Wild birds respond differently to the first long days of a year
The lengthening of days in late winter is an important signal that stimulates the reproductive activity of many animals. Animals living in the milder climatic conditions of southern Europe usually begin breeding earlier in spring compared to animals living in colder habitats further north. Scientists have now discovered that day length affects gene activity differentially in the brain of great tit populations from central and North Europe. This is particularly important because climate change has resulted in warmer temperatures in spring, and therefore day length has become a less reliable signal for the coming of spring. Since warmer spring temperatures also cause the insects that the birds need to feed their young to be available sooner, birds will have to change their breeding schedules accordingly.