Indiana Bat

Revised* 2007 Rangewide Population Estimate

 

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Estimates are based on winter surveys conducted at all known Priority 1 and 2 hibernacula throughout the species' range. Additional data from Priority 3 and 4 hibernacula has also been included when available.

 

USFWS Region	State	2001	2003	2005	2007	% Change from 2005	% of 2007 total
Region 2	Oklahoma	0	5	2	0	-100.00%	0.0%
Region 3	Indiana	173,111	183,337	206,610	238,009	15.2%	50.8%
	Missouri	18,999	17,722	16,102	15,895	-1.3%	3.4%
	Illinois	21,677	43,646	55,166	54,095	-1.9%	11.6%
	Ohio	9,817	9,831	9,769	7,629	-21.9%	1.6%
	Michigan	20	20	20	20	0.0%	0.0%
	Total	223,624	254,556	287,667	315,648	9.7%	67.4%
Region 4	Kentucky	51,053	49,544	64,611	71,250	8.6%	15.2%
	Tennessee	9,564	9,802	12,074	8,906	-26.2%	1.9%
	Arkansas	2,475	2,228	2,067	1,829	-11.5%	0.4%
	Alabama	173	265	296	258	-12.8%	0.1%
	Total	63,625	61,839	80,048	82,243	2.7%	17.6%
Region 5	New York	29,671	32,981	41,727	52,803	26.5%	11.3%
	Pensylvania	702	931	835	1,038	24.3%	0.2%
	West Virginia	9,714	11,444	13,417	14,745	9.9%	3.1%
	Virginia	969	1,158	769	723	-6.0%	0.2%
	New Jersey	335	644	652	659	1.1%	0.1%
	Vermont	246	472	313	325	3.8%	0.1%
	Total	41,637	47,630	57,713	70,293	21.8%	15.0%
Rangewide Total:		328,526	364,030	425,430	468,184		100.00%
2-yr. Net Increase of:			35,504	61,400	42,754
% Increase of:			10.8%	16.9%	10.0%

 

 

* Missouri's 2001-2007 estimates had previously assumed 50,550 Indiana bats in Pilot Knob Mine (PKM) based on external fall capture rates at the mine's primary entrance, but a February 2008 internal survey of this mine documented a total population of 1,678 Indiana bats (Elliott and Kennedy 2008, unpublished technical report; available at http://www.utexas.edu/tmm/sponsored_sites/biospeleology/pdf/index.htm). The Service considers this new data to more closely estimate the true population within the mine and adjusted the Missouri estimates accordingly. Some other, smaller adjustments were made based upon the discovery of new hibernacula in Kentucky and New York in 2008 (i.e., we assumed the same number of Indiana bats that wee found at these new sites in 2008 were also present in 2007).

 

Compiled by Andy King, U.S. Fish and Wildlife Service, Bloomington, Indiana, Ecological Services Field Office from data gathered from bat biologists throughout the species' range. (andrew_king@fws.gov).

 

 

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Compiled by Andy King, U.S. Fish & Wildlife Service, Bloomington, Indiana, Ecological Services Field Office from data gathered from bat biologists throughout the species' range. (andrew_king@fws.gov)

 

Indiana Bat Rangewide Population 1981-2007

 

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Last updated: October 1, 2009