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Veterinarians Replace Broken Wing Feathers, Announce Plan to Clean Up Discarded Fishing Gear

February 26, 2007

Wing TransplantMonday, February 12, closely watched by reporters and television crews, wildlife veterinarians William Ferrier and Shannon Riggs replaced the broken wing feathers of a black-crowned night-heron by grafting new feathers onto existing feather shafts.

Ferrier is the director of the California Raptor Center at the School of Veterinary Medicine. Riggs works at the Oiled Wildlife Care Network and is based at the San Francisco Bay Oiled Wildlife Care and Education Center in Cordelia, CA, where the implantation took place.

The bird was initially injured by monofilament (fishing) line that had wrapped around its right wing. The heron had been found at the UC Davis Arboretum, dangling from a tree.

Ferrier describes the implants:

This procedure, knows as "imping" is a falconry tool which has been performed for hundreds of years by ancient falconers. Falconers usually only replace one or two broken feathers. In the case of the heron, all the flight feathers on one wing needed to be replaced.

This is an uncommon procedure, but one that the Raptor Center performs when birds arrive with damaged flight or tail feathers. Modern day imping is usually performed under general anesthesia or heavy sedation. This decreases the stress on the bird and allows more precise placement of the feathers since the bird does not move while anesthetized.

The feather, once it has stopped growing, is essentially a dead tissue made of a proteinaceous material called keratin. (Keratin is also found in hair, fingernails and skin.) The feather shaft is hollow. As a result, this is not a sterile surgery that involves disruption of viable tissues.

Imping involves using a solid dowel material, usually made of bamboo, tailored to exactly fit into the shaft of the feather. The bamboo is glued into the shaft of the donor feather. The bamboo is then inserted into the remaining shaft, which is attached to the bird, and glued into place. Since feathers are generally curved, the location of the implanted feather needs to be exact so that it matches the conformation of the bird's wing. Adjacent feathers are used to judge the implant location. When all of the flight feathers are missing, the intact wing is used to estimate the appropriate location of each new feather.

The bird was successfully released the morning following the implants. Ferrier and Riggs had expected the bird would need at least a week to recover, but it was flying so well after surgery that they judged it in the best interest of the bird to release it back into the wild as soon as possible. The heron will retain the implants until new feathers grow in after its annual molt.


As the surgery concluded, Kirsten Gilardi, a wildlife veterinarian with the school's Wildlife Health Center, announced that a new initiative of the California Lost Fishing Gear Recovery Project is also taking flight. Gilardi, executive director of the center's SeaDoc Society, has coordinated the lost gear project since it began in 2005.

Gilardi hopes to raise awareness about the dangers of discarded fishing gear. She explains that even small amounts of debris can cause serious problems. "This heron was caught in a fairly small piece of line that damaged its feathers and prevented it from being able to fly. Lost and discarded gear poses a risk to wildlife, boats and people."

Starting in March, the Wildlife Health Center's SeaDoc Society will enlist volunteer divers to clean fishing debris caught around the pilings of public piers from San Francisco to San Diego County. Teams of 2-3 divers will use knives and shears to remove accumulated fishing line and hooks from the piers. Cleaning a whole pier will take about one or two days, Gilardi predicts.


She says, "To encourage individuals to dispose of unwanted fishing line appropriately, instead of throwing it in the ocean, project volunteers will also provide white plastic tubular bins on piers where people can recycle their hooks, line, or other equipment." Gilardi expects
volunteer divers and wildlife rehabilitators to donate hundreds of hours of time and effort to help the project succeed.

In 2006, The SeaDoc Society, working with commercial fishermen, recovered 10 tons of submerged commercial fishing equipment around the Channel Islands off Ventura and Santa Barbara counties, including lobster traps, fishing rods and a 5,000-square-foot purse seine net. Gilardi notes, "More than 100 traps still in good condition were given back to fishermen, saving them thousands of dollars in replacement costs."

Ferrier adds, "Wildlife are impacted by humans on a daily basis. This heron represents one example whereby fishing line that was not disposed of properly entangled a bird's wing and left it helpless. Lead sinkers, if ingested by waterfowl, can result in lead poisoning."

What can you do? Ferrier says, "Simple acts, such as disposing of fishing line and cutting six-pack plastic rings can help decrease our impact on wildlife."

When injuries occur, he concludes, a veterinarian may need to step in. "Fortunately, with the help of groups such as the Wildlife Health Center and the California Raptor Center, there is help for affected wildlife."


The School of Veterinary Medicine centers mentioned in this article rely on public funds, foundation gifts and grants, and private donations to accomplish their missions.

If you would like to support these services and veterinary research that makes a difference in the health of wildlife and the environment, please call us today. (530) 752-7024. 
Media contact:

Lynn Narlesky
, Communications
School of Veterinary Medicine Office of the Dean
(530) 752-5257