate IBD (r = 0.486, P < 0.05). Though genetic differentiation among populations was generally low, significant interpopulation genetic structure, likely arising from some degree of philopatric behavior and a lack of hibernacula-associated mating sites within the Mississippi River Alluvial Plain, was observed. [ABSTRACT FROM AUTHOR]

Indiana bats ( Myotis sodalis) are capable of exploiting ephemeral resources in structurally complex, interior forests. Consequently, surveying for this species is difficult, and even in areas harboring known populations, documenting presence remains a challenge. We aimed to determine what factors affected probability of detection ( p) and site occupancy (Ψ) for Indiana bats when sampling with acoustic bat detectors near an active maternity colony. From May to August 2012 and 2013, we passively sampled 71 random points near Indianapolis, Indiana, with Wildlife Acoustic SM2BAT+ detectors. On average, sampling occurred ∼2.2 km from maternity colony roosts, which contained ≥ 150 bats by mid-July. Habitat and landscape covariates were measured in the field or via ArcGIS. We reduced model covariates with Pearson's correlation and principal component analysis. Indiana bat calls were identified using Bat Call ID software. We used Presence 6.1 software and Akaike's Information Criteria to assess models for detectability and occupancy. Detectability of Indiana bats increased as 'forest closure' and mean nightly temperature increased, likely due to reduced clutter and increased bat activity, respectively. The null model best explained Ψ, but models were likely underpowered from few Indiana bat detections. Higher rates for Ψ were observed near agricultural lands, indicating this cover type may fulfill certain habitat requirements for Indiana bats within the study site. Overall, detection rates were low even when sampling near a concentrated population on its maternity grounds, likely due to limitations inherent to bat detector technologies. Managers should be aware of the limitations of using passive acoustic sampling as a means by which to document presence-absence for this endangered species. [ABSTRACT FROM AUTHOR]

After accounting for body size, bats have the longest lifespan of all mammals. Little Brown Bats ( Myotis lucifugus) are one of the most common and widely distributed mammals in Canada; however, little is known of their longevity. We captured bats in Cypress Hills Interprovincial Park, Saskatchewan in May 2015, as part of long-term bat research in the Park that began in 1991. On 31 May 2015, we captured 16 female Little Brown Bats in a maternity colony, including a bat that was originally captured and banded as an adult in 1993. This capture record indicates that the female bat was at least 23 y old and this record represents the oldest bat record in Saskatchewan. Little Brown Bats in eastern North America have declined dramatically due to white-nose syndrome, a fungal disease responsible for the quickest wildlife die-off in history. Pre-infection natural history data for Little Brown Bats are important as the disease spreads through central Canada. [ABSTRACT FROM AUTHOR]

Highlights: [•] Network characteristics of Myotis septentrionalis may vary among colonies. [•] Individual maternity colonies occupy distinct roosting areas on the landscape. [•] Simulations suggest colony fragmentation is related linearly to roost loss. [•] In simulations, colonies are robust to loss of <20% of roosts. [Copyright &y& Elsevier]

Most eastern North American Myotis roost in forests during summer, with species forming maternity populations, or colonies, in cavities or crevices or beneath the bark of trees. In winter, these bats hibernate in caves and are experiencing overwinter mortalities due to infection from the fungus Pseudogymnoascus destructans, which causes white-nose syndrome (WNS). Population recovery of WNS-affected species is constrained by the ability of survivors to locate habitats suitable for rearing pups in summer. Forests in eastern North America have been severely altered by deforestation, land-use change, fragmentation and inadvertent introduction of exotic insect pests, resulting in shifts in tree distributions and loss of large-diameter canopy-dominant trees. This paper explores patterns in use of tree roosts by species of Myotis across Canada and the United States using meta-data from published sources. Myotis in western Canada, the Northwest, and Southwest selected the largest diameter roost trees and also supported the largest maximum exit counts. Myotis lucifugus, M. septentrionalis and M. sodalis, three species that inhabit eastern forests and which are currently experiencing region-wide mortalities because of WNS, selected roosts with the smallest average diameters. Recovery efforts for bark- and cavity-roosting Myotis in eastern North American forests could benefit from management that provides for large-diameter trees that offer more temporally-stable structures for roosting during the summer maternity season. [ABSTRACT FROM AUTHOR]