Cuckoo bird-Reasons For Decline
The Cuckoo is a migrant from sub-Saharan Africa. They arrive in late April to June and leave late July or August, though they may rarely be seen until September. More numerous in southern and central areas they are (sparsely) spread all over the UK. It returns to west, central and southern Africa for the rest of the year, where its decline is also noticed. In Britain the Cuckoo inhabits moorland, open country, farmland, hedges and the periphery of woodland but also enters our gardens in its quest for a parasitic host to lay its egg.
It is far from clear which are the major factors influencing the falling population of the Cuckoo. UK nesting host decline (dunnock, robin, reed warbler, meadow pipit, Spotted Flycatcher and Pied Wagtail) is possible. Decreases in moth populations which the Cuckoos eat as caterpillars may also be contributing. Farming methods, pesticides and herbicides, general pollution and reduction in habitat perhaps all take their toll as they do with other species of wildlife. Other explanations suggested are Africa's changing habitats, farming production changes and the attrition of bird numbers during migration from Africa to Britain. Current estimates are 10,000 to 20,000 breeding pairs in the UK.
How can we help?
In our gardens, we can feed the hosting species and incidentally encourage other garden birds, Try to refrain from spraying pesticides so encouraging insects in the breeding season. Cuckoos themselves favor hairy caterpillars and have an adapted digestion to process the poisons these caterpillars can contain. They do eat other caterpillars and other insects as do the host birds. A compost heap would become a helpful source of worms and other insects.