A visit to WWT Slimbridge is a completely unique experience from one month to the next. In the summer months breeding birds are in full swing and the first waders are returning from the Arctic. In the cold winter months the reserve is a hive of activity for migrants such as Bewick's swans and you stand a good chance of catching a glimpse of a short-eared or barn owl.
Here's what you can expect to see and when to help with planning your visit...
This is the period for which Slimbridge is really famous, as it offers great quality winter birds in very large numbers.
Of course, the most famous species are white-fronted geese and Bewick's swans, both of which breed in Arctic Russia. White-fronted geese are the most significant species to the WWT as they are the reason that Sir Peter Scott started the Trust. In his early days at Slimbridge, 7,000 white-fronts would have been present each winter on the New Grounds.
Sadly, today we are lucky if we have 500 of these geese spending the winter with us. They are not in any trouble, but most now choose to winter in Holland as it is now warmer than in the past.
But no matter how many white-fronted geese are present it is always a pleasure to watch this species and listen to their lovely calls. The best place to see them is the Dumbles (from the Holden Tower) or Tack Piece (from the Zeiss Hide). Every night they fly over the grounds and roost on The South Lake and although it's quite dark by this time, the sound is great.
The Bewick's swan is another bird that Peter Scott dedicated much of his time to watching and studying. In fact the Bewick's Swan research program at Slimbridge is the longest ongoing study of any species of bird in the world.
Since the early 1950's, the Bewick's swans have been fed by a Warden three times a day on the Rushy. Although during the day they will be seen all over the reserve feeding on the managed grass, the Rushy really is the place to see them. Every day at 4pm, we do a commentated feed on the Rushy with the public able to enjoy stunning views from the Peng Observatory.
Bewick's swans are unique as they can be recognised individually by their bill patterns, so during the talk individuals can be pointed out to the public. Peter Scott was the first person to notice the individual bill patterns of these birds. Individual Slimbridge Bewick's swans have been known to return to Slimbridge for 29 years in a row!
It’s not just Bewick’s swans that come in for the afternoon feeds either - around 2,500 wildfowl arrive by late afternoon ready for feeding. From the Peng Observatory you can enjoy stunning views of pintails, pochards, tufted ducks, gadwalls, teals and many others at very close range.
There is often a very big roost of starlings at this time of year that do their amazing acrobatic displays over the grounds at dusk. We have had as many as a quarter of a million Starlings roosting at Slimbridge. This also attracts many predators like sparrowhawks and peregrines that come in to the mass of starlings.
During this time of the year large parts of the reserve are deliberately flooded and it is quite normal to see 45,000 water birds feeding. It’s not uncommon to see 8,000 European wigeons, 6,000 golden plovers, 2,000 dunlin, 800 curlew and 12,000 lapwings.
Also spotted redshank, little stint and ruff can all be seen in internationally important numbers here during the winter. The Zeiss Hide has been an excellent place to see great bitterns in recent years, where the views of this bird can be prolonged and close.
The Robbie Garnett Hide feeding station is a great place to see water rails feeding in the open, Lesser redpolls, siskins and a few brambling. Patient scanning from the Martin Smith Hide will almost guarantee jack snipe amongst the many common
In this period, the more unusual sightings can include Tundra bean geese, pink-footed geese, brent geese, American wigeon, green-winged teal, Iceland gull, glaucous gull, snow bunting and Lapland bunting.
March is one of the quieter months of the year as all the winter birds have left and most of the summer birds are yet to arrive. By the middle of March though we would expect to see quite good numbers of sand martins and common chiffchaffs while the last week of March normally sees the first northern wheatears and barn swallows beginning to arrive.
It can also be a good time to see Mediterranean gulls on The South Lake. In recent years up to five birds have been present, and hopefully its only a matter of time until they breed here.
The black-headed gull colony here is now up to 50 pairs and this in itself is always fun to watch. Things really begin to liven up in April when most of the summer warblers arrive and with them cuckoos, common redstarts, whinchats, yellow wagtails and a few hobby.
But May really is the best month of the spring, if not the year. The estuary now comes alive with waders moving through towards the Arctic. Large numbers of ringed plover, dunlin, sanderling, common sandpiper, curlew, black-tailed godwit, bar-tailed godwit and greenshank can be seen most days.
Also smaller numbers of whimbrel, little stint, turnstone and curlew sandpiper can also be seen. Migrant waders can turn up anywhere but the South Lake Hide and the Zeiss Hide are always worth a check.
But for great views of the waders on the river a walk out to our Shepherd's Hut Hide as the tide is coming in can be very productive. On the land it is a great time to see numbers of whinchat and wheatear, reed and sedge warbler and sometimes a few grasshopper warblers.
