Why do birds migrate each year, what paths do they take and what opportunities exist in our county to catch magnificent birds in flight as part of their astounding and long journeys? Paul is on hand to answer all these questions.

One of the most exciting aspects of wildlife watching in Derbyshire is witnessing the response of our birds to the changing seasons.

Naturalists have always been fascinated by the arrival and departure of birds in spring and autumn, though in the past they struggled to understand what was actually happening.

For a long time, many people thought that birds, like hedgehogs and bats, hibernated, though they never actually found any evidence of birds sleeping through the winter.

The sight of tree creepers huddling together on long, cold nights during winter and birds flying down chimneys and into caves made some people think they were going to hibernate.

Today we know that birds migrate (over 4,000 species do so to some extent), and this can be an incredibly complex and hazardous experience.

To celebrate this marvel of the natural world two days have been designated as World Migratory Bird Days in 2023, May 13 and again this month - October 14.

There are a number of events planned but the main focus for the majority of birders is to spend an hour or two on the 14th to reflect just what migration means to them and to consider what birds have to endure in the modern world as they fly, in some cases incredibly long distances, to their winter home.

In Britain approximately 50% of all our birds migrate, which means that around half the birds we see in Derbyshire in the summer have disappeared and been replaced by a new set of birds in winter.

Great British Life: Geese migrating across Derbyshire Photo: Paul HobsonGeese migrating across Derbyshire Photo: Paul Hobson

This may seem odd. Why do some birds leave us to fly south to find food whilst others join us for the winter to do exactly the same thing?

The main reason for migration is to find food, and different birds feed on different things.

A host of birds – such as warblers, cuckoos, nightjars and pied fly catchers - join us for the summer and they all feed on insects which are found in abundance at that time of year.

However, as autumn creeps in, these birds start to feel fidgety, a phenomenon we term Zugunruhe, migratory restlessness, which is caused by a hormonal change which occurs in their bodies.

As the summer migrants start itching to get away, the same is happening with birds which breed much further north, such as whooper and Bewick's swans as well as a host of duck and geese species.

These birds are vegetarians so the relatively mild British winter where open water and grassy fields hardly ever freeze provide ideal feeding habitats, and as we expand our wetland areas such as at Carsington, Willington and Williamthorpe we should be able to capitalise on attracting these winter visitors to stay in the county.

Great British Life: Geese migrating across Derbyshire Photo: Paul HobsonGeese migrating across Derbyshire Photo: Paul Hobson

However, you don't have to visit these amazing local places to see the winter geese and swans because their V shaped skeins regularly fly across Derbyshire and the Peak District and they are not difficult to spot.

Migration is far more complex than the simple changeover of birds going south in autumn however and there is an east-west migration that also takes place, particularly with our blackbirds.

When we watch and listen to the blackbirds in our gardens during the spring and summer many of us don't realise that the birds that chase each other through the winter are new arrivals from icy eastern Europe.

There is another type of movement, altitudinal migration, which those of us who walk the moors experience when we mourn the loss of curlews and meadow pipits during the late summer and autumn. These birds are travelling down to the warmer lowlands and, in the case of many curlews and redshanks, to the coast.

One of the more reassuring aspects that wildlife exhibits is its incredible adaptability. Migration, in a few limited cases, demonstrates this as some birds change the habit of generations.

In our gardens blackcaps can now be present all winter but these are not our summer birds, they have already flown south.

Great British Life: Male blackcap in winter feeding on fruit cake Photo: Paul HobsonMale blackcap in winter feeding on fruit cake Photo: Paul Hobson

They are a small population of blackcaps from southern Germany which migrate north to Britain. One theory is that they are responding to the increase in garden bird food that has occurred over the last few decades as more people feed birds in the winter. Whether this is a good thing or not is open to debate.

When birds migrate long distances they have established flight paths. Bird watchers call these flyways and our birds navigate along the African-Eurasian flyway.

The speed that some of them hurtle down their specific flight path can be truly jaw-dropping and some birds will fly huge distances without even stopping.

However, most of them do have regular pit stops to refuel and take a well-earned break and one of the main aims of October's World Migratory Bird Day is to highlight the crisis that is happening at many of these crucial stopovers.

Great British Life: Osprey on migration Photo: Paul HobsonOsprey on migration Photo: Paul Hobson

In some areas drainage has reduced, or even destroyed, wetland sites which are so important for ospreys, and an increase in agriculture has removed vital habitats. The problems of our summer migrants is truly a global one.

Hopefully, many people will spend an hour or so this month contemplating the problems and marvels of our local birds' departures and arrivals.

Our farms will be losing their swallows and martins. The urban swifts, the first migrants to leave us, will have already gone.

Our woods will have already lost their warblers and flycatchers and the winter thrushes, such as redwings and fieldfares, will be steadily replacing them.

The uplands will now be much quieter without their ring ouzels and curlews but, on the flipside, the wetlands will be rich with winter ducks.

There may not be much that you think you can do to help birds during their migration but we can all do a little.

Possibly the most important thing to do would be to join a local wildlife group or the RSPB who, on your behalf, can lobby, campaign and take part in global wildlife events to protect the threatened pit stops during migration which will have a positive impact in the future.

You can find out more about World Migratory Bird Day at worldmigratorybirdday.org.

Great British Life: Curlew in flight Photo: Paul HobsonCurlew in flight Photo: Paul Hobson