echolocation pass count

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-...

Maximum Likelihood Estimator and Nightly Acoustic Count Values as Weight of Evidence of Bat Maternity Activity

SEAFWA Journal Volume 10, March 2023

Since the spread of white-nose syndrome in North America, several bat species have shown precipitous declines in abundance and distribution. With lower netting detection probabilities for the currently threatened but proposed endangered northern long-eared bat (Myotis septentrionalis) and endangered Indiana bats (Myotis sodalis), determination of presence or absence for regulatory clearance often has shifted to the use of acoustic sur- veys. However, acoustic surveys are unable to differentiate between non-reproductive individuals versus a maternity colony. We used...