Brenda has been ringing birds at Blashford for many years, and it has been a pleasure to observe some of her winter ringing sessions. The practise of bird ringing generates information on the survival, productivity and movement of birds, and is an important method to help us understand locally and nationally (and globally!) how and why populations are changing.
All bird ringing is conducted following BTO (British Trust for Ornithology) protocols by trained and licenced ringers, with assistance from supervised trainees. If you would like to learn more about this head to https://www.bto.org/our-science/projects/ringing.
A morning ringing… it’s an early start!
Birds are most active in the morning (not the sort of just before lunch lazy morning, the real ‘sun just got up and is only just peeking over the trees’ type of early!), so the mist nets are set-up to make the most of this, and as a general trend more birds are caught early, with the numbers tapering down until the nets are closed around lunchtime.
Mist nets are an invaluable piece of equipment for ornithologists, providing a safe method to catch birds for research. A mist net is made of very fine nylon netting and is almost invisible, hence the term ‘mist’. Each net has 5 evenly spaced thicker horizontal strings called trammels, which are secured to vertical poles at each end of the net to ensure even tension. Between each trammel is fine netting that arcs down into a sort of pouch. They fly into the net and fall into a pouch and await careful extraction. This is the part I find fascinating. On each net check (regular intervals throughout the session) Brenda determines which side of the net the bird flew into, so that she can extract it successfully. She uses a variety of holds to ensure the bird stays still and can be untangled from the net without harm. Once extracted they are placed into a small drawstring bag for safekeeping and taken back to the area which has been set up for processing.
Biometric data is taken for each bird (e.g. wing length, weight) and age/sex determined (depending on time of year) by identifiable features related to moult, feather colouration and feather shapes, or if during certain times of year the presence of e brood patch or cloacal protuberance (CP). If the bird is a re-capture then it will already have a ring, but if it’s a new bird then a small metal ring is fitted around the right leg which has a unique identifiable number. The rings are made of wide, flat metal, which is pressed around the leg, ensuring the join is smooth and the edges are flush. Once the ringer is confident the ring can move up and down the leg with absolutely no impact on the bird’s movement, it is then released. Brenda has a fantastic way of teaching and is exceptionally calm and patient and has one bespoke piece of kit that she made herself, a knitted bird! This bird can be used to practise specific handling techniques, be fitted with bird rings etc, so that when a trainee comes to handle a live bird they are more confident in their abilities.
These unique ring numbers are vital, as the data on re-capture can tell us how old the bird is, where it may have flown from (therefore its range), helping to inform bird conservation efforts. This morning we caught around 25 birds, and (bearing in mind I class myself as ‘not really a birder’) being able to see so many birds up close and learn about their markings has really helped me in my quest to be better at bird ID!