Honey Buzzard (Pernis apivorus)
There’s no question that the Honey Buzzard looks like a raptor, with its hooked bill, large talons and long, broad wings – there is little to distinguish it from many a Common Buzzard, for example. Yet in its lifestyle, and particularly in its manner of feeding, the Honey Buzzard is cast in a quite different mould and, for a large bird of prey, a distinctly odd and unexpected one.
By Andreas Trepte – Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=54344804
The main surprise is that the Honey Buzzard’s main summer prey is not vertebrates, as might be expected for a bird of its size, but invertebrates – and very specific ones at that. It is the scourge of social insects, and in particular wasps and hornets, eating adults, pupae, larvae, and even the comb from their nests, the latter habit giving rise to its name. It seems remarkable that it can sustain itself on such small pickings, yet it clearly can, since it is a widespread and fairly common species over much of Central and Northern Europe. It does supplement its diet with some larger food, especially birds and their eggs, but there is little to suggest that these are essential, except perhaps in the early part of the season, in May, when the birds have just arrived back from their wintering grounds in tropical Africa. For the most part, this bird is a consummate insect specialist.
By Nicolas Weghaupt – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=41658967
Finding and catching wasps is hardly achieved by high flights and dramatic chases, so the Honey Buzzard’s foraging is played out in secret under the forest canopy, and along broad rides and woodland edges. When hunting a bird will fly slowly along at no more than treetop height scanning for flying insects, or it will simply sit on a perch and watch their comings and goings. Remarkably, it will also regularly search for nests by wandering along on the ground, and it has been observed hiking no less than half a kilometre on foot for this purpose. Whatever method it uses, once it has located a wasps’ nest it simply digs it out wherever it is lodged, which is often in a tree trunk, or on the ground. It then consumes the insects or comb on site. The Honey Buzzard has reduced openings to its nostrils to prevent earth getting in while it is digging in the soil, and long, thick claws to do the actual work.
Not surprisingly, the wasps react angrily to this intrusion and attack the Honey Buzzard vigorously. Somehow though, a bird working a nest always appears unmoved by the attempted stings. It has specialised scaly feathers on its face that act as a kind of armour to them, and its feet and legs are similarly protected. The only deferral to a wasp’s firepower is that before swallowing an adult, the Honey Buzzard snips off its sting first. Otherwise it seems quite unaffected.
The best wasp harvest only lasts for a comparatively short season, peaking between June and August, and this is the time that Honey Buzzards breed. During pair formation the sexes perform a variety of aerial displays, one of which is unique to the species. It is based on a common bird of prey manoeuvre, flying up and then swooping down on an undulating course; but as the displaying bird reaches the top of its “wave” it stalls for a moment, lifts its wings high over its back and shakes them rapidly, as if trying to dry them, before beginning its descent.
The nest is built high in a forest tree, often a beech, between 10m and 20m off the ground. It is often placed on top of an old crow or Common Buzzard’s nest, and varies considerably in size. During its construction and beyond, the birds bring in a lot of sticks with live green leaves still attached; it is not known whether this foliage is for camouflage purpose, or helps with nest sanitation in some way. The two eggs are incubated mainly by the female, and not long after they hatch, the chicks begin to ingest their unusual diet.
From ‘Birds: A Complete Guide to All British and European Species’, by Dominic Couzens. Published by Collins and reproduced with permission.