Sperm whale dive behavior characteristics derived from intermediate-duration archival tag data

Area of Science:

• Marine Biology
• Animal Behavior
• Ecology

Background:

• Sperm whales (Physeter macrocephalus) are deep-diving predators crucial to mesopelagic ecosystems.
• Understanding their diving behavior is key to assessing their ecological role and conservation needs.

Purpose of the Study:

• To characterize the diving behavior and activity budgets of sperm whales in the Gulf of California using advanced tracking technology.
• To differentiate between foraging and other behaviors based on dive profiles.

Main Methods:

• Deployed Advanced Dive Behavior (ADB) tags on 27 sperm whales in the Gulf of California.
• Tags recorded depth and location data at high resolution for up to 34.5 days.
• Utilized hierarchical cluster analysis to classify dives into six categories based on depth and duration.

Main Results:

• Recovered tags provided data for up to 26.6 days, recording a median of 42.6 dives per day.
• 77% of dives were deep (>290m), categorized as V-shaped, Mid-water, Benthic, or Variable, likely for foraging.
• Shallow dives (<30m) were classified as Short- or Long-duration, suggesting resting or socializing.

Conclusions:

• ADB tags provide unprecedented multi-week insights into sperm whale diving behavior and activity budgets.
• Dive patterns suggest distinct behaviors, with deep dives linked to foraging and shallow dives to social or resting activities.
• Observed coordinated movements and dive patterns of tagged whales provide insights into their foraging strategies on heterogeneous prey fields.