I was down at the Ballachuan Nature Reserve today with several other volunteers, David Croucher and the Scottish Wildlife Trust Reserve Manager, Simon Jones to try and find evidence of the Marsh Fritillary butterfly.

The butterfly flies in late May and June. The female then lays batches of eggs on the underside of Devil's-bit Scabious leaves. From July until late September the black, spiny caterpillars feed together on Scabious leaves inside a silken white web.

During the winter they hibernate together in this small web, hidden in the sward. The caterpillars emerge in February or early March and separate; sometimes wandering several metres to find fresh Scabious leaves. By late April–early May the caterpillars change in to a chrysalis and emerge as adult butterflies 2–3 weeks later.

It was these webs we were searching for amongst the damp, flower-rich grasslands of the marsh. Grassland which contains a mixture of rushes, heather, long tussocky grass and the plentiful Devil's- bit Scabious.

It was a glorious day, but hard work stumbling amongst the tussocky grass and marsh but we were fortunate to find approximately fifty of these silken webs, with their small black caterpillars searching for food.

It will be interesting to return on a warm sunny day next June to organise a transect count of the butterflies to see how many have survived the life cycle.

September can be an interesting month with birds passing through on reverse migration and breeding birds returning to their wintering grounds. This has already begun with numbers of Wigeon and Teal increasing gradually on the Lochan, and Curlew, Redshank and Oystercatcher in Balvicar Bay.

Similarly Goosanders which are normally found in freshwater habits can sometimes move to estuaries and sheltered bays following breeding. This morning was such an occasion as a female eclipse Goosander was feeding in the Balvicar Bay.

The remaining migrant warblers such as Willow Warbler and Whitethroat will all have left by the end of the month along with the hirundines, Sand Martin, House Martin and Swallow, the latter usually being the last to leave.

Other species such as Chaffinch, Greenfinch, Goldfinch, Linnet, Yellowhammer and Twite start to flock in autumn along with Starlings and some Corvids. There is safety in numbers from predators and when food is sparse during the winter, flocking can help find what's available.  For if a few eyes are good, then more eyes are better.