Kansas Mammal Atlas

Distribution:
The evening bat is an Austral migrant that occurs throughout the southeastern United States and a small area of northeasternmost Mexico north to southern Michigan and Pennsylvania. In Kansas, the species likely occurred only in the East in the past but has dispersed westward with the development of corridors of riparian woodland. The species seemingly is becoming much more common and widespread than it formerly was. The evening bat is now the most commonly captured species in riparian woodlands throughout much of Kansas. A specimen obtained along the Colorado state line in Stanton County is the only bat of this species yet found in far western Kansas and represents one of the westernmost localities of record for the species.  Recently, this species has also been captured in eastern Colorado and western Nebraska. It is likely that this species will continue to expand its range westward, following riparian corridors and more heavily wooded areas.
I am unaware that any fossils of this species have been reported in the scientific literature.

(, Museum Voucher) (, Observation) (, Literature Record)
Open icons are questionable records; Click on a marker to view details.

• Occurrence Summary:  
• 112 Total Records 
• 90 Museum Vouchers 
• 22 Other Observations 

Some county occurrences indicated below may be too imprecise to map above.
County Breakdown: County Name (# occurrences):
Barber (20); Barton (1); Clay (4); Cloud (2); Comanche (1); Douglas (4); Ellis (14); Ford (1); Franklin (3); Jewell (7); Johnson (1); Kiowa (7); Leavenworth (5); Lincoln (3); Miami (1); Morris (1); Ness (1); Osage (1); Osborne (1); Pawnee (1); Phillips (4); Rooks (22); Russell (1); Sedgwick (1); Stanton (2); Trego (3);

Natural History:
Evening bats inhabit deciduous woodland, where they roost in hollow trees and buildings. According to the scientific literature, females form maternity roosts throughout the range of the species, and the females and young are known to fly south for the winter. Historically, males remained in the south all year. However, it is now evident that both adult males and females are found throughout Kansas, and it is currently unknown whether this species migrates or overwinters in Kansas. Evening bats leave their roost to forage early in the evening. When foraging, evening bats fly slowly above clearings and ponds. If caught in the open by a storm, they hunker down in an alternate site, sometimes for several days. Females or young bats that have foraged unsuccessfully follow a successful forager to his or her food resources.
Adults may attain the following dimensions; total length 83-99 mm; length of tail 35-39 mm; length of hind foot 8-9 mm; length of ear 12-14 mm; weight 9-14 g. I found no data on longevity in this species.
The evening bat apparently is a beetle strategist, although it also consumes occasional representatives of the orders Lepidoptera and Hymenoptera. Of special interest to farmers is the fact that this bat feeds heavily on cucumber beetles, which is a major agricultural pest because the adult feeds on vine crops and the larva is the southern corn rootworm.
Known predators on evening bats are snakes, owls, housecats, and raccoons.  
Breeding presumably takes place in autumn. The following May, pregnant females form nursing colonies. They give birth to 1 to 3 (usually 2) pups in June. The sex ratio at birth is biased toward males. Mothers nurse their own young during the first 2 weeks after birth, but then they have communal nursing. At this time, females nurse unrelated females but not unrelated males. As a result, young males experience a high rate of mortality from starvation. Young begin to fly at about 3 weeks of age. Males leave the roost first, in August, whereas females remain in the roost until September. Females exhibit phylopatry and return to the same roost to raise their young. So far as we know, males never return.

Occurrence Activity:

Remarks:
Kansas populations of this species are referable to the subspecies Nycticeius humeralis humeralis.

Bibliography:

Account Last Updated:
8/21/2018 7:55:52 PM