BIO00020I Examination Candidate Number: Desk Number: University of York Department of Biology B. Sc Stage 2 Degree Examinations 2016-17 Behavioural Ecology Time allowed: 1 hour and 30 minutes Total marks available for this paper: 80 This paper has three parts: Section A: Short answer questions (30 marks) · Answer all questions in the spaces provided on the examination paper Section B: Problem questions (20 marks) · Answer all questions in the spaces provided on the examination paper Section C: Long answer question (marked out of 100, weighted 30 marks) · Answer either question A or question B . Write your answer on the separate paper provided and attach it to the back of the question paper using the treasury tag provided . The marks available for each question are indicated on the paper · A calculator will be provided For marker use only: 1 2 3 4 5 6 7 8 9 10 For office use only: Total as % page 1 of 13
BIO00020I SECTION A: Short answer questions Answer all questions in the spaces provided Mark total for this section: 30 1. a) Give specific examples of two animal contests that vary in their severity. Explain why natural selection might favour these different degrees of severity. (4 marks) Answer: e.g. Some contests between male Bowl and Doily spiders are severe (1 mark). It is an ESS because it allows both contestants to balance the likely rewards and risks that will be accrued by continuing, which generally differ for different individuals (1 mark). Other examples are possible. e.g. Speckled wood butterfly contests are always resolved without lethal fights with owners victorious over intruders (1 mark). Evidence suggests that this is because subspot owners have an extrinsic advantage due to higher body temperatures causing an asymmetry in fighting ability which intruders are able to assess (1 mark). Other examples are possible. Learning outcomes addressed: Recognise or recall learned information to demonstrate understanding of how natural selection moulds the behavioural strategies of animals. Evaluate, theorise and calculate the relative merits of alternative behavioural strategies. Feedback: This was generally answered pretty well. People interpreted the question in diverse ways; for example some named two species which show the variation intraspecifically, and that was fine; others just two species with different types of fight, also fine. People generally found it easier to name an example than explain it, so most marks were lost in the latter part. Marks were generally awarded for the latter if the costs and benefits of fighting were mentioned in a way that made sense. 2. a) Animal signals can be modified adaptively according to the presence or absence of other species. Give an example of such a signal, explaining how it is modified, why the modification might be adaptive, and explain whether you would expect it to be honest. (6 marks) Answer: several possible examples were given in the lecture e.g. male narrow-mouthed toads (1 mark) have songs whose frequencies are less similar to those of congeneric species