Eptesicus innoxius ( Gervais, 1841 )

Salas, Jaime A, Loaiza S., Christian R & Cadenillas, Richard, 2023, Eptesicus innoxius (Chiroptera: Vespertilionidae), Mammalian Species 55 (1033), pp. 1-9 : 1-7

Eptesicus innoxius ( Gervais, 1841)

Harmless Brown Bat

Vespertilio innoxius P. Gervais, 1841: 35 . Type locality “Omatope” (= Amotape), Piura, Peru.

Vespertilio (Vesperus) innoxius : J. Tschudi, 1844a:247. Name combination.

Vespertilio espadae Cabrera, 1901:368 . Type locality “Babahoyo,” Los Ríos, Ecuador.

Eptesicus espadae : E. Festa, 1906:6. Name combination.

Eptesicus punicus O. Thomas, 1920:364 . Type locality “Puna” Isla Puná, Guayas, Ecuador.

Eptesicus innoxius : Cabrera, 1957:107. First use of current name combination.

CONTEXT AND CONTENT. Order Chiroptera , suborder Yangochiroptera , family Vespertilionidae , subfamily Vespertilioninae, tribe Eptesicini , genus Eptesicus , subgenus Eptesicus . Synonymy follows Davis and Gardner (2008). Eptesicus innoxius is monotypic ( Cláudio 2019c).

NOMENCLATURAL NOTES. The original description of Eptesicus innoxius was based on the specimen (MNHN [Museum National d’Histoire Naturelle] 6987) collected in Amotape, Piura, by Louis F. Souleyet and F. Eydoux in January 1838, and posteriorly described and designated as the holotype by H. Gervais (1841). The generic name, Eptesicus , comes from two Greek words: epten, meaning fly, and oikos, meaning house; in reference to the custom of flying near houses; the species name, innoxius , “in” is a Latin prefix that means not, without; and “noxius” of noxiosus, which means not offensive, harmless ( Tirira 2004). English names for E. innoxius are harmless brown bat, harmless serotine, Pacific brown bat, Pacific serotine, southwestern brown bat; vernacular Spanish names are murciélago café inofensivo, murciélago vespertino inofensivo, murciélago inofensivo del suroccidente, murciélago marrón del Pacífico ( Tirira 2004, 2017; Davis and Gardner 2008; Cláudio 2019c; Pacheco et al. 2021).

DIAGNOSIS

Eptesicus innoxius ( Fig. 1 ) is a small bat that can be distinguished from similar species of Eptesicus in South America by the combination of the following characters: forearm length = 32–40 mm, greatest length of skull = 13.9–15.8 mm, and length of maxillary toothrow = 5.2–6.0 mm ( Thomas 1920; Davis 1966; Albuja 1999; Davis and Gardner 2008; Díaz et al. 2016, 2021; Tirira 2017). Dorsal hairs of E. innoxius are woolly, short, with a length of 9 mm or less (5–6 mm), and bicolored, with blackish bases and dark brown to grayish-brown tips; ventral hairs have light brown bases and buffy to whitish tips ( Davis 1966; Albuja 1999; Brito et al. 2018; Cláudio 2019c).

Other South American Eptesicus similar in size to E. innoxius are E. orinocensis (Orinoco serotine) and E. diminutus (diminutive serotine), but these species differ from E. innoxius by the following combinations of external morphologic characters. Eptesicus orinocensis presents a forearm length ≤ 38 mm, greatest length of skull ≤ 15.3 mm, maxillary toothrow length between 5.1 and 5.7 mm; dorsal pelage is light brown, with lighter tips and ≤ 6 mm in length ( Ramírez-Chaves et al. 2021). Eptesicus diminutus presents a forearm length = 30–37 mm, greatest length of skull ≤ 15.2, maxillary toothrow length ≤ 5.4; dorsal hairs are short (≤ 6.3 mm) and bicolored with dark brown bases, and brown to yellowish brown tips ( Davis and Gardner 2008; Cláudio 2019d; Acosta et al. 2021). These species are allopatric with E. innoxius and would not be found in the same area as E. innoxius . Eptesicus orinocensis is restricted to the Orinoco basin in Colombia and Venezuela ( Ramírez-Chaves et al. 2021), and E. diminutus occurs to the southeast in Brazil, Paraguay, Uruguay, and Argentina ( Davis and Gardner 2008; Cláudio 2019d).

