Knowledge of our wildlife is vital if we are to protect it. Understanding how species react to the issues that face them, such as development and climate change, helps us to provide the right kind of habitat for them at the right time.

BBOWT invests in local knowledge. To gather as much data as possible, we run a programme of surveys. These rely on experienced naturalists and help to train new people to recognise key species and report findings. Both amateur and professional naturalists have been carrying out surveys on BBOWT nature reserves for years, but most of the data was collected in an ad hoc manner. To make sure our reserves really are the best possible spaces for local wildlife, it is vital that the work we do is based on accurate scientific knowledge.

In 2002, BBOWT launched the Reserves Surveying Programme to standardise the way data was gathered. By using consistent methods, information can be analysed to determine population trends and the condition of habitats. It is then possible to review the success of our work.

Survey work ranges from monitoring protected species like great crested newts and hazel dormice, to bird, butterfly and dragonfly surveys.

We know what makes each reserve special. From the wildflower-rich hay meadow of Woodsides Meadow, to the scarce southern damselflies of Dry Sandford Pit, the key features of each BBOWT nature reserve have been identified.

At Hartslock Nature Reserve, near Goring, chalk grassland, scrub, woodland and the monkey orchids have been identified as key features. Each of these features has a number of characteristics assigned to it which can be measured. Each characteristic has a range in which it can vary without cause for concern. The monitoring of all these characteristics shows us what condition the feature is in and if a problem needs addressing.

To monitor the characteristics of the chalk grassland at Hartslock,we undertake an annual butterfly survey and a habitat condition rapid assessment every three years.

This year, 311 individual surveys on 66 nature reserves will have been undertaken by 102 volunteer surveyors, 16 BBOWT conservation trainees and 18 BBOWT staff.

Nick Marriner is now into his fourth year as a BBOWT volunteer surveyor. Since 2007 Nick has made almost 100 survey visits and recorded over 90 bird species on his routes at the trust’s Upper Ray Meadows Nature Reserve.

He said: “Surveying for BBOWT has not only helped my field identification skills, it’s given me a discipline to my birdwatching hobby that makes me really appreciate and value the everyday sightings.

“Being able to do this in the ever-dramatic, ever-changing habitat that the Upper Ray Meadows offers, and knowing that my data has helped in a small way to improve the lot for our local wildlife, makes it even more exciting.”

The April count of the snake’s-head fritillaries at Iffley Meadows this year revealed 41,622 plants, the second increase in numbers since the low count of 2008 — a result of the 2007 floods.

A mid-summer hay-cut followed by cattle grazing, as well as managing the ditches to avoid major flooding, is allowing the fritillaries to flourish.

Early indications suggest the settled spring and summer weather has allowed butterflies to have a much better season.

Small tortoiseshells, a once common garden butterfly, have declined by 80 per cent since 1990 in south-east England.

But the good news is that they have been seen more frequently on our surveys this year. Their decline has been blamed on climate change and a tiny parasitoid fly, Sturmia bella (first noted in Britain in 1999), which kills tortoiseshell caterpillars after they inadvertently eat its eggs.

Other butterfly ‘winners’ this year include black hairstreaks and common blues.

If you are an experienced naturalist and would like to help BBOWT survey wildlife contact Colin Williams on 01865 775476 colinwilliams@bbowt.org.uk