Telling Arctic Tern from Common Terns is not easy (see April blog). I have only once seen the two together– the Arctic’s were breeding in a dense colony and a single pair of Common Terns were breeding in a near-by harbour. The translucent primaries and secondaries of Arctic’s is difficult as is the blood red bill without a black tip that often darkens to blackish in breeding plumage. The terns at Hobson’s Park are definitely Common Terns – I think there are two breeding pairs – the photos below show the flight patterns of the two terns. The sharp blackish edge to the underside of the primaries in Arctic Terns compared to the diffuse grey undersides of Common Terns is a good way of distinguishing the two species – but not always easy to see.

I agree with Rob Pople (BTO) – I think the terns fishing along Riverside, opposite the boat houses and in the Long Reach near Ditton Meadows are from Hobson’s Park. At 21:00 on 1^stJune – Strawberry Fair night – a diving Common Tern with its catch headed over the City towards Hobson’s. I saw the Long Reach terns doing the same last year.

Two Black Terns at Hobson’s Park was an excellent find (Pete Holt – www.cbcwhatsabout.blogspot.com) and coincided with a small influx in Norfolk and Suffolk.

Blackcaps have been one of the commonest song birds across our study area all month, together with a strong arrival of other warblers. A small copse at the end of Arbury Road on 3^rd May had singing Blackcap, Chiffchaff, Common Whitethroat,and Lesser Whitethroat. Lesser Whitethroats have been a feature of this spring; in addition to April records I have heard birds singing at the following locations: Cherry Hinton Brook (behind Sainsbury’s), Coldham’s Common, Brierley Close and Cherry Hinton Chalk Pits (2) plus Garden Warbler, Blackcap (2) and Common Whitethroats (2) also at the chalk pit. Swifts arrived in numbers on 8^th May and are using the Swift tower in Logan’s Meadow. On 7^th May a Chiffchaff was still singing behind the Riverside Museum and on 12^th the Chiff was still singing in gardens in Gilbert Road.

The City Centre Peregrines have had a difficult time. On 29^thApril, the male bird was found injured in Newnham College grounds probably damage by a collision during high winds. It was taken to the Raptor Centre near St Ives to recover, leaving the female to feed the chicks alone. On 30^th April, she was seen recovering cached prey and on 1^stMay a third bird appeared – possibly another male. (see Twitter: @cambsperegrines). On 27^th May I photographed the fledged bird below. On 7^th May the female Peregrine at the second city site seemed to be firmly sitting on eggs. A Hobby was over Highsett on 31^st May.

A singing Reed Warbler was a good find in Mill Road Cemetery (sorry date and observer mislaid). I have seen them before in unusual places in mid to late May – Romsey Road, Asda carpark – Beehive Centre. They may be late migrants from Eastern Europe that often have a more mimetic song. Reed Warblers were also singing at Hobson’s Park. Corn Buntings are singing in Hobson’s Park – it’s the best place I know to see this uncommon and charismatic farmland bird; they can easily be seen singing from the tops of the saplings. A territorial Yellow Wagtail was displaying at a farmland site on the north edge of our study area on 31^st May.

I have seen a pair of Turtle Doves, but just outside our study area, heading towards a regular breeding site. Turtles Doves have become so rare that breeding numbers are now being collected and collated by the UK’s Rare Birds Breeding Panel.

A visit to Byron’s Pool and Trumpington Meadows on 30^th May with the Wildlife Trust’s bat experts, Anita and David, recorded Common and Soprano Pipistrelles and excellent views of Daubenton’s bats and a hunting Barn Owl. A visit to Addenbrooke’s Hospital on 4^th June counted 81 House Martin’s nests that appeared to be actively used or freshly repaired with nesting birds inside.

The British Ornithological Union, which manages and supervises the list of British birds has added/reinstated a 30-year-old record of Falcated Teal duck without considering any new written or visual evidence of the original record. Reinstate the Cambridge Moustached Warblers, I say, that were seen by all the top Cambridge birdwatchers in 1946 but rejected 60 years later in 2006 by the BOU!

bobjarman99@btinternet.com– 4^thJune 2019