IN A recent nature notes, I expressed surprise at seeing a raven flying over my house in the direction of Wimbledon common on December 12. Since then, a pair of ravens has been spotted over Putney Heath.

Centuries ago, ravens were a common sight scavenging on London's streets until persecution drove them away. Well-known nature writer, Stephen Moss, tells me the raven population has risen sharply in the west country recently and the birds are spreading eastwards, so they are clearly making exploration flights with a view to expanding their range even further, rather like buzzards and red kites which have spread their wings further afield over the past decade. So, it's clearly a case of watching this airspace over southwest London.

Meanwhile, songs of robins are gaining strength by both day and night as spring approaches and the musical canary-like twittering of goldfinch flocks is heard around my garden feeders for most of the day.

However, another bird whose population has escalated over the past couple of years is the rose-ringed parakeet. Their constant loud yelping begins at dawn and continues throughout the day. I find their calls most annoying. When they approach my garden feeders all the other birds fly off rather than being confronted by what I call noisy 'bully birds'!