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These documents complement our online bat acoustic classes to assist with identification of bat echolocation calls to species.
Our Resources
(click link above for document)
A compilation of range maps for all 47 species that occur in the US and Canada. Many are outdated and inaccurate, so please use with caution.
Distinguishing Canyon (PAHE) vs. Tricolored (PESU) Bats
This graphic is meant to help distinguish tricolored (Perimyotis subflavus) and canyon (Parastrellus hesperus) bats acoustically in areas where their ranges overlap. Here, we plot representative echolocation calls from both species across a range of call duration lengths. Overall, our observation is that tricolored bats tend to produce echolocation calls at a slightly lower minimum frequency (Fmin; 40-43 kHz) than canyon bats (44-47 kHz). As well, tricolored bats tend to produce echolocation calls with a flat lower slope (<0.2, as measured by SonoBat). We have not quantified these differences, and much overlap in call characteristics remains between these two species. We recommend that in west Texas, east New Mexico, and southeast Colorado where these species may co-occur that researchers only assign species classifications for the most extreme versions of these calls. That is, only identify the flattest, lowest Fmin calls as tricolored bats and the steepest, highest Fmin calls as canyon bats. Place everything else in a canyon/tricolored (PAHE/PESU) bat species group.
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