Natalus jamaicensis ( Goodwin, 1959 )

Tejedor, Adrian, 2011, Systematics Of Funnel-Eared Bats (Chiroptera: Natalidae), Bulletin of the American Museum of Natural History 2011 (353), pp. 1-140 : 46-50

Natalus jamaicensis ( Goodwin, 1959)

Figure 22

Natalus major jamaicensis Goodwin, 1959: 9 . Type locality ‘‘St. Clair, St. Catherine Parish, Jamaica, British West Indies.’’

Natalus stramineus jamaicensis: Linares, 1971: 83 . New combination.

Natalus major: Morgan, 1989: 686 . Part, not Natalus major Miller, 1902 .

Natalus jamaicensis: Dávalos, 2005: 95 . New combination.

HOLOTYPE: AMNH 182000, adult male, skull and skin in fluid, collected by C.B. Lewis in St. Clair Cave (locality 250 in appendix 1), St. Catherine Parish, Jamaica on 5 March 1954. The skull is complete and the skin is in good condition.

DISTRIBUTION: Jamaica, known to be extant at the type locality only (fig. 23).

DIAGNOSIS: A large representative of Natalus with a long forearm (44.1–44.8 mm) relative to its skull length (17.4–18.1 mm); medial margin of ear pinna straight; lateral margin of ear pinna deeply notched; nostrils small, oval, opening ventrolaterally; ventral pelage monocolored; dorsal pelage bicolored with hair bases lighter than tips; hair at base of claws short and inconspicuous or long and thin, never forming tufts; premaxilla not inflated, with maxilloincisive suture anterior to infraorbital foramen; maxilla above molars concave; palate ending caudally at 2/3 the distance between M3 and tip of pterygoid process; caudal margins of maxilla in ventral view forming an acute angle with longitudi- nal axis of skull; basisphenoid pit shallow; postorbital region narrow, with sides nearly parallel, in dorsal view; braincase rising abruptly from rostrum, with an angle greater than 60u between dorsal plane of rostrum and frontal plane of forehead; braincase rounded in dorsal profile, with breadth almost as great as length; postorbital constriction, its sides almost parallel; caudal margin of ascending ramus of mandible perpendicular to alveolar margin of dentary; I1 not visible in lateral view, being obscured by I2; mesostylar crest of M3 absent. A comparison of diagnostic characters between N. jamaicensis and other species of Natalus is summarized in table 5.

DESCRIPTION: Size large (forearm length 44.0–47.0 mm; greatest skull length 17.2– 18.1 mm; weight 5.9–7.3 g); muzzle long and dorsoventrally flattened; nostrils elliptical, opening ventrolaterally on shallow depression on margin of upper lip; upper lip thickened; lower lip markedly thickened and constricted along dorsal and ventral margin, with numerous transversal grooves; small, smooth central pad on dorsal margin of lower lip; natalid organ medium size and elliptical, extending from caudal base of rostrum to crown of head; ears relatively long (15.3–19.1mm); ear pinna funnel shaped; pinna with markedly pointed tip; medial margin of pinna straight; lateral margin of pinna deeply concave; five to six small ear ridges along lateral margin of distal pinna; ventral region of ear pinna greatly expanded, covering the eye and tragus in lateral view; medial ear margin thin and flexible; tragus short, lanceolate, and twisted into helixlike structure; tibia (24.3–25.7 mm) slightly longer than half the length of the forearm; calcar long and thin, occupying about half the length of the free edge of uropatagium; free margin of uropatagium with sparse fringe of thin hairs; wings relatively broad, with 3rd metacarpal (40.8– 42.8 mm) slightly longer than 5th metacarpal (39.9–41.4 mm); wings attach to tibia above ankle; pelage dense and lax; hairs long (9– 11 mm, dorsally; 6–7 mm, ventrally); pelage usually darker dorsally than ventrally; dorsal hairs bicolored, with tips darker than bases; ventral hairs usually slightly bicolored and rarely monocolored; pelage color from buff with tips sepia or ochraceous (tawny olive; pl. 1); ventral hair bases are buff with tips pinkish buff; dense mustachelike hair tufts along lateral margins of upper lip and on dorsum of muzzle; mustache formed by dense, lax, irregularly arranged, and ventrally curved hairs; natalid organ covered with thin hairs; skull long and relatively slender with moderate rostral flexion; rostrum long and slender, with sulcus between nasals short, shallow, and confined to point of flexion between rostrum and braincase; moderate rostral palatal emargination; maxilla concave dorsal to molars; braincase greatly inflated (globular), rising abruptly from rostrum; braincase in dorsal view nearly circular; sagittal crest well developed; postorbital constriction narrow, its sides nearly parallel; maxillary branch of zygomatic arch thin, less deep than twice the height of crowns of last molars; pterygoids nearly parallel; palate extending caudally to more than half the distance between bases and tips of pterygoids; basisphenoid pit shallow; longitudinal medial ridge on basisphenoid present; ectotympanic small, covering less than half of periotic; upper incisors short and peglike; I2 obscuring I 1 in lateral view; upper premolars slightly increasing in size from P2 to P4 and crowded; mesostylar crests on M1 and M2 short and straight, mesostylar crest absent on M3; cingular cusp of p4 medium sized and broad; molars cusps relatively broad; spinous process of humerus about as high as capitulum; thorax relatively short and wide; ribs markedly expanded craniocaudally and extensively in contact with one another; vertebrae C7 to T1 fused among themselves and to ribs; vertebrae T12–L4 fused entirely without vestige of sutures, forming a laterally compressed column; lumbar column relatively short and concave ventrally; vertebrae L5 and L6 free; caudal vertebrae 4 to 7 longer than distance from ischium to iliac crest of sacrum.

