from The Guardian, UK edition, Amy Fleming

Now is the perfect time to boost the biodiversity of any outside space you have – whether by buying your cat a bell or ditching the insecticides.

With humans – and our polluting, road-killing, noisy machines – largely out of the way, nature is having a big party. This is one of the few positives of lockdown to which we can cling, witness and even encourage. “The land taken up by gardens in the UK is greater than the area of all our national nature reserves,” says Mark Fellowes, a professor of ecology at the University of Reading who specialises in interactions between humans and wildlife, as well as urban ecology. Everyone with outside space, he says, “can become a nature reserve manager. You can do really simple things to affect biodiversity where you live.”

These days, even the most lackadaisical gardeners are taking a greater interest in whatever outside space they have, not least because panic food-buying seems to have segued into panic food-planting. Grow bags have become hard to come by and the Royal Horticultural Society (RHS) has reported increased inquiries about growing fruit and vegetables.

But whether or not people are growing new things, terraces, balconies and gardens are receiving unprecedented levels of attention this spring. If we employ a few biodiversity-boosting tricks, we can keep the nature party in our backyards going for good.

Feed the birds, not the squirrels

The British Trust for Ornithology says that Britons spend between £200m and £300m a year on bird-feeding products. “Half of households at some point feed birds in their garden,” says Fellowes. It’s one of the key ways we can commune with nature, and during cold winters it can help birds survive.” But during the breeding season, roughly March to June, putting food out can attract nest predators, too. “Squirrels and magpies are the two most common,” says Fellowes. In one of his studies, more than 44% of feeders were visited by squirrels.

As such, investing in a pest-proof feeder is important. Fellowes recommends those that close if a squirrel, or anything heavier than a small bird, lands on them. This does not mean bird tables should be banned, but Fellowes recommends “putting small volumes out regularly, clearing it up and putting out food the squirrels don’t like”. Goldfinches love niger seed, for example, which squirrels eschew.

Keep feeders clean

“Disease can spread through feeders every now and again,” says Fellowes. “Our greenfinch population was badly affected by trichomonosis that was probably spread via bird feeders. It’s not definite, but all the circumstantial evidence points in that direction.”

Install nest boxes and bricks

When people get nest boxes, says Fellowes, “they get very keen and they can put cameras in the boxes. It’s fantastic: nature on your doorstep that you can really connect with.”Advertisement

Birds such as blue tits and great tits would naturally nest in nooks and crannies in woodland trees, so boxes are important in cities, especially if you live in a modern development. Fellowes recommends WoodStone, brick or woodcrete boxes. Not only will they last longer, he says, but also, “if you have wooden nest boxes, woodpeckers can raid them and predate the chicks”. Of course, this would happen in the wild, too, but it is a bit of a buzzkill if you are enjoying the chicks.

Fellowes suggests trying boxes for a variety of birds: “You can get nice ones for robins, nuthatches and sparrows, which haven’t been doing brilliantly – a lot of that seems to be around losing nesting sites.” You can buy swift boxes, too, and even bricks made specifically for swifts or bats, if they are in your area (they tend to be near water in urban zones). Nest boxes need to be cleaned out at the end of the year. “As fantastic as it is to watch leopards in South Africa or cheetahs in the Serengeti, that’s not our nature,” says Fellowes. “The nature on your doorstep is just as interesting and worthy of attention.”

Resist insecticides

Birds can’t feed their chicks the seed you put out. Chicks need bugs, so it is not a good idea to kill them. “Urban birds tend to have fewer offspring than ones in the countryside,” says Fellowes. “That’s probably to do with the amount of insects that are available to feed on in the breeding season.”

Unless you are competing in the Chelsea flower show, he says, “your garden can deal with a few aphids. And if you allow natural insect populations to grow, you will attract ladybirds, which eat aphids and have crashed in numbers.”

Plant for invertebrates

We, and the cute animals we love, cannot survive without insects. And invertebrates, from bumblebees to butterflies, can be awesome in themselves. “They will do much better if you have a range of plants,” says Fellowes. “Ideally, a good mix of native species, because our insects are more likely to feed on those.” Plants with flowers that need to be pollinated are essential for bees, hoverflies, moths and butterflies; try to ensure that something is flowering in each season. The RHS’s website offers guidance. “The traditional English cottage garden is an absolute haven for insects,” says Fellowes. “You can’t go wrong with things like foxgloves and hollyhocks.”

