IB Topic E6- Further Studies of Behavior: Book Correlation: 11.12/11.13/11.14 Web Activities: 51A

Social Organization of the Honey Bee Live in groups of 20,000 – 60,000 Three castes: Queen: one female Lays eggs that hatch into larvae- if larvae are fed a special diet (more protein) they will develop into queens Drones: fertile males Workers: Most bees are workers infertile females

Bee Society Drones only role is to mate with queen, which can lay 1500 eggs a day. Worker bees gather food, feed the queen, and keep the hive clean. The worker bees are worked to death, and drones are only tolerated during the spring and summer when the queen mates, and are driven out at other times. When a new queen is needed, she hatches and takes her first flight, during which she is inseminated by several drones. She will then ‘swarm’ with members of the old hive and go establish a new hive. honey bee biology

Naked Mole Rat: Social structures are unusual for mammals: Live in colonies underground Only the queen will reproduce with a few males Other females are workers- tunnelers, defenders, or food gathers If queen dies the larger female workers will fight until it is clear who the new queen will be The sterility of the workers is not genetic but maintained by the queen, possible using pheromones.

Natural Selection: May act at the colony level rather than the individual level Example: In the case of food shortage a worker could feed the queen but starve herself The queen and the worker are closely related so this behavior is likely to spread because the queen is likely to survive and spread the genes that caused the workers behavior.

Altruistic Behavior Altruism- behavior which benefits others and involves risk or cost to the performer. (Note: IB does not consider parental care to be an example of altruism). Ex: Worker bee- dies defending colony against attacking wasp- never reproduces only looks after the colony Ex: Naked Mole Rats of East Africa- “frequent workers” dig tunnels and bring food, “infrequent workers” are larger and occasionally help with heavier tasks, “non-workers” live in the central nest, keeping the breeding female and her young warm and protected.

Altruistic Behavior Cont… Side-Blotched Lizard: live for one year Three different colors found inside the throat- yellow, orange, blue Orange- very aggressive and take territory from other lizards Yellow- sneak in and mate with females of other males Blue- unrelated males form partnerships to defend territory So… orange defeats blue, which defeat yellow, yellow won’t confront orange but will sleep with their wives Vampire bats- if they go without food for two days they can die. If one bat doesn’t feed, another will regurgitate food and share. This is done regardless of whether the bats are related or not. Why? “You help me now, and I’ll help you later”.

Why did altruism develop? Altruistic behavior can increase the probability that at least some of your genes will be passed on, even if it is not through your own offspring.

Foraging Behavior: Bluegill fish and Daphnia Fish will choose largest prey when given a choice. In nature they choose the prey that appears the largest When prey is abundant they choose the largest, when prey is scarce they choose one that may be smaller but is closer so appears larger. More profitable to catch the closer than larger fish

Mate Selection and Exaggerated Traits: Females choose their mates: Ones with best genes Ones with ornaments (easier for predators) must have good genes to survive Males need to attract mate: Must have something that grabs her attention Males may fight for dominance: Dominant male reproduces Both males may get harmed

Rhythmical Variations: Daily or yearly changes in activity Hummingbirds- slow down metabolism at night in order to save energy and egg-laying in spring Value of Rhythmical Variations: Coral- Mass spawning at same time for males and females- best chance of reproduction Deer- fertile period is in November so babies are born in spring Roe deer- fertile in summer when healthy and the embryo “floats” in the uterus and has little growth until December when it attached and has normal growth