Ch 6. Social Behaviour Flashcards
Many animals live in social groups ranging in number from two to several thousand.
What are the advantages of living in social groups?
- Reduced risk of predation
- Easier to catch food/tackle larger prey
- Easier to find a mate
- Have help with raising young.
What is social hierarchy?
A type of social behaviour involving the members of a social group being organised into a graded order of rank, resulting from aggressive behaviour between members of the group.
Describe the type of hierarchal behaviour demonstrated in BIRDS.
If newly hatched birds (such as pigeons) are kept together, one will soon emerge as the dominant member of the group. This bird is able to peck and intimidate all other members of the group without being attacked in return. It therefore gets first choice of any available food.
The lower rank/status you are in the group, the more pecks you can recieve/the fewer pecks you can give. This is called the pecking order.
Describe the type of hierarchal behaviour demonstrated in WOLVES
The dominant male has certain rights such as; first choice of food, preferred sleeping places, and available mates.
The dominant male asserts his rank by employing social signals. The dominant wolfs visual display of ritualised threat gestures is normally impressive enough to assert his authority over other members of the social group. These in turn demonstrate their acceptance of his status by making submissive responses.
How do Killer whales carry out cooperative hunting?
They hunt in groups (called pods). In a river mouth, a pod will sweep along in a line to catch migrating salmon.
In coastal waters the same pod will encircle a shoal of herring and concentrate them into a seething mass. The whales then thrash the herring with their tails to stun them and gorge themselves on a catch of food that would be unavailable to a solitary predator.
How do Lions carry out cooperative hunting?
They employ ambush strategies involving predators driving prey towards others that are hidden in cover and ready to pounce.
How do Dogs/Wolves carry out cooperative hunting?
These take turns at running down a solitary prey animal to the point of exhaustion and then attacking it.
In case of lions, wolves and dogs, the group of predators tends to concentrate its efforts on a prey animal that has become separated from the rest of the group/heard. This is often a young and inexperienced or old and infirm animal, making it an easy target.
What are the advantages of cooperative hunting?
- All members of the predator group obtain food, regardless of rank (although the dominant male still receives the largest portion).
- They are able to tackle larger prey groups than they would by hunting alone.
What is social defence?
This is “safety in numbers”, protection from predators by staying together in a large group. i.e. being in a shoal, hear, flock.
What benefits are there in social defence to the prey? (2)
- This means that there are many eyes to look out for predators and alert the group.
- It also makes it harder for predators to pick out one animal from the rest.
Where are must ox found?
In regions of Canada and Greenland.
What is the natural environment of musk ox?
Completely open land, with no scrub or woodland to use for concealment.
What is the natural enemy of musk ox?
Other than humans, wolves are their main predators.
How do musk oxen carry out social defence?
When threatened a heard of musk oxen form a protective group with the cows and calves in the center and mature males at the outside (as they have huge horns which they direct outwards). Individual rules are good and packs are driven off by a combined charge.
This form of social defence is called mobbing.
How to Quails carry out social defence?
Bob White Quails roost in circles with their heads to the outside. If disturbed the circle acts as a defensive formation by ‘exploding’ in the Predators face. By the time the enemy has recovered from the confusion, the birds have flown away to safety.
