3.6 Social Insects and Social Behaviour Flashcards
(36 cards)
What is social hierarchy?
social hierarchy is when animals within a social group claim a ranked position within that group, determined by both aggressive and display behaviours
positions range from the strongest to the weakest individual within the group
social hierarchy can be seen in packs of wolves and social groups of chimpanzees
What are advantages of social hierarchy?
reduces physical fighting and injury
conserves energy
genes from the strongest individuals are passed onto the next generation
DONT FORGET!
Social organisms live in groups and may work together to their mutual benefit
they have behaviours that are adapted to group living
What is cooperative hunting?
animals hunt together in a group in order to maximise the chance of finding and bringing down prey.
in this way larger prey animals may be hunted, providing more food energy
example; harris hawks hunt rabbits in teams
What are the advantages of cooperative hunting?
kill is shared among all members of a hunting group
larger prey may be hunted
higher chance of finding and killing prey than if hunting individually
What are social defence against predation?
vigilance
herd movement
altruism
kin selection
What is vigilance?
individual members of a social group will look out for predators while others feed
this benefits the whole group and increases the chances of survival
vigilance behaviour can be seen in prairie dogs and barnacle geese while grazing
What is herd movement?
a herd of animals will keep close together while travelling as there is safety in numbers
females and young are positioned towards the centre of the herd for protection
with watchful males on the perimeter
group works together to mob or attack a predator to protect offspring
flocking schooling and herding - animals move together to make it more difficult for predators to pick off individuals from a group
What is altruism?
this is unselfish behaviour which benefits the survival chances of other members of a social group, at a cost to the individual.
what is reciprocal altruism?
In social species such as chimpanzees, the cost of helping another individual is outweighed if the helper is repaid this is reciprocal altruism
Example of altruism - Vampire bats?
vampire bats who have hunted successfully might share food at the roots with those who have not the successful hunter on one occasion might be unsuccessful later and need to obtain food from a previous recipient
What is kin selection?
this is altruistic behaviour which specifically benefits the survival chances of close relatives within a social group
e.g. adult chimpanzees giving their food to juvenile members of the social group
this ensures survival of shared genes by increasing the juveniles chances of reproductive success.
Example of Kin selection - Donor long tailed tits?
donor long tailed tits with no offspring might feed the recipient offspring might feed the recipient offspring of other parents in times of food shortage long tailed tits live in loose colonies with related individuals so that recipient offspring of one parent might share some of the donors genes
DONT FORGET
social behaviours have evolved and are adaptations which increase an organisms reproductive success
What will a truly social insect society will have?
cooperative care of the young insects
parents and their offspring living together
the development of a caste system
What are social insect societies?
ants, bees, termites and wasps live in colonies where different adults play different roles
reproduction and survival depend on all members of the colony working together
the majority are workers who labour together to raise their relatives
the efficiency and success of the group depends on the workers foregoing reproduction, which allows them to focus all their efforts on their other tasks including defence of the colony
this ensures that their genes are passed onto the next and following generations through their breeding relatives
What is communication in social insects?
the social structures of insect colonies relies on effective communication:
- honey bee workers perform a waggle dance to inform the other workers of the direction and distance to a particular food source
- some insects use chemical messengers known as pheromones. Certain ants, after finding food, lay down a pheromone trail when returning to the nest. This attracts and guides other ants to the food source
Within a bee colony there exists three distinct social levels. Name and explain them?
queen bee - is the only bee within the colony that produces eggs. other female bees do not produce eggs and become worker bees. The eggs of the queen bee are fertilised by male drone bees
worker bee - female daughters of the queen bee and share similar genes. instead of reproducing they defend and maintain the hive together with the drone bees
drone bee - male bees that fertilise the eggs laid by the queen bee. they work in the hive to maximise the survival chances of the offspring by guarding the hive, foraging for food, cleaning and building new cells, storing pollen and feeding larvae
What are keystone species?
keystone species are those which have a particularly important impact on their ecosystem
without keystone species, the species diversity of the ecosystem would decrease and the ecosystem may cease to exist
social insects are often keystone species
bees, ants, and termites exist within complex social structures benefiting the environment by providing ecosystem services such as pollination, decomposition and natural biological control of populations
What are examples of keystone species?
honey, bees and wasps - pollinate flowering plants, including many food crops
termites - build mounds which provide habitats for other species; provide protein rich food for many animals; are decomposers, so recycle soil nutrients
ants - pollination, nutrient turnover, seed dispersal
DONT FORGET
pollination is the transfer of pollen from anther to stigma in a flowering plant
without pollination plants could not reproduce
What are primates?
primates are humans, a large, diverse group of mammals including monkeys and apes
What does the long period of parental care in primates allow?
gives time for young to learn complex social behaviours by watching and copying others
chimpanzees learn to make tools such as termite fishing sticks and leaf sponges
what are social groups in primates?
most primates live in social groups where there is competition for resources (such as food/mate) so conflict can arise.
