Ben Lewis of the RSPB hails the remarkable journey of the returning migrants to our shores.

Spring… the time of the year that many naturalists look forward to the most. It has seemed like quite a long, cold and at times, wet winter so it's time to say goodbye to the various beasts from the east that have caused havoc across the country and hopefully welcome the warmer weather that spring so often brings.

Of course being a warden, birder and naturalist myself, what I really look forward to is the wildlife that the warmer conditions bring out. Many millions of migrant birds are currently flying all the way from Sub-Saharan Africa to reach our shores. It is a staggering journey to undertake and seems like a huge amount of effort to go to, but they do it for their own survival and to give their youngsters the best possible start in life. They take advantage of our mild climate, with plentiful water supply, and large number of insects in summer.

When it gets to April my thoughts rapidly turn to looking at the weather patterns in

Europe and I try to predict when we are likely to see a northerly movement of these southern species. Clearly a nice southerly wind all the way from southern Europe will see large numbers of warblers and other migrants arrive, however these weather patterns are seldom seen and the birds tend to arrive in waves, almost like squadrons of fighter planes going to battle.

Working on a nature reserve like RSPB Strumpshaw Fen, I get to appreciate all of the subtle changes that are happening around the reserve. One day I might hear that there has been an arrival of chiffchaffs, the next may be blackcaps singing their flute-like song; these arrivals keep on coming until we are full up and bird song rings out from all of the trees, bushes and reedbeds across the reserve.

There is usually a set schedule to the returning migrants at Strumpshaw Fen starting with chiffchaffs and blackcaps, followed closely by garganey and sand martins in late March. By mid-April the second set of warblers have arrived, willow warblers sing from every available willow tree, and the reedbed contains reed, sedge and grasshopper warblers all competing with each other to sound as big and attractive as

they can.

As we get into late April and early May we have a full set of migrants, the reserve is once again alive with cuckoos calling, bitterns booming, warblers singing from all habitats and swifts and swallows are in aerial pursuit hawking insects from around our heads.

Another interesting observation during the migration period is that many different species travel together, the most notable being the sand martins, house martins and swallows, these birds all eat insects so travel together as the insect supplies increase on their way north from Africa. This is common knowledge to most people, however there is a fourth species that follows them north

on their journey too - the hobby. This is a small migratory falcon which feeds on the swallows and martins as they travel, a perfect migratory symbiosis!

When all of the migrants return, the reedbeds and woodland can sound very loud and confusing. I run a three-session 'improvers birdwatching course' each spring. Within each of the three sessions we head out into the different habitats within Strumpshaw Fen and unpick the dawn chorus, learning how to identify some of the more tricky species as well as learning how to identify all of the bird songs and calls that we encounter. Last year we saw and heard at least 80 species on the course and everyone felt much more confident in identifying of birds we encountered and had a much greater understanding in what to look and listen for to aid identification.

We still have a few places left for this year's course, which starts on April 17. To enjoy this bird song in all its glory, you can also join us on one of our two early morning dawn chorus events.

For more information on both of these events visit: www.rspb.org.uk/strumpshawfen or call 01603 715191.

Whatever you do this spring, make sure you get back to nature and enjoy the great outdoors, it really is more than just a breath of fresh air!