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Islands host high numbers of endemic species, and the latter are especially exposed to human-driven habitat alteration because their population size is constrained by the limited space and resources found in insular systems. Extreme events linked with climate change and direct anthropogenic stressors may synergistically affect endemic species, and even push them to the brink of extinction. Bats include many insular endemics whose life traits make them excellent candidates to test the effects of both climate-change driven events and direct human disturbance. The Mediterranean island of Sardinia is home to the endemic long-eared bat Plecotus sardus. Within the island, this recently described species is restricted to a limited range where suitable habitat is present. This makes the species extremely vulnerable to human action. Here we use Plecotus sardus as a model to assess the response of insular endemic bats to climate change and human disturbance, exploring demographic trends across two decades. Overall, roost count data for all known reproductive sites showed a steep (-63.4% between 2003 and 2020) population decline, so that the current estimated population size is only 36.5% of that observed in 2003. Colony growth rates are strongly affected by recurring wildfires around reproductive sites, summer precipitation and temperature extremes, pointing to climate change as a primary threat to the species along with direct human interference. Such anthropogenic pressures may therefore rapidly expose island endemic bats to a high extinction risk. Based on our analysis, Plecotus sardus is among the most threatened mammals, and likely the rarest bat species, in Europe. Thus, we urge that (1) similar assessments are conducted on other insular endemic bats in Mediterranean Europe, (2) IUCN Redlist categories are revised according to new analyses, and (3) recovery action plans are immediately developed and implemented to revert the current population trends.

241. Sardinian Long-eared Bat Plecotus sardus French: Oreillard de Sardaigne / German: Sardinien-Langohr / Spanish: Orejudo de Cerdena Taxonomy. Plecotus sardus Mucedda et al., 2002, “interior of a cave at Lanaitto’s Valley, Oliena District, Nuoro Province, middle-east Sardinia, Italy (40°15'29"N, 9°29'13"E, 150 mas.l.).” Previously treated within either P. austriacus or P. auritus, but recently elevated to species level based on morphological and molecular data. Monotypic. Distribution. Sardinia. Descriptive notes. Head-body c. 45 mm, tail ¢.b 1 mm, ear 37- 5-39 mm, hindfoot 6-7-7- 7 mm, forearm 41-1-42- 2 mm. Dorsal fur woolly (c. 10 mm long), brownish, with hairs tricolored (dark brown bases, then grayish, with dark brown tips); ventral fur whitish or pale brown, with bicolored hairs (dark brown and whitish). Ears pale brown; tragus distinctive compared to congeners, being large (over 18 mm) and broad (over 6 mm), dark brown at base and yellowish at tip. Muzzle narrow, with round gland under chin. Wings brown, inserting at base of toe. Thumbs large; claws and hindfoot have sticking hair. Calcar long (c. 18 mm) and slender, with small lobe at tip. Penis is almost cylindrical, unlike in the Brown Longeared Bat (P. auritus) and the Gray Long-eared Bat (P. austriacus); differs from the Alpine Long-eared Bat (P. macrobullaris) in baculum shape. P* is minute. Habitat. Very little information. Of three reports, two were from karstic areas with forests nearby at medium elevations, the third being at the coastline. It is suspected that the species is a forest-dweller, foraging within woodlands, and roosting in caves. Food and Feeding. No information. Breeding. Only four maternity colonies are known with a total estimate of under 1000 breeding bats, but reproductive patterns remain poorly studied. Activity patterns. No information. Movements, Home range and Social organization. No movements have been reported. Status and Conservation. Classified as Vulnerable on The IUCN Red List. Limited forest remains in Sardinia, while deforestation is increasing; the species may be at real risk of extinction in the near future. Also, roost visiting and disturbance may threaten potential roost sites. Bibliography. Bosso et al. (2016), Dietz & von Helversen (2004), Dietz & Kiefer (2016), GIRC (2004), Mucedda et al. (2002), Pacifici et al. (2013), Piraccini (2016e), Simmons (2005)., Published as part of Don E. Wilson & Russell A. Mittermeier, 2019, Vespertilionidae, pp. 716-981 in Handbook of the Mammals of the World – Volume 9 Bats, Barcelona :Lynx Edicions on page 869, DOI: 10.5281/zenodo.6397752

Sardinia is home to three bat species of chief conservation importance, the endemic Plecotus sardus as well as Myotis punicus and Rhinolophus mehelyi, for which Sardinia is the Italian stronghold. We carried out two gap analyses overlapping the network of protected areas present on the island respectively with 1) the occurrence records of all species and 2) the binarized maps obtained from maximum entropy models. Unlike the other two species, P. sardus known records are confined to the central sector of the island and its suitable habitat partly overlaps with that of M. punicus but not with R. mehelyi. Due to its uniqueness and restricted range P. sardus requires a very specific management strategy for its protection to be successful. Both analyses led to the conclusion that all species considered require more extensive protection than is currently granted so that urgent measures should be taken to improve the current situation.