What wildlife can be found in Devon's river estuaries?

Winter visitors love the food offerings provided by our estuaries

During the year I have been looking at wildlife habitats in the county and as part of this series I have discussed the wildlife of upland and lowland rivers, this month I take the river to its conclusion at the estuary.

In Devon we have the full range of estuary sizes from the compact Rivers Otter and Axe to the expansive flat reaches of mud at the mouths of our big rivers such as the Exe and Tamar on the south coast and the Torridge/Taw on the north coast. Some of our estuaries are examples of rias, or flooded river valleys. Dartmouth and Kingsbridge are two good examples, here we have steep sided valleys leading down to the estuaries and trees dipping their leaves into the salty water at high tide.

Redshank. (Image: David Chapman) The reason why birds love estuaries is that the mud contains a higher calorific value of food than any other substrate on earth. There are plenty of tiny crustacea as well as various worms and other invertebrates.

Birds which breed in colder parts of the world head to Devon in autumn to take advantage of this rich food supply and our mild climate; for this reason winter is the peak time for bird numbers but autumn is a good time to see a greater variety of species because this is when they are migrating, and we invariably get some visitors which won’t stay for long. Identifying waders can be daunting but it’s a good idea to start with the obvious ones.

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Oystercatcher

Oystercatcher (Image: David Chapman) Of the large waders we have curlews, brown birds with down-curving bills and oystercatchers which are black and white with bright red bills. Slightly smaller we have two waders with long straight bills, they are black-tailed and bar-tailed godwits. Smaller again we have redshanks and greenshanks, named because of their leg colour, with medium length, straight bills. It’s only really when we get onto the small waders that things start to get tricky but just take it one at a time.

Sandpiper (Image: David Chapman) One small wader to look out for in September is the common sandpiper, a bird which breeds on upland rivers in the north of the UK and migrates to Africa for winter. It’s an easy one to identify because it habitually bobs its tail. Another bird which is currently winging its way to Africa, and which might be seen around our estuaries is the osprey. Owing to conservation efforts to reintroduce this bird to various parts of the UK we are increasingly likely to come across one of these amazing fish-catching birds of prey in Devon at this time of year.