Nature's calendar

A photo of a bank of snowdrops in flower

Living things co-ordinate their activities with the seasons. Birds nest when the weather is warm and there is food for their young. Flowers need to be ready when bees are around to pollinate them. One of the results of climate change is that these patterns will change and in some cases be disrupted.

These changes in timing - phenology - are not evidence that climate change is caused by greenhouse gases, but it is one of the easiest ways to see for yourself that the climate of Scotland is warming.

'Out of more than 500 spring and summer biological events, such as wild birds laying eggs, emergence of aphids or butterflies, and flowering of plants, 74 per cent show some evidence of being earlier.'
Scottish Natural Heritage (SNH)

Scottish Natural Heritage has brought together information from a wide range of sources to show how Scotland’s biodiversity is changing, presenting a huge amount of information on flowers, birds and insects and the way they are responding to climate change.

Flowers bloom earlier: the average change is 3.2 days earlier every ten years over the last 100 years.
Migrating birds arrive earlier: the average change is 2.6 days earlier every ten years over the last 100 years.
Butterflies become adult earlier: the average change is 2.7 days earlier every ten years over the last 100 years.
Plankton blooms in the North Sea now appear 3 days earlier every ten years over the last 100 years.

The comma butterfly has recently been spotted in gardens as far north as Tayside.

These changes could be relatively harmless for wildlife, especially if everything changed at the same rate, but different species respond to climate in different ways. We are beginning to see evidence of problems as species change at different rates; insects appearing before the plants they feed on, migrating birds arriving before their food is available.

'These results show that species are responding at different rates to the effects of warming temperatures on land, air, freshwater and sea, and this could ultimately mean that timings of natural events will become so out of balance as to affect food webs and competition between species. The challenge now is to develop conservation plans which will help vulnerable species adapt to these continuing changes here in Scotland, as well as supporting ongoing international initiatives to reduce carbon emissions.'
Professor Colin Galbraith, Director of Scientific and Advisory Services, SNH

Photo credit: (above) M. Oxbrow

Available for use under Creative Commons Attribution-NonCommercial 2.0 conditions.

Photo credit:(below) Tracey Dixon