A Human World

It's very noticeable when we walk in the woods that surround Golspie that, the closer we come to buildings where people live, the greater the level and variety of bird song, so it wasn't with any surprise that I read in a recent New Scientist that New York contains more species than Yosemite National Park and that Australian cities shelter more endangered species per square kilometre than non-urban areas. It's partly that many inhabitants of our built environment like seeing wildlife in their midst so encourage them, and partly because some species of wildlife, whether we like them or not, have learned to exploit an opportunity - foxes are an example - and so fare far better in inclement weather.

Our garden is probably a good example of the consequences of what's happening. We put out seeds, peanuts and fat throughout the year with the result that those species which are prepared to risk close encounters with the resident humans benefit the most. In our case this is three species of tit, house sparrows, chaffinches, dunnocks, blackbirds and jackdaws. Of these, the one which has done best must be the blue tit, of which we can have upwards of half-a-dozen on the feeders at any one time.

Birds that are less confident about risking proximity with humans therefore suffer so, for example, song thrushes are losing out to blackbirds. As a result, humans are influencing the balance of species in and around their habitation, with wider consequences. For example, at this time of year the herring gulls are beginning to nest on the town's roofs, and can become very aggressive both in finding food - such as tourists' fish-and-chips - and in defending their young when they leave the nest. However, what the gulls have exploited has made them hugely successful - residents admit that we have far too many gulls so weren't too sad when they read that they were suffering from bird flu.

As we develop more and more of our environment to our needs so more and more wild species have to make a choice: learn to live with humans or risk a drastic drop in the survival chances of your species.