Many of us have a fairly fixed idea of what bird migration means – some species come in from a long way away, some species go out to far-flung climes, others stay put. Most commonly, we might think of swifts and swallows – those long-distance specialists who herald the start of summer. But is it really that simple? Perhaps not.

Traditional spring migration is a big deal. Birds such as cuckoos, swifts, swallows, house martins, come here to breed in the spring, stay through the summer, then leave in late summer or early autumn. At the same time, birds that have been here through winter are leaving for their own breeding grounds. The Humber Estuary hosts more than 100,000 wintering waders and wildfowl through the cold months. At this time of year, many of those are heading north to their own preferred breeding grounds in Iceland or above.

But not all movement is inter-continental – migration also happens within the UK itself. Those of us lucky enough to have birds visiting our garden may think that the bird we see year-round is ‘ours’ – the same bird every time. It certainly can be – but some British ‘resident’ birds move south in winter, leaving Yorkshire for the sunnier climes of, say, Cornwall.

Some birds migrate over an even shorter distance. Birds such as curlew stay in the UK year-round, but still have their own mini-migration moving from upland breeding sites to winter estuarine feeding spots. This can – and does – happen without the bird ever leaving Yorkshire.

So why do birds go to all this effort? Essentially, migration is a bird trying to get the best of all worlds; maximising their feeding opportunities, breeding where there is a good suitable food supply, such as flying insects for swifts, and then moving elsewhere before that food supply dwindles.

It’s a high-stakes gamble, and a strive for balance - there may be nearly two months between the first wheatear and the first spotted flycatcher coming into the country. Birds such as blue tits that stay here year-round, and the earliest migrants like warblers such as chiffchaff, whitethroat and blackcap, aim to get a jump start on the breeding season by being here nice and early so their first brood is hatching just as the first flying insects and caterpillars are emerging. Some of these earliest migrants have even ceased to become migrants at all, with blackcaps rapidly becoming commonly-spotted garden birds.

Unfortunately, the early bird does not always get the worm – and climate change has a big role to play in that. Migration is something our birds have evolved to do over millions of years, and is strongly affected by temperature and available food resources. Many birds leave their winter feeding grounds because the temperatures are too hot for their chicks – but an extra-cold winter or a wet summer the year before means that birds who arrive early in the season may not get the food they rely on in time. Some birds may not even make it here at all – cuckoos that migrate across Spain to and from the African continent are struggling with increased drought and reduced food sources to refuel en-route. 

Whether a bird travels thousands of miles or just tens of miles, they face immense challenges that we know are growing worse every year. It is important we create as much space for our birds as possible – space with abundant native wild food sources – and we are honoured to care for over 100 nature reserves across the county that aim to provide this safe haven space.