Morphometric analysis and roosting ecology of bat species Pteropus Medius in Mansehra, Khyber Pakhtunkhwa, Pakistan

Abstract Morphometric measurement and roosting ecology of Pteropus medius were aimed to find out in Mansehra district of KP, Pakistan. Total 3149 numbers of bats were found in eight biological spots visited; Baffa Doraha, Darband, Dadar, Jallu, Hazara University, Garhi Habibullah Chattar Plain and Jabori, in total 299 numbers of different species of trees including; Morus alba, Pinus raxburghi, Eucalyptus camaldulensis, Morus nigra, Grevillea robusta, Brousonetia papyrifera, Platanus orientalis, Ailanthus altissima, Hevea brasiliensis and Populus nigra. Morphometric features were measured and found vary according to sex of the bats. The average wing span, wing`s length from tip of wing to neck, from thumb to tip of wing and the body`s length from head and claws were recorded to be 102.98 cm, 49.07cm, 28.7 cm and 22.78 cm respectively in males while 93.67 cm, 44.83cm, 24.78cm and 22.78 cm respectively in female bats. Mean circumference of the body including wings and without wing were measured as 22.78 cm and 17.29 cm in males and that of female were 20.07 cm and 16.9 cm. Average length of thumb 3.64 cm, ear`s length 3.1 cm, snout 5.62cm, eye length were 1.07 cm for both sexes and length between the feet in extended position were16.3 cm. Generally different measurement of males bodies were found to be greater than female such as mean body surface area, mass, volume and pressure were found to be 2691.79 cm2, 855.7gm,1236.4 ml and 295.77 dyne/ c m 3 for male and 2576.46 cm2, 852.71gm,1207 ml and 290.2 dyne/ c m 3 respectively for female. While weight and density for both males and females bats were same with mean of 8.59 newton and 0.701 g/m3. Findings of current reports can add valued information in literature about bats, which can be used for species identification and conservation.

Now advanced method are advised to differentiate species with same morphological characters on the basis of variations in their phylogeny (Russo et al., 2006), but theses equipment are of high price to be purchased in many developing countries.Therefore bat zoologists in most part of the world use classical morphological traits and behaviour of bats to identify them (Nagorsen and Brigham, 1993;Harris, 1974).Among which factors such as skull biometry are also used for identifications (Hill and Smith, 1984;Jacobs et al., 2006).Identifications keys of chiropteran species are one of the authentic ways to recognize them (Daniel, 2009;Srinivasulu et al., 2010).Many reports on bats have been published across the globe such as Hutson et al. (2001); Houston et al. (2004); Russo et al. (2006); Jacobs et al. (2006); Weller et al. (2007); Pereswiet-Soltan (2007); Kelm et al. (2008); Kalka et al. (2008); Williams-Guillen et al. (2008); Whitaker and Karataş (2009); Srinivasulu et al. (2010); Ghazali and Dzeverin (2013); Rummel et al. (2019); Anderson and Ruxton (2020); MacCraken et al. (2021).But, no proper consideration has been offered towards bats and few reports are available on this regards from the northwestern part of Pakistan which is the habitat of many numbers of species of animals.Current study can be value addition to present literature on bats as current site of study have divers species of Bats which need exploration.

Study area
Current study was carried out in Mansehra (34.3313°N, 73.1980°E) district of PK (Pakhtunkhwa), Pakistan.Where Eight (n=8) biological spots were visited to check different sites that where could be find communities of bats.

Data collection
Net and slingshots were used to capture bats samples (Pteropus medius) from eight selected sites.All the safety steps were followed and transported to parasitology laboratory, Department of Zoology, Hazara University, Khyber Pakhtunkhwa, Pakistan for further morphometric analysis.

