As I mentioned on Monday, swallows are arriving. They might be a bit slow to return because of bad weather here and in Europe, but be patient - they're on their way.

If you get a good look at a swallow and see its unmistakeable forked tail, it's easy to identify. But beware - there are other, similar, birds out there to confuse you.

House martin by Graham CatleyThe house martin is quite similar to the swallow, having glossy, dark blue wings, but is a bit less graceful and a bit plumper.  

Like swallows, they build a nest from mud, but it's usually on the side of a building, under the eaves, rather than inside a barn, for example. 

Watch out for their bright white rumps and short, forked tails.

They're social birds and quite chattery - their calls sound a bit like 'jik, jik.'

Sand martin by Graham CatleyThe sand martin is smaller than the swallow or house martin. It has brown wings and a brown stripe under its chin. It's also quite a social bird and can be seen feeding in flocks over water.

Watch out for sand martins flying along rivers. They excavate their own nest burrows in loose soil like riverbanks, or even sometimes in big piles of sand at quarries or in drainage holes on concrete riverbanks.

They have a buzzing, fizzy kind of call: 'vvvvzsssszzz'. Or something like that.

Swift by Nigel BlakeThe swift is in a different family to the swallows and martins, but arrives in the UK slightly later - around the end of April.

They nest in buildings, especially old ones which have plenty of gaps where they can squeeze in and nest in the roof space.

Swifts hardly ever land except when they're nesting - they spend their entire lives flying around, even sleeping and mating in mid-air. 

They're pretty noisy beasts around their nest sites. Listen for a high-pitched 'sreee, sreee, sreee'!

Have you seen any other newly-arrived migrants yet? Let us know!