Three congeners, E. andinus (little black serotine), E. chiriquinus (Chiriquinan serotine), and E. fuscus miradorensis , occur in proximity to the geographic distribution of E. innoxius and can be distinguished using a combination of size and color and length of dorsal hair ( Davis and Gardner 2008; Tirira 2017; Cláudio 2019a, 2019b, 2019c; Ramírez-Chaves et al. 2023). Eptesicus andinus can be distinguished from E. innoxius by its larger size: forearm length = 37–44.4 mm, greatest length of skull = 15.9–18 mm, length of maxillary toothrow = 6.1 mm. The pelage of E. andinus is long and fluffy (9–10 mm), dorsal hairs are slightly bicolored, with dark brown bases and slightly lighter tips; ventral hairs have dark brown bases and tan tips ( Davis 1966; Cláudio 2019a).

Eptesicus chiriquinus can be distinguished from E. innoxius by its larger size: forearm length = 42.5–48.9 mm, greatest length of skull ≥ 15.8, length of maxillary toothrow ≥ 6.1 mm ( Davis and Gardner 2008; Cláudio 2019b). Additionally, E. chiriquinus presents a sagittal crest and lambdoidal crest that are well developed and overhang the supraoccipital, forming a triangular helmet; these crests are short or absent in E. innoxius and E. andinus resulting in a lack of the triangular helmet ( Simmons and Voss 1998; Davis and Gardner 2008; Acosta et al. 2021; Díaz et al. 2021). The dorsal fur of E. chiriquinus is long (8–14 mm) and soft; dorsal hairs are unicolored and vary from blackish to dark brown; ventral hairs have dark brown bases and lighter tan tips ( Cláudio 2019b).

Eptesicus fuscus miradorensis can be distinguished from E. innoxius by its large size: forearm = 48.54–51.13 mm, greatest length of skull = 18.5–21.2 mm, length of maxillary toothrow = 7.06–7.91 mm; additionally, dorsal fur of E. miradorensis is long (9.0–11.0 mm), lustrous, smooth, and shiny brown to golden yellow ( Acosta et al. 2021; Ramírez-Chaves et al. 2023).

GENERAL CHARACTERS

Ears are medium-sized, triangular, naked, wide, and rounded on the tip; the tragus is relatively broad, short, and slightly curved ( Fig. 1 ; Cláudio 2019c). The wing membranes are brownish and naked, the plagiopatagium reaches the base of the toes, the underside of the uropatagium may be sparsely haired, the caudal membrane is developed, accompanied by a tail that protrudes slightly; the last caudal vertebra and one-fourth of the penultimate extend beyond the interfemoral membrane ( Cabrera 1901; Davis 1966; Brito et al. 2018; Cláudio 2019c).

The rostrum is wide and obtuse, and the nasal septum has a slightly vertical depression in the middle. The supraorbital process of the skull ( Fig. 2 ) is poorly developed; zygomatic arches are narrow and weak ( Davis and Gardner 2008; Díaz et al. 2016; Sánchez et al. 2019). The nasal opening has a U-shape, similar to Eptesicus brasiliensis (Brazilian serotine— Davis 1966; Díaz et al. 2016, 2021).

Ranges of external measurements (mm, and mass in g; parenthetical n) of males and females, respectively, collected from different localities in Ecuador and Peru were: total length, 74–94 (10), 67–94 (16); head–body length, 44–56 (10), 40–61 (16); tail length, 27–41 (11), 24–39 (16); ear length, 7–19 (11), 9–18.5 (16); forearm length, 33–39 (11), 32–39 (16); length of hind foot, 4–10 (11), 5–10 (16); tragus length, 5–9 (5), 6–9 (11); and body mass, 5.5–12 (4), 5–9 (13). The range of forearm length for 3 males and 13 females (sexes combined) from San Jacinto de Yaguachi (Guayas Province, Ecuador) was 36.3–40.4 mm. All these measurements were taken by Carlos Ibañez from specimens housed at Estación Biológica de Doñana (EBD).

