Green oases
Continuing our occasional series on habitats, Dominic Mitchell looks at parks and gardens in Britain’s towns and cities, and their importance to both birds and birders
Continuing our series on habitats, Dominic Mitchell looks at parks and gardens in Britain’s towns and cities, and their importance to birds and birders.
Population centres are often characterised as the antithesis of the natural environment: manmade wastelands of brick, concrete, tarmac and steel, layered over time into sprawling metropolitan areas and lacking authentic habitats for wildlife. But appearances can be deceiving, and the reality of urban development and its relationship to nature is much more complex.
To understand the landscapes of our towns and cities, we first need to consider the true nature of the built environment. The Office for National Statistics Built-Up Areas dataset defines the term ‘urban’ simply as any area “irreversibly urban in character” (Brownbill and Dutton 2019), but this still includes, for example, natural habitats around the periphery of urban sites, larger areas of green space in urban environments such as parks and rivers, and private gardens.
Overall, urban areas account for about 8% of the UK’s total land surface, equating to some 18,329 square km – an area 20% larger than the combined acreage of Norfolk, Suffolk, Essex and Cambridgeshire. It’s sobering to consider that such a vast part of the country is now determined to be irreversibly urban, and that metropolitan areas will only continue to expand in size.
Yet urban zones are not birdless – far from it. Every town and city has its open spaces, and within these broadly defined areas there are often fragments of more traditional habitat types, from grassland and woodland to scrub and marshes, many of them integrated into public parks. Depending on location and extent, these amenity areas can be important refuges for a surprisingly large range of bird species. Add to that the considerable habitat available in private gardens, and perhaps the outlook is not so bleak.
Natural capital
London is an excellent example of habitat diversity in Britain’s urban areas. The capital has many green spaces, from the Royal Parks – themselves varied in character – and remnants of ancient woodland to recreation grounds and city squares. Factor in private gardens, which are estimated to make up around one-fifth of Greater London by area (Woodward et al 2017), and the self-declared national park city’s 1,572 square km are surprisingly green.
This is unequivocally reflected in the birdlife. Of the impressive 370 species that have been recorded within a 20-mile radius of St Paul’s Cathedral, the great majority have occurred in the London boroughs, which between them boast an astonishing 3,000 parks (Mayor of London 2021).
One of the best-known is Hampstead Heath, located just four miles north of Buckingham Palace. Rather than heathland as its name implies, this popular site is a mixture of woodland, woodland edge, acid grassland and hedgerows, with some 30 ponds adding to habitat diversity. In many ways its avifauna typifies that of other large parks in London and elsewhere, with relatively healthy populations of a range of species.
Stock Dove, Eurasian Hobby,
Tawny Owl, Green and Great Spotted Woodpeckers, Common Kingfisher, Eurasian Nuthatch, Eurasian Treecreeper, Goldcrest and Mistle Thrush are among the resident species on the Heath, some of them easier to find there than in similar rural locations. Perhaps more surprisingly, Firecrest bred twice in the Nineties and Common Buzzard has recently taken up residence – it seems extraordinary that the latter species, not known to breed in East Anglia and the South-East as recently
as the 1988-91 national atlas, has now penetrated so far into the capital. Selective examples of what might seem ‘unusual’ park birds elsewhere in London include Little Owls breeding in multiple sites across the city and Reed Warbler colonising reedbeds far into the centre; I once even heard Cetti’s Warbler blasting out its song at Camley Street Natural Park, a stone’s throw from the Eurostar terminal at St Pancras Station. But on the debit side Lesser Spotted Woodpecker, widespread and relatively numerous in the capital’s green spaces 30 years ago, barely hangs on, Lesser Redpoll has ceased breeding and Willow Tit – the type specimens of which originated from London – no longer occurs at all.
Broadly similar species composition is likely to be found in the parks and open spaces of every town, city and conurbation across the country, nuanced to available habitats and reflective of local or national distribution patterns. There are exceptions, of course, and sometimes these are notable – like the Dartford Warblers found breeding in 2006 in Sutton Park in the West Midlands, one of the largest urban parks in Europe, or the inland colony of Northern Fulmars on Salisbury Crags in Edinburgh’s Holyrood Park, overlooking the Scottish Parliament.
Seasons of change
It is in spring and autumn, however, that birding in parks is usually most rewarding. As everywhere, migration brings not only a range of species that do not occur at other times of year, but also the possibility of scarcer visitors, and perhaps even genuinely rare species. From mid-March to mid-May, departing winter visitors and incoming summer migrants significantly boost the diversity of species and volume of birds at sites everywhere. After a lull of two months or so, return passage lasts from the second half of July potentially until early November, only this time numbers are augmented by young birds.
