VOICES
Urban Birder David Lindo visits a city steeped in history – including a birding landmark – as he joins the students in Cambridge
A
s we all know, Cambridge is a university town steeped in history and whose streets are riddled with millions of bookish students riding bikes. When I came to visit recently, I could not stop myself from being captivated by the architecture of the impressive university buildings or from feeling conscious of my profound lack of education. But here’s a sobering thought; Cambridgeshire is the least wooded county in the least wooded country in Europe. That thought certainly had me scratching my chin as I stood with Peter Herkenrath, the Chairman of the Cambridgeshire Bird Club along an icy stretch of the River Cam. He dropped that fact on me while we were in the centre of Cambridge counting some chilly looking Black-headed Gulls that were variously congregated on the moored barges or on the frozen river itself. Cambridgeshire’s lack of woodland appears to be verified by the Woodland Trust. Thankfully, there are still tracts of woodland in and around the city rich enough in their biodiversity to sustain healthy populations of wildlife. I was still pondering tree cover as Peter and I walked through Jesus Green, just north of the city centre and close to Jesus College. Despite the multitudes of people who play football, rounders and other sports there, particularly during the summer months, the urban birding is still good. The stretch of the Cam there supports the exotic Mandarin plus Common Terns that gracefully hawk over the water’s surface during the summer. A few pairs may breed on a nearby flat roof but it has never been proven. Walking around The Backs, the imaginatively named characterful gardens and woodland at the backs of the colleges, was a pleasant experience. Much of the area is private although there is some limited access. Aside from breeding Coal Tits and Goldcrests it is the only place in the city to find Nuthatch – a rare (ish) species in Cambridgeshire. The college buildings harbour the occasional Black Redstart while Grey Wagtails breed along the ever-present River Cam. There have been a couple of interesting species show up in the city over the years like the Leach’s Petrel that incongruously flew past Castle Hill to the north of the city centre. Perhaps Cambridge’s biggest ornithological head turner was the pair of Moustached Warblers that nested in 1946 at Cambridge Sewage Farm at the northern city limits. Darker crowned with a stronger supercilium and a more rufous tone than their Sedge Warbler cousins, Moustached Warblers are partially migratory marshland denizens of parts
of eastern Europe and southern Asia. After the Cambridge birds initial surprise discovery they were watched for hours on a daily basis for a few weeks by a group of birders that included the roll call of the most eminent ornithologists of the day. Many of the observers made quite detailed notes that all seemed to point towards this most unusual vagrant. For years the record stood despite the slight murmur of disagreement from a few ornithologists who felt that the birds were no more than aberrant Sedge Warblers. After listening to the story and reading the original accounts, I too was convinced that Britain had indeed received a visitation from this unlikely species. I was therefore shocked to hear that the record was finally thrown out by the British Birds Rarity Committee (BBRC) in 2005. It was for good reason, as it appeared that it was a case of mass hallucination. Closer scrutiny of the notes and descriptions had found a number of inconsistencies that helped to rule out Moustached Warbler. The BBRC sleuths found that the case for Sedge Warbler was significantly strengthened when it was realised that the observers had based their prognosis on the field guide of the day’s illustration of Moustached Warbler that only showed its underparts – hardly useful for identification. Crucially, the ‘one last thing’ moment – to quote the great Columbo, was that observers universally remarked that the birds had pale legs. This is a Sedge Warbler feature as Moustached Warblers’ legs are dark. The case was solved. The moral, I guess, is that when on a twitch we must always ask ourselves the question: why is the bird that we are watching what they say it is? We ended our day at the delightful Milton Country Park, very close to where the infamous sewage farm used to be and home to winter parties of Gadwall, Shoveler, Teal and other common waterfowl species. During the summer, the expected common breeding warblers are readily seen but it is also a good place to find a few regularly nesting Cetti’s and Grasshopper Warblers plus a couple pairs of Nightingales. We were watching a Water Rail feeding at close range around an unfrozen water margin when a hitherto cryptically camouflaged Snipe suddenly jumped up and slanted its body sideways towards the bewildered rail, flashing the rusty feathers of its splayed tail. The whole episode seemed to last a nanosecond, with the Water Rail resuming its foraging and the Snipe sitting down to again melt into the wintry vegetation. I had never seen that kind of behaviour before, but I will never forget it!
BEST SITE: Milton Country Park CITY LIST: C120 Many thanks to Peter Herkenrath and John Charman for additional information. For more information on birding in Cambridge: Cambridgeshire Bird Club: www. cambridgeshirebirdclub.org.uk; Cambridge RSPB Group: www.rspb.org.uk/groups/cambridge