Measurements (mm) of the holotype (adult male) of Vespertilio espadae collected in Babahoyo ( Ecuador) by Marcos Jiménez de la Espada and described by Cabrera (1901) were: head–body length, 50; tail length, 37; ear length, 11; tragus length, 0.5; forearm length, 38; thumb length, 0.6; length of second digit, 36; length of third digit: metacarpal length, 34; length of first phalanx, 13; length of second phalanx, 12; length of fourth digit: metacarpal length, 32; length of first phalanx, 11; length of second phalanx, 0.8; length of fifth digit: metacarpal length, 31; length of first phalanx, 0.9; length of second phalanx, 0.5; tibia length, 14; length of hind foot with nail, 0.8; and calcar length, 14.

Measurements (mm) of the holotype (adult male) of E. punicus collected in Puná Island (Guayas, Ecuador) by Perry O. Simmons and described by O. Thomas (1920) were: head–body length, 42; tail length, 35; ear length, 13; forearm length, 34.9; length of metacarpal III, 33.7; length of first phalanx, 11.8; length of phalanx 2, 11.4; length of metacarpal IV, 32.5; length of first phalanx, 10.2; length of metacarpalV, 31.0; length of first phalanx, 7.6; tibia length, 14.2; length of hind foot, 0.7; greatest length of skull, 14.6; condylobasal length, 13.9; zygomatic breadth, 8.8; mastoid breadth, 7.4; breadth of braincase, 6.9; least postorbital breadth, 3.6; length of maxillary toothrow, 5.4; greatest breadth across upper molars, 5.9; greatest breadth across upper canines, 4.2; greatest length of mandible, 9.9; and length of mandibular toothrow, 5.7 ( Thomas 1920; Carter and Dolan 1978).

Mean values (mm; parenthetical range) of some external and craniodental measurements for 4 males and 13 females, respectively, collected from 11 localities in Ecuador and Peru ( Davis 1966) were: greatest length of skull, 14.9 (14.3–15.6), 15.1 (13.9–15.8); zygomatic breadth, 9.3 (8.8–9.6), 9.55 (8.9–10.0); cranial breadth, 6.85 (6.5–7.3), 6.9 (6.5–7.1); length of maxillary toothrow, 5.4 (5.2–5.5), 5.5 (5.2–6.0); width across M2–M2, 5.9 (5.7–6.1), 6.2 (5.9–6.4); mandibular length, 10.9 (10.5–11.4), 11.0 (10.5–11.7); length of mandibular toothrow, 5.8 (5.6–6.0), 5.9 (5.5–6.4); forearm length, 36.7 (35.3–38.5), 37.0 (34.0–38.7); length of third metacarpal, 34.3 (33.3–36.2), 34.5 (31.5–35.3); phalanx 1: digit 3, 12.8 (12.5–13.2), 12.7 (11.5–13.2); phalanx 2: digit 3, 11.2 (10.3–12.5), 11.0 (10.0–12.0).

