| Date | May 2011 | Marks available | 1 | Reference code | 11M.3.SL.TZ1.13 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 1 |
| Command term | State | Question number | 13 | Adapted from | N/A |
Question
Common guillemots (Uria aalge) are large sea birds of the auk family. They breed in colonies at high densities but make no nest. Their single egg is incubated on bare rock. Alloparenting behaviour is frequently observed, where non-breeding birds will take care of other chicks. Scientists fitted electronic time-depth recorders onto twelve common guillemots and recorded five different activities during the chick-rearing period: at the colony, in flight, resting or active on the sea surface and diving. The pie charts below include pooled data from all birds showing overall time budget and time budget at sea.
State which activity takes up least of the overall time budget of the guillemots.
Calculate the percentage of the overall time budget the guillemots spend resting on the sea surface.
...........................%
Outline the activity of guillemots at sea.
Suggest two reasons, other than breeding, why birds spend more time at the colony than any other activity.
Markscheme
in flight
1
4
× 1
6
×100;
4.2 (%); (Allow answers from 4 % to 4.2 %)
birds spend most of time active on the water;
more or less the same time in flight, diving and resting in water; Need all three parts for the mark.
birds need to rest/sleep to recover energy/digest food / are inactive at night;
moulting makes them flightless;
defending territory / protection of young / other example of social behaviour;
Examiners report
The correct answer of “in flight” was given by most students.
This was probably the most challenging calculation question on the paper, and many candidates found the information in the pie charts difficult to interpret. However, a few strong candidates were able to answer correctly.
The majority realised that the birds spent about the same time in flight, diving and resting in the water, but spent more time active on the water, so gained two marks for this question.
Most candidates could give two correct reasons for birds spending more time at the colony.
