D1 is a female Bald Eagle and sister (from an earlier clutch) to D14. She hatched at the Decorah Eagle nest in 2011. We determined her gender by measuring her when we fitted her with the transmitter. Female Bald eagles are larger than males. Her size put her firmly in the female category.
We were able to track D1 locally after putting the transmitter on her. The photographs below were taken in the summer and fall of 2011.
About the Transmitter
The transmitter is made by North Star Science and Technology: http://www.northstarst.com, or check facebook: https://www.facebook.com/NorthStarScienceTechnology. It is a small rectangular backpack that attaches to the eagles via teflon straps. It weighs about 55 grams, or roughly 2 ounces, and is solar-powered. Northstar's website lists the operational life as indefinite, but probably 2-4 years: our eagle biologist had one last as long as seven years.