The examination of these data supports the contention that selection of the roost by S. kuhlii and its population was varies throughout the seasons among the habitats in Uttar Pradesh, India shows its wide distribution in the region. S. Kuhli was often observed to have a normally distributed average number of bats in a roost, with observed roost population sizes ranging from one to nine individuals per roost throughout the season, and of the roost type, resulting in the population of this species being healthy. As a result roost population depends on the space inside the roost, in the habitats like man-made structure as well as cavities in trees. While in the present study also found occasionally large numbers of S. kuhli in a palm tree with more than about three hundred individuals per roost. Earlier study has also reported that the colony size of S. kuhlii could be from a few individuals to several hundred (Smith and Xie 2008).
The cavities of roost in manmade structures, as well as trees, were playing a significant role in roost selection with the season. As a result, abandoned buildings and monuments offered more abandoned cavities or holes which was often occupied by S. kuhlii (Bhartiy and Elangovan 2020), moreover the monuments were more inhabited by S. kuhlii due to often less predator's effect was observed such as cat, snake and some other vertebrates predators etc. because this is a protected place that comes under the Archaeological Survey of India. The degree of protection supported the claim that the high protection habitat could yield a maximum population size; accordingly, the monuments showed a high degree of protection and thus a maximum colony size was observed followed by abandoned buildings and tree holes. The selection of high-quality roosts influences on survival and fitness of bats while a poor-quality roost invites predation. Consistently, Monuments provide a stable climate and higher protection from predation throughout the year even in adverse conditions. This could be the reason S. kuhlii preferred monuments for roosting over an abandoned building and tree holes. Trees provided the least level of protection and possibly stable climatic conditions compared to monuments and abandoned buildings. In unfavorable conditions like heavy rain or low ambient temperatures, found warm and dry conditions in the monument and abandoned building roost which is suitable for the healthy population of S. kuhlii, but did not found in trees like this. So buildings roost may play a crucial role during the critical life stages such as reproduction. Likewise many species of bats such as Megaderma lyra (Subbaraj and Balasingh 1986), Nycteris grandis (Fenton et al. 1990), Nyctalusleisleri (Shiel and Fairly 1999) and Antrozous pallidus (Lewis 1994), greater sac-winged bat, Saccopteryx bilineata (Bradbury and Emmons 1974; Bradbury and Vehrencamp 1976), greater mouse-eared bat, Myotis myotis (Dietz et al. 2009), spear-nosed bat, Phyllostomus hastatus (Santos et al. 2003), and free-tailed bats such as Tadarida brasiliensis and Mops condylurus (Vivier and van der Merwe 2001) use building as a shelter for roosting. Kurta (1992) reported that building-roosting bats gave birth earlier than their conspecifics roosting in foliage or trees that are the advantage of building-dwelling roost over tress dwelling roost. However, an earlier report suggested that on roosting ecology of S. kuhlii, modify the fronds of a fan palm, Livistona rotundifolia as tent roost and live (Rickart et al. 1989). Whereas trees provide the very least stable temperature, humidity and protection from the predators, therefore the selection of tree roosts was less compared to monuments and abandoned buildings.
Although the height of the roosts did not matter for the selection of roosts between habitats with the seasons, their roosts were often found at moderate heights, creating healthy roosts with colony sizes ranging from a meter to four meters. Speculation that moderate elevation assorted with resting places of other animals; these can be birds' nests as well as abandoned holes or cavities, resulting in a lack of precise detection of prey by predators. If high and low roosts can offer more predators, then high altitude roosts can be easily visible but low altitude roost predators can easily reach their roost, which is a life threat for bat survival. While few studies have been reported that high roosts also offer bats greater protection from predators (Rydell et al. 1996; Vonhof and Barclay 1996). Another reason may also play a crucial role in roost selection because Scotophilus kuhlii is a low flier which could be a possible reason for the preference of roosts at medium height. The cavity lengths of all roost types and across the seasons were positively correlated with population size which shows a significant role in roost selection. The length of cavities was varied among roost types and associated with protection. Further, the larger size of cavity length was providing more space to S. kuhlii for roosting. As a result, increasing the surface area of roosts. And varied among roost types and determined the fitness, i.e. roost occupancy. Therefore, perhaps the roost surface area was positively correlated with the population size. Previous studies report that the roost area may be an important factor in maintaining a healthy colony that helps in thermal maintenance during hibernation by social clustering (Veilleux and Veilleux 2004). The social organization directly depends upon space inside roosts used by bats, which limits the number and their ability to cluster together (Kunz 1982). Willis et al. (2006) reported that female big brown bats (Eptesicus fuscus) preferring roost with larger cavities and cavity volume was positively correlated with roosting-group size.
