Question 2: Describe Achieved

The honey bee (Apis mellifera) is active by day, and its pollen foraging is tied to its circadian rhythm. Bees find their way around and back to the hive by cues from their surroundings, including the Sun’s position as a compass, and can forage 5 km out and still get home when cloud hides the Sun. In a total solar eclipse the Moon covers the Sun completely, so bees meet darkness at a time they normally would not. Biologists compared foraging on an ordinary day with the day of a total eclipse. Their graph (Figure 4) is greyed out in NZQA’s public copy; as the schedule reads it, ordinary-day foraging climbs through the morning to a peak near 1:30 pm and eases off slowly in the late afternoon, while on the eclipse day it is normal until the eclipse, falls to a handful of bees in totality, comes back only slowly, and stays under the ordinary day until after 3 pm, when it rises above it.

Describe the honey bee’s diurnal circadian rhythm, the cues it uses to find its way home, and its foraging on a normal day and on the eclipse day.

The 2025 paper, page 6 ↗ Marking schedule, page 4 ↗

Work it out

Try it on paper first. Stuck? Take one hint at a time.

1 What do “diurnal” and “circadian rhythm” each mean?
A diurnal animal is active in daylight and rests at night. A circadian rhythm is a cycle that repeats about every 24 hours, run by an internal biological clock and kept in time by cues such as light.
2 What does a bee use as a compass on a sunny day?
The Sun: it flies at a set angle to the Sun’s position to hold its direction out to the flowers and back to the hive.
3 What else can it use, especially when cloud hides the Sun?
The pattern of polarised light in the sky, landmarks such as trees and buildings that it has memorised near the hive, the scent of its hive and of flowers it has visited, and possibly the Earth’s magnetic field.
4 What does Figure 4 show for a normal day?
Foraging builds through the morning, peaks at about 1:30 pm, and tails off slowly through the late afternoon.
5 And for the eclipse day?
Normal until the eclipse; during totality only a few bees are out. Afterwards it recovers slowly, stays below a normal day until about 3 pm, then climbs past it.

Answer Honey bees are diurnal: active by day, resting at night. Their foraging follows a circadian rhythm, a cycle of about 24 hours run by an internal clock and kept in time by light. On a sunny day they use the Sun as a compass, flying at a set angle to it. They also use polarised light in the sky, memorised landmarks near the hive, the scent of the hive and of flowers, and possibly the Earth’s magnetic field, which help when cloud covers the Sun. On a normal day foraging builds through the morning, peaks about 1:30 pm and falls slowly in the late afternoon. On the eclipse day it is normal until the eclipse, drops to a few bees during totality, recovers slowly, and is below normal until about 3 pm, after which it climbs past the normal day.

What the marker wanted

Achieved Describes, one point each: a diurnal animal; a circadian rhythm, including the internal clock; landmarks for homing; the Sun or polarised light for homing; scent for homing; the Earth’s magnetic field for homing; foraging on a normal day; foraging on the eclipse day. Any four make A4.

The schedule marks the question as one answer from N0 to E8. Achieved points count first: one or two give N1 or N2, three A3, four A4. Above that, two Merit points give M5 and three M6, then one Excellence point E7 and two E8.

In our words, from NZQA’s 2025 marking schedule.

Common mistake

Using “diurnal” and “circadian” as if they meant the same. Diurnal is when the bee is active (by day); circadian is the roughly 24-hour internal rhythm that times it. NZQA’s 2025 report asks candidates to keep the two apart.

How did it go?

Got it moves it further out. Review brings it back tomorrow.