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 PresentationTRANSCRIPT
NOTES ON MALE SPERM WHALE REACTIONS TO KILLER WHALE ATTACK
IN A HIGH LATITUDE FEEDING GROUND
Marta 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 1
Late 90´s:
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 90º 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!!