COMPARISONS: The large body size (forearm length 44.0–47.0 mm) of Natalus jamaicensis readily separates this species from the continental and Lesser Antillean species of the genus Natalus ( Natalus stramineus , forearm 36.9–41.9 mm; Natalus tumidirostris , forearm 35.0–42.0 mm; Natalus mexicanus , forearm 34.0– 40.6 mm; and Natalus lanatus , forearm 35.4–38.6 mm), and from species of the genera Nyctiellus and Chilonatalus . Natalus jamaicensis is best distinguished from other greater Antillean Natalus ( N. primus and N. major ) by discrete cranial or external characters.

Cranially, N. jamaicensis is a very distinctive species. Its skull shows several modifications concomitant with its high degree of cranial flexion. First, in N. jamaicensis the frontal plane of the braincase raises very steeply from the rostrum, in an angle greater than 60u, a condition that is unique among species of the genus Natalus . Second, the braincase of N. jamaicensis is markedly

inflated and almost as wide as long, and as a result has an almost circular profile in dorsal view. In all other species of Natalus the braincase is longer than wider and thus appears oval shaped. Third, the postorbital constriction of the skull of N. jamaicensis is proportionally narrower than in all other species of Natalus , with sides almost parallel in dorsal view, while in all other species of Natalus the sides of the postorbital constriction markedly diverge anteriorly. In addition, the rostrum of N. jamaicensis is flattened dorsally to a greater degree than in other species of Natalus , and shows a marked reduction of the sulcus between nasal bones, and a concave shape of the maxilla in the area dorsal to the molars. The concave maxilla is a readily observed character and is sufficient to diagnose N. jamaicensis because all other species of Natalus have markedly convex to markedly inflated maxillary bones.

Natalus jamaicensis is less well differentiated in external morphology, and no discrete external character has been found to distinguish it from N. major . It differs in its straight medial ear margin from most continental species of the genus (except N. lanatus ), which have slightly to deeply concave medial ear margins. From N. lanatus it can be distinguished by the lack of hair tufts at the base of claws, which are present in N. lanatus . From Natalus primus , N. jamaicensis can be distinguished by its concave lateral margin of the ear pinna, which is straight in N. primus .

VARIATION: Secondary sexual dimorphism in Natalus jamaicensis was detected in two cranial measurements: breadth across canines and mandibular tooth row ( table 12 ).

NATURAL HISTORY AND CONSERVATION: Natalus jamaicensis is known from just two localities, in only one of which (St. Clair Cave, St. Catherine) it is represented by an extant population. From the second locality, Wallingford Cave, St. Elizabeth, it is known by a single subfossil mandible. In St. Clair Cave, N. jamaicensis has been found at the entrance of a hot passage ( Hoyt and Baker, 1980) through which runs a permanent stream and in a protected lateral recess 3.7 m above the floor of the hot passage ( Goodwin, 1970). The bats usually hang from one foot and keep a distance between individuals of about 10 cm ( Goodwin, 1970). A total of nine other bat species are found in St. Clair: Artibeus jamaicensis , Chilonatalus micropus , Erophylla sezekorni , Monophyllus redmani , Mormoops blainvillei , Phyllonycteris aphylla , Pteronotus macleayi , Pteronotus parnellii , and Pteronotus quadridens ( Hoyt and Baker, 1980) . Goodwin (1970) found N. jamaicensis in close association with Chilonatalus micropus but forming separate groups. Similarly, Hoyt and Baker (1980) noticed that these two species were spatially segregated with N. jamaicensis occupying the first 50 m of the hot passage and being replaced in deeper areas by a larger colony of C. micropus . St. Clair cave is located in an area of semideciduous forest (1472 mm annual precipitation) at 100 m above sea level.

In spite of occurring in a single cave, it has been extensively collected, being represented by at least 78 museum specimens. The size of St. Clair’s colony appears to be very small. Observers have usually found it to be much less numerous than that of C. micropus (Hoy and Baker, 1980; Genoways et al., 2005). The only numeric estimate is that of Goodwin (1970) who reports only about 50 bats of this species in St. Clair. A total of 25 females taken in July and December did not show signs of reproductive activity ( Goodwin, 1970).

Nothing is known of the diet and nocturnal activity of N. jamaicensis . As in other natalids this bat probably forages with slow flight in cluttered habitats. Its flight has been described as fluttery and mothlike ( Goodwin, 1970). Natalus jamaicensis dehydrates very rapidly when taken outside the caves where they roost ( Hoyt and Baker, 1980).

Natalus jamaicensis may be the most critically endangered species of all natalids and one of the world’s mammals in greatest risk of extinction. Traditionally treated as Natalus stramineus , it was listed as critically endangered by the IUCN’s (IUCN, 2010) until 2008. It was considered the rarest of Jamaican bats by Goodwin (1970) and McFarlane (1986) yet,alarmingly, it has been intensively collected, apparently being more common in museum collections than in the wild (see above). This species’ only known roost site, St. Clair Cave, receives no form of official protection ( Dávalos and Eriksson, 2003), and is thus open to unregulated human visitation. St. Clair Cave, in addition, has resident populations of feral domestic cats that feed on the bats (species not specified) and rats of the cave ( McFarlane, 1997). A brief mistnet survey of St. Clair in December 2001 by Dávalos and Eriksson (2003) failed to detect this species. Immediate efforts are needed to understand this species’ conservation requirements and to formulate a plan for its protection.