Morphometric analysis
The bats samples were anaesthetized with the help of chloroform and killed in vacuum chamber.Bats were fitted on white sheets with help of paper pins and the body parts such as width, and length as well as circumference was measured with scale.While body mass were calculated by digital scales.To get volume of each specimen of bats graduated cylinder were used and other parameter such as pressure, weight and density were evaluated through chemical formulae; Pressure p = w/A, where (w) are the weight of bats and (A) area.
Density D = m/V, (m) are the mass of bats and (V) is volume Weight W = mg, (m) are mass and g gravitational acceleration

Introduction
Vertebrate diversity is severely affected due to increased anthropogenic activities in aquatic and terrestrial habitats.Ecosystem changes result in changes to the habitats of species (Hassan et al., 2021a, b).The biological diversity of each ecosystem depends on the ecological services delivered (Hassan et al., 2023).Chiropteran are different from all other mammals which have wings, make them able for flight freely, and are second major mammalian order after rodents, and are diverse enough almost 1,232 species of bats are known which contribute to one fourth of 5,487 total mammal and contribute 20% out of total wild animals.Pakistan's ecosystems contain a broad variety of life and wealthy natural habitats (Hassan et al., 2020).In Pakistan bats comprise about one fourth of the known mammalian species which comprise 50 species with 26 genera and 8 families (Roberts, 1997;Simmons, 2005;Simmons, 2010;Schipper et al., 2008;Kunz et al., 2011).In Indian subcontinent 119 bats species have been reported (Bates and Harrison, 1997).Among which the contribution of bats from Pakistan are 56 species (Mahmood-ul-Hassan et al., 2009).Bats were adapted to access to a varity territories, having most climatic zones and earthbound land types, it's feeding on fruit, leaves, nectar, flowers, fish, blood, small mammals, and insects but the majority are feeding on insects (Schnitzler and Kalko, 2001).Pteropus medius (Indian flying fox) have accommodated in sub order megachiroptera in the family Pteropodidae which live in colonial form in trees that keep them safe from various dangers (Richmond et al., 1998;Cheke and Dahl, 1981;Rainey and Pierson, 1992).These Indian fruit bat have been reported to be inhabitants of trees such as Acacia species, Ficus, Bauhinia, Tamarindus indica and Casurina Samanea saman species (Chakravarthy et al., 2009).While in Pakistan these are reported in trees like Ficus bengalensis and Broussonetia papyifers (Roberts, 1977).The habitat preference depends on factors such as secure from predators, environmental stresses and resource availabilities (Kunz, 1982).They use special unique sense echolocations to locate their niche and preys etc. (Schnitzler et al., 2003).Bats play important role in ecosystem such as regenerations of forest and maintain plants populations' structure and distribution as well as in food chain (Heithaus et al., 1975;Fleming et al., 1998;Estrada et al., 1993).
Humans' activities badly affect biodiversity at all level.Degradation of habitat mostly brought many bat species to the side of extinction.Monitoring of bats for long time is thus necessary to know the negative impact of human on the diversity of bats all over the world (Meyer et al., 2010).Unluckily 8 species of bats have gone through extinction, and among which of bats which feed on fruits are at high risk (Clawson, 2002).As human population increased deforestation occur for agricultural and housing purposes have vanished roosting sites of these bats (Mickleburgh et al., 2002;Fujita and Tuttle, 1991;Mildenstein et al., 2005).In Pakistan less attention has been given to conservation of bars (Butt and Beg, 2001).The correct identification of these species is key step to conserve them.In the world, scientists use many approaches and processes to identify different species of bats.

Roosting site analysis
Different roosting sites and trees species were noted in each biological site and direct roost calculation method were used for Pteropus medius colonies calculation (Rodríguez-Herrera et al., 2008).

Statistical analysis
Descriptive statistics, ANOVA and Pearson correlation were applied to measure mean variances and correlation, previous verification of normal distribution and variance homogeneity (Zar, 1999) by using SPSS 18, and ORIGIN PRO 9.0 for graphing.

Morphometric profile
Morphometric measurement of the current study showed that generally size of different body part of male bats is larger than that of female bats.The average measurements in males bats were recorded to be wing span (102.98 cm), wing`s length from tip of wing to neck (49.07cm), from thumb to tip of wing (28.7 cm) and the body`s length from head and claws (22.78 cm).While 93.67cm, 44.83cm, 24.78cm and 22.78cm respectively in female bats.Mean circumference of the male body including wings were 22.78 cm and without wing were measured as 17.29 cm.While these measurement in female bats were 20.07 cm and 16.9 cm respectively.In the same way mean body surface area, mass, volume and pressure in male bats were found to be 2691.79cm 2 , 855.7gm, 1236.4 ml and 295.77dyne/ 3 cm respectively.
While these measurement in female bats were measured as body surface area 2576.46 cm 2 , mass 852.71gm, volume 1207 ml and pressure 290.2 dyne/ cm .However some measurements were same in both sexes and found exactly equal in length such as average lengths of thumb 3.64 cm, snout 5.62cm, ear`s length 3.1 cm, length between the feet in extended position 16.3cm while eye length were found to be 1.07 cm.Weight and density for both males and females bats were also same with mean of 8.59 newton and 0.701 g/m 3 respectively (Tables 1-2).And at 5 th site Dadar n=34 trees (Grevillea robusta n=7, Eucalyptus camaldulensis n=12, Pinus raxburghii n=15).6 th site Jabori n=33 (Pinus raxburghi n=16, Populus nigra n=11, Morus alba n=6).And 7 th Jallu numbers of trees were n=30 (Hevea brasiliensis n=21, Melia azedarac n=9).While at 8 th biological site Hazara University trees counts were n=20 (Eucalyptus camaldulensis n=13, Pinus raxburghii n=7) (Table 3).

