Baby boom

As RSPB members may have already read, we’re in the midst of a ‘baby boom’! As we head towards summer, keep your eye out for more and more youngsters learning to take to the wing for the first time. Mike Unwin, nature writer and enthusiast recently wrote an article for our members exclusive magazine Nature’s Home. We thought it was too good, and too cute, not to share a snapshot of Mike’s words on natures nursery season and our youngsters’ perilous and exhilarating worlds. 

There’s no ignoring it. Scruffy, squawking and squatting on the pavement: a baby herring gull. Its parents’ piercing cries ring out overhead. What happens now?  

If, like me, you live in a seaside town, this scenario may be familiar. From late June, these unkempt urchins appear in force, waddling over roofs and sometimes crash-landing among us. And it’s not only baby gulls. Youngsters of many species are making their first inept sorties into our world, from starlings on the patio to fluffy ducklings on the park pond. Faced with such apparent helplessness, it is tempting to get involved. But before we interfere, we need to understand what’s happening.  

Herring gull chick – Mike Bowler (rspb-images.com) 

Baby steps 

The process through which a bird leaves the nest is called fledging – thus, a juvenile that has recently left is known as a fledgling. Most fledglings are barely smaller than their parents, but are easy to distinguish by their scruffy plumage, stubby wings and tail, and dull colours. It is also clear from their begging and fluttering behaviour that these youngsters are still far from the finished article.  

For many fledglings, it takes a day or so after leaving the nest before their flight feathers are developed enough for their first, wobbly flight. For some, flying is a prerequisite for leaving. Blue tit fledglings usually have a predator-deterring sheer drop outside their nest hole so must be able to flutter to the nearest branch. Before they leave, they’ve been flapping their tiny wings to build up strength. When the moment comes, typically early in the morning, they flutter out one by one to take their chances. 

Bringing up baby 

The speed of the fledging process is impressive. When the chicks hatched two or three weeks earlier, they were blind, naked, and wholly reliant upon their parents – typically, the female keeping them warm while the male brought in food. They grew quickly, soon opening their eyes and acquiring their fluffy ‘natal down’. By the time they were big enough to leave, staying behind was no longer an option. The nest had become too cramped, smelly and parasite-infested. Besides, their exhausted parents wanted them out: they had stopped the food parcels and were calling to them enticingly from outside the nest.  

This development strategy – remaining in the nest from naked hatchling to feathered fledgling – is typical of many bird groups, including songbirds, pigeons and raptors. Such species are termed ‘altricial’. Others, however, take a different approach. Wildfowl, gamebirds, waders and other ground-nesters are termed ‘precocial’ birds. Their chicks hatch with eyes open and a covering of camouflage down, ready to rumble and raring to go. In some species the chicks will be out of the nest, running or swimming behind their parents within 24 hours of hatching.  They are still vulnerable, and it will be another two weeks or so before they can fly or stay warm by themselves.   

Female mallard duck with ducklings – David Kjaer (rspb-images.com) 

Parent priorities 

For parents, fledglings are the fruit of labours that started months earlier, with courtship. Now they have their work cut out looking after their brood. Some species, such as lapwings, defend them aggressively, dive-bombing intruders. Others, such as peregrine falcons, teach them to hunt – bringing back prey for practice. Post-fledging parental care lasts from just a few days in starlings to more than a year in eagles. The male/female division of labour also varies: in most songbirds, a pair shares the load; in ducks, the male disappears when the eggs are laid; in waders, the female departs soon after the eggs hatch, leaving the male to take over.  

Different birds expend their breeding energies in different ways. Most songbirds invest heavily in egg production: they produce large clutches but spend less time on childcare. For them, it’s all about quantity: they flood the market with offspring, hoping that some will make it through. Other species, including raptors and seabirds, produce fewer eggs but devote more care to the hatchlings. For these species, it’s about quality: fewer fledge but the survival chances of each is greater.  

Life outside the nest 

Fledglings must learn fast. Most soon move away from their nest and lie low. Danger lurks everywhere, including from raptors, such as sparrowhawks, with their own brood to feed. The youngsters’ priority is to build up strength before the weather changes. Come autumn, migrants such as swallows face a long, hazardous journey south, while resident species such as great tits must prepare to survive a harsh winter. This is binge-feeding time: late summer’s bonanza of berries and insects is vital for building up the fat reserves they’ll need to survive. 

By autumn, fledgling songbirds will have completed their first moult, replacing their juvenile body feathers with a new set (though retaining wing and tail feathers until the following year). In this new ‘immature’ plumage they look more like adults but still lack tell-tale markings: immature bullfinches, for example, have no black crown; young goldfinches have no red face. Only in their next moult do they acquire full adult finery. Slow-maturing species, such as gulls, get through four or five years of plumage changes before they finally reach breeding maturity. 

Not all immature birds go it alone. Youngsters of some species, such as crows and gulls, form winter flocks: adolescents learning the ropes together. Others stay with their families: young geese migrate in family groups, learning the route from their parents, while a few species, from long-tailed tits to moorhens, stick around until the new year as ‘helpers’, assisting their parents in raising the next brood. 

Swallow fledgling soon out of the nest – Tom Marshall (rspb-images.com) 

A helping hand? 

So, back to that squawking herring gull chick. With luck, it will survive. After all, it can already fly (sort of) and its parents are on hand. But we must also accept that it may not. Even if it gets through the early days, winter is just around the corner. Food is harder to find for a novice, while storms and accidents take a toll. In the majority of birds, most fledglings don’t survive their first year. Even in species as resourceful as a magpie, fewer than 35% make it.  

To us, this may seem brutal. But – to risk a cliché – it is nature’s way. Loss is built into the system. Birds’ breeding strategies have evolved over millennia. Thus, while the fate of an individual youngster may tug at our heartstrings, our intervention (however well-intentioned) would generally only skew the natural balance.  

In recent decades, however, even house sparrows have been unable to hold their population steady. Where we must help is by taking better care of the world into which these youngsters fledge. Environmental damage is the main cause of breeding failure in many UK species. Studies have revealed how, for example, modern farming reduces critical food supplies at key times, from weed seeds for turtle doves to aerial insects for swifts.  

Climate change, meanwhile, disrupts weather to deadly effect. Excessive rain means house martins cannot capture enough flying insects to feed their chicks, while drought causes their mud nests to crumble. If we really want to help baby birds, we need to start living more sustainably. And here there are plenty of ways in which we all can – and must – get involved.  

So, be on the lookout for these fuzzy youngsters as they learn the ropes. It can be tough heading out into the big wide world, especially when all you’ve seen is the inside of a nest box, hedgerow or cliff nook. For some birds it doesn’t always go to plan. We’ve put together some top tips of what to do if you do find a baby bird hopping around on the ground with no parent in sight. 

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