Abstract

International Bird Rescue (IBR) operates two wildlife hospitals in California that function as referral hospitals for aquatic birds requiring rehabilitation in the greater San Francisco Bay and Los Angeles areas. Since its founding in 1971 after the Arizona and American Standard oil spill in San Francisco Bay, IBR has rehabilitated approximately 15,000 brown pelicans (Pelecanus occidentalis) including 4,854 since 2002, and as many as 952 in a single year. Twenty-five to forty percent of IBR's brown pelican admissions are due to fishing hook and line injuries each year. Affected birds present with several types of injuries that may affect the gular pouch and keratinized bill. Untreated, these pelicans are unable to feed and will starve.

Birds are typically received for care emaciated, hypothermic, and anemic, and fare best if fully stabilized over several days prior to any surgical procedures. Pouch injuries that render birds unable to eat may be temporarily repaired with the application of surgical staples, which allows birds to eat and recover from dehydration and emaciation prior to surgery. Turning a cold, starving bird into a vigorous feisty animal prior to surgery allows the best prognosis. Definitive repair may occur at the surgeon's convenience up to several weeks after admission.

As described by Williams (1988), the pouch consists of an inner and outer layer of stratified squamous epithelium with a skeletal muscle layer sandwiched between. A technique modified from the method described in that paper is currently used at IBR and results in healing times of less than 2 weeks for even extremely large lacerations. Other injuries that are often seen involve avulsion of the pouch skin from the mandible or fishing line injuries to the commissures of the mouth, leaving sometimes large areas of exposed bone or devitalized keratin. Although rarely life-threatening, these injuries can take many months to heal without intervention. To speed birds to a releasable condition, these injuries may be repaired by freshening and splitting the avulsed skin edge and suturing it to mandible keratin as an advancement graft after heavy debridement of the mandible. With time, the grafted skin will eventually remodel to become heavily keratinized. Utilizing these and other techniques, IBR has treated and released several hundred brown pelicans with severe soft tissue damage to the mouth.

* Presenting author

Literature Cited

1.  Williams TD. Surgical repair of the gular sac of the brown pelican (Pelecanus occidentalis). J Zoo Anim Med. 1988;19(3):122–125.