Ringing the Changes in Bird Populations

swanSeveral weeks ago, the Library Twitcher [LT] was walking along Camber Dock in Old Portsmouth and spotted a Mute Swan with a Darvic ring. LT memorised the Darvic’s letters, number and colour, and practically flew to a computer in order to report the sighting. “Report a sighting? What are you on about?!” thinks you…

Scientists use a number of ringing schemes in order to help them track bird populations. Members of the public can participate by reporting sightings (and are encouraged to do so! All those extra sightings really help scientists gather information about bird populations – information that scientists are unable to gather on their own). Yesterday, the bird ringer emailed with details about the mute swan, and LT was very happy to have assisted with a scientific study as a “citizen scientist”. To be honest, LT was very close to boring library colleagues to tears with the details of the bird….

Here’s what is known about P2N, a Mute Swan, gender unknown:

2009 Hatched. Location: Christchurch, Dorset
2010, April Ringed as P2N Orange
2011, February Gosport area
2011, September, October Keyhaven, Hampshire
2011, December Old Portsmouth, reported as having a mate
2014, January-February Gosport area
2014, May Old Portsmouth, with a mate?

P2N is (unknowingly) part of a long terms study of the swan population in the Hampshire Avon Valley, and those two years without a report are very intriguing…. It is supposed that P2N was breeding somewhere not often visited by humans, as it was last seen in 2011 with a mate.

“As you can see there are a number of gaps in the history of this bird, so every report is useful in building up the picture” of the bird’s life, said the researcher. Ringing helps researchers identify specific individuals as many birds do not have markings that help to identify individuals (tigers and zebras are examples with very clear markings that researchers can use, just like a human fingerprint).

Obtaining life histories of species helps us understand how the animals live in the world – where they go, what they eat, how long they live, etc. This information is vital to helping determine what is happening to the populations, and plays a key role in protective legislation. The same type of information (and more!) about people and society in the UK is collected by the Office for National Statistics – we just don’t wear Darvic rings.

If you encounter a ringed bird, and can see the ring numbers, letters, and colours without endangering yourself or the bird, please report it at the EURING website. You could help avoid a year without any information for that bird.

For more detailed information about ringing birds, please see the British Trust for Ornithology website.

Library Twitcher

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