194.

Meridional Serotine

Eptesicus isabellinus

French: Sérotine isabelle / German: Mittelmeer-Breitfligelfledermaus / Spanish: Murciélago hortelano mediterraneo

Other common names: Isabelle’s Serotine, Isabelline Serotine Bat

Taxonomy. Vespertilio isabellinus Temminck, 1840,

“les environs de Tripoli,” Libya.

Eptesicus isabellinus was typically included under E. serotinus, but a number ofgenetic studies support its recognition as distinct. J. Juste and colleagues in 2013 and I. V. Artyushin and colleagues in 2018 reported conflicting data between mitochondrial and nuclear genes in which E. isabellinus was sister to all other Old World species of Eptesicus using mitochondrial genes, but L. isabellinus wassister to E. pachyomus and E. serotinus using nuclear genes, supporting the traditional view that E. isabellinus and E. pachyomus are subspecies of E. serotinus . Eiptesicus isabellinus is retained as a species here because there is strong support forits specific status. Two subspecies recognized.

Subspecies and Distribution.

E.i.isabellinusTemminck,1840—NEAlgeria,Tunisia,andNWLibya.

E. i. boscai Cabrera, 1904 — S Portugal, S Spain, N & C Morocco, NW Algeria, and Canary Is (Lanzarote I).

Descriptive notes. Head-body ¢.62-76 mm, tail 43-56, ear 12-18 mm, hindfoot 8:5-13 mm, forearm 44-2-53-8 mm; weight 15-27 g. Femalesare slightly larger than males. Dorsal pelage of the Meridional Serotine varies from pale yellowish brown, with creamy sheen, to nearly golden (hairs are slightly darker basally); venteris paler, with no clear demarcation with dorsum. Bare muzzle, cheeks, ears, and membranes are distinctly dark brown. Ears are subtriangular and broadly rounded, with five transverse folds on outer margins; tragusis about one-third the ear length, posterior margin is smoothly convex, and tip is bluntly pointed. Tail extends ¢.2-3 mm past uropatagium, and calcar is robust, reaching one-third to halfway to tail tip; wings are attached to base of each foot. Baculum is broadly Y-shaped, with moderately deep basal bifurcation, appearing to be thicker near tip than in the Eurasian Serotine ( E. serotinus), but is otherwise similar. Skull is similar to that of the Eurasian Serotine in overall structure, large, and robust, and condylo-basal lengthis ¢.18-2 mm; zygomatic arches are flared laterally; rostrum is broad and flat; lacrimal ridges are prominent; forehead profile is straight in lateral view; sagittal crest is low but distinct; and lambdoidal crests are moderately developed. I* is bicuspid, with clearly present secondary cusp; I® is small and slightly higher than cingulum of I?; and lower molars are myotodont. Chromosomal complement has 2n = 50 and FNa = 48 (Tunisia).

Habitat. Variety of habitats from semi-deserts to temperate ecosystems (Mediterranean forests and shrublands) and open agricultural areas or urban gardens from sea level up to elevations of ¢. 1800 m. Meridional Serotines tend to forage around water sources or sites with high relative humidity such as riverbanks with cluttered vegetation. In the northern part of its African distribution,it is also found in dense oases in desert and semi-desert habitats.

Food and Feeding. The Meridional Serotine primarily eats beetles ( Coleoptera), moths ( Lepidoptera), and flies ( Diptera). In southern Spain in a semiarid urban landscape, diet was mainly characterized by Scarabaeidae (Coleoptera) and Diptera, but it varied widely seasonally. Depending on prey availability, it also feeds upon other taxa such as Lepidoptera and Hemiptera that are not available year-round. Four fecal samples and three digestive tracts from Libya contained primarily Hymenoptera (Formicoidea) and Coleoptera (mostly Scarabaeidae and Cerambycidae along with Carabidae, Curculionidae, Staphylinidae, and Tenebrionidae), and anotherfive fecal pellets only contained Lepidoptera . The Meridional Serotine is mostly an aerial hawker, but it occasionally gleans prey from the ground or vegetation. Foraging habitats are commonlysituated around and close to roosts so they do not need to commute long distances every night.

Breeding. After exiting hibernation, femalesstart to aggregate and form maternity colonies in late April and early May. Adult females appearto give birth in late May and early June, often having twins. In Tunisia, four lactating females were captured in earlyJune. Lactation can last until mid-August, and then coloniesstart to break up. Mating occurs in August-October, during which males usually make social calls from their roosts.

Activity patterns. The Meridional Serotine usually roosts in rock crevices, hollow trees, bridges, and buildings and very rarely in caves, mines, or underground sites. In contrast to the Eurasian Serotine, winter and summer roosts do not change, and in some locations,they are found in the same roosts year-round. Hibernation sites are poorly known, but it is generally assumed that they occupy the samesites in summer. Hibernation occurs from late October to March in some areas, but in others such Tunisia, it seems to be active year-round. Search calls are indistinct from the Eurasian Serotine, with highly variable FM/QCFcalls. In some regions, calls of Meridional Serotines also get confused with species of Nyctalus . In Morocco, average start frequency was 42.3 kHz, end frequency was 25-3 kHz, peak frequency was 27-4 kHz, and duration was 11-5 milliseconds. In another study in Morocco, start frequencies were 33-7-36-3 kHz (mean 35-1 kHz), end frequencies were 22-4-24-2 kHz (26-9 kHz), peak frequencies were 25-8-28-3 kHz (26-9 kHz), durations were 5-6-16-3 milliseconds (9-7 milliseconds), and interpulse intervals were 128-5-362-7 milliseconds (244-2 milliseconds). In Tunisia, peak frequencies of 21-7-30-3 kHz (25-3 kHz) were detected. Recordings in Spain had maximum frequencies of 20-4-65-5 kHz, end frequencies of 18-5-28 kHz, peak frequencies of 23-4-35-8 kHz, durations of 2-:3-22.5 milliseconds, and interpulse intervals of 59-5-263 milliseconds.

Movements, Home range and Social organization. Meridional Serotines are generally solitary until females form maternity colonies during breeding season; males are almost always solitary. Males and females usually roost separately throughout the year. Maternity colonies have tens to hundreds of females and their young. All reported maximum annual distance movements are less than 40 km, mostly undertaken by males, which are responsible for gene flow among populations. Females normally show high fidelity to their roosts and are strongly philopatric. The Strait of Gibraltar does not represent a movement barrier or isolation source between European and African populations. In agricultural areas, they are suspected to accumulate contaminants from their diet.

Status and Conservation. Classified as Least Concern on The IUCN Red List. It is common in some areas (e.g. southern Spain, Morocco, and northern Algeria).

Bibliography. ACR (2018), Artyushin et al. (2018), Aulagnier (2013h), Baker et al. (1974), Benda, Cerveny etal. (2010), Benda, Spitzenberger et al. (2014), Dalhoumi, Aissa & Aulagnier (2016a, 2016b), Dalhoumi, Morellet et al. (2017), Dietz & Kiefer (2016), Disca et al. (2014), Harrison (1956b, 1963b), Horta et al. (2015), Hutterer et al. (2005), Ibanez et al. (2006), Juste (2016b), Juste, Benda et al. (2013), Juste, Bilgin et al. (2009), Lison, Haz & Calvo (2014), Lisén, Lopez-Espinosa et al. (2015).