QUANTIFYING DYNAMIC HABITAT USE OF THE NORTH ATLANTIC RIGHT WHALE USING AN INDIVIDUAL MOVEMENT MODEL

Rapid warming in the Northwest Atlantic has caused declines of North Atlantic right whale prey, late-stage Calanus finmarchicus, in their historic and protected foraging areas. This led to a rapid redistribution of right whale foraging patterns, and their unexpected presence in new habitats increased mortality rates due to ship strikes and gear entanglement. Annual distribution and birth rates have been linked to fluctuations in the abundance of prey; however, patterns of individual foraging behavior and reproductive success in relation to changes in their environment have not been investigated. The population has been monitored since 1980, and individuals can be identified by unique callosities and markings. Tracks were created using consecutive sightings of known individuals from 1977-2022 that were no more than 30 days apart (sightings = 57,216; tracks = 12,032). A Brownian bridge movement model was applied to quantify potential habitat use for each track incorporating movement variance and time in between sightings. Daily distributions were produced for each modeled individual and summed to show population trends of peak abundance and seasonal patterns in habitat regions. The modeled habitat distributions provide insight into how individual health and behavior scale to population level response in a changing environment.  These methods improve spatial distribution predictions in intermittently observed animals beyond stationary sightings, and could be applied to other species confined to movement in bodies of water over various spatial and temporal scales. 

Presentation Preference: Poster

Primary Presenter: Abigail Kreuser, University of South Carolina (akreuser@seoe.sc.edu)

Authors:

Abigail Kreuser, University of South Carolina, School of the Earth, Ocean, and Environment  (akreuser@seoe.sc.edu)

Erin Meyer-Gutbrod, University of South Carolina  (emgutbrod@seoe.sc.edu)