A new scientific research paper by International Bird Rescue points to a significant success in the rehabilitation of starving or even severely injured California Brown Pelicans. The published paper proves that these seabirds can be effectively rehabilitated and reintroduced to the wild, with some even surpassing previously estimated lifespans for the species. This is particularly encouraging news for the pelicans recently released following the Brown Pelican crisis.
The research paper, published in the journal Marine Ornithology in 2023, was authored by Bird Rescue’s Director of Medical Research and Veterinary Science Dr. Rebecca Duerr, Deborah Jacques of Pacific EcoLogic, Bart Selby, a San Francisco Peninsula naturalist and a prolific observer of and advocate for Brown Pelicans, Bird Rescue Director of Operations Julie Skoglund, and Bird Rescue Projects Specialist Suzanne Kosina.
The study focused on the overall survival duration of 1,418 Brown Pelicans rehabilitated between 2009 and2019 who were released with numbered blue leg bands for easy identification along with their federal bands. It also evaluated how specific conditions, injuries, or medical issues during their care impact their survival after release.
Brown Pelicans, who were federally listed as endangered until 2009, face numerous risks to survival, including fishing gear injuries, roost disruption, periods of poor forage fish availability, oil spills, harmful algae blooms, adverse weather events, and legacy contamination from the toxic materials that landed them on the Endangered Species Act in the first place (link to SeaGrant DDT+ page). Another new threat appeared in 2021: a strain of Highly Pathogenic Avian Influenza that has been wreaking havoc on bird populations worldwide.
Re-sighting data were obtained from the US Geological Survey’s Bird Banding Laboratory, Bird Rescue’s citizen science online reporting forms, and non-breeding communal roost site surveys. Increased awareness of the Blue-banded Brown Pelican Program resulted in a large number of post-release re-sightings.
The findings of this study support that Brown Pelicans that meet Bird Rescue’s criteria for release are generally fit to resume life in the wild, even when stranding with serious injuries or during mass starvation events. Former Brown Pelican patients from Bird Rescue may be expected to live an average of at least six years post-release, and many birds survive much longer. Pelicans rehabilitated from oil contamination exhibited the longest average minimum longevity among all the medical issues studied, and no major differences were found in post-release longevity based on the medical problems birds faced.
Why it Matters
This research is crucial because it addresses the gap in data regarding the survival and long-term outcomes of rehabilitated animals after their release. With limited data available and few wildlife rehabilitation organizations equipped to track and analyze re-sighting information, understanding how former rehabilitation patients fare in the wild is essential for improving rehabilitation practices and conservation efforts. By filling this gap, scientists can better assess the effectiveness of rehabilitation programs, understand the prognosis of future injured wild animals based on their problems, and enhance our strategies for ensuring the successful reintegration of released wildlife into their natural habitats.