_Specimens._--_Boaco_: Los Cocos, 14 km S Boaco, 220 m, 28; San
Francisco, 19 km S, 2 km E Boaco, 200 m, 3. _Carazo_: 3 km N, 4 km
W Diriamba, 600 m, 25. _Managua_: 6 mi WSW Managua, 3.
This relatively large mastiff bat has not been reported previously from
Nicaragua. Specimens from several localities in Boaco were captured in
mist nets over streams; most of those from northwest of Diriamba were
shot in the early evening as they foraged high around large trees in a
coffee finca, but several were netted over a water-filled concrete tank
or found in the water in the tank as detailed in the account of
_Eptesicus furinalis_. At Los Cocos, bats that we netted seemed to be
emerging from a hollow located high in a tree over the stream.
Selected measurements of _M. p. pretiosus_ from Nicaragua, which
compare favorably with those of topotypes from Venezuela, are listed in
Table 4 along with measurements of _M. ater_ and _M. sinaloae_. The
taxonomic relationships of _M. pretiosus_ and _M. ater_ are less than
clear, and some authors (Handley, 1966b:773, for instance) have
suggested that the two may be conspecific. Whatever their ultimate
relationships may prove to be, two distinctive taxa seem to be present
in Nicaragua; the larger is assignable to _ater_ and the smaller to
_pretiosus_, as currently understood. Furthermore, the presumed
presence of two large _Molossus_ with dark-based hairs elsewhere in
Central America (Dilford C. Carter, personal communication) and in
southeastern Mexico (Goodwin, 1956:4; Goodwin and Greenhall, 1964:20)
argues for specific recognition of _pretiosus_.
The species _ater_ and _pretiosus_ differ mainly in size (Table 4),
some measurements clearly separating the two when sexual dimorphism is
considered. Also, the average weights of 18 nonpregnant females and
four males of _pretiosus_ (all adults) collected on 20 February 1968 at
Los Cocos, were 20.9 (14.6-23.8) and 27.0 (24.6-31.7) gms, respectively,
significantly smaller than corresponding figures for 11 nonpregnant
females and nine males of _M. a. nigricans_ taken two weeks later on
the Cosigueina Peninsula--29.1 (26.1-33.0) and 32.9 (29.3-35.1) gms. It
is of note that we have not collected these two large species at the
same localities in Nicaragua, and it is possible that one competitively
excludes the other in local situations.
TABLE 4.--Selected measurements of adults of three species of
_Molossus_ from Nicaragua.
Table Legend:
Col. A: Number of specimens averaged or catalogue number, and sex
Col. B: Length of forearm
Col. C: Greatest length of skull
Col. D: Condylobasal length
Col. E: Zygomatic breadth
Col. F: Breadth of braincase
Col. G: Length of maxillary toothrow
Col. H: Breadth across upper canines
====================================================================
A B C D E F G H
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_Molossus ater nigricans_, Departamento de Chinandega, Nicaragua
Average 10 ([Male]) 49.5 23.2 20.2 14.3 11.0 8.2 6.1
Minimum 48.2 22.8 19.9 14.1 10.5 8.0 6.0
Maximum 50.7 23.5 20.5 14.9 11.2 8.3 6.3
Average 10 ([Female]) 49.0 22.0 19.2 13.6 10.7 7.8 5.8
Minimum 47.1 21.5 18.8 13.3 10.5 7.6 5.6
Maximum 51.2 22.5 20.0 14.1 11.0 8.2 6.1
_Molossus pretiosus pretiosus_, Departamento de Boaco, Nicaragua
Average 8 ([Male]) 45.1 21.7 18.8 13.4 10.6 7.6 5.9
Minimum 44.1 21.0 18.3 13.1 10.2 7.4 5.6
Maximum 46.1 22.2 19.1 13.7 10.9 7.9 6.1
Average 23 ([Female]) 43.6 20.2 17.7 12.5 10.1 7.3 5.2
Minimum 41.0 19.5 17.2 12.2 9.5 7.1 5.0
Maximum 44.8 20.7 18.2 13.1 10.4 7.6 5.6