Eucalyptus camaldulensis 13
Table 2. Mean of mass, weight and other parameter of both male and female bats.1).

Statistical results
There were no statistically significant difference among mean of bats colonies at all biological site as the result of one way anova showed that P > 0.05 (P=0.833).From this result we may predict that bats have no sites preference according to current data.However these bats colonies were dependent on trees numbers and were strong positive correlated with numbers of trees present at each site (r = 0.930, p =0.000).Which means that numbers of trees have direct impacts on bats colonies.In other words high numbers of trees in biological spots would have high numbers of colonies according to correlation result of current study.Furthermore the result of correspondence analysis showed that bats prefer to roost on Populus nigra as maximum colonies were found on tree species Populus nigra (Tables 4-5).

Discussion
Identification of bats specimen and different biometrical features were measured through externally morphological analysis (Jacobs et al., 2006;Hill and Smith, 1985).The average wing span of male bats were found to be 102.98 cm and 93.67 cm in female in current study as compared to previously published reports such as Simmons (2005) where the wingspan was 884±18.17mm of the killed P. medius.Wing span have been reported in range of 112.58 ±1.90 cm (Khan et al., 2021).Thumbs have been reported for adhering to trees as similar opinion was assumed by (Bennett, 1993).Furthermore, other measurements of the current study such as length of snout 5.62 cm, ear were 3.1 cm, length amid the feet 16.3 cm in stretched position and length of eye were 1.07 cm.The possible reason behind the difference among current morphometric measurements with other published reports may be due to body size, age and sex of the bats.As many published reports have showed, generally male bat of species P. medius are larger in size as compared to female bats (Khan et al., 2021;Marimuthu et al., 1998;Thatcher, 2004).However, Surface areas of bats in present study were 295.77cm 2 for both sexes.Many reports have been showed that Surface areas of bats may be varied according to sex, as body surface areas were reported by Kumar et al. (2016) to be 2691.79cm 2 male and that 2576.46 cm 2 for female.In current study average mass of bats were 869.6 gm, weight 8.59 newton and density 0.701 g/m 3 in both sexes.Which were in similarity range with other published reports such as published study of Khan et al. (2021) have reported the mass of male bats 855.7 gm and average mass of female bats 852.71 gm, Similarly Roberts (1997) reported body mass of bat 600 to 1600 gm and reported that females were usually smaller than males.On the other side Rahman et al. (2015) have reported larger value of average mass of bats 1121.9±38.9gm.This difference with current report may be due to variances among different factors of bats for instance age, sex and habitat of different biological spot.In addition present study showed that the numbers of trees in biological spots have direct positive impacts on bats colonies as these roosting trees are shelters and keep them safe from predators and environmental stress.Same reports have been reported by different researchers such as Rainey and Pierson (1992), Richmond et al. (1998).

Conclusion
Current study showed that different biological spot sites have different counts of bats colonies which were dependent on trees numbers at each site.Furthermore as their measurement have showed the male bats were larger in size than female.Studies like this should be conducted to accurately identify each and every species of bats and campaign, seminars and program should be arranged regarding bats to conserve them.

Figure 1 .
Figure 1.Mean of bats at different biological site.

Statistics Factors (Length and width) N Minimum Maximum Mean (cm) Std. Deviation (Male bats)
N: Number of samples of bats measured.

Table 3 .
Number and types of different roosting trees at each site.

Table 4 .
Non-significant differences among the means of bats at each site.

Table 5 .
Correlation between numbers of trees and bat colonies at all sites.Rehbar, B. et al.