This activity uses data from the Environmental Change Network (ECN) Indicators of Climate Change in the UK website and the Woodland Trust’s UK Phenology Network website. Both have data on seasonal changes that are regularly updated. The activity sheet directs students to particular parts of these websites. A spreadsheet containing data provided by the UK Phenology Network can be accessed from the activity homepage. This contains data on the timing of a wide range of seasonal events with temperature records provided for the same period, 1976–2001. There are no questions on the Student Sheet relating to those data. As an alternative to using the websites, students could be given this data and asked to investigate one or more of the events. They could look for any changes in timing of the event and compare this with the temperature records. These data are used within the ICT support to illustrate how to use Microsoft Excel to draw graphs.
The Nature’s Calendar website contains numerous interactive maps that can be used to explore the changing timing of events. The book Phenology Uncovered by Nicky Slater and Kate Lewthwaite, published by the ASE, contains activities that use the maps on the Nature’s Calendar website. This includes looking at the synchrony of the orange tip butterfly and garlic mustard on which the butterfly caterpillars feed; both appear to be emerging earlier.
Answers
Q1 There appears to be a trend towards earlier emergence since 1977, possibly corresponding with the average rise in Jan–Feb temperatures since 1977. More prominent is the pattern of early emergence in warm springs and late emergence in colder springs; note the late emergence in 1979 and 1986. (Defra suggest that a 1 °C increase in temperature is associated with a 16-day advance in first appearance.)
Q2 Butterfly and moth activity and development are very sensitive to temperature because insects are poikilotherms (cold-blooded). They are also fairly easy to identify.
Q3 Certain aphids and moths are important pests of crops, trees and other plants, so any changes in their behaviour have economic implications.
Q4 The two variables show a negative correlation. With lower temperatures, such as occurred in 1996 (14 °C), the mean flight date was later in the year.
Q5 The orange tip butterfly appears only to occur in central and southern England. There are no recorded flights of the butterfly in northern England, Scotland or Northern Ireland. This may suggest that the limit of the butterfly distribution is reached in central England, which may be related to temperature. One would expect this northern limit to move further north if
temperatures rise. In fact, the butterfly does appear in the whole of the UK apart from northern Scotland, but has not been recorded at the ECN sites.
Q6 a First spawning has been observed to occur earlier. First spawning: in 1996,
mid-February; in 2000, mid-January; in 2005, end of November 2004; in 2010, end of December 2009; in 2015, end of December 2014.
b Frogs’ spawning is temperature dependent; further north it takes longer for temperatures to become warm enough for spawning to occur.
c Climate change is predicted to produce fluctuations in temperature. If frogs have spawned early in a warm period and then the temperature falls the spawn may not survive. Frogs only lay eggs once a year so all reproductive opportunity for the year will be lost.
Salters-Nuffield Advanced Biology Resources
Safety checked, but not trialled by CLEAPSS. Users may need to adapt the risk assessment information to local circumstances. Activity 5.22 Student Sheet
DEBUNKING THE MYTH OF POLAR BEAR HAIR
Purpose
To recall ideas about adaptation and natural selection
To consider the role of the scientific community in validating new evidence
For this activity you should work in small groups. Look at each of the cards in turn and discuss the ideas and questions. Consider the cards in the numbered order. Once all of the cards have been discussed reflect on your discussions by completing the questions on page 2.
Card 1
Polar bears appear white
What is the advantage to the polar bear in appearing white?
What might be the disadvantage to the bear in being white?
Card 2
Polar bear hair contains no pigment. Their hairs are transparent.
Suggest why polar bears look white, although their hairs are transparent.
Card 3
Polar bear hairs are hollow.
Suggest any advantages and disadvantages of hollow hair structure.
Card 4
Polar bear skin is black
Suggest why this feature might have been a selective advantage for the polar bear.
Card 5
The rough inner surface of the polar bear hair scatters visible light, making it appear white. Researchers have
published results of experiments showing that polar bear fur absorbs UV light. The researchers suggested that the hollow hairs may be acting as ‘optic fibres’, transmitting the UV light to the skin.
Comment on these results and ideas, including any advantages and
disadvantages of hairs acting as optical fibres.
Card 6
Published experimental results show that the polar bear hairs do absorb UV light, but it is not transmitted down the hair. The researchers suggest that it might be the hair protein keratin that absorbs the UV light. But they have not investigated this experimentally.
Comment on these findings. How does this information influence your discussions of Card 5?