The sun's rays came down on the fen in golden columns between the intermittent patches of cloud, as the wind rushed through the verdant reedbeds. A grasshopper warbler sang distantly from the marsh-grasses, providing an undulating buzzy backdrop to the guided walk.  

My friend and NWT ambassador Nick Acheson led our trek the marshland, pointing out numerous plants which rely on Norfolk's rich habitats. We paused to admire the beauty of meadowsweet, ragged-robin, greater birds-foot trefoil and so much more. But, having taken a moment to scan the various magenta and lilac tones of dactyloriza marsh-orchids, my glance flitted skyward. And if I hadn't looked up, I would not have seen one of Britain's rarest birds: the honey buzzard. 

First to catch my eye was a hunched shape flying toward me, wings drooped low at its sides. It was clearly a bird of prey but lacked the raptorial prowess of species such as osprey or golden eagle. Nevertheless, it utilised a medley of elegant swoops and slow, flowing flaps, creating an elegant, relaxed impression. I excitedly hissed, "honey buzzard!" to the rest of the group. They turned their heads up to the bird, now gliding low overhead. Through my binoculars all the key features came into view; a dark carpal patch, thickly chocolate-barred underparts and a gleaming lemon eye. This elusive denizen of the forest had made a wonderful and rare appearance in Norfolk, and I was overjoyed to bear witness to it.  

The bird continued to wheel and glide over the woodlands, showing three distinct tail-bars and ochre upperwings. It quickly trailed over the willows and finally dropped down over a ridge. The weather turned and rain poured down on us and we were forced to move on, but as I walked away through the swaying reeds, I heard a shrill siren-like wail from afar; its goodbye call, resounding through the landscape. I muttered a "thank you" in return. 

The honey buzzard is one of the UK's rarest breeding birds, with a staggeringly low population of 56 pairs. This makes it a category 5 rarity according to the Collins Guide to British Birds. Its scarcity and secretive habits make it a very tricky bird to find, but due to its similarity to the common buzzard, it is often overlooked.  

The species breeds in large, undisturbed woodland with open, flowery rides, and preys on insects. The majority of its diet comprises of wasp and bee larvae, readily collected directly from nests. The downside of hunting hymenopterans is the risk of being stung, which is a frequent impediment when an individual is predating a hive. As a result of its diet, the honey buzzard has evolved some amazing adaptations. The feathers on the face are short and scaly, giving protection against stings; the bill is small and hooked (this is perfect for tearing apart honeycombs); the feet are also scaly to grasp the honeycombs to take them back to the nest. Essentially, these birds are built to eat wasps! 

But the honey buzzard is also a very slight bird, lacking the bulk of other predatory raptors. This makes it a target for species such as goshawk, which live in similar habitats and can kill honey buzzards. It has, however, evolved to look extremely similar to the more powerful and threatening common buzzard as a deterrent, thus reducing the risk of death.  

So how do you identify a bird that is specifically evolved to be unidentifiable? Well, despite the plumage being almost identical to common buzzard, the belly and coverts stand out as being sparsely barred black rather than densely streaked brown, giving a uniform and tidy appearance. Many birds, especially males, also show a clear-cut "hood", where there is a distinction between dark face and pale throat. In males, the upperwings are entirely slate-grey as opposed to the chocolate-brown displayed by buzzards. 

Perhaps another way to separate the honey buzzard is to look at the jizz, or overall impression of the individual. When the common buzzard soars, it does so on raised wings tilted at a shallow upwards angle. But the honey soars on wings drooped below body level.  

But there's always a catch! A juvenile is the ultimate test for aspiring birders, some having literally a feather's difference to a common buzzard. The only reliable way to tell is by it’s chest markings; the common buzzard has an obvious pale breast-band in a v-shape, whereas the honey has a clean uniform colour on the body, whatever that colour may be. The species' plumage is extremely variable! The above image is a typical adult male, which you are most likely to see. 

Standing on a high viewpoint in July or August gives you the best chance of a sighting, probably of singles gliding serenely over the treetops. You should overlook a large area of coniferous and deciduous woodland with a telescope at the ready; honey buzzards are shy and wary of people!  

The mystical honey buzzard is at the forefront of my mind for this month's birding, but to see it is by no means an easy task. You have the information, so all you need now is a strong dose of luck!