Rhinolophus mehelyi

Rhinolophus mehelyi

Mehely’s horseshoe bat (Rhinolophus mehelyi Matschie, 1901) is a bat belonging to the Rhinolophidae family.

Systematic –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Animalia,
Phylum Chordata,
Mammalia class,
Superorder Laurasiatheria,
Order Chiroptera,
Suborder Microchiroptera,
Rhinolophidae family,
Genus Rhinolophus,
Species R. mehelyi.
The term is synonymous:
– Rhinolophus carpetanus Cabrera, 1904.
Within this species the following subspecies are recognised:
– Rhinolophus mehelyi subsp. judaicus (K.Andersen & Matschie, 1904);
– Rhinolophus mehelyi subsp. mehelyi Matschie, 1901.
– Rhinolophus mehelyi subsp. tuneti (Deleuil & Labbe, 1955).

Geographic Distribution and Habitat –
The Rhinolophus mehelyi is a bat widespread in the Palearctic Ecozone.
It is present, in particular, but in a fragmented way, in the Iberian Peninsula, south-eastern Europe, northern Africa from Morocco to the Nile delta in Egypt and in the Middle East up to Afghanistan.
In Italy it is present only in Sardinia and in the eastern part of Sicily.
Its habitat is that of Mediterranean vegetation, woods and mountain forests, clearings and semi-desert scrublands up to 2,000 meters above sea level.

Description –
The Rhinolophus mehelyi is a medium-sized bat, with the following lengths: head and body between 42 and 64 mm, forearm between 47 and 56 mm, tail between 16.2 and 37 mm, foot between 9 and 12 mm, ears between 18 and 23 mm, for a weight of up to 23 g.
Its fur is long, soft, dense and velvety.
The dorsal parts have a greyish-brown color with the base of the hairs being lighter; the muzzle is lighter with a darker mask around the eyes, while the ventral parts are white.
The ears are relatively short.
The nasal leaf has a tapered lancet with almost parallel edges and a blunt end, a triangular connective process and a hairless saddle, with parallel edges, the end broad, rounded and bent forward.
The anterior portion is narrow and with a central hollow at the superficial base.
It has greyish-brown wing membranes, with the first phalanx of the fourth toe relatively short.
The tail is long and completely included in the large uropatagium.
The upper first premolar is located outside the alveolar line.
The karyotype is 2n=58 FNa=60, 64 in the population of Romania and Azerbaijan.
This bat emits high-cycle ultrasound with long duration pulses at a constant frequency between 105 and 112 kHz.

Biology –
Rhinolophus mehelyi reaches sexual maturity at two years for males and three for females.
The mating season usually occurs in autumn.
She gives birth to one young at a time in May or June.
The mothers nurse the cubs with their mother’s milk and the cubs gradually become independent and begin to learn to fly and hunt on their own.
Life expectancy is up to 12 years.

Ecological Role –
Rhinolophus mehelyi lives in caves and prefers limestone areas with nearby water. It is known to roost in caves alongside other bats such as Rhinolophus hipposideros, Myotis myotis and Miniopterus schreibersi. It prefers to perch in the warmest cavities, such as those found in the Cova de Sa Guitarreta (Mallorca), while hanging free on the roof of the cave.
Inside caves and rocky crevices it forms large colonies of up to 5,000 individuals, often together with the other bats mentioned.
It enters hibernation in the winter during which it moves to the shelters towards the entrances, while in the summer the females form nurseries. Predatory activity begins in the evening. The flight is slow and highly maneuvered, characterized by short glides. It is a sedentary species.
As regards nutrition, this bat feeds on lepidopterans and to a lesser extent on beetles and dipterans captured in the vegetation or occasionally on the ground.
This bat emerges at dusk, hunting on the ground on warm slopes and also in bushes and trees, preying on moths and other insects.
Constant frequency sound is between 105 and 112 kHz (audible to humans), with a short frequency dip at the end of the signal, normally lasting between 20 and 30 milliseconds. There is some frequency overlap with other bats.
A behavioral study conducted in 2014 revealed that the peak frequencies of echolocation calls emitted by male and female Rhinolophus mehelyi accurately reflect their size and body condition. In the experiment, larger males were shown to have higher calling frequencies that attracted females twice as often as males with lower calling frequencies. In contrast, males appeared to choose females randomly. This distinction suggests that females choose males based on the frequency of their calls for the indirect benefits of having healthier and fitter offspring. The mating system is therefore comparable to a lek, making female mate choice a selection factor in the evolution of call frequency in males that may counteract other selective pressures imposed by their ecological niche.
Regarding its conservation status, the IUCN Red List, considering the estimated population decline of 10% in the last 10 years due to human interference in refuges, classifies R. mehelyi as a vulnerable species (VU).

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Gordon Corbet, Denys Ovenden, 2012. Guide to the mammals of Europe. Franco Muzzio Editore.
– John Woodward, Kim Dennis-Bryan, 2018. The great encyclopedia of animals. Gribaudo Publisher.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/208088656/original.jpeg