June 3, 2009


The Wildlife Conservation Society has been engaged in water bird surveys in Mongolia since 2005. During the summers of 2007 and 2008 part of this work has focused on the marking of birds to facilitate studies of migration and population characteristics. Birds are fitted with colour marks such as neck collars (geese and swans) and leg flags (waders) that can be easily identified by observers in the countries through which the birds migrate and spend the winter. By reporting observations of marked birds, observers help us piece together the bird’s life histories, their movements and needs and in so doing assist in our ability to conserve them.

How to report resightings?

If you observe a marked bird, please make a note of the sighting and record the date and location on which the observation was made. Neck collars are marked with a two or three digit code that enables us to identify the individual bird. Where possible please try to include this code as it increases the value of the observation. Observations can be reported by e‐mail in a variety of languages:

– In English to Martin Gilbert
– In Mongolian to Enkee Shiilegdamba

Also, if your bird continues to be seen in the same location, please continue to provide updates and let us know when the bird finally moves on as this will provide additional important information to help build a picture of the bird’s needs.

Bar-headed Goose, Koondhakulam Lake, India, March 2009.
© Arun Kumar

Where have birds been marked?

The birds have all been marked in the aimags (provinces) of Bulgan, Hovsgol and Arkhangai in northern Mongolia. Marking work takes place in partnership with the State Central Veterinary Laboratory, with the consent of the Ministry of Nature and Environment and Institute of Biology. Swans and geese are captured while moulting, either at night using boats and spotlights or by herding during the day. Shorebirds are caught while on migration using mist nets.

How are birds marked?

Birds have been marked using a number of techniques appropriate for use in each species. Each method has been well established and has been shown to have no impact on birds ability to feed, breed or behave normally. Methods used include:

1) neck collars

Coloured plastic neck collars have been widely used for studying the movement and life history of long necked waterfowl such as geese and swans. The WCS has been fitting coloured neck collars to four species in Mongolia:

Each collar is inscribed with a unique alphanumeric code comprising two or three digits depending on the size of the collar (examples are shown above). For Swan Geese and Bean Geese the collars comprise a number inscribed horizontally and a two digit number inscribed vertically; it is necessary to record both in order to identify the individual bird with certainty.

2) leg flags

Coloured plastic leg flags are widely used to study the migraFon of shorebirds. The technique uses coloured plastic tags applied to the right leg of the bird, which denotes the country, or region in which the bird was marked. The Australasian Wader Studies Group manages the scheme for the East Asian-Australasian flyway and has nominated the flag combination blue over green to indicate birds flagged in Mongolia.

leg-flagged Red-necked Stint.
© Nial Moores / Birds Korea

About the Wildlife Conservation Society

The Wildlife Conservation Society saves wildlife and wild lands through careful science, international conservation, education, and the management of the world’s largest system of urban wildlife parks. These activities change attitudes toward nature and help people imagine wildlife and humans living in sustainable interaction on both a local and a global scale. WCS is committed to this work because we believe it essential to the integrity of life on Earth.

For more information contact us at the Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, New York 10460, or visit us on the web at

No comments: