All of Australia (except the northeastern peninsula) and Tasmania (Strahan, 1983).

Biogeographic Regions: australian (Native )

The head and body of Nyctophilus geoffroyi are covered in light gray to brown thick fluffy fur, with darker shades dorsally, and lighter shades ventrally. The ears are large, elongate, and joined across the forehead by a band of integument. The tragus is short. The tail extends to the end of the uropatagium. Fur is absent on wings and connecting membranes. Nyctophilus geoffroyi possesses a well developed noseleaf (unusual for vespertilionids) with a Y-shaped central groove. Its molars are dilambdadont and its canines small (Strahan, 1983).

Range mass: 6 to 8 g.

• Terrestrial

Nyctophilus geoffroyi exploits a wide range of habitat, including man-made structures such as attics and awnings. It roosts in dead trees, under tree bark, under rocks, in bird nests, and in caves. One study found that it prefers dead trees for roosts, particularly dead Banksia trees (Hosken, 1996). It tolerates a wide range of climate, including semi-arid, temperate, and tropical. It can tolerate extreme heat with temperatures up to 104 degrees Fahrenheit. Like other vespertilionids, Nyctophilus geoffroyi is also capable of handling cold conditions by entering torpor for much of the day in winter months. While in torpor body temperature is lowered and metabolic rate drops, conserving energy (Strahan, 1983; Hosken, 1999).

Terrestrial Biomes: desert or dune ; savanna or grassland ; chaparral ; forest ; rainforest ; scrub forest ; mountains

The diet of Nyctophilus geoffroyi consists primarily of a variety of airborne insects captured in flight using both echolocation and sight (Grant, 1991). Several authors have also noted that N. geoffroyi captures insects such as beetles from branches and bark, and even from the ground, and is a low flying predator (Nowak, 1997; Strahan, 1983, Grant, 1991). This view has been questioned, however, by Brigham et al. (1997), who observed that N. geoffroyi rarely descends to the ground, but rather spends most of the time 2-5 meters above the ground. Bailey and Haythornthwaite (1998) demonstrated that N. geoffroyi can also use its hearing to locate insects that generate sound, such as crickets, independently of echolocation.

Nyctophilus geoffroyi forms maternity colonies in spring, and young are born in the late spring or early summer. Maternity colonies are made up of as few as 10 to more than 100 individuals. Gender composition varies regionally, and some colonies are composed wholly of pregnant females, while others contain males and females. Females give birth to one or two offspring (twinning is common), which are typically left in the roost for about six weeks, after which time they begin to fly and hunt with their mother. Parental-offspring relationships apparently do not last after weaning (Strahan, 1983; Hosken, 1997).

Range number of offspring: 1 to 2.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous

Nyctophilus geoffroyi is found in great abundance locally. Because it exploits habitat made by humans, such as garages, barns, and attics, its numbers may have even increased in developed areas. Since many of the insects it feeds on, however, also feed on crops, the use of insecticides could be detrimental to bat populations (Strahan, 1983). Additionally, outside of the populated areas where N. geoffroyi is typically observed, it was found roosting only in dead trees in old-growth forest. No roost sites were observed in re-growth forest, suggesting that the preservation of old-growth forest may be necessary to preserve populations of N. geoffroyi in undeveloped areas (Taylor and Oneill, 1988; Hosken, 1996).

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

Because Nyctophilus geoffroyi often chooses human structures to nest or roost in, and has even been found in laundry left out to dry (Strahan, 1983), it is considered a pest by some. Its close proximity to humans also presents the possibility of transmitting diseases, although I found no reference any disease transmitted by this bat.

Nyctophilus geoffroyi consumes a great biomass of insects, many of which are destructive to agriculture or are considered pests (Strahan, 1983).