As is usual in mid July, the Scrape is a great place to test your bird ID skills with migrant wading birds passing through, young birds fledging, gulls and terns gathering after their post-breeding dispersal from breeding elsewhere in NW Europe, and ducks rapidly losing their bright colours to adopt the female-like moult plumage known as eclipse. Consequently, many of the birds that you see on the Scrape may not match the pictures in your field guide - and you never know what unusual visitors may call in next.

Such was the case on Tuesday when there was a superb test of tern identification on South Scrape with all of the following seen during the day: Sandwich terns, including the first chicks to fledge at Minsmere since 1978; common terns, included fledged chicks and a dark-billed first summer bird (in what is known as Portlandica plumage; a similarly aged Arctic tern, and a stunning adult roseate tern. 

Roseate terns are the rarest breeding seabird in the UK, with almost the entire population nesting on Coquet Island off the Northumberland coast. They are scarce visitors to Minsmere, usually in July as they begin their journey south to Africa. They are much paler than any of our other terns - even the Sandwich terns - and appear almost white bar their black cap, black bill and red legs. In breeding plumage they can acquire a soft rose-tint to their underparts - hence the name. Sadly the roseate tern didn't linger and was only seen on Tuesday.

Roseate tern by Jon Evans

The two first-summer terns can be initially mistaken for roseate terns as they too have black rather than red bills. However, bot differ in their darker upperparts and white forehead. The differences between the two species are subtle though, with Arctic terns having shorter legs and a shorter bill than common terns, so positive identification is tricky. Both of these first summer terns were still present yesterday.

As well as the terns, the annual summer build up of little gulls has begun on the Scrape, with up 18 seen daily this week. Little gulls are beautiful gulls. As their name suggests, they are tiny, being similar in size to the terns. Adults are white with yet black hoods and in flight show a dark underwing. Immature birds have a diagnostic W-shape on their upperparts in flight. Size alone should be a key ID feature though. They do not breed in the UK, but once they've finished breeding in Eastern Europe and Siberia they disperse west and gather in flocks around the North Sea coasts.

Little gull by Jon Evans

Other gulls on the Scrape include black-headed and Mediterranean gulls with fledged chicks, lesser black-backed gulls and herring gulls, as well as a kittiwake or two. With lots of avocets still present there's plenty of white and black birds to spot on the Scrape.There's also lots of mainly brown ducks as teals return to join the mallards, gadwalls and shovelers and all moult out of their breeding finery.

There are also several more colourful birds to look for on the Scrape. These include varying numbers of black-tailed godwits, several spotted redshanks, common redshanks, dunlins and lapwings, and one or two ruffs, common sandpipers, green sandpipers, greenshanks, ringed and little ringed plovers and oystercatchers.

Of course, there's plenty to see away from the Scrape too. The purple heron was still putting in occasional appearances at Bittern Hide until yesterday, but hasn't been reported yet today. There have, however, been regular sightings of bitterns, bearded tits, reed warblers, hobbies and marsh harriers, as well as three otters at Island Mere and a kingfisher at Bittern Hide. At least one of the Savi's warblers is still singing at Island Mere, too.

Woodland birds are harder to spot at this time of year, but a cuckoo has been seen several times between the Work Centre and Whin Hill today - this is one of 70 species to spot that has been harder to find this year, and they won't be with us much longer so it's worth looking for them this week. The woods are, however, good places to look for butterflies, including the gorgeous white admiral. Beewolves, pantaloon bees and other mining bees and wasps are still proving popular in the North Bushes, as are the six-belted clearwing moths on the North Wall.

Cuckoo by John Bridges (rspb-images.com)