'Yeah, yeah,' I hear you say, 'this spring will never arrive.' But it's true that our summer migrant birds are on their way - I've seen them with my own eyes!

Just before Easter I was lucky enough to spend a week at the Strait of Gibraltar Bird Observatory, which is run by the Gibraltar Ornithological and Natural History Society. As well as monitoring the birds on the Rock of Gibraltar by ringing, we spent a lot of time staring into the sky and across the bay.

Gibraltar's position, near the closest point of Europe to north Africa, makes it a really good place to watch migration as birds try to take the shortest route across the sea. It's about 13 miles as the eagle flies between Africa and Gibraltar.

(You can just about see Morocco in the photo above, about a third of the way from the left, and the Spanish coast right of middle)

An eagle-eyed view

Good Friday was particularly good for birds of prey. From about 9 am, when improvement in the weather meant that migrants began to cross the Strait, we watched constantly and identified and counted the birds that flew over our heads.

Top of the pops were booted eagles, with 586 counted, then black kites (490) and sparrowhawks (188). By 6.30 pm things had stopped and it was definitely time for a celebratory beer!

My favourites were the short-toed eagles which had the misfortune to fly in right over the breeding colony of yellow-legged gulls on top of the Rock. Angry cries from the gulls alerted us to their presence as they harassed the poor eagles. One eagle skimmed just above the roof of the observatory and I was captivated by its yellow eyes as it dodged the irate gulls snapping at its tail.

We're unlikely to see any of those birds making it as far north as the UK (although we have sparrowhawks here, they probably don't move as far as north Africa or southern Europe). But the good news is that there were some of the species that we're expecting here any day now.

They're coming!

A steady trickle of swallows flitted north, as did house martins. You might not expect it, but there were also large number of goldfinches heading back to their breeding grounds, plus linnets, greenfinches and chaffinches. In the trees and bushes on the Rock lurked willow warblers and chiffchaffs, with a sprinkling of redstarts - all birds that could be headed our way.

One of the last birds of the day was an osprey that approached low over the bay, also pestered by gulls, as it flew over the tankers and bulk carriers lying at anchor, past the lights of the docks and jetties at Algeciras. Where was it heading? There's no way of knowing, but we know from satellite-tagging that British-breeding ospreys often make their sea crossing here.

I know that birds are capable of all kinds of amazing feats, but there's nothing quite like seeing it for yourself. So keep your eyes peeled - the first swallow of spring is on its way.