After last week's beautiful warm weather, it feels decidedly cooler today - more like February than late April, in fact. However, the weather system that is passing over the UK has brought with some exciting birds - and brought them down low.

The main arrivals with the weather system were swallows and martins, with large flocks swooping low over Island Mere this afternoon. Sand martins have been numerous for several weeks, feeding over the reedbed and excavating burrows close to the visitor centre. Although we've had a few swallows and the odd house martin for a few days now, there was a notable increase, with at least 100 swallows and 50 house martins present today. Even more excitingly, there were at least half a dozen swifts too - a clear sign that spring is well and truly here, even if the temperatures suggest otherwise.

Swallow by Jon Evans

All of these swallows, martins and swifts were hunting insects, which they catch and eat on the wing. They in turn can fall victim to that master aerial hunter, the hobby. These fast, maneuverable falcons have also just returned from Africa, and until the dragonflies and emerge emerge, they often turn their attention to martins for dinner. 

The first large red damselflies have already emerged from the reedbed ditches that were home to their larvae for the past year, but with colder weather forecast again for the weekend, it may be a few more days until we start to see a mass emergence of damselflies. Butterflies seen so far this spring include orange tip, green-veined white, peacock, speckled wood and small tortoiseshell.

Warblers are also insect eaters, though tend to catch them either by picking them off leaves or darting out in short flycatching flights. All of our breeding warbler species have now returned, though numbers of some species remain low, with the main arrivals expected in early May. Reed and sedge warblers can be heard vying for a mate in the reedbed. The Savi's warbler is still singing intermittently around the southeast corner of Island Mere, and a grasshopper was heard a couple of times this week between North Wall and East Hide. Blackcaps, garden warblers and chiffchaffs are singing in the woods, with whitethroats, lesser whitethroats and willow warblers in more scrubby areas.

Blackcap by Ian Clarke

Perhaps our most popular songsters are nightingales, and several have now returned to Westleton Heath, where you can also find turtle doves and woodlarks singing - please ask at the visitor centre for directions to the best places to hear them. Cuckoos are also back, but only heard occasionally at the moment, mainly around Island Mere.

Out on the Scrape, Sandwich tern numbers peaked at 175 this week, with at least 30 common terns and one Arctic tern also seen. More than 300 Mediterranean gulls have been counted at dusk, though about 100 are usually present during the day, alongside 1500 pairs of black-headed gulls. Alongside the avocets, lapwings, redshanks, oystercatchers and black-tailed godwits on the Scrape, look out for dunlins, turnstones, single ruff and spotted redshank, or bar-tailed godwits, and a greenshank has been seen on Lucky Pool.

What will this weekend's storms bring in with them?