Feeding enrichment methods for Pacific walrus calves

Area of Science:

• Marine Mammal Behavior
• Animal Welfare Science
• Captive Animal Management

Background:

• Walrus calves in captivity require enrichment to prevent stereotypic or negative behaviors due to reduced natural foraging opportunities.
• Developing effective enrichment strategies is essential for maintaining the psychological well-being of young pinnipeds.

Purpose of the Study:

• To evaluate the effectiveness of four different food dispenser types in occupying two walrus calves.
• To assess the practicality of these dispensers for use by zoo keepers.

Main Methods:

• Two walrus calves were presented with fish in four distinct dispenser types: ice, a nine-hole container, a two-hole container, and ice in a one-hole container.
• Behavioral observations were conducted during 90-minute test periods to record the time spent interacting with each dispenser.
• Keeper feedback on dispenser practicality was also considered.

Main Results:

• All four feeding methods influenced walrus calf behavior, with varying levels of engagement between individuals (32-95% and 14-57% of test periods).
• Significant learning and dietary shifts in the calves prevented direct comparison of dispenser effectiveness over time.
• The nine-hole container was identified as the most practical dispenser for keepers and remained in frequent use.

Conclusions:

• Food dispensers can effectively occupy captive walrus calves, but individual responses vary.
• Dispenser practicality for keepers is a key factor in sustained use.
• The nine-hole container demonstrated both engagement potential and keeper utility, suggesting its value in walrus husbandry.