Croydon garden wildlife survey

The Association of Croydon Conservation Societies initiated this survey of the wildlife of Croydon gardens as a result of Croydon’s Local Agenda 21. The various sections in it are: mammals, amphibians, reptiles, butterflies, insects and birds.

The survey is divided into the four seasons of the year and we ask those taking part to note the maximum number of a particular species that they see at any one time, over each three-month period.

Looking at the results section by section from 1997 to 2001 we see that for mammals the fox is the commonest visitor, occurring in 95% of gardens in 2001. The hedgehog was seen in just 10% of gardens in 1997, rising to 21% in 1999, but falling back again to 9% in 2001.

Numbers of amphibians have remained reasonably stable with frogs being the most common, seen in 72% of gardens in 2001.

So far adders and grass snakes have not been recorded in Croydon gardens, however slow worms were found in 9% of gardens and lizards have gone from 12% in 1997 to 4% in 2001.

Butterflies have had mixed fortunes over the past five years, most dramatically Small Tortoiseshells fell from 76% to 31% over the 1997-2001 period. Other butterflies falling in numbers over this period include Painted Lady and Peacock. Butterflies rising in numbers included the Gatekeeper, Speckled Wood, Meadow Brown and Holly Blue.

Ten insects are listed on the survey, of these the 7 Spot Ladybird was found in 84% of gardens in 1997 but went down to 61% in 2001. Stag beetles and grasshoppers have also fallen in numbers.

The much-reported decline in the house sparrow population is reflected in our survey. In 1997 they were found in 92% of gardens but were down to 77% in 2001. This has meant that during the year no sparrow was observed in 23% of Croydon gardens. Despite rumours to the contrary, song thrushes have actually maintained their numbers; however, mistle thrushes have declined from 42% to 25%.

Malcolm Jennings

[If you would like to help with the 2003 survey contact Malcolm Jennings through our Comments & Queries page.]

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Last updated March 11^th 2003
© 2003 Croydon Natural History and Scientific Society Limited