Doha: College of Arts and Sciences at Qatar University (QU) graduate Maktom Abdulrahman, B.Sc. in Environmental Sciences, has conducted Qatar’s first nationwide bat survey.
Bats are considered a keystone species, making them an essential component of many ecosystems and serve as bioindicators for many environmental stressors. Therefore, it is vital to study and keep track of them. This study aims to provide information on the bat species and their distributions in the country and the potential influences on bat distribution of land-use changes.
Two species of bats have been previously recorded in Qatar: Geoffroy’s trident leaf-nosed bat, Asellia tridens, and desert long-eared bat, Otonycteris hemprichii. The bat survey was conducted between September 2018 and April 2019.
The research looked for potential roosting and activity areas such as sinkholes/caves, old water wells, bridges, and farms, focusing on finding the sinkholes/caves.
Maktom was able to find six sinkholes and caves. The study also attempted to cover as much of the country as uniformly possible under logistical constraints (56 sites in total). The bat detector was moved in and around the site by a 4x4 vehicle and/or on foot. If it detected any bat call during that period, the bats were classified either “present” or “absent” at that site.
The study ranked a site as a roost when: 1) more than two bats were visibly detected emerging from the structure shortly after sunset, and 2) the site had a structure appropriate for bat roosting (e.g., abundant houses, cave, or sinkhole).
A total of 287 acoustic ultrasound recordings were collected across Qatar, of which 169 were bat call sequences. Maktom & Dr. Yamaguchi identified three species Asellia tridens, Pipistrellus kuhlii, and Otonycteris hemprichii.
Asellia tridens was the most widely distributed bat species in Qatar, with 107 calls recorded.
The occurrence of A. tridens in Qatar is considered uncertain in the latest version of the IUCN Red List of Threatened Species. However, this research confirmed its presence in Qatar. In addition, this study reported the presence of Pipistrellus kuhlii in Qatar for the first time.
Due to the geographical proximity, bats may colonise southern Qatar from the main Arabian Peninsula more easily than the north of the country. Alternatively, in the north of Qatar, with a high concentration of irrigated farms, the bat populations may be affected by pesticide use. Bats may be more sensitive to pesticide use compared to other mammals.
Four of the five roost sites appeared to be occupied by a single bat species, either Asellia tridens or Otonycteris hemprichii, based on detection of calls. The single exception was the Mudhlem sinkhole site in the south where two call sequences of Pipistrellus kuhlii were recorded whilst call sequences of Asellia tridens dominated the site. However, it is not certain if the sinkhole is used as a roost site by Pipistrellus kuhlii. This may suggest the possibility of interspecific competition, where the more abundant Asellia tridens limits the range expansion of Otonycteris hemprichii and Pipistrellus kuhlii within Qatar.