Roosting Ecology of Bats

Many of the cave-dwelling bat species are under threat, because of destruction of caves such as filling or converting for other uses, human disturbance and loss of foraging habitats. In this study, cave-dwelling bat species and habitat preferences were investigated in Northwest of Central Anatolia in spring, summer and winter. Investigations were performed in 26 caves hosting (15) and not hosting (11) bats. Temperature, humidity, length of caves, distance to nearest settlement, paved road, water source, agricultural area; height, width and orientation of cave entrance and activity of cave values were determined. Seven out of 10 recorded bat species were evaluated as new records for the area. There was a significant preference for caves which were situated at lower altitude, far from paved road and close to water source. Bats were mostly found in longer caves. Caves with entrance oriented to northwest and southeast were preferred by bats. Undertaking effective conservation measures to maintain especially eight threatened bat species which were found in the region should be a priority for conservation management plans.

Bats utilize limited types of bridges as roost sites during the day, but few studies have described daytime microclimatic variability or the seasonal use of these bridges, especially in the eastern United States. We surveyed bridges in southeastern North Carolina used by bats as day roosts on a biweekly basis between July 2002 and February 2003. During each survey, we documented bat diversity and two microclimate parameters (temperature and light) thought to influence roost-site selection. Two-hundred and nineteen individuals of three species (Myotis austroriparius, Corynorhinus rafinesquii, and Pipistrellus subfiavus) roosted under 15 of the 423 bridges and culverts surveyed. Some bridges served as daytime roosts during the entire study period. The number of bats and number of colonies increased during the summer and then decreased throughout the fall and winter. Roost and control microclimate differed significantly, with bats preferentially selecting warmer and darker daytime roost sites. Roost and control rnicroclimate changed significantly throughout the latter half of the study period as deciduous trees lost leaves and ambient temperatures dropped. The decline in number of bats and number of colonies was more closely correlated with changes in temperature than in light intensity.

During day roosts surveys for bats in the Parque Nacional Natural Tayrona, northern Colombia, we found occupied tents made of leaves of the palm species Sabal mauritiiformis and Cocos nucifera. We found Artibeus jamaicensis and Uroderma convexum using the tents, with groups of U. convexum ranging from 1 to 23 individuals, and a single occurrence for A. jamaicensis. A tent was simultaneously occupied by U. convexum and Thecadactylus rapicauda (Squamata). Although tent-roosting is known to be a widespread behavior for stenodermatine bats, these are the first observations of tent-roosting bats in northern Colombia and highlight a high potential for finding tent-using bats in the region. RESUMEN. Uso de tiendas de hojas por Artibeus y Uroderma (Chiroptera, Phyllostomidae) en el norte de Colombia. Durante una búsqueda diurna de refugios de murciélagos en el Parque Nacional Natural Tayrona, en el norte de Colombia, encontramos tiendas hechas de hojas de las palmeras Sabal mauritiiformis y Cocos nucifera. Encontramos a Artibeus jamaicensis y Uroderma convexum utilizando las tiendas, con grupos de U. convexum que variaban de 1 a 23 individuos y una sola ocurrencia de A. jamaicensis. Una tienda era ocupa-da simultáneamente por U. convexum y Thecadactylus rapicauda (Squamata). Aunque se sabe que el acampar en tiendas es un comportamiento generalizado para los murciélagos stenodermatine, estas son las primeras observaciones de murciélagos tienderos en el norte de Colombia y destacan un alto potencial para encontrar murciélagos que usan tiendas en la región.

In Miami-Dade County, FL USA, Florida Bonneted Bats, Eumops floridanus, have been documented to utilize a wide array of both natural roosts and artificial structures, including bat houses. Here, we provide a more comprehensive summary of day roosts for the Florida Bonneted Bat in Miami-Dade County as an addition to the data included in Webb et al. 2021 and provide suggestions for improving the comparison of body condition scores for the species across diverse landscapes. These additional data suggest new conclusions on day roost selection, characterization of day roosts, and range for the species. This species has been found to roost across the heterogeneous urban, suburban, semi-natural, and agricultural landscapes found throughout Miami-Dade County, and their roosts are not confined to a particular area or region. Roost site selection does not appear to be associated with a particular architectural
style in developed areas and potential roost cavities can be found in a diverse array of natural and artificial structures. This more comprehensive dataset will provide for a more accurate assessment of the species within developed landscapes and better guide conservation measures and strategies.