The shapes of roosts played a key role in the roost selection of S. kuhlii as the shape of roosts was associated with the protection level. Out of total roosts observed, the most preferred was 'T' shaped roost followed by '┐/┌' shaped, unbranched tunnel and crevice. The area of 'T' shaped roost was always higher than '┐/┌' shaped, unbranched tunnels and crevice, and thus the preference of 'T' shaped roost was higher than other types of the roost. During the study period, it was often observed that in "T" and "L"-shaped roosts, whenever, an attempt was made to catch them (S. kuhli), they migrated to other sites inside the roost. Besides, it played an important role in the breeding season, the roots thus becoming the maternity roosts. Because the puppies used to hide inside such a place in the absence of the mother. While nature like this, rare was found in another roost such as in un-branch holes and crevices.
The shape and size of roost directly affect the microclimate of roost (Entwistle et al. 1997; Vonhof and Barclay 1997; Williams and Brittingham 1997), which is directly related to the survival of bats and the developments of their offspring (Racey and Swift 1981; McNab 1982). There was no significant difference in the shapes of roost among three different seasons which shows the highest preference to 'T' shaped roosts showing significant differences among the shapes of the roosts with habitats.
The humidity of roosts was varied according to the seasons but did not matter on roosts selection of S. kuhlii, perhaps so there was no significant difference among the seasons except summer have the least humidity of the roosts. Previous studies have been shown that stable microclimates such as humidity and temperature would help lower the metabolic rate and energy expenditure of bats (Usman 1988). For successful reproduction, water, as well as energy, is an important factor (Kurta et al. 1990) and in small bats, water balance is very sensitive to temperature and humidity (Herreid and Schmidt-Nielson 1966). So many authors reported that bat roosts such as maternity roost, hibernacula roost with high humidity (Twente 1955; Herreid 1963; Clawson 1979; Van Der Merwe. 1987; Churchill. 1991; Baudinette et al. 1994; Clark et al. 1996; Betts 1997). High humidity reduces evaporative heat loss (Bakken and Kunz 1988; Webb 1995) and prevents dehydration (Vander Merwe 1973). Webb et al. (1995) also reported that the high ambient temperatures and RHs would tend to slow down the evaporative water loss of active bats. The warm and stable temperature of maternity roosts allows breeding females to reduce their energy expenditure that remains them active and homeothermic for a longer period. Previous studied reports that S. kuhlii selecting roosts with almost high and stable humidity and temperature without much change within the seasons (Shek and Chan 2006). Harbusch and Racey (2006) reported that buildings offered suitable temperatures during gestation and lactation periods that are critical for the survival of their offspring.
The present study showed that roost temperature was always slightly cooler than the ambient temperature in summer and warmer in winter, as a result taking advantage of the energetic saving during hibernation. Warmer of roost means lower the metabolic rate and increased rate of gestation, postnatal growth and long survival rate (Racey 1982; Kunz 1987; Zahn 1999). And also crucial factors for survival in winter, to low investments of energy, as a result, cooler roost needs more energy to warm compared to worm roost. Therefore, colonies of S. kuhlii were often maintained roost warm temperature and lower metabolic rate through the position of roost occupancy such as anterior and posterior. During summer and monsoon, it was occupied on the peripheral position of roost and in winter it was a shift to the interior position of the roost in monuments and abandoned buildings and the tree cavities. It was seen the roost sifting is a common of S. kuhlii over the season and adverse condition. In winter S.kuhlii sifting in a deeper hole/cavity into roost and in summer income out on the periphery.
The distinct characteristics between occupied roosts and unoccupied tunnels available adjacent to the occupied roost showed that S. kuhlii selects its roost wisely as the roosts influence survival and fitness. This study revealed that the factors such as roost cavity length and shape, roost surface area, roost height and associated protection influence the roost selection of S. kuhlii. The outcome of this study could be useful to understand the life history and future conservation of S. kuhlii. The roost height above the ground, tunnel length and height of roost entrance differed significantly between occupied roost and available unoccupied tunnels. However, the tunnel width did not differ significantly between occupied roost and unoccupied tunnel. It shows that the roost selection in S. kuhlii is influenced by various factors. Barclay et al. (1988) reported that roost of small to medium-sized entrances may provide better insulation and protect the interior from extremes of weather. Although, several studies have shown that several bat species (Tidemann and Flavel 1987) and other cavity dwellers (McComb and Noble 1981) uses cavities with entrance holes not much larger than themselves, thus excluding larger predators and competitors. In this study, the selection of roost by S. kuhlii was not random among available cavities. There were differences in roost height above the ground, length of the tunnel, the width of the entrance, the height of roost trees and dbh of occupied roost and unoccupied roost. The degree of protection plays a critical role in roost selection. The results showed that the degree of protection was driven principally by tunnel lengths, the shape of roosts and optimum roost height at different roost habitats. The degree of protection was highest in monuments followed by abandoned buildings and tree holes. A maximum number of individuals of S. kuhlii were found roosting in monuments followed by abandoned buildings and trees.