notes on male sperm whale reactions to killer whale attack in a high latitude feeding ground

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NOTES ON MALE SPERM WHALE REACTIONS TO KILLER WHALE ATTACK IN A HIGH LATITUDE FEEDING GROUND. Marta Acosta, Heike Vester , Ricardo Antunes , I va Kovacic & Luca Tassara. INTRODUCTION. Killer whales have a broad diet - PowerPoint PPT Presentation

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Diapositiva 1

NOTES ON MALE SPERM WHALE REACTIONS TO KILLER WHALE ATTACK IN A HIGH LATITUDE FEEDING GROUNDMarta Acosta, Heike Vester, Ricardo Antunes, Iva Kovacic & Luca Tassara

INTRODUCTION Killer whales have a broad diet

Aggressive interactions may underline ecological interactions (e.g. prey competition)

To date, agressive interactions between killer and sperm whales, refer to female groups with calves

First compilation of (3 events) harassment/attack of killer whales towards adult male sperm whales and their response

EVENT 1Late 90s:

A small group of killer whales was observed approaching and harassing a male sperm whale, that responded by defecating until the attackers left

EVENT 230/07/2009:

A male sperm whale that surfaced in the middle of a group of killer whales feeding on herring triggered an aggressive response. The whale repelled the attack by shaking its peduncle 90 sideways

EVENT 323/07/2011:

4 sperm whales vs 5 killer whales (1 calf) Sperm whale diving interruption and clustering Acoustic response: 5R, 5+1 Silent killer whales? Slight wounds

CONCLUSIONS First compilation of killer whale harassment/attack on male sperm whales Not homogeneous sperm whale response First evidence of social response among males Killer whale behaviour consistent with previous reports Predator-prey? Competition?

THANKS!!

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