It’s been a strange spring with some icy conditions and heatwaves too! Luckily our wildlife is used to the ups and downs of British weather.
The British Isles lie on the western edge of Europe and our climate is influenced by ocean currents such as the Gulf Stream. This makes winters and springs milder than landlocked countries in northern Europe. One very obvious way to see this is by visiting the pools of bluebells which flood our woodlands each spring. Our mild, damp Atlantic climate is perfect for bluebells, which flourish here. Some of the best shows of bluebells in the world are in British woodlands.
Why is Britain a wildlife migration hot spot? Find out in this BBC iWonder guide.
But our springs can be very unpredictable and in 2018 we’ve seen some very cold spells, including the notorious “Beast from the East” at the end of February and early March. Prolonged icy spells like this can hold up plant growth so that spring flowers bloom later and leaf-buds are slower to burst.
If this happens, pollinating insects may not find food. Birds that feast on insects such as caterpillars, which eat the new leaves, may have to delay their breeding seasons to wait to feed their chicks. In the short-term the odd spell of weather won’t make a permanent difference if populations of insects and birds are strong.
Find out more about how you can help birds and insects this summer.
Springwatch Producer Nikki explains how doing nothing can be more helpful than you think!
But a trend for wetter or warmer springs produced by long-term climate change can catch wildlife out. Studies of pied flycatchers, which winter in western Africa, show that when they arrive in European woods, they rely heavily on caterpillars as food for their chicks. In milder springs, the trees come into leaf earlier and the caterpillars hatch sooner to eat them - bad news for the flycatchers because by the time they produce chicks, the caterpillars have already become chrysalids and are harder to find.
Their life-cycle is now “out- of- sync” with that of their prey and so they rear fewer youngsters. Only by changing their migration patterns to suit the earlier springs can they keep up and that may take many generations.
For some migrants though, long-term climate change has been a bonus. Blackcaps and chiffchaffs are two warblers which are increasingly braving the milder British winters. Blackcaps are tucking in to the food we put out on bird-tables and chiffchaffs are wintering near sewage farms where they find lots of flying insects. Although some of our blackcaps and chiffchaffs still winter south of the Sahara, most are spending the colder months much closer and so have less distance to travel to their breeding territories when spring arrives.
Both are doing well and you can hear them singing in woods and even gardens with lots of trees.