In terms of birding ‘experience’, the London parks that combine a mix of habitats with vantage points for watching visible migration fare best. Northern Wheatears are the vanguard in March, quickly followed by Common Chiffchaffs, Blackcaps and, less widely, Sand Martins. April is the key month in spring, and the third week (or thereabouts) the surprisingly consistent and rather narrow peak ‘window’.
I remember one such April day on Hampstead Heath, when male Common Redstart, Whinchat, Northern Wheatear and Wood Warbler all lit the place up – and this was the day after a male Pied Flycatcher had completed its four-day stop-over. At my current local patch of Alexandra Park, another notable late April day combined Ring Ouzel, Pied Flycatcher and Western Osprey. Such richly rewarding days are the exception and not the rule, but are played out in parkland patches up and down the country, every year.
A phenomenon more significant in autumn than spring is visible migration, and this is where those vantage points really come into their own. Ideal conditions for experiencing the spectacle of waves of birds passing over inevitably vary locally, and may also be impacted by prevailing weather on the coast. But with practice it should be possible to identify the optimum combination of wind direction, visibility and time of day that is most likely to produce significant visible movements of birds.
Again using the example of London’s
Alexandra Park, local birders have come to expect strong movements of thrushes, finches and other diurnal migrants in October and the first half of November, when the wind is between north and south-east, and with cloud cover to keep the birds at lower altitude. Starting at dawn or soon after, Redwings begin moving and within a couple of hours can number into four figures, along with Fieldfares in the low hundreds and Chaffinches also into three figures. Small numbers of less common migrants such as Lesser Redpoll, Eurasian Siskin and Reed Bunting are usually involved, too, and the occasional European Stonechat or Northern Wheatear might drop out of the sky to pause its journey.
Every once in a while something more unusual will pass over – perhaps a Ring Ouzel, Common Crossbill or Hawfinch – to keep observers’ interest piqued. On one memorable morning in the park in October 2020, I picked up a juvenile Common Crane drifting into view over the north London skyline.
Such occasions provide the adrenaline shot that keeps observers going back for more. Birders have turned up genuinely extraordinary finds in their local parks, like the Cory’s Shearwater over Regent’s Park, central London, on 15 September 2016, the four-day Baillon’s Crake that roosted up a drainpipe at Mowbray Park, Sunderland, in May 1989, and the Blackthroated Thrush in Bristol’s Victoria Park for two days in February 1996.
Closer to home
Notwithstanding occasional hardweather movements of wildfowl, Northern Lapwings and thrushes, winter is often a quiet time for birding in parks. In contrast, gardens come into their own in the colder months. Although more fragmented in terms of habitat, a major advantage they offer is food – just one regularly topped-up feeder is enough to keep a garden on the radar of roving tit flocks, finches and other species for weeks on end.
Residential gardens in urban areas in Britain occupy just over 5,100 square km, roughly equivalent to the size of Northumberland, and account for 29.5% of the total urban area (Brownbill and Dutton 2019). They can be important for certain species: habitat-specific density estimates derived from the BTO/JNCC/ RSPB Breeding Bird Survey suggest that 62% of the House Sparrow population, 54% of Common Starlings and 33% of Blackbirds breed within human-occupied sites (Newson et al 2005).
Gardens also act as bellwethers for a wide range of species, evidenced through trends identified by the RSPB’s Big Garden Birdwatch survey in January every year. With almost half a million people taking part, this citizen-science project has become a national institution and also underlines the importance of garden birds at a human level – all the more so in towns and cities, given that 83% of us live in urban areas.
Gardens have probably never been watched more intensively than during the past 12 months, with the pandemic necessitating long periods at home. I’ve always fed garden birds, and observing them much more at home recently has led to a better understanding of their behaviour, movements and even individual differences. Increased provision of food has also encouraged sizeable finch flocks to visit my small city garden regularly, while nocturnal sound recording in spring and autumn has shone a light on the movements of such previously unrecorded species as Eurasian Wigeon, Little Grebe, Whimbrel and Common Sandpiper.
No less important, perhaps, is the vital connection with nature that gardens and local green spaces provide, an essential benefit for mental health and wellbeing for us all. ■
Acknowledgements
Thanks to Bob Watts for comments on a draft of this article, and to Reuben Braddock for feedback on Hampstead Heath.