Flashcards in Animal Behaviour- Migration and navigation Deck (20)
What are the definitions of the following terms;
Orientation: Taking up a particular direction irrespective of destination.
Navigation: Directed movement towards a goal/ target location.
Homing: Returning to a starting point after an outward journey; may be across familiar or unfamiliar terrain.
Migration: Movement in response to seasonal changes in habitat
What is home-range navigation for?
Part of everyday activities- nest or burrow, food, breeding grounds etc
Where does the arctic tern migrate to and from?
From the arctic home-range to the antarctic
What distance ranges can wandering albatrosses cover in a single foraging trip?
Between 3,600 to 15,000km in a single trip
Up to 80km/h and up to 900km per day!
Why may animals migrate?
Resources, breeding and over wintering sites
Why do Botswa(nian?) Zebras migrate from Makgadikgadi pans to the Okavango delta in the dry season?
In dry season, the pans become dried out and this is not good for grazing zebras. The Okavango delta become wet and lush in the dry season. This is due to the southern movement of the rain that gets trapped at the delta
Why do Christmas island crabs migrate from the forest to the coast?
To breed in breeding season. Males excavate burrows, females choose a burrow and mate. They then stay there for a couple of weeks and lay their eggs in high tide and these are washed out to sea. The larvae develop then return back to land a month later
Why do monarch butterflies migrate?
For over wintering sites
An orientation tool is trail following. What is this?
Leave a trail of chemicals to be able to find your way back, ants use this
An orientation tool is beaconing. What is beaconing?
When an animal heads towards a prominent feature of a goal- could be visual or odour e.g pheromones
Homing is part of navigation. Explain what homing is specifically?
Homing is when you need to return back to a set point after a journey whereas navigation involves many other things such as just finding your way around
Route reversal is a type of homing tool. What is it?
Simply when you follow exactly your steps back to a certain place
What is path integration?
A homing tool where an animal calculates the vectors of its journey so it can cut across and back home/to the start point without having to follow the route back (desert ants do this)
How do ants carry out path integration?
Work out distance by optic flow/ the pace at which things move past them
Work out bearing by using their polarization compass
Name one more tool used in homing.
Landmarks- can be visual, olfactory and local navigation
In long distance navigation, it's important to know orientation. How can the sun be used as a compass?
Use sun position (azimuth) to work out where the North is. It is important to consider the rotation of the earth and so animals must have an internal clock. Pigeons who have had their clock shifted experimentally have trouble navigating
How may animals still use the sun for navigation if they cannot see it?
Using polarisation compass. Different vibrations of the light/ polarisations can help figure out what position you are compared to the sun
How can nocturnal animals navigate/ orientate?
Using the stars e.g dung beetles
What other compass can animals use?
Magnetic field (just like our hand held compasses). Evidence that animals can do this comes from when birds are put in a container with no visual of the sky, when they wanted to migrate they go to the side of the funnel it wants to migrate to