Eusocial Animals

Question 1

Comment on animal societies

Answer 1

• animals live in groups for many reasons, like ________ (list)
• these groups evolve into societies with more structured rules and organised systems, concerning:

1. how members divide tasks
2. how needs of the group are communicated to each other
3. how tasks are adjusted as per group needs
4. cooperation and conflict
5. more structured, elaborate nests

Question 2

definition of eusocial animals

Answer 2

‘eu = truly’ social. eusocial is a level of social organisation in animal societies (Ref: Batra 1966). - examples include: honeybees, ants, hornets and termites

3 features:

1. Co-operative brood care - e.g. workers help raise offspring that are not their own (alloparenting!)
2. Reproductive division of labour- colony members are divided into reproductive castes (queens) and non-reproductive castes (workers).
3. Overlap of generations - offspring assist their parents in brood care and other tasks of colony maintenance e.g. foraging, defending

and are further divided into 2 categories:

a) primitively eusocial
b) highly eusocial

MAKE SURE YOU EXPLAIN THE 2 SUBCATEGORIES WITH EXAMPLES IF THIS IS A LONGER ANSWER

Question 3

examples of eusocial animals

Answer 3

1. honeybees
2. hornets
3. ants
4. termites

Question 4

explain primitively eusocial animals

Answer 4

• display some level of cooperative behavior, like brood care or division of labor, but lack highly specialized caste systems seen in more advanced eusocial species like ants, honeybees and wasps
• No Queen-Worker Dimorphism: all individuals are morphologically similar. They do not have specialized body structures for specific roles (e.g., a large queen versus smaller workers with distinct physical structures suited to their specialised roles of reproduction and colony maintenance respectively)
• Dominance or reproductive roles are determined by behavioral interactions or social hierarchy rather than physical differences.
• example: paper wasp (polistes dominulus) - all females are capable of laying eggs, but only the dominant female reproduces. Subordinate females assist in nest building, brood care, and foraging, but retain the potential to reproduce if they become dominant later on.

Question 5

explain highly eusocial animals

Answer 5

• exhibit a complex level of social organization characterized by clear division of labor, cooperation and specialised caste systems, where each caste has specific roles essential to success of the colony
• Queen-Worker Dimorphism: distinct physical and functional difference between the queen and the workers
• Example: Honeybee (Apis mellifera): queen is much larger than the workers, has reproductive abilities and sole purpose is laying eggs. She is fed and groomed by the workers and does not participate in foraging or nest building. Smaller, sterile female workers have non-reproductive roles like foraging, defence and brood care
• other examples: ants, termites, hornets, yellowjacket wasps