Bird watchers’ hopes in the discovery of a new species of hawk have been shot down after a New Zealand farmer was revealed to be spray painting the birds pinkish-red and releasing them for fun. In a judge’s decision released this week, Grant Michael Teahan was found guilty of two charges of ill-treating an animal after he defended the charges in court. In early 2009, locals were mystified by the appearance of the strangely colored hawks and sent photos of them in to the local newspaper.When one of the hawks was killed by a car the spray painting was discovered.
The SPCA began investigating and Teahan was uncovered when he asked his nephew to send a YouTube clip to the media, showing a man catching and shooting a magpie in a home-made trap, which was covered in pinkish-red spray paint. Computers seized at Teahan’s Dannevirke property had files, photographs and films relating to red hawks deleted. Another file showed a cow that had been spray-painted with “Merry Christmas”.
Various people thought maybe it was a new type of bird or whatever, but it became obvious somebody was actually painting these hawks. (Modified from the Herald-Sun of Melbourne, Australia.)
Fifty years ago, researchers used to paint birds, especially waterfowl, with brushes, glue colored feathers to their heads, and even inject duck eggs with dye so the young came out colored. Solid lines were painted on the underwings of Mourning Doves when it was discovered that painting their heads disrupted mating behavior. Gull colonies also rejected dyed members. I seem to remember that Russians would spray paint swans orange, and when a few of them showed up in the U.S. they caused a stir. Aerial spraying techniques to mass-mark birds in roosting or nesting colonies use colors of fluorescent particles that are sprayed from crop dusters. The marker is visible under long-wave UV light when a bird is examined in hand and is retained for several months or until molt and behavioral changes are not likely because the marker is not visible in daylight.
When I was an undergraduate, I worked for a graduate student who was studying the energy costs of molting in House Sparrows. We dyed each of the tail feathers a different color so we could easily tell which had molted. At the end of the experiment, we released all the sparrows and then fielded phone calls for the next few weeks about the odd birds that showed up in our area of Illinois. Look at this photo of a blue Herring Gull. It was taken in Pennsylvania but according to wildlife officials it was probably one of the gulls dyed in Chicago to determine where “nuisance gulls” were coming from.
The problem with dying or painting birds or marking them with flags or collars or anything else obvious is that it makes them an oddball among their species and often attracts predators. So relatively inconspicuous bird bands are used to mark birds.