Red Gulls in Central Park

I photographed this red/pink Ring-billed Gull in a flock on the Harlem Meer. I did not think this bird had come by his coloration naturally and so I did some research to try and find out more.
What I found is that researchers frequently dye birds to help track their movements. This bird was probably dyed with Rhodamine.

Rhodamine is a highly fluorescent dye that is used by researchers for a number of things. Water quality researchers use rhodamine to investigate things like groundwater tracing, dispersion and mixing, circulation in lakes, and stormwater retention.

Ornithologists used Rhodamine B to track migrating birds. Colonial waterbirds are most often marked with dye, making individual birds easier to track. Typically the dye wears off in 2-3 weeks and does not harm the bird.

I contacted the person in charge of issuing Federal bird banding permits at the USGS Patuxent Wildlife Research Center but he never responded to my query. I guess I shouldn't be surprised since Patuxent hasn't made any changes to their Web site since 2001. I guess it's true what they say about the "gears of government" grinding slow.

More information about marking birds for scientific study can be found in this document: http://oacu.od.nih.gov/WildBirdGuide.pdf by The Ornithological Society.

More photos of this bird on my Web site: http://www.calvorn.com/gallery/photo.php?photo=5893