The Birds of Pont Croesor

Pont Croesor

When we think of birds and Pont Croesor on the Glaslyn we immediately think of Ospreys. The breeding Ospreys are the main attraction in summer in this picturesque corner of North Wales, of course, but all year round there is so much interesting birdlife in the area both for the casual nature-watcher and the serious birdwatcher alike.

Before the Ospreys settled to breed on the Glaslyn in 2004, Pont Croesor was best known for the large numbers of Whooper Swans that spend the winter months on farmland adjacent to the bridge. With up to 80 individuals in most winters, this is currently the largest herd of Whooper Swans in Wales. Numbers fluctuate not only from winter to winter but also throughout each winter which indicates that there are birds who join the herd for a few days or weeks even before moving on to pastures new.

In most winters, a few colour-ringed individuals may be seen amongst the herd. These will be individuals which have been ringed on the breeding ground in Iceland in summer. A few ringed Whooper Swans have been seen on the Glaslyn in several successive winters and have been subsequently recorded in Ireland and other parts of the British Isles.

Whooper Swans may be seen on the Glaslyn between October and April although one or two injured individuals who have lost the power of flight, like the famous and much-loved ‘Stumpy’, have no choice other than to spend the rest of their lives on the Glaslyn rather than migrating to Iceland each spring.

Whooper Swan

Bewick’s Swans are a relatively scarce visitor to Pont Croesor with no records in most winters and only single digit numbers occasionally passing through in spring in other years.

Mute Swans are a common sight on the Glaslyn throughout the year. Several pairs breed every year but a successful outcome is dependent on low rainfall and the absence of floods during May. There is no better sight to gladden the heart on the river around Pont Croesor in summer than a pair of Mute Swans with a number of cute cygnets in tow. A sizeable herd spends the winter amongst the Whooper Swans and up to 50 non-breeding Mute Swans spend a few weeks around Porthmadog Harbour each summer.

The fields around Pont Croesor also attract large numbers of feral geese throughout the year but mostly in winter. Most of these are Canada Geese (up to 600!) and Greylag Geese. It is worth checking through these large flocks in winter, though. A handful of Pink-footed Geese, White-fronted Geese, Bar-headed Geese and Barnacle Geese are recorded most winters whilst rarities like the Snow Goose, Bean Goose and Egyptian Goose have also occurred although most of these are considered to be escapes. Take care whilst checking through the flocks as there are many hybrid geese present to catch you out!

Twenty four species of ducks have been recorded around the Glaslyn area but only a few of these will be encountered around Pont Croesor. One of the most colourful ducks to be seen here is the Mandarin Duck which escaped from local collections in the 1990’s. A few pairs of this attractive duck now breed annually on the Glaslyn and its tributaries. Small flocks may be seen on the river both sides of the Pont Croesor visitor centre but you need to be patient to see them as they are a very wary duck and will see you a mile away!

The Mallard is the most numerous breeding duck on the Glaslyn and large flocks occur in winter. Only a few pairs of Teal stay to breed but this is another common wintering duck with flocks of several hundred individuals a regular sight on the marshes. The most numerous duck on the Glaslyn in winter, the Wigeon, does not breed but is a winter visitor from Scandinavia, Russia and Iceland. Their distinctive whistling call is a quintessential part of the marshes in winter.


Other ducks you are likely to encounter on the river at Pont Croesor include diving ducks like the Goosander and the Red-breasted Merganser, both of which breed on the Glaslyn. The rare Smew has been seen once at Pont Croesor whilst Goldeneyes are regular in winter (and occasional in summer). When the lakes of Snowdonia are frozen over in winter one or two Tufted Ducks and Pochards may also spend a few days on the river waiting for a thaw so that they can return to the lakes to feed.

The riversides and the fields around Pont Croesor are attractive to a number of wading birds. Most of the waders seen on the Glaslyn are estuarine in their nature and will be seen feeding out on the sandy and muddy parts of the estuary. But some farmland specialists like the Lapwing and the Curlew continue to breed in small numbers on the floodplains around Llanfrothen and Prenteg. Common Sandpipers are a regular sight in summer flying up and down the Glaslyn by the Osprey Viewpoint and a few breed in the vicinity of Pont Croesor. A few Oystercatchers, Redshanks and Snipe add to the variety of waders whilst Dunlin, Little Ringed Plover and Black-tailed Godwit and a few other waders have all been listed as visitors to the Pont Croesor area.

