All species › Bats › Vesper bats › Corsican Myotis
Corsican Myotis | Myotis nustrale
Myotis nustrale | Myotis nustrale
Myotis nustrale is the species of the Natterer's Bat complex that occurs only on Corsica. Puechmaille, Dool, Beuneux and Ruedi described it in 2023, with a type locality near Albertacce in Haute-Corse at about 1100 m. The Corsican bats turned out to have their own mitochondrial haplotypes and nuclear alleles not found anywhere else. The species name is Corsican for 'ours'. In the description: forearm 38.4 to 41.3 mm, weight 5.5 to 9.5 grams. In 2024 it was assessed as Critically Endangered on the Red List.
No photograph of a living wild animal of this species with a suitable Creative Commons licence exists. Do you have one that meets the rules? Send it in.
Tracks
All known day roosts are in cliffs, rocky outcrops, stone bridges or an artificial tunnel. The only known maternity colony numbered about 60 bats. There are otherwise hardly any external signs, and the call cannot be assigned to species.
Identification
A medium-sized Myotis with relatively long, unnotched ears and a straight tragus reaching beyond half the length of the conch. The upperparts are greyish brown and the underparts whitish, with a sharp line of demarcation. The edge of the tail membrane carries two rows of stiff hairs, and the calcar is long and S-shaped. The wing is attached at the base of the toe. Adults have a dark pigmented spot on the lower lip; according to the describers this character is not known in the other species of this group in Europe. The holotype, a female, measures: forearm 39.5 mm, head-body 42 mm, tail 40 mm, ear 18.5 mm, tragus 10.9 mm, hind foot 7.8 mm. The call consists of short, strongly modulated pulses from above 105 kHz down to about 25 kHz; according to the describers it is too variable to identify the species.
Similar species
On Corsica this is the only known species of the Natterer's Bat complex; the fringe of stiff hairs along the tail membrane separates it from the other Myotis species on the island. Its closest relative is the Cryptic Myotis (M. crypticus), from which the mitochondrial cytochrome b gene differs by 7.5 % on average; the skull resembles that of M. crypticus more than the slightly larger and more robust skull of Natterer's Bat (M. nattereri). Ears and tragus are relatively longer than in Natterer's Bat and M. crypticus, but the describers point out that their sample is small. It shares the wing attachment at the toe with Natterer's Bat and M. crypticus; in M. escalerai and M. zenatius it is at the metatarsus. The dark chin spot is the only external character the describers name as diagnostic; how reliable it is in a larger sample has not been studied. Outside Corsica any identification rests on DNA.
Habitat
The species is known mainly from mountain forests. Radio-tracked females hunted in dense maquis with evergreen oak, or in more open forest with Corsican pine, both high in the canopy and closer to the ground. For its roosts it depends on rock; the describers compare its ecology and roosts with those of M. escalerai.
Where the animal is most at home, classified with EUNIS — the European standard for habitats.
Distribution
Corsica only. The describers estimate the area of occupancy at 1300 km² and the extent of occurrence at 2400 km². The handbook earlier mentioned a possible occurrence of M. crypticus on Corsica and Sardinia; the Corsican population is now this species.
Way of life
Radio-tracked females hunted within 8 km of their day roost. No data on diet, reproduction, hibernation or longevity have yet been published; the species has been described only since 2023 and few bats have been studied. Observations of hibernation have not been published for this species.
Where and when to look
On current knowledge, a bat with a fringe of stiff hairs along the tail membrane on Corsica is this species. Disturbance of rock roosts, including by climbing and abseiling, is one of the threats mentioned; keep your distance at cliffs and old stone bridges in the mountains. Capturing and handling bats requires a licence throughout the European Union.
Conservation status
Critically Endangered (CR) on the global Red List, assessed in 2024. The describers already considered the species 'globally endangered' because of its small range, small population and limited connectivity between populations, and regarded it as vulnerable to climate change. Threats mentioned are forest fires, which limit hunting habitat, and disturbance of rock roosts by climbing and abseiling. In the European Union it falls, like all bats, under Annex IV of the Habitats Directive.
Scientific name
Myotis nustrale | Ruedi, Beuneux, & Puechmaille in Puechmaille, Dool, Beuneux, & Ruedi, 2023
Ruedi, Beuneux, & Puechmaille in Puechmaille, Dool, Beuneux, & Ruedi described the species in 2023 and placed it straight away in the genus where it still stands. Myotis is Greek, from mys, genitive myos, 'mouse', and ous, genitive ōtos, 'ear': 'mouse-ear'. nustrale is Corsican for 'ours, our own', placed as a pronoun in apposition to the genus name: the species occurs on Corsica and nowhere else. The specimen the first description was based on came from France, Corsica.