Foraging In Pinnipeds And Seabirds Flashcards
What can be used to identify population structure in grey seals?
Photographic identification
What are the problems of foraging in a marine environment?
Navigating in a featureless environment
Prey distributed vertically as well as horizontally
Prey are not normally visible from the surface
Environmental factors e.g tides
Spatial distribution of prey
Why is oceanography important?
Determines the location of the food
Determines where food gets aggregated or concentrated
What is bathymetry?
Upwelling caused by currents and bottom structure
What are fronts?
Temperature and salinity discontinuity
What are eddies?
They result from circulation patterns and are warm and cold core ring jets
Where does productivity tend to be higher?
Higher latitudes
What is El Niño?
It’s a weather phenomenon where the sea temperatures increase massively and affect productivity
What is La Niña?
It’s very cool water compared to normal conditions
What affect does El Niño have on marine vertebrates?
They have to forage further
Have to leave their pup longer to forage
Have to do more work to get their food
What is the definition of a dive and what are the components?
A period of submersion
Descent, bottom time/foraging time and ascent
What is a dive cycle?
The dive time and time spent at the surface
What is a dive bout?
A group of dives
What are some of the factors that can affect foraging behaviour?
They prey species Prey movements and location Bathymetry Time of year Sex of animal Time of day Physical state of the animal
What can diving behaviour be constrained by?
Light levels
Predators
Diving ability
