Marine Mammals - Aaron Purdy Flashcards
What groups comprise marine mammals – Aaron mentioned 5 ?
- Cetaceans (whales, dolphins, porpoises)
- Pinnipeds (otariids & phocids)
- Sirenian (sea cows)
- Ursids (polar bears)
- Mustelids (sea otters)
What does ‘galumph’ mean? (just a fun question)
To move around like a sea lion
How do you distinguish between a California versus Steller’s sealions based on colour, body shape, body size, vocalization?
California Sea Lion
- Darker
- Slender
- Smaller
- Bark
Stellar Sea Lion
- Lighter
- Chunkier
- Larger
- Roar
Who is the largest pinniped and what family do they belong to? Where do you see them typically?
Elephant seals – Phocidae.
Mexico??
What cues would you use to locate cetaceans (he mentioned at least five cues)?
- can identify species from size/shape of blow
- can identify by fluke shape, skin colour/texture, pectoral fin size, behavior, location
- can identify by auditory/olfactory cues
- can identify by other species (marine birds) indicate whales are present
What are some of the distinguishing characteristics of Odontocetes (same as question 4 of the notes)?
- Teeth
- One blowhole
- No ventral pleats
- Echolocation
- More social
- Non-migratory
Contrast the distinguishing characteristics of dolphins and porpoises (same as question 11 of the notes).
Dolphin
- 1.5 to 10 m long
- Forehead bulges, distinct beak, long rostrum
- Teeth cone shaped (unlobed)
- Curved dorsal fins
Porpoise
- 1.2 to 2.2 m (smaller)
- Blunt snout, no beak, short rostrum
- Teeth spade shaped (2-3 lobes)
- Fin is triangular (not curved)
How would you distinguish a harbour porpoise from a Dall’s porpoise (size, group size, colour patterns, which one associates with boats, where do they generally hang out (i.e., likelihood of seeing them)?
Harbour Porpoise
- 1.75 m
- 1-5 per group
- Shallow coastal waters
- Elusive
- special concern
- Counter shading
Dall’s Porpoise
- 2m
- 4-20 per group
- Coastal/oceanic
- Fast moving
- Not at risk
- White patch on sides & on dorsal fin
Characteristics of resident killer whales
Residents
- Fish eating
- SRKW: 73
- NRKW: 230 ish ?
- Do not interbreed
- Dorsal fin rounded with pointed trailing tip
- Very open saddle
- Males – tall dorsal (maybe slanted forward)
Characteristics of transient killer whales
Transient
- Mammal eaters
- Single male goes off and hunts and returns to mama
- Pointed dorsal
- Saddle extends past midline of dorsal fin
Characteristics of off-shore killer whales
Offshore
- Around 300
- Prey on fish & sharks
- Threatened
- Teeth ware down over time.
- Faint saddle
- Fin rounded at tip
- Silent when hunting
What are the characteristics of sperm whales: size, skin characteristics, teeth, prey, blowhole
- M: 18 m, F:14 m
- 15 – 30 individuals
- Deep long dives (1 hour, 1000 m)
- No teeth on top jaw
- Wrinkled skin, scrapes/scratches
- Not at risk
- Blowhole: off to left, shoots forward
- Tiny little dorsal fin
What are some of the distinguishing characteristics of Mysticetes (same as question 4 of the notes)?
- Baleen (no teeth)
- Two blowholes
- Ventral pleats
- No echolocation
- Generally solitary
- Migratory (arctic - equator)
Who is the smallest of the baleen whales?
Minke
What is the very distinct aspect of the minke whale – identification wise
White band on pectoral fin
This whale tends to show its pectoral fin as it feeds?
Humpback
Which whale has the massive pectoral fin?
Humpback whale
This whale species has had a large increase in abundance in recent years?
Humpback whale
What are some of the unique feeding styles of humpback whales?
Bubble net feeding and lunge feeding (breaching)
What whale is the largest animal on planet earth?
Blue whale
What is the most rare whale in the BC waters?
Northern Pacific Right Whale
Explain some of the threats to cetaceans – Aaron mentioned 8 threats.
- Whaling ended in 1967, still feeling effects
- 24, 427 killed whales in 60 years
- Contaminants – bioaccumulation (remain in body)
- Food supply (chinook) – competing with humans
- Entanglement in fishing nets
- Conflicts with fishing industry
- 100 incidents of non-compliance with (approaching whales) – noise, disruption of natural behaviors
- Air pollution