The spring really is the time to see our kingfishers that nest in front of the well-named Kingfisher Hide. They may well be sitting on their second clutch by the end of May. There are four nesting pairs at Slimbridge, and each pair will often have three broods each summer. So by July there can be as many as 30 kingfishers on site!
If the weather is perfect, it is possible to see good numbers of common and Arctic terns as well as black and little terns. If there's a stiff northerly wind,
Arctic, great and pomarine skuas can be seen migrating up the estuary.
Lapwing and common redshank can both have well grown young on the reserve by the end of May. Of course it goes without saying that this is an excellent period for rare birds such as cattle egret, great white egret, purple heron, night heron, glossy ibis, spoonbill, temminck's stint, whiskered tern, pied flycatcher and wood warbler.
The early part of June can still be very good for migrants especially small waders on the Estuary. Breeding birds are in full swing and the 100 Acre and South Finger reed beds are now very busy. At least 180 pairs of reed warblers, many sedge warblers and reed buntings are very busy in these areas raising young.
The South Finger is also an excellent spot to see blackcaps, lesser whitethroats, whitethroats and chiffchaffs. Other breeding birds around the grounds and reserve include water rails and cetti’s warblers.
This is a great time of year to explore our private 800 acre reserve on a Wild Safari. On the guided two hour tour you may well see many little egrets and grey herons, as well as breeding wildfowl like tufted ducks and shovelers.
With so many dragonflies now on the wing it is a really good time to see our local hobbys hunting over the reserve. The pools are also alive with common terns and little grebes. You may also see grass snakes and if you are very lucky a wild otter on safari.
July sees the first returning waders from the Arctic. Ruff still in their wonderful breeding plumage may often be seen in good numbers. Also sanderling, little stint, common sandpiper, turnstone, greenshank, ringed plover and dunlin all can arrive in good numbers.
It really is the time for green sandpipers and Slimbridge often gets the second highest count in the UK. They normally arrive in the last weeks of June and peak by late July - the Rushy and the Tack Piece are the best areas to see them.
Species such as wood sandpiper and curlew sandpiper may turn up if the weather conditions are right.
The last week in July can produce the first returning northern wheatears, common redstarts, whinchats and even a chance of a spotted flycatcher.
Rarities can include white stork, ring-billed gull and our rarest sighting ever a white-tailed lapwing!
If there are any prolonged strong south westerly winds during this period, a patient observer could be rewarded with a few seabirds. European storm-petrel, leach's petrel, manx shearwater, gullimot, razorbill, northern gannet, fulmar, shag and any skua may be seen on the river.
Now is the time that all of the juvenile waders begin to appear on the river and the scrapes. Curlew sandpiper and in recent years pectoral sandpipers are regulars on The South Lake.
This is the best time of the year to see numbers of warblers. Lots of willow warbler, common chiffchaff, blackcap, lesser whitethroat, common whitethroat and a few garden warblers pass through.
Wildfowl begin to arrive with a large number of European teal arriving in August. Migration is now in full swing and almost anything can turn up or pass through at any time. These two months are the best to see osprey and marsh harrier migrating down the river and using the reserve to feed up on the way.
August and September are the best months of the year to see and find rare birds. Again anything is possible with some recent sightings being: aquatic warbler, marsh warbler, wryneck, kentish plover, semipalmated plover, baird's sandpiper,white-rumped sandpiper, temminck's stint, buff-breasted sandpiper, dotterel, red-necked phalarope and Bonaparte's gull.
October brings large movements of passerines like redwing, song thrush, fieldfare, blackbird, chaffinch, siskin, linnet, skylark and meadow pipits. And with them smaller numbers of brambling, lesser redpoll and reed bunting.
White-fronted geese can arrive in September but tend to arrive in mid October, whereas the Bewick's swans tend to arrive between 22 October -1 November. Late October is an excellent time to see the jack snipes from the Martin Smith Hide that feed with many common snipes and a few water rails.
Wildfowl numbers build daily at this time of the year. Pintail and pochard are the most obvious arrivals and their numbers really swell at this time of the year. It can be a good time of year for owls too with often several short-eared owls and barn owls present, and some years long-eared owls may be found.
December gales have produced large numbers of leach's petrels (250 were seen one year) and great skuas are likely but any seabirds are possible.
It is worth carefully scanning through the greylag goose flock (300 birds) for Continental greylag geese that occur in small numbers most years, as do pink-footed geese and sometimes wild barnacle geese.
Rarities at this time of year have included American golden plover, temminck's stint, snow goose, red-breasted goose, glaucous gull and yellow-browed warbler, Siberian chiffchaff and Richard’s pipit.
WWT Slimbridge, Bowditch, Slimbridge, Gloucestershire, GL2 7BT