Midterm 1 Flashcards
I did a lot of the data on whales come from
Whaling logs
What are some methods for estimating cetacean population
Mark recapture, surveys, genetics
What is mark recapture
Using artificial marks that are made, using natural marks like the tale of the whale or scratches on the fan.
Our surveys conducted
Buy air, ship, land
What are the population growth rates of cetaceans like / general trend
Low maximum population growth rates
The number of Wright Wells how very proud the years with a huge population decline happening presently… The question is how many were there and how are they figuring this out
Historical methods - add catches and births, pre-whaling pop size
Genetic methods
- estimate mtdna + # of females needed to produce it
Total pop size proportional to # breeding females
What’s the problem with the historical method and genetic method of estimating cetacean population size
There are huge discrepancies and differences between the population size from these two methods
mysticetes social structure
Safe from predators, pray our car easily, strong seasonality and their environment for migrations, mom calf bond, if you other bonds because of interactions for feeding and breeding
Most Mysticetes do not cooperatively feed together, they are groupings are usually temporary during the summer feeding season however there is one exception to this… Which one cooperatively feeds together and how
Humpback form a bubble net
Return the winter breeding they usually congregate in what type of waters and why
Calm, relatively warm water. They do this because there’s a higher chance of calf survival
Who has more power in the meeting decisions
Females
Explain sperm competition during the winter breeding season
Right wheels display this, they make enough sperm to blast out the previous emails sperm
Female is surrounded by a number of males with her belly up at the circus so that the males can’t access her genitals, males are underneath and have a mobile penis that can search for the female and deposit it sperm
What are songs used for
Mating rituals
How do the songs of the males for example in humpbacks dispersed geographically across the oceans
They move eastward across oceans
What are some characteristics of a meeting ritual songs
All male sing the same songs to attract females, song changes from year to year, songs change from location
How do odontocetes differ from mysticetes in feeding
Go after Faster moving fish, prey difficult to catch
Who is more social mysticetes or odontocetes why
Odontocetes
Need to protect young because born smaller and prone to predators
River an insurer dolphins and B12 a very similar to hump back feeding… How do they feed
Disturb the bottom and create mud nets with bubbles
Food in small quantities leads to what kind of odontocetes structure
Solitary or small groups
River or inshore dolphins - mud nets
Food in large quantities + odontocetes
Massive amounts of mammals aggregate because predictable food stock
Harbour porpoises bay of fundy
Food in large unpredictable quantities +odontocetes
Large groups
Tropical pelagic dolphins
Difficult prey to catch + odontocetes
Structured groups i.e orcas
Coordinated orca wave to eat seal
The sociality of larger more socially complex groups is related to what
Care of young and predators
How do you sperm whales adapt their diving when they have a calf in their group
They stagger their dive so that the young calf is never left alone at the surface