Mean ± SD and ranges (mm; parenthetical n) of selected craniodental measurements for males and females, respectively, collected from 12 different localities in Ecuador ( Albuja 1999; Carrera et al. 2010), were: greatest length of skull, 14.56 ± 0.50, 13.98–15.60 (9), 14.59 ± 0.37, 14.08–15.35 (11); condylobasal length, 13.50 ± 0.58, 12.73–14.31 (9), 13.17 ± 0.43, 12.26–13.84 (11); braincase breadth, 5.26 ± 0.21, 4.97–5.45 (7), 5.32 ± 0.15, 4.97–5.53 (11); braincase height, 7.23 ± 0.23, 7.06–7.66 (8), 7.22 ± 0.23, 6.86–7.56 (11); zygomatic breadth, 9.27 ± 0.35, 8.77–9.85 (8), 9.41 ± 0.33, 8.75–9.76 (10); mastoid breadth, 7.51 ± 0.25, 7.03–7.87 (9), 7.57 ± 0.25, 7.12–7.90 (11); postorbital constriction, 3.76 ± 0.13, 3.60–3.95 (9), 3.75 ± 0.12, 3.59–3.94 (11); least interorbital breadth, 5.04 ± 0.29, 4.66–5.59 (7), 4.92 ± 0.16, 4.74–5.28 (11); palatal length, 6.48 ± 0.34, 6.22–7.17 (7), 6.58 ± 0.31, 6.05–6.97 (11); length of maxillary toothrow, 5.41 ± 0.19, 5.12–5.74 (9), 5.38 ± 0.18, 5.12–5.62 (11); length of mandibular toothrow, 5.84 ± 0.23, 5.53–6.32 (8), 5.89 ± 0.18, 5.65–6.16 (11); length of upper molar toothrow, 4.32 ± 0.13, 4.09–4.52 (7), 4.33 ± 0.17, 4.05–4.54 (11); width across canines, 4.26 ± 0.19, 4.06–4.64 (8), 4.31 ± 0.18, 3.92– 4.56 (11); width across molars, 6.08 ± 0.25, 5.86–6.59 (9), 6.06 ± 0.22, 5.75–6.37 (11); mandible length, 10.61 ± 0.38, 10.17–11.26 (9), 10.53 ± 0.31, 10.05–10.98 (11—measurements taken by Christian Loaiza from specimens in the QCAZ [Museo Zoología of Pontificia Universidad Católica del Ecuador], EPN [Escuela Politécnica Nacional], and MECN [Museo Ecuatoriano de Ciencias Naturales] collections).

DISTRIBUTION

Eptesicus innoxius is endemic to western Ecuador and northwestern Peru, in South America, in dry and rainforest ecosystems ( Fig. 3 ; Brack-Egg 1986; Pacheco et al. 2007, 2021). It occupies the following ecoregions in both countries (sensu Olson et al. 2001): Ecuadorian dry forest, Esmeraldas and Chocó mangroves, Guayaquil flooded grassland, Gulf of Guayaquil mangroves, Sechura desert, Tumbes-Piura dry forests, and Western Ecuador moist forests. The habitat in Ecuador is characterized by the following biogeographic regions and provinces: Equatorial Chocó (Chocó), Coastal Mountain range and Jama-Zapotillo (Equatorial Pacific), and Catamayo-Alamor (Southern Andes— MAE 2013); also includes dry and semidecidous tropical forests in primary and secondary dry forests, wetlands, secondary and disturbed forests, grasslands, leafless shrub areas, mangroves, thorn forests, and banana, papaya, cocoa, and mango plantations, frequently near bodies of water ( Albuja 1999; Cadenillas et al. 2007; Pacheco et al. 2007; Carrera et al. 2010; Tirira 2017; Linares and Zavala 2018; Cláudio 2019c; Paz-Ramírez and Salas 2019; Loaiza et al. 2020).

Eptesicus innoxius has been registered in 44 localities in western Ecuador and northwestern Peru, including the islands of Puná and Santay. In Ecuador, it has been recorded in Esmeraldas, Santo Domingo de los Tsáchilas, Los Ríos, Guayas, Santa Elena, El Oro, and Loja provinces, and in Peru, the departments of Tumbes, Piura, and Lambayeque ( Fig. 3 ; Davis 1966; Albuja 1999; Simmons 2005; Pacheco et al. 2007; Davis and Gardner 2008; Tirira 2012, 2017; Díaz et al. 2016; Cláudio 2019c; Loaiza et al. 2020). All records of E. innoxius are located to the west of the Andes mountain range, and its geographic distribution comprises coastal lowlands and humid forest (northwest) where it is less abundant, dry forest (southwest), and western subtropics (foothills), where it is more abundant ( Albuja 1999; Tirira 2008, 2017; Carrera et al. 2010; Brito et al. 2018).

