Sunday, 11 August 2013

Birds, bugs and butterflies: attracting nature to your garden

For many years I've tried to attract wildlife to my garden; perhaps there's something extremely relaxing about watching other components of the biosphere go about their business. Even the closest I lived to the heart of London, a largely overgrown garden provided a haven for all sorts of creatures from tiny wrens via boisterous squirrels to the odd, slightly mangy fox. Although I've discussed the behavioural changes seemingly present in urban animals I thought it would be worth exploring the pros and cons of attracting various critters to your garden.

As a child our family supported winter visitors, usually with bread crusts for birds and cow's milk - for some unknown reason - for hedgehogs. I've since learnt that the latter is a very poor choice as hedgehog food, so where the idea came from I don't know. Mind you, much bacon rind is probably too salty for birds, so I wonder how many animals we killed with our kindness! If you want to feed hedgehogs, cat and dog food is apparently among the suitable alternatives. Not that these days we put anything out for the hedgehogs that occasionally appear in our garden, often disappearing behind the wood pile at night when I'm out at the telescope (and startling me with their sudden snuffling). The reason isn't due to being anti-hedgehog, but the food would most likely attract other, less welcome rodents such as rats and mice.

Interestingly, hedgehogs are amongst the survivors brought to New Zealand by acclimatisation societies in the Nineteenth Century, along with many European bird species that also congregate in our garden: sparrows, blackbirds, starlings, song thrushes and various finches. As a side note, it would be interesting to tabulate these against the many imported species that didn't survive their first year in the New Zealand wild, such as robins and emus; clearly, there's some unknown adaption criteria going on here.

One problem I frequently faced in the UK but don't any more is the seemingly inexhaustible ingenuity of squirrels in getting to the content of bird feeders, as described in the post above. However, possums imported from Australia fulfil a similar, if nocturnal role in New Zealand, and are a major pest for numerous reasons. Again, keeping bird food for only birds is a primary consideration. Not that birds don't show cunning when it comes to getting at food: I remember visiting the Zealandia eco-sanctuary near Wellington many years ago and seeing the kaka bush parrot feeding from mini bins opened via foot pedal - that's the parrot's foot, not a human one.

Back to now. So why attract wild animals to your garden? Usually it's a two-way gain - humans watch the antics for minimal expenditure and the fauna get food, shelter or even a bath. It offers children a close up view of nature and the realisation that you don't have to go to zoos and wildlife parks for the experience: nature is all around us. It also introduces them to the diversity of the local biosphere as opposed to just the typical, ‘grand' fauna such as African savannah species or large sharks and rays that are kept in zoos and aquaria. To this end, the UK's Royal Society for the Protection of Birds (RSPB) organised the Big Wild Sleepout last weekend, the idea being to camp in your own garden or at an organised event in order to hear and possibly even see the nocturnal creatures we don't usually come into contact with. I only tend to be outside at night if I'm at the telescope, and must confess to frequently hearing the unmistakeable cry of the morepork, New Zealand's only native owl, but have yet to see one.

Talking of owls, birds are the obvious favourite to attract to your property, since it's easy for them to get around and escape from predators such as domestic cats. According to the RSPB over half of UK adults have fed garden birds. In recent years organisations have started to take advantage of all this previously unrecorded observational data by encouraging the public to submit sighting reports for collation. These projects range from observing familiar creatures such as butterflies and ladybirds, to tracking the growth of invasive species such as New Zealand stick insects in the UK's South West. The RSPB, which is a veteran of collecting such data, utilised a weekend in January this year for their Big Garden Birdwatch, the world's largest wildlife survey.

Following the State of Nature report released in May this year, it sounds like this sort of project hasn't come a moment too soon. The new assessment was compiled by twenty-five British wildlife organisations including the RSPB and makes for a sobering conclusion. It found that 60% of the 3,148 UK species under assessment have declined over the last half century, with slightly over 10% deemed under threat of extinction in the UK. It's impossible to know if the situation is similar in other nations, but such worrying statistics suggest that any help given by the public to aid biodiversity can only be for the better. But as per the hedgehogs and milk example, what other pitfalls are there to befriending fauna?

