Tuesday, 10 November 2009

Renewing an acquaintance

It was mild night, the almost complete blanket of cloud helping to retain some of the unseasonable daytime warmth; warmth that would dissipate rapidly into a clear autumnal sky. The cloud had plunged the wood into darkness, thickening the shadows and hampering our attempts to erect fine nets without resorting to the light of our headtorches.

We were here to catch a Tawny Owl or two, luring them into our nets with taped territorial calls. Choosing a likely spot within the narrow finger of woodland, we set two nets in a dogleg, placing the tape machine in the angle where the two met. Once the tape was running, broadcasting the territorial hoot of a male Tawny Owl, we retreated further into the darkness to listen and wait. The distant drone of cars carried across the lakes, disturbing what would otherwise have been a perfectly still night. Even so, the wood was alive with sounds: delicate rustlings among the leaf litter that could only be mice or shrews, stirrings from the wildfowl at roost and a distant series of whistle-like notes that may have been one of the local Otters. What there was not, however, was any sign of an owl; we would need to reposition our net.

A little later into the evening, and with the cloud starting to break up, we found ourselves in another piece of woodland, nets in place and tape running. Here, larger animals were abroad: Badgers pushing through the stands of now dying Bracken, murmurings of Jackdaws, roosting nearby and a few soft calls that could (just) have been an owl. The tape had seemed too quiet all night, frequently stopping unannounced, and we’d discussed the need for better equipment before we next ventured out ­– this had been something of a test run in any case. After half an hour without response we decided to call it a night.

It came as something of a surprise, then, to find a Tawny Owl sitting in the bottom shelf of the net. She was beautiful and quite calm as we lifted her clear. The owl already sported a metal ring, complete with a unique number that identified her as an old friend ­– the female from a local territory. Having measured her wing (which gives a measure of structural size), we weighed her and examined wing and tail feathers for signs of moult. Subtle differences in the colour and pattern of individual feathers showed that she had feathers from three different generations ­– Tawny Owls only moult a few of their flight feathers each year. She was looking fit and well, ready for the breeding season ahead, and she quickly slipped back into the darkness as we let her go.

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