The northernmost record of E. innoxius was reported from Recinto Pedro Carbo (MZUGM [Museo de Zoología Universidad de Guayaquil] 532; 0°22 ʹ 08.3 ″ N, 79°58 ʹ 39.3 ″ W; Esmeraldas Province, Ecuador), a locality in coastal lowlands ( Loaiza et al. 2020); the southernmost record was reported from Puerto Etén (USNM [National Museum of Natural History, Smithsonian] 103923–103927; 06°55 ʹ 34.8 ″ S, 79°51 ʹ 52.8 ″ W, 5 m altitude; Chiclayo Province, Lambayeque Department, Peru — Tschudi 1844b; Thomas 1920; Koopman 1978; Pacheco et al. 2007; Loaiza et al. 2020); the easternmost record was reported from Bosque Protector Otongachi (QCAZ 17184; 0°19 ʹ 14.5 ″ S, 78°57 ʹ 06.2 ″ W, Santo Domingo de los Tsáchilas Province, Ecuador); the westernmost record was reported from Amotape (MNHN 6987; 04°52 ʹ 59.4 ″ S, 81°00 ʹ 55.5 ″ W, Piura Department, Peru). An unusual record of E. innoxius in the locality of Santa Rosa (Imbabura— Lee et al. 2010) was later identified as Myotis riparius (riparian myotis— Romero 2022). Eptesicus innoxius occurs from sea level up to 900 m ( Tuttle 1970; Tirira 2017; Brito et al. 2018; Cláudio 2019c), but there are records in both countries of occurrence above 1,200 m ( Davis 1966; Graham 1987).

FOSSIL RECORD

Humeri from Pleistocene deposits from the Talara Tar Seeps of northwestern Peru (Piura) were assigned to Eptesicus cf. innoxius ( Cadenillas and Martínez 2005) . In addition to fossil remains of E. cf. innoxius , remains of E. andinus , E. furinalis , and an undescribed potentially extinct species were discovered at this site ( Moretto et al. 2017). The conventional radiocarbon (14 C) analysis placed the Talara site between 13,616 ± 600 and 14,418 ± 500 years CAL BP ( Churcher 1966); however, newer calibration techniques placed Talara between 14,500 and 17,000 calendar years before present ( Lindsey et al. 2022).

FORM AND FUNCTION

The dental formula of Eptesicus innoxius is i 2/3, c 1/1, p 1/2, m 3/3, total 32 ( Davis and Gardner 2008; Tirira 2017). The skull of E. innoxius broadly conforms to that described for the genus. The upper inner incisors are large and bifid, external incisors are sharp and very short, barely reaching the middle of the external lobe of the others. The maxillary canines are robust, twice the length of the inner incisors; immediately behind each of them there is a single premolar, large in size, without a gap or diastema behind the canine ( Cabrera 1901; Díaz et al. 2021). Mandibular incisors are small, trilobed, and similar to each other in size and shape; the canine is three times longer than the mandibular incisors; the lower P1 is one-half shorter than the P2, which is slightly shorter than the canine; the last upper molar is reduced in overall size ( Simmons and Voss 1998; Albuja 1999).

ONTOGENY AND REPRODUCTION

There is no data on the ontogeny of Eptesicus innoxius . Information on the reproductive status and seasonal patterns of pregnancy and parturition of E. innoxius is scarce ( Graham 1987). Reports from Ecuador include a breast-feeding female that was collected in Barraganete, Bolívar Province, in April 1980 ( Albuja 1999); a male with testes in scrotal position was collected in Isla Santay, Guayas Province, in the dry season on July 2018 (MZUGM 0728; J. A. Salas, in litt.). In Peru, there is a report of a scrotal male collected in the locality of Palo Negro (Piura), on October 2012 (R. Cadenillas, in litt.).

Information and field observations of other species of Eptesicus suggest a bimodal breeding pattern, with parturition occurring only during the warmer parts of the year; breeding activity of males was also bimodal, as indicated by testis size ( Myers 1977; Kurta and Baker 1990; Mies et al. 1996; Esbérard 2012). The number of offspring per pregnancy in members of Eptesicus varies from one to four ( Nowak 1995), although two embryos are more frequently observed ( Myers 1977; Mies et al. 1996; Esbérard 2012).

