migration range of the Eastern Small Footed bat

[hewhocaves]

anyone know the migration range of the ESFB?

It's habitat is as follows:


I think at this point the most we can say is that it is coincidental to the movement pattern of WNS. Unfortunately, it looks like the ESFB is one of the least understood bats.

[wyandottecaver]

the short answer is no I dont. As you note, small footed bats are not well understood because they "hide" i.e. roost in cracks, crevices, under rocks, etc. No doubt one of the main reasons CBD chose them, there could be hundreds in a cave and you might never see them.

[driggs]

In Ontario, two [Myotis leibii] were recovered in summer 16 and 19 km from the winter hibernation cave (Hitchcock 1955).

Source: http://www.natureserve.org/explorer/servlet/NatureServe?searchName=Myotis+Leibii+

The CBD "chose" the Eastern Small-footed because it is rightly classified as "critically imperiled" or "imperiled" in every single state within its range, as the above link shows (see: Distribution). These little guys are unfortunately so rare that there's not much known about their habits.

Their tiny size and masked face ranks them at the top of my list for cutest bat species, though I've only been lucky enough to see one in real life.

BTW, in case you were wondering, I believe that the species name is pronounced LEE-bee-eye.

[wyandottecaver]

Driggs, true. Because by their nature these smallest of Eastern bats are difficult to locate and survey. Thus, while all quoted bat populations are estimates based on observation, for a species whose very behaviour lends itself to non observation, using those estimates as reliable indicators of abundance or comparisons to other more easily observed species is flawed.

From the USFWS 2001: Current Status and Conservation Strategy for the Eastern Small-footed Myotis (Myotis leibii)

"....Abundance of the eastern small-footed myotis is extremely difficult to assess or predict. The species has
always been considered uncommon or rare throughout its range (Choate et al. 1994; Wilson and Ruff
1999), and populations and occurrences of this bat are relatively scattered and small. The eastern smallfooted
myotis is often overlooked or incorrectly identified in traditional bat surveys particularly during
hibernation. This is because, unlike many cave-roosting bats (found most often on cave ceilings and
walls),the eastern small-footed myotis is sometimes found under rocks and talus on cave floors, or wedged into
cracks in cave walls and ceilings (Krutzsch 1966; Libby, pers. comm.; MacGregor, pers. comm.).
Until recently, mist netting efforts have concentrated on streams or ponds, but relatively new information
suggests that numbers of captures of the eastern small-footed myotis in these habitats may be limited..."

"...During hibernation, some bat species form mixed sex colonies that can
be quite large, consisting of up to several thousand individuals. However, this species does not seem to
form large colonies during hibernation. Although groups of 50 or more small footed-myotis may pack
into crevices at some sites (Barbour and Davis 1969), researchers are more likely to find a single
individual or small group wedged in a crevice with only the blackish mask and ears visible upon careful
inspection. Occasionally, individuals can be found mixed with other species of bats or hanging singly..."

"..In the report “Species of Special Concern in Pennsylvania” by Genoways and Brenner (1985), the Pennsylvania
Biological Survey assigned Myotis leibii the status of “threatened.” It is clear, however, that additional
work needs to be done with appropriate survey and monitoring techniques throughout the species’ range
before the true status can be determined..."

[Spike]

Thinking about the roosting habits of Eastern Small Footed bats reminded me of this paper by Jean Krejca. While it's not a bat paper it deals specifically with trying to asses abundance of little critters that go places we can't see. Also the paper deals with critters that don't migrate or ever leave caves.

http://www.utexas.edu/tmm/sponsored_sit ... krejca.pdf