Automated tracking of wild hummingbird mass
Submitted by avianbiology on 12 September 2014.
A male ruby-throated hummingbird (Archilochus colubris) approaches an artificial feeder outfitted with a passive-integrated transponder reader and a precision electronic balance. As this bird, which is implanted with tag “384.199C8436E6”, perches to feed it is detected and its mass is automatically recorded. At the time of this photo (9:25 AM EST on June 6, 2014), the bird weighed 2.65 g. This individual was initially tagged as a juvenile (> 2 months of age) on August 11, 2012, making it almost 2 years old at the time the photo was taken.
In this study the authors examine the use of automated collection of hummingbird mass data using low-cost, low-power radio frequency identification (RFID) technology. In a field study in southern Ontario, wild hummingbirds were captured, subcutaneously implanted with passive integrated transponder (PIT) tags, and released over a three-year period. Tagged hummingbirds were detected at specially designed feeder stations outfitted with RFID readers coupled with a perch secured to a digital balance. When tagged birds visited the feeder, transponder detection initiated the recording of the perched hummingbird's mass at regular intervals continuing as long as the bird remained. With this approach it´s possible to get robust serial measures of physiological parameters such as mass over time.
Below you can see a short video of a hummingbird feeding on one of the specially designed feeders.
You can access the paper below