Natalus major Miller, 1902

Tejedor, Adrian, 2011, Systematics Of Funnel-Eared Bats (Chiroptera: Natalidae), Bulletin of the American Museum of Natural History 2011 (353), pp. 1-140 : 56-60

Natalus major Miller, 1902

Figure 27

Natalus major Miller, 1902: 398 . Type locality ‘‘near Savaneta, Santo Domingo,’’ Dominican Republic.

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

HOLOTYPE: USNM 101395, adult male skull and skin in fluid, collected by W.M. Gabb between 1869 and 1871 ‘‘near Savaneta (locality 195 in appendix 1), Dominican Republic.’’ The skull is complete (fig. 27) and the skin is in good condition.

DISTRIBUTION: Hispaniola, including the Dominican Republic and Haiti (fig. 23).

DIAGNOSIS: Forearm long (41.1–45.0), skull long relative to forearm, breadth across canines large (3.9–4.5), maxillary tooth row (7.5–8.0); medial ear margin straight; lateral ear margin deeply notched; nostrils small, opening ventrolaterally; ventral hairs monocolored; dorsal hairs bicolored, hair bases lighter than tips; hair at base of claws short and inconspicuous or long and thin, never forming tufts; maxilla dorsal to molars convex, not inflated; postorbital region with sides widely diverging rostrally; point of flexion between rostrum and braincase dorsal to the anterior edge of orbit; palate ending caudally 2/3 of the distance between M3 and tip of pterygoid; caudal margins of palatine wing of maxilla forming an acute angle with longitudinal axis of skull; basisphenoid pits shallow; caudal margin of ascending ramus of mandible perpendicular to alveolar plane of lower molars; I1 not visible in lateral view, obscured by I2; mesostylar crest on M3 absent. A comparison of diagnostic characters between N. major , and other species of Natalus is summarized in table 5.

DESCRIPTION: A large natalid (forearm length 41.1–45.0 mm; greatest skull length 17.0– 18.1 mm; weight 5.5–10.0 g); muzzle long and dorsoventrally flattened; nostrils elliptical, opening anteroventrally 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 medium sized (13.0– 18.9 mm); ear pinna funnel shaped with 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 (23.2–25.4 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 wide, with 3rd metacarpal (40.3–42.7 mm) slightly longer than 5th metacarpal (38.3–41.2 mm); wings attach to tibia above ankle; pelage dense and lax; hairs long (7 mm, dorsally and ventrally); pelage usually darker dorsally than ventrally; dorsal hairs bicolored, with tips darker than bases; ventral hairs monocolored; dorsal hair bases buff to drab with tips sepia to fuscous brown (pl. 1); ventral hairs creamy buff; dense mustachelike hair tufts along lateral margins of upper lip and across muzzle; mustache formed by dense, lax, irregularly arranged, and ventrally curved hairs; natalid organ covered with thin hairs; skull long and relatively broad with moderate rostral flexion; rostrum short and broad, with moderate sulcus between nasals; moderate rostral palatal emargination; maxilla convex dorsal to molars; braincase greatly inflated, rising gently from rostrum; braincase elliptical in dorsal view; sagittal crest well developed; postorbital constriction wide, its sides diverging rostrally; 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 and fused to ribs; vertebrae T12–L4 fused into a laterally compressed column without vestige of sutures; lumbar column relatively long and not particularly concave ventrally; vertebrae L5 and L6 free; caudal vertebrae 4 to 7 longer than distance from ischium to iliac crest of sacrum.

COMPARISONS: Unique morphological features are not apparent in Natalus major . It, therefore, must be distinguished from other species of Natalidae by a combination of shared diagnostic characters. From species of the genera Chilonatalus and Nyctiellus , Natalus major is distinguished by its large size (forearm length. 41.1 mm) and by genericlevel characters ( table 3 ).

Natalus major can be easily distinguished from continental and Lesser Antillean species of Natalus on the basis of its larger forearm length and its straight medial ear margin. Natalus mexicanus has a slightly concave medial ear margin and its forearm is shorter than 40.0 mm. Only very large individuals of N. stramineus , N. tumidirostris , and N. espiritosantensis reach the forearm length of the smallest individuals of N. major , yet in the first three species, the medial ear margin is concave. Natalus lanatus , on the other hand, has a straight medial ear margin, but its forearm is shorter than 38.0 mm.

From Natalus primus , N. major can be distinguished by size, ear, and cranial characters. Relative to N. major , N. primus has a larger forearm (more than 46.0 mm; the forearm is shorter than 45.0 mm in N. major ), has a straight lateral ear margin (concave or notched in N. major ), and is characterized by deep basisphenoid pits (shallow in N. major ), the presence of a mesostylar crest on M3 (absent in N. major ), and an elongated premaxillary region (reflected in a laterally visible gap between I2 and the upper canine and a rostrally projecting I1; in N. major neither the gap between I2 and the upper canine, and I1 are visible in lateral view).

Of all natalids, Natalus major is most similar to Natalus jamaicensis in size and external characters, but can be easily distinguished by its wide postorbital region with sides widely diverging anteriorly, whereas the postorbital region in N. jamaicensis is narrow and with sides nearly parallel. The maxilla of N. major is convex dorsal to the molars, whereas that of N. jamaicensis is concave. Also, the braincase of N. major is oval in dorsal profile (with length greater than the greatest breadth) and does not rise abruptly from the rostrum (in an angle smaller than 55u), whereas that of N. jamaicensis is nearly circular in dorsal profile (with length similar to greatest breadth) and rises abruptly from the rostrum in an angle greater than 60u.

VARIATION: On average, males of Natalus major are significantly larger than females in length of tibia (Tukey; P, 0.05) and breadth across canines (Tukey; P 5 0.05; table 15). Geographic variation is not apparent in this species. Most individuals have been collected in neighboring localities of the northwest of Hispaniola and other localities on the island are represented by only one or a few individuals.

Young adults with silky, grayish pelage have smaller zygomatic breadths even though the remaining cranial dimensions are similar to that of full adults. A specimen from Haiti (KU 150721), which Timm and Genoways (2003) speculated could belong to a separate subspecies because of its smaller dimensions and coloration, appears to be a young adult.

NATURAL HISTORY: Natalus major is known from 30 localities (including two represented by fossil remains only) of which at least 10 have been roost sites, nine of them caves and one a large hollow tree ( Timm and Genoways, 2003). The caves where N. major has been found range from small to very large, are always humid, and often contain hot chambers and bodies of water. Most of these caves have a phreatic origin, with wide chambers and constricted entrances, but some are also fluvial caves characterized by

linear passages. One was a sea cave with its floor partially inundated by the tide. N. major roosts in loose groups of less than 10 to more than 50 individuals, occupying areas of low ceilings (including solution cavities) or cave walls. Individuals hang from one or both feet, without body contact with the substrate or among themselves, and keeping a distance between individuals of about 10 cm (pl. 19- A). Occasionally, pairs of individuals are found hanging back to back. Natalus major can coexist at roosts with 10 other bat species ( Artibeus jamaicensis , Brachyphylla nana , Chilonatalus micropus , Erophylla bombifrons , Macrotus waterhousii , Monophyllus redmani , Mormoops blainvillei , Phyllonycteris poeyi , Pteronotus quadridens , and Pteronotus parnellii ), but it has never been found in multispecies groups. It usually tolerates disturbance for long periods and can occasionally be caught by hand while roosting, but this happens only when a colony has not been disturbed for a long time. On second and third visits to a cave the bats are usually alert and the groups move to alternative roosting sites within the cave at the slightest disturbance (e.g., the beam of a flashlight). When retreating from disturbance, the bats fly close to the floor and walls of the caves (pl. 9-B).

Natalus major is found from semiarid lowlands of thorn scrub (Pepillo Salcedo, Dominican Republic, 883 mm annual precipitation; locality 187) to degraded wet forest (Camp Perrin, Haiti, 2841 mm annual precipitation) and from sea level to about 1000 m (locality 182). Little is known of the diet or reproduction in this species. Young adults have been found in late October, indicating that parturition and lactation probably take place from July to September, as in Natalus mexicanus . Natalus major is the most common of Greater Antillean Natalus , being represented by 105 museum specimens, most of which have been captured in the northeast of the Dominican Republic. Roosting colonies may reach a few hundred individuals.

Natalus major begins its foraging activity shortly after sunset. One individual was mistnetted at 15:39, at least 4 km away from any known cave where the species roosted. A

second individual was mistnetted well after dark entering a cave not used by the species as a day roost, suggesting that night roosts may be used at least occasionally. It has a very slow and maneuverable flight and dehydrates quickly if taken outside the cave during daytime.

Natalus major is listed asnear threatened in IUCN’s Red list of Threatened Species (IUCN, 2010). Yu and Dobson (2000) considered this species ‘‘very rare,’’ yet their conclusion was based on distribution and ecological data from Hoyt and Baker (1980), who listed the type localities of N. major major and N. major jamcensis as the only localities of N. major (sensu lato), and based their natural history account on N. jamaicensis . Even though it is represented by relatively few specimens compared to continental species (e.g., N. tumidirostris and N. mexicanus ), it seems ubiquitous throughout Hispaniola (particularly in the moist northeast) and is one of the most frequently encountered bats in the island’s caves. Given that a significant proportion of the many caves that may remain unsurveyed in Hispa- niola’s protected karstic areas (e.g., Parque Nacional Jaragua and Parque Nacional los Haitises) probably harbor this species, N. major may be more accurately regarded as of least concern for conservation. Nonetheless, considering that this species is restricted to Hispaniola, adequate population assessments should be undertaken to evaluate its potential conservation needs.

Tables

TABLE 15 Summary of measurementsa of Natalus major

		Females					Males
	N	Mean	(Min.–Max.)	SD	N	Mean	(Min.–Max.)	SD
Weight	4	6.7	(5.5–7.6)	1.1	9	7.5	(6.0–10.0)	1.3
Forearm length	11	43.5	(41.1–44.8)	1.0	22	43.4	(42.0–45.0)	0.9
Length of tibia, dry	2	21.4	(21.3–21.4)	0.1	7	22.7	(21.9–23.8)	0.7
Length of tibia*	8	23.6	(23.2–24.3)	0.4	14	24.2	(23.3–25.4)	0.7
Length of 3rd metacarpal	7	41.3	(40.3–42.3)	0.8	12	41.6	(40.5–42.7)	0.7
Length of 5th metacarpal	7	40.1	(38.3–41.2)	0.9	12	40.3	(38.9–40.9)	0.6
Length of ear	9	16.1	(14.0–18.9)	1.5	20	16.0	(13.0–17.9)	1.2
Length of penis		–	—	–	12	4.5	(3.6–5.8)	0.7
Length of natalid organ		–	—	–	9	7.0	(5.4–8.3)	0.9
Greatest skull length	2	17.3	(17.0–17.6)	0.4	11	17.7	(17.3–18.1)	0.2
Zygomatic breadth	2	9.4	(9.3–9.4)	0.1	11	9.5	(9.3–9.6)	0.1
Braincase breadth	2	8.7	(8.6–8.7)	0.1	11	8.8	(8.6–9.0)	0.1
Breadth across molars	2	6.3	(6.1–6.4)	0.2	12	6.3	(6.1–6.4)	0.1
Breadth across canines*	2	4.1	(4.1–4.1)	0.0	10	4.3	(4.1–4.4)	0.1
Maxillary tooth row	2	7.7	(7.6–7.7)	0.1	12	7.8	(7.6–8.0)	0.1
Mandibular tooth row	1	8.1	—	–	8	8.2	(8.0–8.4)	0.1
Postorbital breadth	2	3.4	(3.3–3.4)	0.1	12	3.4	(3.2–3.5)	0.1
Depth of braincase	1	7.2	—	–	7	7.1	(6.9–7.3)	0.2

a Descriptive statistics of measurements for each sex. N 5 sample size; SD 5 standard deviation. Weight is given in g; all other measurements are given in mm. See text for description of measurement methods. Measurements significantly different between sexes (P,0.05) are followed by an asterisk (*).