Over 40 South Yare Wildlife Group members attended a fascinating talk by David White from the BTO’s Garden Ecology team at Poringland Community Centre on 14 October.
Rodney Aldis introduced the evening, explaining why gardens are the focus of SYWG’s Wild Patch project and the reason for choosing Poringland as the venue. Poringland has had the lion share of new house building in south Norfolk which means there are a lot of new gardens in the village. However, only two people who live in those new developments attended so we failed to reach the target audience. We need to discuss how we can reach out beyond the already converted if we want to improve our area for wildlife.
David first gave an overview of the results from the analysis of the recent BTO/Springwatch national garden survey. Data from over 221,000 gardens were entered, which is a sample between 1 and 2% of the national total. One of the main points that stood out was that only 41% of gardens had long grass (although there is some regional variation). The percentage is higher in western Wales and parts of Scotland and lowest in central England. This is likely to affect the habitats available for insects and other invertebrates. The sample is also likely to be biased in favour of wildlife enthusiasts entering their gardens so the actual percentage of gardens without long grass is likely to be lower than 41%. The data is still being analysed so we expect to hear more about the conclusions in a few months time.
David went through in some detail the results of the Garden Birdwatch Scheme which has been running for 25 years and has recorded some significant changes during this time. While house sparrows are still common occupants of gardens, their numbers have declined and they are not found in all gardens. London in particular has seen large declines possibly due to the loss of nesting sites as houses are renovated. Starlings, which were once one of the most abundant birds found in gardens, have also declined. Greenfinches have been hit by a disease carried by collared doves, trichimonasis, although they appear to be slowly recovering. Chaffinches have also declined recently. Some good news though as goldfinches though have been increased markedly over the study period, probably due to milder winters.
The risk of disease illustrates the need for good feeder hygiene. David said feeders should be cleaned every fortnight and people should stop feeding if any sign of disease is found. Another disease that can occur is avian pox which results in bulbous lumps in birds, especially in great tits which are rather prone to it. David also showed some examples of birds with beak abnormalities, something which is becoming more common in the large urban parts of the country. He thought there was probably a PhD project in discovering the reason or reasons… is it they find it easier to find food and compete than in rural areas?
The collared dove is one of the stand out success stories as a coloniser first arriving in the 1950s and now occupying most gardens and farm yards. Woodpigeons have also increased as garden visitors and residents. As a general point, plant eating species are faring better than those that require insects. Another success story although still concentrated in London and the South East at the moment is the ring necked parakeet. They are hole nesting birds and it remains to be seen what impact if any they have on other hole nesters such as woodpeckers.
Another general point is that many of the species are more common visitors late in the winter when food in the countryside becomes scarce. Numbers drop in the spring when many birds leave to breed in rural habitats or migrate north. This does indicate that gardens are not the preferred habitat for many species. Milder winters have led to some of the blackcaps that spend the summer in central and western Europe migrating westwards to Britain rather than making the longer journey to Africa.
Overall, The Garden Bird Watch study shows the changes that have and are taking place in our bird populations. Different species are rising and failing for different reasons but we can reasonably conclude that a warming climate, loss of insect life and disease are some of the main factors and no doubt there are causes of which we not understand fully or we are unaware of.
We can also say that as more land is used to build houses and infra-structure that the role of gardens is likely to increase as a habitat for birds and other wildlife – hence the desirability of people being aware of what they can do to improve them as wildlife habitat. SYWG very much wants to thank David for an extremely interesting talk which is very pertinent to the aims of our Wild Patch project. We fully encourage everyone with a garden to take part in the study when they have the chance.
Words by Rodney Aldis