It is fairly widely known that common foodstuffs such as salted peanuts and desiccated coconut should not be given to birds, but how many people remember to soak white bread before putting it out so that it doesn't swell inside the animals' stomachs? Although you can buy purpose-made bird seed mixtures it is cheaper - and frequently better - if possible to grow a bird-friendly garden yourself. It depends on what species live locally, but some birds like open lawn for insect feeding, others prefer overgrown areas (the goldfinches in my garden are very keen on the latter) whilst other species prefer fruit or nectar direct from the tree or bush.

Silvereyes eating apple

It isn't just birds either: as a child I remember a buddleia bush that attracted at least four species of butterfly whilst here in New Zealand a swan plant (a type of milkweed) plays host to dozens of monarch butterfly caterpillars over the summer. In addition, praying mantises lay their egg sacks on just about any vertical surface in our garden, masonry or timber, so spring sees a profusion of baby mantises heading for undergrowth. The trick is to keep them away from the swan plant; otherwise the caterpillars tend to disappear in their early stages at the expense of the mantises...

In contrast to planting your own, commercial ready-made food mixtures may have large carbon footprints or be grown in developing nations that could better use the land and effort for growing their own food. In addition, messy eaters will cause seeds to drop onto the ground where sterilised seeds can choke native growth and the non-sterilised ones germinate: we once even had a hemp plant that grew several metres in a month or so from some spilt seed!

Therefore having plants or garden layouts that provide food for birds can be as good as leaving out scraps or purpose-bought food. I suppose the main difference with the latter two is that you can place them where you like for ease of viewing. After all, watching birds eat is the primary attraction. Although you can buy bird feeders I prefer to make my own, with a variety of success rates depending on the design. The most popular to date has proved to be table hung from a cherry tree, with half apples spiked on nails attracting a regular stream of silvereyes. Here in New Zealand you can even feed nectar eaters such as tuis via an old wine bottle containing sugar solution.

Bird nectar feeder

One important issue is when you should feed wildlife. The best time of year is obviously winter, when natural foodstuffs are least available. As a general rule, it's probably best to stop feeding once chicks arrive, so that both they and their parents don't start relying on human support. However, in addition to providing food you can also create habitats suitable for assorted wildlife from mammals to invertebrates. As a boy I made a nesting box for a Cub Scout badge, but it was never inhabited, probably being located in too low and too busy a position for birds to consider safe. Today you can buy all sorts of homes and feeders suitable for different species and climates so there's no shortage of easy options. The RSPB recently started supplying a free guide to building animal homes in your garden, ranging from bird box to hedgehog shelter. I can even claim success with my homemade weta motel (current resident: one female tree weta), although it took some time to gain any inhabitants other than numerous, small cockroaches. Note the weta legs poking out of the hole below!

Weta motel

Most of these are generally great aids to wildlife and observing wildlife, although I find the idea of building small ponds not particularly attractive since any standing water in my gardens usually attracts biting insects to lay their eggs in it. When I lived in East London any empty plant pot that collected rainwater swarmed with wriggling mosquito larvae in next to no time. Not nice!

The one thing about this sort of amateur interaction with biology is that you can do as much or little as you like as quickly or slowly as you like, but you are bound to get some form of success. Having said that, there are still plenty of species I'd like to spot in my garden. I have a large pile of volcanic stone that would look good in a far corner of the back garden as a potential lizard home; friends down the road are lucky enough to have skinks and geckos around their grounds. I'm also ever hopeful of various sections of rotting timber serving as home to peripatus -  a.k.a. velvet worm - an ancient form of life that lies somewhere between worms and arthropods. Although I've definitely seen some small white things that might just possibly be very young ones...

Tree weta