OUR WILDLIFE CENSUS RESULTS REVEALED

On this day that only slips into our lives once every four years, it is fitting that we should look at something truly important. The results of our second annual Wildlife Census – which we asked you, our readers, to conduct by recording the species you spotted in your garden during June 2019 – have come out and they make fascinating, if salutary, reading.

With the exception of specialised environments such as mountain and moorland or the seashore, our gardens have become the most accurate barometer of the state of the nation’s wildlife. So monitoring what is actually there has become essential if we want to know how bad – or good – things really are. Then, from that knowledge, we can take action. The really good news is that the most relevant and helpful action can be done by everybody, almost without any extra expense, in their back gardens.

So let’s take stock. The survey looks at 58 creatures, from mammals such as weasels, foxes, hedgehogs and bank voles to all the common garden birds, as well as reptiles, insects, butterflies and, for the first time, earthworms. Good news on the latter, by the way – 77 per cent of respondents recorded seeing earthworms in their gardens and, as regular readers of my column will know, earthworms are one of the gardener’s greatest friends as they mean your soil is good and, as a result of their work, will get even better.

Other positive news is that ladybird and green shield bug sightings are appreciably up – but I’m afraid that’s about it. There are 16 other creatures, including lacewings, goldfinches, bumblebees, starlings and pipistrelle bats, that are up – but all by low, single-figure percentages on 2018’s results.

The most common birds are, not surprisingly, blackbirds, robins, blue tits and house sparrows, with the vast majority of people reporting their presence in their garden. These are essentially woodland birds that have adapted incredibly well to gardens, and long may that last. It surprised me to discover that until the end of the 18th century blackbirds were usually only to be seen in woodland, where they were quite shy, but the huge increase in suburban and urban gardens in the 19th century provided them with the perfect home, and they have increased accordingly.

The really important measure of a healthy wildlife population, however, is not so much the success of any one species but the number of different species that you share your garden with. We could lose half of the British population of blackbirds – which would be an appalling disaster – but there would still be a lot left. Lose half of our grass snakes or lime hawk-moths, though, and it would be a catastrophe from which they may never recover. In other words, it is those things that you do not see much that are the most precious.

In some cases it is an amber warning, where individual species are showing an alarming rate of decline. Wren and mistle thrush sightings are down by 5 per cent, which is a significant decrease in one year. Small white butterflies are down by a really serious 13 per cent. The small white is one of the most common butterflies in the UK, which masks that kind of decline because there are still an awful lot around. But any negative trend, from however healthy a base, is a warning sign because suddenly you can reach a tipping point – when the numbers get so low that the position becomes very hard to reverse.

This is now the case with hedgehogs, which have seen a catastrophic decline over the past 30 years. They have almost disappeared from farmland, with gardens becoming their last sanctuary. The good news is that more than a quarter (28 per cent) of the nearly 8,000 people who took part in the survey saw a hedgehog in their garden last year and numbers are holding steady.

But it is well worth analysing why some people had hedgehogs in their gardens and not others – allowing for the fact that, as with all the species involved, especially nocturnal ones like hedgehogs, there will be a significant number that are not noticed at all.

The survey reports that of the people who saw a hedgehog, 89 per cent have a tree and 83 per cent have a hole in their fence that allows hedgehogs to move from garden to garden. Finally, 55 per cent of sightings were by people who used no chemicals in their garden. The analysis of this is that trees and hedges are vitally important for the whole food chain – along with long grass and ponds and a certain amount of untidiness that not only provides cover for small mammals like hedgehogs, but also encourages insects, which are an essential part of their diet. We know that hedgehogs have territories that span a number of gardens, and that holes in fences for them to get through are essential. We also know that using slug pellets is actively harmful. The irony is that hedgehogs are poisoned by the pellets after eating the slugs, not the pellets. So by not using slug pellets, you not only save the hedgehog but also allow it to eat up your slugs.

There is a wider lesson to be taken from the hedgehog example. The fact that 55 per cent of respondents who spotted a hedgehog did not use chemicals is good. But the other 45 per cent did – which is really bad for wildlife and utterly unnecessary and counterproductive for gardens. It maintains a vicious cycle of boom and bust in your gar

den, and means just plain bust for insects, birds and mammals. Healthy plants will resist most problems, be they from pests or disease, and a healthy garden with lots of assorted wildlife is extremely good at healing itself. I have not used any kind of chemical in my garden for more than 25 years and it has not turned out too badly.

The ‘pest’ that is eating your broad beans or roses will certainly be food for a predator, which may in turn be predated on by something else. Unless you understand the whole food chain, from the smallest sub-microscopic organism in the soil to the apex predators such as sparrowhawks, owls and badgers, focusing on any one part of it is a meaningless and harmful waste of time.

However, the sad truth is that the survey shows a number of steady declines that are not attributable to any particular gardener or garden practice but just to the trends of modern life. One of the saddest is the spectacular decline of swifts. Only 27 per cent of people in urban

and suburban areas reported seeing these lovely summer visitors last June, and only 33 per cent of people living in the country. I have certainly noticed a dramatic reduction in the skies above my garden over the past 20 years.

Nothing you can do in your garden this year is going to immediately take the number of swifts back to the levels of 20 years ago. But we can work together both to start to reverse the decline and also to stop other species suffering the same loss. There are a number of easy actions that will make a real difference in both the long and short term, as well as making your garden

even more beautiful and enjoyable for yourself (see above).

The results of the survey show that people with the most different features in their garden have the most wildlife. Trees, hedges, long grass, wildflowers, ponds, decaying wood, piles of leaves – there are lots of ways to support wildlife but variety is very important. In fact, if you have nine wildlife features in your garden you’re likely to see twice as many species than if you have just one. And remember it’s the number of species that counts, not the numbers of any single species.

OVERLEAF THE RESULTS OF OUR CENSUS AT A GLANCE

Hedgehogs are holding their own but small white butterflies are in decline