Background. The territory of the Samarskaya Luka is known as the site of the
largest winter concentrations of M. daubentonii in Russia, where annually up to
2,500 animals gather in various artificial dungeons. Spatial differentiation occurs
between individuals of different sex at the end of hibernation. Most reproductive
females leave the wintering area migrating to more distant areas. Males remain in
the wintering areas, as well as a very small number of non-reproductive females.
Nulliparous females do not waste energy on bearing, birth and feeding of the young,
so the extent of their summer activity and the utilization of space and time should be
as much as possible similar to those of males. The work purpose is to study the character
of utilization of habitable space and forage time by M. daubentonii remaining
in the area of wintering in the Samarskaya Luka conditions.
Materials and methods. The research was conducted in July 2016 in the north of
the Samarskaya Luka (Samara region, Russia). We caught and attached radio transmitters
to one adult nulliparous female and one adult male for the purpose of detecting
animal shelters and analyzing the extent of their night activity and forage space
utilization. As an aid, ultrasonic detection was used.
Results. The main summer shelters for males and nulliparous females in the
Samarskaya Luka are hollows of deciduous trees. The evening flight begins in
50–60 minutes after sunset. Animals spend on average 53.2 ± 1.8 % of the total
night time on night activity. The peak activity of the species is in the period from
22.30 to 23.30 (Moscow time). The Return to shelter takes place at 01.00 – 02.00,
with the second departure before dawn unregistered. The sizes of the female’s habitat
and the male’s one were 384.2 and 306.2 ha, respectively. There are five types of
hunting spaces. Most of the night time the animals spend hunting in the above-water
areas (70.2 and 83.9 % for the female and the male, respectively), where they mostly
stay near the shore. However, there have been identified some differences in the nature
of the use of habitats. The female spent more time than the male to feed over the
river bed, under the canopy of the forest and over the streets of villages. The male
fed much longer over the surface of the water in the immediate vicinity of the shore.
There were no significant differences between the observed individuals only when
hunting on forest edges. No intraspecific and interspecific aggressive contacts were
noted during the observations. Conclusions. In the conditions of the Samarskaya Luka, the nulliparous female
and the male of M. daubentonii, remaining for the summer in the wintering areas
have similar habitats and activity parameters. Most of the night time animals spend
on hunting in the above-water areas of coastal zones. The female and the male have
differences in the nature of habitat use, which can be explained by a decrease in
competition for spatial and forage resources when a high density of animals is attained
in individual feeding areas.

The selection of roosts is considered a critical factor to the survival of Noctilio albiventris. Thus, we
located and identified N. albiventris day roosts in the Pantanal, near the Miranda River. We
identified four species of tree: Banara arguta, Inga vera, Ocotea diospyrifolia and Vitex cymosa.
Additional studies are important to understand the impact of specific requirements in the
selection of roosts for Noctilio albiventris and to compare the observed patterns in different
environments.

Sharing resources with conspecifics or heterospecifics can involve costs like increased competition or higher pathogen infection risks as well as benefits such as information on the location, quality and availability of resources. Depending on the consequences of sharing resources, the responses of individuals towards resources used by conspecifics and heterospecifics can range from ignoring them through avoidance to attraction. Within bats it is well known that colony members share information about day roosts and roost switching is often coordinated within the colony. However, little is known about roosting interactions between distinct colonies of conspecifics or heterospecifics. In this study, we investigated roosting interactions between five co-occurring bat colonies that belong to three forest-living species (Myotis bechsteinii, Myotis nattereri, Plecotus auritus). Occupied roosts were continuously monitored with an automatic RFID system over three maternity seasons. Furthermore, we used simulations to test whether colonies preferentially occupied recently used roosts of other colonies. We found no evidence that the roosting behaviour of the M. bechsteinii colony was influenced by the co-occurring heterospecific colonies. In contrast, P. auritus and M. nattereri frequently explored roosts of conspecific and heterospecific colonies, respectively. Nevertheless, with largely separated roosting ranges, the three P. auritus colonies avoided occupying roosts that had been inhabited by conspecific colonies. In contrast, M. nattereri specifically occupied recent roosts of all three P. auritus colonies. Our results give evidence that co-occurring colonies of conspecific and heterospecific bats can influence each other's roost usage. Our findings have implications for both our understanding of inter-and intraspecific resource sharing among distinct social groups and the management of forest-living bats that are of conservation concern.