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.

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.

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!

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...

Don't Catch the Cod: the ebb and flow of marine biology in the UK

About quarter of a century ago I was walking along the north Welsh coast when I came across an extraordinary sight: dozens of large, pink jellyfish, some a metre across, were lying stranded on the beach. I later discovered that these were Rhizostoma octopus - jellyfish despite the name and so-called because of their eight tentacles - marooned during a gathering to breed. In a country not known for unusual fauna, events like this give food for thought about the unknown creatures living just off our shores. Since fifty to eighty percent of all life resides in the sea, there's obviously a lot more out there besides cod, haddock and plaice. Another exotic but almost unknown organism that inhabits British waters is Regalecus glesne, a species of oarfish that grows up to 11 metres long and is therefore probably the longest bony fish in existence today. With more than a passing resemblance to the classic sea serpent of yore this king of herrings has rarely been seen alive, with only around fifty known strandings over the past two and a half centuries. Incidentally, this category excludes the cartilaginous basking shark, at 20 tons the second largest fish in the world and commonly to be found around the British coastline. Lucky for us, it's a filter feeder!

For a nation where it is impossible to live much more than 100 km from the sea, we appear astoundingly ignorant of our marine neighbourhood. In an early example of what has now become a cliché, pioneer environmentalist Rachel Carson pointed out in The Sea Around Us (1951), that the oceans remain the last great frontier on Earth. We are only now realising just how little we know about the role marine organisms play in everything from climate stability to food chains. Speaking of marine cuisine, a thoughtful example of changing attitudes can be found in Arthur C. Clarke's 1957 novel The Deep Range, which concerns the herding of whales for food, at least until a Buddhist leader campaigns for the slaughter to stop. Interestingly, it was the recordings of humpback whale song in the 1960s that started the anti-whaling movement, gaining popularity through the 1970s (including a UK top-forty single Don't Kill the Whale in 1978), leading to an eventual, if not outright, ban in 1986. Not that, if given half a chance, several nations wouldn't like to see 'scientific whaling' increased to the level of commercial operations...

If whaling shows the traditional viewpoint of the oceans as a limitless larder, another popular notion but somewhat at odds is to treat the sea as an ever-obliging rubbish tip. Despite the likes of Jacques Cousteau starting campaigns as early as 1960 to halt the dumping of nuclear waste from ships, it is generally recognised that the Irish Sea is one of the most radioactive in the world thanks to land-based pipelines. The rest of our coastal waters aren't much better off, being subject to pollution from oil, bilge water, sewage and nitrogen fertiliser run-off, all of which do little for the health of marine organisms. As an extreme example, in 1988 half of Britain's seal colonies were lost due to immune deficiency linked to pollution, with smaller-scale outbreaks reoccurring since.

Going back to the perception of the sea as a food store par excellence, the E.U. announced last year that over 80% of fish stocks in the region were over-fished, the classic example of the fishfinger's friend, North Atlantic cod, having reduced by over 98% in three decades. Whilst many people may not worry whether their children eat pollock/pollack or coley instead, a rapid decline in a few species could have unforeseen consequences, as with the proliferation of a rapidly expanding Humboldt squid population which is currently supplanting the dwindling number of sharks as top predator off Mexico's west coast.

But at least as important as well-known species are the minute marine organisms that will continue to require a high level of research for decades to come. Microscopic phytoplankton are responsible for at least half of all photosynthetic activity, thereby regulating atmospheric oxygen content, in addition to being the base of many food chains. Evidence is even beginning to favour the CLAW hypothesis (the 'L' being co-author James Lovelock), in which one group of phytoplankton is viewed as an essential component of the cloud condensation cycle. So what happens 'down there' may have an enormous influence of what goes on over our heads. The Gaia hypothesis (in the strictest feedback loop sense) could be alive and well, after all...

Whilst we are currently lacking the kind of public fervour seen in the 1970s anti-whaling campaigns, marine biology in the UK appears to be flourishing. There are about sixty higher education courses to chose from with an apparently good success rate in obtaining relating jobs. The subject is often taught as one of several components, including conservation and oceanography; what interests me is this way it so readily interacts with other disciplines, ranging from chemistry to meteorology, and thereby uses a wide gamut of scientific tools, from observation satellites to remotely-operated vehicles or ROVs. On that basis alone it is currently one of the most exciting areas of science in Britain, as well as being increasingly relevant to our quality of life. One scheme involving British scientists in recent years was some of the earliest research into pouring iron sulphate powder into the oceans, in an effort to stimulate plankton production (and thereby other marine life), reduce carbon dioxide, and decrease atmospheric temperature. The recent licences issued for nine new offshore wind farms around the UK will presumably provide research for marine biologists too, as current studies indicate the short-term disruption is more than compensated for by the turbines doubling as artificial reefs.

An example outside the scope of the promising Marine and Coastal Access Act 2009 but now under active consultation, is the controversial campaign to turn the Chagos archipelago in the British Indian Ocean Territory into the world's largest marine reserve. Although protection status would obviously be a positive move, the primary downside would be the permanent dispossession of the local inhabitants: such is the complexity facing sustainable development projects. Closer to home, we can't all be involved in marine conservation, but it's very easy for anyone to help preserve biodiversity - simply find an alternative to cod to go with your chips!

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