CHAPTER 11
EXTENDING YOUR IDEAS
1. i D
ii. I
iii. G
iv. A
v. E
vi H
2. a. The control group.
b. There appear to be two subgroups within the groups – an upper (1–5) and lower (6–10) hierarchy. The most dominant birds in each group (1 and 2) probably spend too much energy in maintaining their dominant positions or fighting amongst themselves, and the most submissive bird (10) probably only feeds after the others have left the feeding trays and thus has inadequate nutrients for good weight gain.
3. Territorial behaviour probably decreases competition for scarce resources needed at breeding time, ensuring the successful rearing of the young. Thus those members of the population able to establish and maintain a territory will breed and pass this ability on to their offspring. Animals with suitable genes are the breeding animals.
4. Both have undergone operant conditioning since the response to the stimulus of both the dog and the human achieves a positive reinforcement.
5. Territories are only usually established during the breeding season with the function of successfully rearing the next generation of the species. If physical fighting occurs in territorial disputes, one or both of the opponents may be badly hurt or killed. This will diminish the chance of success of the young. The use of gestures, bluffs or loud noises usually ensures that the more submissive animal will retreat before physical contact occurs.
6. Females who are on a high protein diet are probably more likely to be successful at both producing eggs and rearing young. Thus the male’s selection is for such females. The selection of the male by the female may be based on body type or specific details of the courtship dance which may indicate the male’s breeding potential. Less energy may be expended in maintaining this bond over the non-breeding season than establishing a new bond at the start of every breeding season.
7. Nest building behaviour is basically innate in that both Fischer’s and the peach-faced lovebirds have a distinctive nest building behaviour which is always carried out. Hybrids of the two species display an intermediate nest building behaviour between the two species which is unsuccessful, since they attempt to tuck long strips of paper between their rear feathers to carry them. After a time they learn to carry them in their beaks, but still attempt to tuck them into their feathers first.
8. Since the males with better body condition are able to mate with more females, their genetic constitution will be passed on to a greater proportion of the offspring than those with less staying power (who die early from stress-related diseases). Female offspring will benefit from their better body condition to breed and successfully rear young, while the males will be able to mate with more females. This genetic factor may also contribute to the survival rate of the offspring.
9. Either case can be argued for, however since there appears to be a great number of differences between general learning and imprinting, many ethologists believe it is an innate behaviour. They base this on the following:
Imprinting only occurs in a short, critical period of time and is specific to one object. The initial response is the strongest and irreversible and it invariably relates to an event some time in the future (e.g. young birds imprint the species characteristics from their parents some time in the first few days of their lives but do not use this information until it is time to breed). Learning on the other hand occurs at any time, is general in relation to the object, has the strongest response to the most recently learnt information, is reversible and relates to an immediate event.
10. a. The magpie arrives at the feeding station where the galah is feeding – body sleek. The galah uses a mild threat (head feathers raised).
b. The galah shows a strong threat stance – wings extended and head feathers fully raised. The magpie is more hunched with wings to the side in a non-threat stance.
c. With the magpie gone, the galah resumes its normal but alert stance.
The galah recognised the magpie as a competitor for food resources. It is possible that it considers it part of his territory and thus feels confident to take on the threatening posture. The magpie, normally a very territorial bird, is probably out of its territory and thus assumes a submissive role in the agonistic encounter. The magpie recognises the communication of threat assumed by the galah.
11. a. Sex.
b. i. Male bower bird at the bower or scrub turkey at the bower.
ii. Female bower bird in his territory.
iii. Good bower, male’s courtship dance.
iv. Female in the bower.
c. Visual stimuli – e.g. the male bower bird can recognise both his own species and the gender; the female recognises the bower of her species.
Postures – the agonistic displays of the male towards other males are threatening; courtship dance to female inviting mating; position of female in bower invites mating.
Vocal – threatening calls to other males and scrub turkeys; song to advertise the position of the bower.
12. This is an open-answer question and either argument can be proposed. However, in the answer:
Terms need to be correctly defined and used appropriately.
Supporting evidence should be supplied and detailed.
There should be evidence of logical sequencing of ideas to build the case for the argument.
13. The crows demonstrate a high capacity to learn which can be considered as highly intelligent behaviour, evidenced by:
· dropping hard nuts on the ground to crack them
· dropping nuts onto pedestrian crossing
· waiting for walking sign before moving onto the crossing to collect the cracked nuts.
It cannot be trial and error learning, as if the crow was hit by a vehicle it would be dead. Thus it must be insight.