With colder nights, shorter days, a myriad of colour and falling leaves, this transitionary season sees lots of too’ing and fro’ing amongst our bird populations too. With so much activity, it’s a time for bird watchers and those interested in our natural world to revel in. Read on to find out who is taking to the skies!

So, why do birds migrate? Most birds are able to withstand freezing temperatures but winter means that food resources become scarcer. A change of location can resolve that. Birds head south towards warmer regions because they will find an abundance of insects, plants and other food sources for the winter. In spring, they’ll migrate back to their nesting areas.

Outbound

Did you know that nearly half of the birds native to the UK fly towards sunnier shores over winter? Some species migrate to Southern Europe and Africa, examples of which include, Hobby, Willow Warbler, Chiffchaff and Blackcap. Some species will have bred here – the Whitethroat for one, whilst others will be passing through the region from their breeding grounds further north. Whilst they make their journeys, some species will be doing a recce for potential nesting and breeding sites – etching them in their memories for their return. Here, at the Trust, we’re hopeful that an adolescent Osprey might see the new nest that is soon to be rebuilt at Stocker’s Lake, as it migrates to North Africa – wouldn’t that be a wonderful addition to have on the Hertfordshire and Middlesex border!

Inbound

Whilst the UK temperatures might not suit many of our native species, over winter it’s milder temperatures can be very appealing for birds, who breed in the likes of Scandinavia and Russia over summer. Water bird species such as Shoveler, Pochard, Gadwall, Wigeon, Water Rail, Common Snipe all arrive from these colder climates to spend the winter here, along with fruit-loving Fieldfare, and Redwing. You will find many winter visitors seeking refuge in our nature reserves, with wetland sites becoming an exciting hive of activity.

How is climate change affecting migration?

Wildlife is a wonderful barometer so it’s not surprising to see that with warming temperatures, climate change is impacting on the behavioural patterns and schedules of migrating birds. Winters are less severe here and, on the continent, meaning that we’re getting fewer of the migrating wetland birds heading over to us. This is called ‘short stopping’ – there’s no need for the birds to head as far as us if conditions are mild on the continent. Temperatures and the availability of food are the key drivers but rising sea levels are also changing the migration of many species. In our region, we are seeing some birds more frequently as temperatures rise and they head further north in the UK – the Cattle Egret is one such example.

Top five destinations for winter visitors in Hertfordshire and Middlesex

• Broadwater Lake and Stocker’s Lake – We’ve gone for two of our nature reserves here – the reason being that that these are the two key refuges for nationally significant populations of water birds in the Colne Valley, including Shoveler and Pochard. The Mid-Colne Valley Site of Special Scientific Interest (SSSI) encompasses the Trust’s Broadwater Lake Nature Reserve, which includes Korda Lake, Long Pond, the River Colne and the western side of Broadwater Lake. To its north Stocker’s Lake, a nature reserve, managed in partnership with its owners, Affinity Water, provides another indispensable refuge for wintering birds. With plentiful food and undisturbed refuges, the valley is extremely attractive to a diverse range of aquatic birds and together, these two sites enable them to exploit other waters across a much wider area to which they can retreat when there is disturbance elsewhere.

• Amwell Nature Reserve – Like the above, Amwell was once a gravel pit but nowadays it is a haven for wildlife with a great variety of habitats and good connections to other nature reserves and habitats along the River Lea. Great Hardmead Lake plays hosts to many winter visitors and with a great viewpoint it makes for excellent serious bird watching or more casual observation. As well as Gadwall and Shovelers, you might be treated to the rare sight of a Smew. Visit in the evening and one thing you are sure to witness is the spectacle of the many wintering gulls that come to the lake in significant numbers. Not just a visual treat but an auditory one too – listen to the screeches, cries and cawing of Black-headed Gulls and Lesser Black-backed Gulls as they reacquaint after a day of foraging far and wide.

• King’s Meads Nature Reserve – as one of the largest water meadows in Hertfordshire, and crossed by various waterways, King’s Meads is a haven for autumn and winter visiting birds. Little Egrets stand out with their snow-white plumage, flocks of Lapwing and wading birds drop by on migration, feeding up in the pools and ditches for their long journeys ahead. As we head into winter, the reserve sees an influx of wildfowl including, Shoveler, Pochard, Wigeon, Tufted Duck and Gadwall. King’s Meads’ pools and ditches also provide winter feeding for Common Snipe. 

• Tring Reservoirs Nature Reserve – also an SSSI, collectively the four reservoirs which make up Tring Reservoirs - Startop's End, Marsworth, Tringford and Wilstone, owned by Canal and Rivers Trust and managed by HMWT as a nature reserve - are one of the best birdwatching sites in southern England. During the colder months, you can find a large number of wintering wildfowl across all four reservoirs, including Tufted Duck, Pochard, Teal, Gadwall, Wigeon and Shoveler with occasional Goldeneye, Goosander and Smew if it gets very cold.

• Lemsford Springs Nature Reserve – this reserve is pretty unique with its spring-fed watercress bed, which is a hugely valuable habitat for aquatic birds, as it does not freeze – even when the temperatures really drop. Along with that, due to targeted habitat management there’s the plentiful supply of freshwater shrimp in the undisturbed lagoons, which means there’s always an abundant food source whatever the weather. Winter 2022/23 was a bumper year for bird watchers visiting the reserve – with up to three Jack Snipe regularly seen, alongside Common Snipe and up to 14 Green Sandpipers.  The reserve’s hides provide great vantage points to watch all the action, as well as protection from the elements!

We hope this blog inspire you to get out and take a look at what’s happening on our nature reserves, in your local wild spaces, or indeed in the skies above your home. Thinking about the journeys some of these birds take is nothing short of miraculous and well worthy of a few minutes of quiet contemplation.