Plant caterpillar food, too

You can’t have butterflies and moths without caterpillars. “As we have simplified and tidied our gardens, we have provided fewer plants that the caterpillars can do well on,” says Fellowes. “Some of the most beautiful species feed on nettles and brambles, and most people won’t want those in their gardens. At this time of year, holly blues are laying their eggs on holly.” They feed on ivy, too. So let a little corner of your space stay wild.

Fellowes suspects that, if you have room, this is the biggest thing you can do for insects – “and all biodiversity in your garden. Ponds across the UK have been disappearing at a massive rate.” They are vital for swallows and swifts, as well as amphibians such as frogs, toads and newts and insects including dragonflies, damselflies and water boatmen. Size is not important. Mini ponds can be made in a bucket, an old sink or something similar. The Royal Society for the Protection of Birds’ website explains how to make one.

Plant a tapestry lawn

Lionel Smith, a colleague (and former PhD student) of Fellowes, has spent years developing a nature-lover’s alternative to a lawn. “Lawns are really not very ecologically friendly,” says Fellowes. “Not much lives in them and, if you fertilise, mow and water them, they’re a net CO₂ contributor, rather than a typical plant that helps absorb CO₂.”

Smith’s idea – the tapestry lawn – was to plant squares of different hardy, perennial flowering plants. “They knit together and you end up with this wonderful lawn that you can walk on, lie on and enjoy,” says Fellowes. “It is full of flowers and is absolutely fantastic for insects – and it doesn’t grow more than about six inches high.”

Embrace weeds

Covering up the spaces between neatly arranged ornamental plants with bark chippings is not great for biodiversity, says Fellowes. If you want to control what plants grow in your beds, it is healthier to grow your chosen plants more densely together – another reason the cottage garden explodes with nature. Perhaps you won’t balk when a dandelion pops up when you know that pollinating insects love them.Advertisement

“I would never suggest anybody must follow my unkempt way of gardening,” says Fellowes. “But if you’re a neat freak, think about how you can get your aesthetics while using species that will also benefit wildlife. Anything positive you do will have an effect. You don’t have to let your garden turn into a jungle.”

Don’t poison slugs

“I absolutely wouldn’t use pellets or the powders that you can put out to kill slugs, simply because hedgehogs can eat them and be poisoned,” says Fellowes. The old beer-trap method is a more responsible way to kill slugs. There are endangered species of slugs, says Fellowes, “but you won’t be getting those in your garden”.

Slugs are excellent food for hedgehogs, amphibians, beetles and birds, so you may consider them worth having in that respect. There are humane traps, too, so you could relocate your slimy garden chompers to somewhere they will be more welcome.

Get your cat a bell

Fellowes is always doing research on cats. A few years back, Fellowes’ team calculated that domestic cats in the UK were killing about 185m prey items a year. “About a million birds a week,” he says. The International Union for the Conservation of Nature says that domestic cats rank third globally among alien species threatening vertebrates.

It is hard to know whether they are currently contributing to species decline in the UK; they may have done their worst long ago. Either way, they are certainly killing a lot of animals and not even eating them. (If you think your cat is an exception, be aware that studies have found that cats bring home only about 20% to 30% of their prey.)

Keeping cats indoors as much as possible is recommended, especially at peak hunting times (dawn and dusk) and if you live near a nature reserve. Also, putting warning bells on collars, says Fellowes, “certainly reduces predation rates”.

Dump them on a compost heap, or just leave them in piles to rot down, and make a home for small mammals, amphibians and invertebrates such as centipedes – “just like in natural woodland”, says Fellowes. They could take months to break down, so you have to think carefully about where to leave them.

Similarly, leaving a little pile of chopped wood will attract stag beetles and solitary bees. Alternatively, you can buy homes for the bees from garden centres. “They’re at their peak at this time of year,” says Fellowes. The homes “attract leaf-cutter bees, which are really cool to watch”. Slow worms love compost heaps, too, and one of Fellowes’ few sightings of a grass snake was in his own suburban compost heap.

The thing to avoid in all of this, says Fellowes, is becoming judgmental. Decking, for instance, may not be the best thing for nature, but if you need it for practical reasons you can still invite nature in with bird boxes and thoughtful planting. “These are things that we can all do,” he says.

30-Second Zoology by Mark Fellowes is published by Ivy Press. To order a copy for £13.04 (RRP £14.99), go to guardianbookshop.com or call 0330 333 6846. Free UK P&P over £15, online orders only. Phone orders, minimum P&P of £1.99.

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