Tag attachment on Passerines (updated)

[Bri Benvenuti]

Hi All - 

I managed to get my post on tag attachment nested in the netbook/sensorgnome thread - sorry about that. 

Thank you for those that have replied. I don't believe the tags that are still attached were too loose, we did have some tag loss last fall with birds that were able to remove their harness. The ones where we are seeing the chafing still had snug backpacks that were comparable to when the tags were deployed (barely able to lift tag off back, not much shifting). We were using this elastic cord: Mandala Crafts 1mm Fabric Elastic Cord. Is this the same as others have been talking about (nylon elastic)? We've purchased several different materials and are  field trialing from now-September by placing them in the marsh (not on birds) and watching for degradation.

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We deployed 0.45g nanotags with 1.0mm attachment tubes on front and back with an 18 cm antenna on Saltmarsh Sparrows (~20g) last fall. We used 1.0 mm elastic cord (jewelry elastic) to create a leg-loop harness with some individually tied on the bird and others with pre-made harnesses.  This summer we have recaptured several birds that still had their tags on but the antennas were missing (presumably pulled out by the bird). All of the birds also had chafing/missing feathers on the upper thighs and back. We were wondering if anyone has experienced this in the past. Also, tips/suggestions for attachment that others are using would be appreciated, as would success stories of harness material that does not cause chafing and degrades relatively rapidly. Ideally, we would like the tags to fall off the birds after ~2 months.  

Thank you! 

Bri Benvenuti 

University of New Hampshire