Noctilio leporinus mastivus (Vahl 1797)

P, S C., L, P A., G, H H., M, M N., L, K C. & C, J, 2007, B B, N L A, Occasional Papers of the Museum 271, pp. 1-20 : 7

Noctilio leporinus mastivus (Vahl 1797)

Specimens examined (11).— Overview Cave , 3.5 km NE of Codrington, 1 ( NMNH); Pigeon Bluff, 17°36'52.7"N, 61°44'9.2"W, 3 m, 10 ( TTU) .

Specimens captured/released (8).— Indian Cave, 17°40'04"N, 61°46'10"W, 1; Pigeon Bluff, 7 .

Additional records.—No specific locality ( Husson 1960:154); Indian Cave (2007 photograph-Cindric).

Husson (1960) first reported the greater bulldog bat from Barbuda based on four individuals collected at an unspecified locality by Hummelinck in July 1955. Length of forearm and cranial measurements of five male and five female specimens from Barbuda are given in Table 1 . Males averaged significantly larger than females in all measurements taken. For five measurements, the significance level was P ≤ 0.001. For mastoid breath the significance level was P ≤ 0.01, and for length of forearm and length of maxillary toothrow the significance level was P ≤ 0.05. In fact, in only the latter two measurements do the ranges of the measurements of the sexes overlap. Davis (1973) assigned circum-Caribbean specimens to the subspecies N. l. mastivus , which was originally described from St. Croix, U. S. Virgin Islands. Measurements of the specimens from Barbuda are within the range of those given by Davis (1973) for a sample of 21 females from the West Indies; therefore, we have followed this arrangement here.

Seventeen N. leporinus were collected as a group on 2 June 2003 using a modified cargo net suspended under a solution pocket in a limestone block/escarpment called Pigeon Bluff at Castle Bay. At this point, the cliff formed an overhang that was at least 6 m deep and permitted the research team full access to the solution pocket in which the greater bulldog bats were located. This vertical cavity was about 3 m above the floor of the overhang, 0.5 m in diameter, and at least 2 m deep. Although the overhang area was well illuminated, the bats at the top of the solution pocket could not be seen without the aid of a flashlight. This colony consisted of 10 males and seven females. One male and one female were juveniles, six of the females were lactating, and four of the males were scrotal. Lactating females and their young were intermixed with scrotal males indicating an absence of sexual or age partitioning in this colony. Average length of testes of five adult males was 7.6 (5-11). Five adult males weighed an average of 61.0 (55.4-69.9), whereas five adult females averaged 51.2 (49.3-53.0).

The specimen that was captured by hand in the Overview Cave roost on 17 January 1983 was an adult male (length of forearm, 86.1) with enlarged testes. Noctilio leporinus were observed in Indian Cave in both 1994 and 2003, and a non-reproductive adult male was caught by hand there on 10 February 1994 (length of forearm, 87.3; weight, 66.2). During the 2007 survey, nine fishing bats were photographed in a domed portion of Indian Cave. Fishing bats were observed in 2003 flying among sea grape trees along the base of a rock face at Gun Shop Cliff, possibly hawking insects. The animals flew close to the ground (<1 m) and deftly avoided several mist nets that were set in the area.