15 February 2018

The Joy of Nesting Birds

Hazel Evans writes:

This week (14th – 21st February) is the BTO’s 21st National Nest Box Week.  Each year we encourage anyone who is interested, to put up nest boxes locally. I’d like to delve in to some of the different aspects for why this is such a wonderful thing to do, and how we can make the most of them.

The first and most obvious reason is to give birds a place to raise their young. In areas of human habitation it can be harder for birds to find places to nest, so putting up a nest box is a good way to ensure there is somewhere for the birds to use. There are many external factors which may affect the outcome of a nesting attempt, but we can offer them a good place to start. You may also choose to put out some appropriate nesting material in the nearby trees and bushes, or grow some plants to encourage insects. Non-native plants in gardens have been found to be a potential detriment to our local birds, they do not provide as much food, because non-native plants may not be able to host as many caterpillars as native plants, so this may be something to consider.
 
Robin feeding it's young. Photo by John Harding

The second reason why putting up a nest box can be important is monitoring. One of the BTO’s strongest assets is the data it has collected through organising monitoring schemes, and the Nest Record Scheme (NRS) is no exception. Now running for over 75 years, close to two million records of nesting birds throughout the UK have been sent in for over 200 species. This includes data from open nesting birds and nest boxes, both of which are highly valuable. As long as the NRS Code of Conduct is adhered to, we can safely record the progress of nesting attempts by counting the number of eggs and chicks and recording the outcome of the attempt and submitting data to the NRS.

Blue Tit fledgling. Photo by Christine M Matthews

The third reason I value nest boxes very highly, is the intrigue and excitement they can provide. Anyone can put up a nest box and monitor what’s inside it and in turn benefit from watching the behaviour of the birds. Interactions with the natural world have been shown to help relieve depression, anxiety and stress. We are living in a time where it is easy to lose touch with the natural world and many children aren’t getting experiences with nature; having a nest box in your garden is an inspiring way to learn about the natural world. Monitoring nests is not something that should be taken lightly but with the knowledge that the data is going to a good cause, it's something we can experience great joy from.

Now is the time when garden birds are just starting to prospect nesting sites in preparation for the approaching spring, so the sooner you can get a box up the better, whether you build it yourself or buy it from the garden centre. There are many bird species which use nest boxes, so if you have a bit more space then you may want to put up a larger nest box, for a Kestrel or owls.

Once used, it is a great idea to clean out old nests the following winter to allow for a fresh start in the spring. To comply with legislation, nests should only be cleaned out between 1 August and 31 January.

01 February 2018

Brit abroad causing a stir

The species, or subspecies, of the Redpoll complex has long been something that birders and ringers have debated; the use of new advances in technology, like sonograms and DNA studies, have only fueled the discussions. There are currently three recognised species, Lesser, Common (Mealy) and Arctic Redpoll, with subspecies also acknowledged (depending on which criteria you use). Identification of these species can be difficult; however, ringers are in the privilaged position of being able to collect detailed data on size (wing length) and plumage to help inform the decision.

Since 2010, the average number of Lesser Redpoll ringed by the BTO Ringing Scheme is 21,000 birds per year. The number of these that are later relocated is quite high in comparison to similar species. They have become increasingly common in gardens (as recorded through Garden BirdWatch) possibly due to garden bird feeding; this also offers additional opportunities for ringers to catch these birds.


https://app.bto.org/ring/countyrec/resultsall/rec16634all.htm
Colour of location: Ringed in Britain and Ireland, Found HereRinged Here, Found in Britain and Ireland

The map above shows the ringing and finding locations for all the Lesser Redpolls that have been ringed or reported in Britain and Ireland. This map will have to be redrawn later this year however, as we have now received details of a bird that had its metal ring read in Spain! During 2017, there were only two sightings of Redpoll in the whole of Spain, so 20 January 2018, when a flock of 15-17 birds turned up, was an exciting day; it was made even more exciting by the fact that one of the birds was wearing a ring!


Adult male Lesser Redpoll. Photo by Jesús Mari Lekuona

Unfortuantely, as the rings on Redpoll are very small, it is very difficult to read the ring number in the field; however, Jesús Mari Lekuona managed to read all but the last number. This narrowed the options down to 10 possible birds, and all of them were Lesser Redpolls of various ages (adult or juvenile), ringed on 14 October 2017 near Cinderford, Gloucestershire by Robin Husbands. As you can see from the photo, this bird is an adult male... and this matched a single bird, ringed at 12.30!

This is the most-southerly recovery of a Lesser Redpoll, although there is a report of a 'Redpoll species' recorded in Portugal (before they were split into three species). In countries where certain species rarely occur, finding a bird with a ring can be really helpful, not only to increase our understanding of bird movements, but also to help validate such an unusual movement.

Thanks to Jesús Mari Lekuona, Ricardo Rodríguez, Jorge Nubla, Oscar Guindano and Jose Ardaiz for getting the ring number and Rare Birds In Spain for letting us know.