Monitoring abundance of aggregated animals (Florida manatees) using an unmanned aerial system (UAS)

Scientific Reports
By: , and 



Imperfect detection is an important problem when counting wildlife, but new technologies such as unmanned aerial systems (UAS) can help overcome this obstacle. We used data collected by a UAS and a Bayesian closed capture-mark-recapture model to estimate abundance and distribution while accounting for imperfect detection of aggregated Florida manatees (Trichechus manatus latirostris) at thermal refuges to assess use of current and new warmwater sources in winter. Our UAS hovered for 10 min and recorded 4 K video over sites in Collier County, FL. Open-source software was used to create recapture histories for 10- and 6-min time periods. Mean estimates of probability of detection for 1-min intervals at each canal varied by survey and ranged between 0.05 and 0.92. Overall, detection probability for sites varied between 0.62 and 1.00 across surveys and length of video (6 and 10 min). Abundance varied by survey and location, and estimates indicated that distribution changed over time, with use of the novel source of warmwater increasing over time. The highest cumulative estimate occurred in the coldest winter, 2018 (N = 158, CI 141–190). Methods here reduced survey costs, increased safety and obtained rigorous abundance estimates at aggregation sites previously too difficult to monitor.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Monitoring abundance of aggregated animals (Florida manatees) using an unmanned aerial system (UAS)
Series title Scientific Reports
DOI 10.1038/s41598-021-92437-z
Volume 11
Year Published 2021
Language English
Publisher Springer Nature
Contributing office(s) Wetland and Aquatic Research Center
Description 12920, 12 p.
Country United States
State Florida
Other Geospatial Big Cypress National Preserve
Google Analytic Metrics Metrics page
Additional publication details