Animal Responses to The Biotic Environment

Remember!!!

• Intraspecific Responses– Between members of the same species

• Interspecific Responses– Between members of different species

Intraspecific Aggressive Behaviour

• Aggression is belligerent behaviour that arises from competition.

• Killing an animal for food is not aggressive.

• If an animal turns and fights, this can lead to fear, which is a key part of aggression.

Fighting

• Animals of the same species compete for the same food and resources so competition is strongest between them.

• When competing for a mate competition is strongest between members of the same sex.

• the winner is the strongest individual, he produces the offspring so the

gene pool is kept strong.

Fighting

• Fighting between members of the same species has become ritualised – the moves are known to both opponents, allowing a winner and a loser without anyone getting to badly hurt.

Antelope will push against each other but will not gore each other.

Giraffes fight with neck wrestling, each animal trying to unbalance the other.video

VideoMost fights between Elephants turn into pushing matches.

Fighting

• Fighting to the death is non-adaptive to most animals.

• Animals that fight have some sort of protection such as tough skin and padding around their necks.

• E.g hippos and elephants seals.

Fighting

• Fighting to the death usually only occurs to eliminate a stranger from another group.

Territories

• Each organism is surrounded by a personal space.

• Usually there is a geographical area that the animals seldom leave – Home Range– This is an area that the animal is familiar with

and will cover regularly looking for food and mates.

– They make their home, nest or lair in the home range.

Terrirories

• The territory is the area around the home base, which the animal marks and defends

• Animals hold territories through aggressive behaviour.

Adaptive features of Territoriality

• It ensures enough space for each animal and sometimes keeps the population in check.

• Reduces the spread of disease and parasites, and makes it harder for predators to find them.

• The most successful male holds the best territory, and passes the best genes on.

Adaptive features of Territoriality

• Once a territory has been established and the resources divided, the losers will spread out and look for resources elsewhere, rather than fighting.

• In some species, males without territories cannot attract a mate, so won’t breed.

• Territories ensure enough food for the animals holding them.

Adaptive features of Territoriality

• Territories ensure a safe and protected home for the young.

• The animals know their territories well so they know where to find the resources that they need.

Home range

Territory

Lair or Nest

Marking and Defending Territories

• Birds mark their territories by singing on the boundaries of their areas at dusk and dawn.

• Males advertise when they are looking for a mate by showing bright colours and displays.

• Animals mark with urine and faeces.– Dogs and cats

Marking and Defending Territories

• Some animals have special scent glands– On the rump– Between the horns – deer– On the wrist – ring-tailed lemurs– Behind the ear - cats

• Crabs wave their claws in frantic signals on the perimeter of their territory.

• Howler Monkeys howl in the morning on the boundaries of their territories.

Territories

• Many animals only show territorial behaviour during breeding season.– E.g. sea birds

Human Territoriality

• The Tribal Territory– Large cities or countries, the borders are

protected with large fences, customs and immigration posts, banners and flags.

– Gangs, political parties sports clubs, social clubs, social cliques, protest groups etc

– Sports matches – face painting, chants etc

Human Territoriality

• The Family Territory– This is a breeding unit with parents and

young.– The bedroom is the nest, we feel safer tucked

up in bed.– This territory can be marked with a fence, a

hedge or a concrete wall.– Inside is marked with our personal things.

Human Territoriality

• Personal Space– This is the area around our bodies that is

private.– Your personal space travels with you.– Many courtship actions are asking permission

to invade the personal space– When people are drunk they forget spatial

requirements and get in your face.

Hierarchies

• Pecking Orders– E.g. in barnyard hens– Hens arrange themselves in a linear order,

the top bird could peck all the other birds, while the bottom bird was pecked by all.

Pecking Order in Hens

A B C DA ------ 3 0 4

B 3 ------ 0 5

C 7 8 ------ 6

D 0 1 0 ------

Hens being pecked

Hen

s pe

ckin

g

Hierarchies

• Dominance is maintained by posture and display.– Making yourself look big with a mane, fluffed

up feathers or fur, standing on hind legs, holding the tail erect.

– Loud snarling, quick slaps or bites– Threat displays of large canine teeth, wide-

eyed glares, hackles up etc

Hierarchies

• A subordinate responds with appeasement gestures which stop the other animal from attacking.– Making yourself look small, lowering head and

eyes, cringing– Tucking the tail between the legs– For many animals exposing their most

vulnerable parts.

1. Threat ..2. Uncertain threat.. 3. Weak threat.. 4. Faint threat - the dog is very uncertain ..5. Fear.. 6. Expression of uncertainty in presence of dog of superior rank

Body Language

• Ref pg 83 text book.

Intraspecific Co-operative Behaviour

• This includes:– Group formation– Courtship and pair-bond

formation– Parental care.

Group Formation

• Hunting• Defence• Protection• Social society• Clumping• Confusion • Breeding

• Divide into 7 groups • Brainstorm ideas as

to why forming a group would benefit your topic.

• Examples of animals that use this behaviour.

Courtship and Pair-bond Formation

• Most animals keep an individual distance away from each other.

• Invading personal space is a threat.• The conflicting tendencies to attack, yet let

another animal come close enough to mate, are often evident in courtship behaviour.

Courtship and Pair-bond Formation

• The sex act is adaptive as it requires:– Co-operation– A temporary suppression of aggressive

behaviour– A system of communication and species

recognition

Courtship and Pair-bond Formation

• Sexual competition by males for the attention of females can be of two types:– They fight each other with a kind of ritualised

combat– They can compete indirectly by attracting

females with special displays or adornments.

Courtship

• This ensures that the 2 animals are of the same species, and may also be a sign to start nest-building or trigger ovulation.

• Aggression is reduced by dances, calls, movements of the whole or part of the body in ritualised sequences, release of chemical pheromones, or touching.

Courtship and Pair-bond Formation

• This allows the pair-bond to strengthen so that more intimate behaviours become possible.

• In many arthropods, the female has to be appeased so that she does not eat the male.

Courtship and Pair-bond Formation

• In birds, the bright colours of courtship make them more vulnerable to predators.

• video• Some birds, such as the bower bird, build

the most beautiful nests decorated with flowers or articles of one colour that the male bird can find. One species makes a bower of dried bones.

• video

Courtship and Pair-bond Formation

• A pair-bond is a stable relationship between animals of the opposite sex that ensures co-operative behaviour in mating and raising the young.

Parental Care

• The survival of the species depends on the breeding population producing adequate numbers to establish a healthy new generation.

• Animals have 2 strategies for this.

Parental Care

• No parental care – a large number of offspring are produced, at least some will survive.

• Have only a few offspring – the parents invest considerable time, effort and food reserves to increase the probability of survival of these offspring.

Parental Care

• The degree of parental care varies in different species:– Eggs may be buried and abandoned e.g.

salmon, turtles and snakes– Elaborate nests may be constructed and

defended e.g. birds and sticklebacks– The offspring may be defended and fed e.g.

birds, bees, ants and mammals