ECOLOGY

Individuals of Eptesicus innoxius were observed flying throughout the night from 1900 to 0500 h ( Linares and Zavala 2018). Roosts occurred under loose bark 40 cm aboveground and inside hollow trees about 1–5 m aboveground; in both cases, open areas of at least 4 m diameter surrounding the trees ( Cláudio 2019c). Eptesicus innoxius has a generation length of 7 years ( Pacifici et al. 2013).

Eptesicus innoxius is strictly insectivorous. Fecal samples contained fragments of Homoptera, Diptera, Coleoptera , and possibly small Lepidoptera ( Linares and Zavala 2018; Cláudio 2019c). Predators of E. innoxius have not been reported to date, but based on previous reports about depredation on bats, it is plausible that due to its crepuscular behavior, diurnal raptors such as hawks are possible predators, as well as nocturnal hunters such as owls ( Mikula et al. 2016; Cadena-Ortiz et al. 2022).

A male specimen of E. innoxius from Ecuador was infected with the trematode Urotrema scabridum (Platyhelminthes, Digenea— Tkach et al. 2019), a small-sized parasite present in other insectivorous bats ( Milano et al. 2016; Mello et al. 2019; Martínez-Salazar et al. 2020). The rabies virus has not been reported in E. innoxius .

Eptesicus innoxius has been caught in mist nets with others bat species including Desmodus rotundus (common vampire bat), Glossophaga soricina valens (Pallas’s longtongued bat), Lophostoma occidentale (western round-eared bat), Phylloderma stenops (pale-faced bat), Phyllostomus discolor (pale spear-nosed bat), Sturnira bakeri (Baker’s yellowshouldered bat), Pteronotus davyi incae (Davy’s naked-back bat), Myotis nigricans (common black myotis), and Molossus molossus (Pallas’s mastiff bat— Cadenillas et al. 2007; Pacheco et al. 2009; Velazco and Cadenillas 2011; Salas et al. 2014; Linares and Zavala 2018; Cláudio 2019c; Pavan et al. 2021).

The geographic distribution of E. innoxius coincides with other endemic bat species that occur in the Tumbesian Center of endemism, such as phyllostomids ( Lonchophylla hesperia —western nectar bat, Platalina genovensium —longsnouted bat, Artibeus fraterculus —fraternal fruit-eating bat), furipterid ( Amorphochilus schnablii —smoky bat), molossids ( Cabreramops aequatorianus —equatorial dog-faced bat, Eumops wilsoni —Wilson’s bonneted bat, Tomopeas ravus — blunt-eared bat), and the vespertilionid ( Rhogeessa velilla, Ecuadorian little yellow bat— Pacheco et al. 2007; Baker et al. 2009; Loaiza 2013; Velazco et al. 2013; Tirira 2017).

Eptesicus innoxius has been registered in shared natural roosts in association with other males of the common black myotis ( Myotis nigricans ) and Pallas’s mastiff bat ( Molossus molossus ) in Isla Santay ( Ecuador — Linares and Zavala 2018), but the species of tree being used as shelter was not indicated. A shared roost by one individual of Pallas’s mastiff bat with E. innoxius in the bark of an Albizia samanea tree ( Fabaceae ) in semideciduous forest has been reported ( Salas et al. 2014). Roosts have also been found in roofs of human facilities in Isla Santay, where small colonies of E. innoxius have been registered, varying from 4 to 6 sexually segregated individuals ( Linares and Zavala 2018). Eptesicus innoxius has been captured foraging over water in open areas ( Davis and Gardner 2008; Linares and Zavala 2018; Cláudio 2019c).

GENETICS

A phylogenetic analysis of ultraconserved elements from eight species of Eptesicus , placed E. innoxius as sister to the clade formed by E. chiriquinus , E. andinus , and E. brasiliensis ( Yi and Latch 2022) . Furthermore, their results were concordant with those of previous studies ( Hoofer and Van Den Bussche 2003; Hoofer et al. 2006; Amador et al. 2018) and suggested that the subgenus Eptesicus is paraphyletic. The current evidence could indicate that a single invasion event of the New World Eptesicus lineage (including Histiotus ) has occurred from one continent to another ( Juste et al. 2013), through trans-Atlantic dispersion ( Yi and Latch 2022).

