Keen’s Long-eared Myotis (Myotis keenii)
Keen’s Long-eared Myotis is a medium-sized Myotis species that measures between 63-94 mm total length and weighs between 4-6 g, They have dark, glossy fur and darker indistinct spots on the back of the shoulder; the underside is paler. Its long ears extend beyond the nose when pressed forward; the tragus is long, narrow and pointed. The ears and wing membranes are dark brown but not black. The outside edge of the tail membrane has a fringe of tiny hairs that can be seen with a hand lens. The calcar has an indistinct keel. The skull has a relatively steep forehead.
Little information is known about Keen’s Long-eared Myotis however, it likely uses tree cavities, rock crevices and small caves as roosting sites. Until recently, the only known maternity colony of Keen’s Long-eared Myotis was on Hot Spring Island in Haida Gwaii. This colony is the only one studied in detail. Most of the natural history data for this species comes from this population. The maternity colony contains about 40 female Keen’s Long-eared Myotis, which roost under rocks heated by a natural hot spring. Temperatures at the roost entrance in summer range from 22°C to 27°C, whereas the ambient temperature varies from 11°C to 18°C because of these warm temperatures, the colony is quite humid throughout the year. The roost is situated below the high tide line and it is often submerged for several hours at high tide. During these periods of high tides the roost is abandoned. On Hot Spring Island, Keen’s Long-eared Myotis forages over hot spring pools and clearings above salal. Recently another maternity colony was found at Knoll Hill near Tahsis, Vancouver Island. Although the exact location of the colony was not found, it was identified by the presence of a reproductive female found in the area and identified as a Keen’s Long-eared Myotis using dna samples. The only known hibernacula are on northern Vancouver Island where Keen’s Long-eared Myotis have been found in 8 caves from 3 separate areas.
Range: Keen’s Long-eared Myotis is the only North American bat restricted to the Pacific coastal region. The few locality records available suggest that its range extends from the Olympic Peninsula in Washington to southeastern Alaska. In British Columbia, it is found on the coastal mainland as far north as the Stikine River, on the Queen Charlotte Islands and on Vancouver Island.
Habitat: The distributional pattern suggests that Keen’s Long-eared Myotis is associated with coast forest habitats.