TY - JOUR
T1 - Sympatry and syntopy of the cricket frogs Acris crepitans and Acris gryllus in southeastern Virginia, USA and decline of A. gryllus at the northern edge of its range
AU - Micancin, Jonathan P.
AU - Tóth, Anikó
AU - Anderson, Rachel
AU - Mette, Jeff T.
PY - 2012/12
Y1 - 2012/12
N2 - The three species of Acris (cricket frogs) have experienced widespread declines in the northern portions of their ranges in the eastern United States since the middle of the 20th Century. In A. blanchardi and A. crepitans, these declines have been observed for decades but remain unexplained. The recently discovered decline of A. gryllus in North Carolina was obscured by sympatry and syntopy with its cryptic sibling species, A. crepitans, which is stable or expanding. The region of decline of A. gryllus is adjacent to its global northern limit, where sympatry with A. crepitans conceals the range limits and conservation status of both species. We investigated the historic and current ranges of sympatric Acris in southeastern Virginia. We established the 20th Century ranges of Acris using 1769 museum catalog records from 282 collection sites and morphometric analysis of 205 specimens from 42 sites. We acoustically identified Acris at 140 choruses in southeastern Virginia in 2010 and 2011. Before 1990, A. gryllus might have ranged further north and west than expected from museum records or published maps. On the Virginia Peninsula at the putative global northern limit of the range of A. gryllus, the species has declined and now occurs only in syntopy with A. crepitans. In contrast, A. gryllus persists in sympatry with A. crepitans in the Chowan basin and remains in allopatry in the Great Dismal Swamp. We propose adapting our approach to sympatric A. gryllus and A. crepitans to investigate other potential declines among sibling amphibians in the Atlantic Coastal Plain.
AB - The three species of Acris (cricket frogs) have experienced widespread declines in the northern portions of their ranges in the eastern United States since the middle of the 20th Century. In A. blanchardi and A. crepitans, these declines have been observed for decades but remain unexplained. The recently discovered decline of A. gryllus in North Carolina was obscured by sympatry and syntopy with its cryptic sibling species, A. crepitans, which is stable or expanding. The region of decline of A. gryllus is adjacent to its global northern limit, where sympatry with A. crepitans conceals the range limits and conservation status of both species. We investigated the historic and current ranges of sympatric Acris in southeastern Virginia. We established the 20th Century ranges of Acris using 1769 museum catalog records from 282 collection sites and morphometric analysis of 205 specimens from 42 sites. We acoustically identified Acris at 140 choruses in southeastern Virginia in 2010 and 2011. Before 1990, A. gryllus might have ranged further north and west than expected from museum records or published maps. On the Virginia Peninsula at the putative global northern limit of the range of A. gryllus, the species has declined and now occurs only in syntopy with A. crepitans. In contrast, A. gryllus persists in sympatry with A. crepitans in the Chowan basin and remains in allopatry in the Great Dismal Swamp. We propose adapting our approach to sympatric A. gryllus and A. crepitans to investigate other potential declines among sibling amphibians in the Atlantic Coastal Plain.
KW - Acris crepitans
KW - Acris gryllus
KW - amphibian decline
KW - Atlantic Coastal Plain
KW - community composition
KW - Fall Zone
KW - range edges
KW - syntopy
UR - http://www.scopus.com/inward/record.url?scp=84872155493&partnerID=8YFLogxK
UR - http://www.herpconbio.org/contents_vol7_issue3.html
M3 - Article
AN - SCOPUS:84872155493
SN - 2151-0733
VL - 7
SP - 276
EP - 298
JO - Herpetological Conservation and Biology
JF - Herpetological Conservation and Biology
IS - 3
ER -