CONSERVATION

In Ecuador, Eptesicus innoxius has been recorded in the following protected areas: Refugio de Vida Silvestre Manglares Río Muisne (Esmeraldas Province), Bosque Protector Cerro Blanco, Bosque Protector La Prosperina, Área Nacional de Recreación Isla Santay, Reserva Ecológica Manglares Churute, Área Provincial de Productividad y Conservación El Retiro de Pucón (Guayas Province), Bosque Protector Río Palenque (Los Ríos Province), Reserva Ecológica Arenillas and Bosque Protector Petrificado de Puyango (El Oro Province), and Bosque Protector Otongachi (Santo Domingo Province— Carrera et al. 2010; Salas et al. 2014; Linares and Zavala 2018; Paz-Ramírez and Salas 2019; Loaiza et al. 2020). Also, it has been recorded in privately owned areas such as: Cerro Cacharí (Los Ríos Province) and Cerro El Muerto (Guayas Province— Loaiza et al. 2020). A recent record confirms the presence of E. innoxius in Bosque Protector Estación Científica Pedro Franco Dávila–Jauneche (Los Ríos Province—J. A. Salas, in litt.; MZUGM-00797). In the occidental slopes of Peru, E. innoxius is present in Coto de Caza El Angolo (Piura Department), Parque Nacional Cerros de Amotape (Tumbes Department— Cadenillas et al. 2007; Pacheco et al. 2007), and Área de Conservación Regional Bosques Secos de Salitral-Huarmaca ( Pavan et al. 2021).

Currently, E. innoxius is listed by the International Union for Conservation on Nature and Natural Resources Red List of Threatened Species as “Near Threatened” (NT) because based on a significant decline of habitat where the species occurs, a population reduction is suspected, and its geographic distribution occurs within a highly fragmented region ( Velazco and Aguirre 2020). In Ecuador, E. innoxius was listed in 2011 as “Vulnerable” (VU— Tirira and Carrera 2011) and has been prioritized in the action planning for bat conservation of Ecuador ( Burneo et al. 2015), with recommendations to increase distributional, ecological, and natural history studies, and review museum collections for taxonomic verification. Also, Burneo et al. (2015) recommended its inclusion as conservation value in protected areas where its presence has been reported. To date, E. innoxius has been protected in four Important Areas for Bat Conservation (AICOM, by its acronym in Spanish) in western Ecuador: Cerro Blanco, Manglares Churute, Isla Santay, Arenillas, and Estación Científica Pedro Franco Dávila–Jauneche ( Álava and Salas 2022; Salas 2022 a, 2022b; Salas and Álava 2022). A recent assessment of Mammal Red List of Ecuador listed E. innoxius in the Vulnerable category, for B2ab (i, iii) criteria: geographic distribution with an occupation area <2,000 km 2, in a region with severe ecological fragmentation, plus an expected decrease of its extent of presence and area of occupation ( Tirira 2021). In Peru, E. innoxius is listed as “Near Threatened” (NT— SERFOR 2018).

Figures

Fig. 1.—An adult female Eptesicus innoxius from Cerro Cacharí, near Babahoyo, Los Ríos, Ecuador. Photograph by JAS.

Fig. 2.—Dorsal, ventral, and lateral views of the skull and lateral view of mandible of an adult male Eptesicus innoxius (MZUGM [Museo de Zoología de la Universidad de Guayaquil] 0699) from Cerro El Muerto, Guayaquil, Guayas Province, Ecuador. Greatest length of skull is 14.5 mm.

Fig. 3.—Geographic distribution of Eptesicus innoxius redrawn by Christian Loaiza from Loaiza et al. (2020). Arabic numbers correspond to provinces in Ecuador: 1) Esmeraldas, 2) Santo Domingo de los Tsáchilas, 3) Manabí, 4) Los Ríos, 5) Guayas, 6) Santa Elena, 7) El Oro, 8) Loja; and Peru departments: 9) Tumbes, 10) Piura, 11) Lambayeque. The gray shading refers to Andes Mountains.