Grey Herons are a regular sight as they patiently fish the slow running stretches of the Glaslyn. In the last few years they have been joined by the exotic Little Egrets which used to be a rarity here but which now outnumber Grey Herons in the area. A rare Great White Egret graced the Glaslyn by Pont Croesor in August 2012. Other fish eaters, like Cormorants and the colourful Kingfisher also take advantage of the abundance of fish in the Glaslyn off Pont Croesor.

Gulls are not everyone’s favourite birds, but they are an integral part of the Glaslyn ecosystem. Sixteen species of gulls have been recorded in the Porthmadog area which includes rarities like Ivory Gull, Ross’s Gull, Laughing Gull and Bonaparte’s Gull. At Pont Croesor, you are most likely to see Herring Gulls and Black-headed Gulls as well as Lesser Black-backed Gulls in summer although Mediterranean Gull, Glaucous Gull and the Little Gull have all been recorded in the vicinity of the bridge.

Although also not high on the list of popular birds, crows are also an important part of the Glaslyn bird scene and have adapted to live and prosper in many different habitats, both natural and man-made. Large flocks of Jackdaws, Carrion Crows and Rooks feed in the farmland around Pont Croesor whilst you may be lucky to see Choughs in the area and Ravens are regularly seen, and heard, flying over the Glaslyn Osprey Visitor Centre.

The vast majority of birds that are on the Pont Croesor list are small passerines. The bird feeders at the Visitor Centre are testament to both the numbers and variety of woodland and farmland birds that occur in this bird rich area. Several species of tits (including Willow Tits) occur and many finch species like Greenfinches and Chaffinches take advantage of the free food on offer. Throw in the odd Great Spotted Woodpecker (one of three species of Woodpeckers in the valley), a Siskin or two and a handful of Lesser Redpolls and the feeders become a colourful spectacle throughout the summer.

In winter, set aside fields near the Visitor Centre attract flocks of Yellowhammers and Reed Buntings which take advantage of specially sown barley in order to feed and survive the winter.  Amongst the other small birds which are regularly seen at Pont Croesor are Wheatears, Pied Wagtails, Meadow Pipits and Stonechats whilst Whinchats have also been seen on a number of occasions.

The ancient oak woodlands around Pont Croesor are the summer quarters of many specialist birds like Pied Flycatchers, Redstarts and Wood Warblers. Many other warblers like Chiffchaffs, Blackcaps and Whitethroats are present throughout the summer but some of them will be heard more often than they are seen. The dawn chorus from Pont Croesor is a joy to behold and this cacophony of sound is welcomed by all who have stayed awake all night to protect the Ospreys at the nest site.

With so many bird species and other potential prey species in the area, it is no wonder there are so many raptors present around Pont Croesor waiting to take advantage of the abundance of prey on offer. Thirteen species of raptors and five owl species have been recorded around Pont Croesor. Most of the owls are nocturnal and will not be seen during the day although there is always a chance of seeing a day-flying Barn Owl or Short-eared Owl in winter. The Buzzard is perhaps the most commonly seen bird of prey although Peregrine Falcons, Kestrels and Sparrowhawks are seen more or less daily from the Visitor Centre. After years of being absent from the Porthmadog area, the Red Kite has now recolonised the Glaslyn. Seeing a Red Kite gliding gracefully above the Visitor Centre is one of the highlights of the day for many of our visitors, second only to seeing the Ospreys of course! In winter, the farmland and marshes around Pont Croesor are home to other birds of prey like the diminutive Merlin and the graceful Hen Harrier whilst the scarcer Marsh Harrier, Hobby and Honey Buzzard have also been noted on passage.


Over 250 bird species have been recorded within a couple of miles of the town of Porthmadog. A good percentage of these have been seen from the Osprey Visitor Centre at Pont Croesor. On any day in summer, you are likely to see up to 40 of these bird species here. From the tiny Goldcrest to the massive Mute Swan, from drab little brown jobs like the Chiffchaff to the colourful Kingfisher, from the resident and sedentary House Sparrow to the Spotted Flycatcher which migrates to South Africa at the end of each summer. You have a chance to see them all at Pont Croesor. Oh, and Ospreys as well!

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