After two weeks away from the reserve, it's amazing how much things have changed. The hedgerows are greening as hawthorn leaves burst open, or shining with the bright white blackthorn blossom, while bird songs and calls fill the air.

Blackthorn blossom near Whin Hill

The dominant sound of Minsmere in spring is the cacophony on the Scrape, with the raucous calls of black-headed gulls interspersed with higher pitched screams of Sandwich terns and "kluut" calls of avocets. Listen carefully and you may pick out the cat-like mewing of Mediterranean gulls or the onomatopoeic calls of kittiwakes, curlews or peewits (AKA lapwings).

Numbers of all of these birds are increasing, with counts of more than 50 Sandwich terns and Mediterranean gulls already, as well as the first reports of common terns and kititwakes back on the Scrape. Large flocks of black-tailed godwits are gathering on migration, and more unusual waders seen this week have included bar-tailed godwit, grey plover, ruff and even an early little stint.

Sandwich tern by Steve Everett

Ducks are still numerous and very visible, especially as the drakes chase females around in courtship rituals: I watched a tight flock of at least 12 shovelers in hot pursuit a single female over the reedbed. Gadwalls, shelducks, wigeons and teals are very obvious too, but most of the pintails have already migrated. At least one pair of garganeys remains, but are proving typically elusive.

Returning to the sounds of spring, it's great to hear an increasing variety and volume of birdsong. Blackcaps and chiffchaffs seem to be everywhere in the woods and sedge warblers are increasingly widespread around the reedbed. Best of all, a grasshopper warbler is reeling away along the new boardwalk, its song sounding like fishing reel being wound in, or the insect that it shares a name with. As is their usual way, it is easier to hear than to see, and is best heard early in the morning.

Talking of early morning, the family of otters were playing in front of Bittern Hide first thing today, before popping up at Island Mere later in the morning. They have been regular at the latter location for the last couple of weeks. A tiny weasel was busy hunting at Bittern Hide today, and I watched a stoat bounding past the hide with a small mammal in its mouth on Wednesday.

Otter at Island Mere by David Naylor

Bitterns have also been putting on a show at both Bittern Hide and Island Mere. We guarantee that someone sees a bittern every day, but don't know who will see it, or where. However, if you are prepared to wait, you should be rewarded with a sighting. Please note due to this bittern activity, Bittern Hide can get full at busy times, so be prepared to try somewhere else instead. Water rails are often seen at Bittern Hide, too, and bearded tits have been showing well at Island Mere.

Great crested grebes are also displaying at Island Mere by David Naylor

Marsh harriers are very obvious around the reedbed at the moment, and buzzards can be seen almost anywhere, so it's worth checking any big raptor carefully. You never know, you might also spot a red kite or peregrine.

The first hobbies should be back any day - as should cuckoos. Nightingales have returned to the heath, but not yet to the car park entrance area. As they are easily disturbed, please only look for nightingales by remaining on the main footpaths. Several wheatears have also been spotted around the reserve. 

One of the highlights of spring is watching the sand martins wheeling around the bank or hawking insects above the reedbed, and I'm pleased to report that they are busy this year. A few swallows have returned too.

It looks like adder season is virtually over. The females have emerged from hibernation and the males have therefore moved away from their basking sites in hot pursuit of mating. This means that they are no longer easy to find. Although you might spot one anywhere, for reliable adder sightings, please wait until next March. If you are lucky enough to spot one, please remember to keep a distance to minimise disturbance to these sensitive snakes - ideally at least three metres. Don't worry, though, where the adders were basking below the sand martin bank, they have been replaced by voracious green tiger beetles and parasitic dark-edged beeflies.

Finally, one of our most popular, but difficult to see, woodland birds has been putting on some great displays this week, as these fabulous photos a nest building treecreepers show. Thanks to regular visitor Les Cater for sharing these pictures with us.