Glyphonycteris sylvestris Thomas, 1896

Simmons, Nancy B. & Voss, Robert S., 1998, The mammals of Paracou, French Guiana, a Neotropical lowland rainforest fauna. Part 1, Bats, Bulletin of the American Museum of Natural History 237, pp. 1-219 : 60-61

Glyphonycteris sylvestris Thomas

VOUCHER MATERIAL: 1 male (AMNH *267897); see table 20 for measurements.

IDENTIFICATION: Useful descriptions and measurements of Glyphonycteris sylvestris were provided by Andersen (1906), Sanborn (1949), Goodwin and Greenhall (1961), Swanepoel and Genoways (1979), and Genoways and Williams (1986). No subspecies are currently recognized (Koopman, 1994).

As mentioned above, most previous workers have placed Glyphonycteris sylvestris in the genus Micronycteris and have discussed differences between sylvestis and other species in that context. We find it more useful to compare G. sylvestris with its congener G. daviesi , noting that these taxa can be easily distinguished based on the following: (1) size

large ( daviesi ; see table 20) versus small ( sylvestris ), (2) dorsal fur unicolored brown or gray ( daviesi ) or tricolored ( sylvestris ), (3) upper outer incisor absent ( daviesi ) or moved dorsally and excluded from occlusion by close apposition of inner incisor and canine ( sylvestris ), and (4) lower incisors with crown height approximately twice crown width in anterior view ( daviesi ) or with crown height approximately equal to crown width ( sylvestris ).

Besides sylvestris and daviesi , the only other named form referable to Glyphonycteris is Schizostoma behnii Peters (1865a) . About this form, Simmons (1996b: 4) wrote:

M [icronycteris]. behnii may be a senior synonym of M. sylvestris , but this has yet to be resolved. The two species are currently distinguished on the basis of size (forearm 37–44 mm in sylvestris , 45–47 mm in behnii ) and the degree of grooving on the upper incisors (prominent in sylvestris , somewhat less prominent in behnii ; Andersen, 1906; Koopman, 1994). Only three specimens have been referred to behnii : the holotype (ZMB 5154), and two specimens in the British Museum (BMNH 69.5.13.3, 69.5.13.4) that Andersen referred to behnii in his 1906 revision. I examined the

latter specimens (both in alcohol, one with skull cleaned), and found that they fall within the range of variation of sylvestris in all measurable dimensions. The forearms of both specimens are broken; Andersen (1906) reconstructed their length as 45 mm, but I estimate the actual length to be closer to 40–42 mm. The degree of grooving of the upper incisors also falls within the range I have observed in sylvestris . Unfortunately, I have not yet seen the holotype of behnii , which Peters (1865[b]) described as having a forearm length of 47 mm.

We have encountered several museum specimens labeled ‘‘ Micronycteris behnii ,’’ but examination of all has shown that they represent either Glyphonycteris sylvestris as currently recognized or are misidentified specimens of other taxa (e.g., Trinycteris nicefori ). The observed range of forearm length in G. sylvestris is 37.0–41.8 for males and 39.2– 43.8 for females ( Andersen, 1906; Sanborn, 1949; Linares, 1969; Swanepoel and Genoways, 1979; Genoways and Williams, 1986; personal obs.), and additional variation seems likely given the relatively small number of available specimens. Although we expect that behnii will eventually prove to be a senior synonym of sylvestris , we have not yet seen Peter’s type in the Berlin museum; therefore, we continue to use sylvestris for the smaller of the two Glyphonycteris species examined to date.

The single specimen of Glyphonycteris sylvestris that we collected at Paracou agrees in all respects with previous descriptions of the species.

FIELD OBSERVATIONS: The single individual we captured at Paracou was taken shortly before dark (at 18:20 hours) in a ground­level mistnet in swampy primary forest dominated by the palm Euterpe oleracea .