acoustic swamping

Assessing Tricolored Bat Acoustic Monitoring for Regulatory Purposes in Relation to Reproductive Period, Cover Type, and Presence of Eastern Red Bats

The U.S. Fish and Wildlife Service (USFWS) allows use of acoustical surveys and automated identification software to determine the presence of the proposed endangered tricolored bat (Perimyotis subflavus). Analytical software is required to assess the probability of species absence on a sitenight basis using a maximum likelihood estimator (MLE) that accounts for interspecific misclassification rates. The current standard for occupancy determination is a returned MLE P-value ≤0.05 at the nightly level irrespective of the number of files identified as tricolored bats. For this species, MLE P...

Second Guessing the Maximum Likelihood Estimator Values for Bat Surveys

SEAFWA Journal Volume 11, March 2024

The U.S. Fish and Wildlife Service allows acoustical surveys and automated identification software to determine the presence of the endangered northern long-eared bat (Myotis septentrionalis) and Indiana bat (Myotis sodalis). Analytical software is required to assess presence probability on a site-night basis using a maximum likelihood estimator (MLE) that accounts for interspecific bat misclassification rates. The current standard for occupancy is a returned MLE P-value < 0.05 at the nightly level irrespective of the number of files identified as either northern long-...