The brown pelican is a large seabird found on the coasts of North and South America. They are known for their huge throat pouches that they use to catch fish. Brown pelicans were greatly affected by pesticide use in the mid 20th century, with populations declining dramatically. Conservation efforts helped populations recover, but they still face threats today. This article will examine if brown pelicans are currently threatened.
What are brown pelicans?
Brown pelicans (Pelecanus occidentalis) are large seabirds in the pelican family. They are one of the largest birds found in North America. Brown pelicans have a wingspan of over 7 feet and can weigh 8-10 pounds. Their most distinctive feature is the large throat pouch connected to their bill. They use this elastic pouch to scoop up fish while diving. The pouch can hold up to 3 gallons of water and fish.
Brown pelicans are found on the Atlantic, Pacific, and Gulf Coasts of North and South America. In North America, they breed from Maryland south to Venezuela, and along the Pacific Coast from British Columbia to Chile. They are year-round residents in the tropics, but northern populations migrate south in the winter.
Brown pelicans mainly eat fish like herring, mullet, and minnows. They capture prey by plunge diving from heights up to 60 feet. Spotting a school of fish, they fold their wings back and dive bill-first into the water to scoop them up. Brown pelicans also occasionally eat amphibians and crustaceans.
Brown pelican population declines
Brown pelican populations declined dramatically between the 1940s-1970s due to impacts from pesticides like DDT. Being at the top of the food chain, brown pelicans bioaccumulated high levels of DDT from the fish they ate. The pesticide caused their eggshells to thin and break during incubation. Nesting success fell to just 1% in 1969 in California.
DDT was banned in the United States in 1972. Since then, brown pelican populations have rebounded significantly due to regulation of pesticides and conservation efforts. However, their population levels have not reached historic numbers again. Other ongoing threats like habitat loss, disturbance, reduced fish stocks, and environmental contaminants continue to impact brown pelican populations today.
Are brown pelicans currently threatened?
Brown pelicans were first listed under the Endangered Species Act in 1970 when they were on the verge of extinction. But after populations rebounded, the brown pelican was delisted in 2009 when it was declared recovered.
The current overall population trend for brown pelicans is increasing. The North American breeding population is estimated at over 620,000 breeding pairs. However, threats remain and population levels are still reduced in parts of their breeding range. Declines have been observed recently in places like Louisiana and California.
IUCN Red List status
The IUCN Red List categorizes species by their risk of extinction. The brown pelican is currently listed as Least Concern. The global population is estimated to be over 300,000 mature individuals with an increasing population trend. However, the IUCN recommends continued monitoring and conservation action since populations may not yet be fully recovered from declines linked to DDT.
Federal protection status
While the brown pelican was delisted under the Endangered Species Act in 2009, it remains protected under the Migratory Bird Treaty Act in the United States. This prohibits direct harm or harvest of brown pelicans without permits.
The state and provincial status of brown pelicans varies across their range:
| State/Province | Status |
|---|---|
| Maryland | Endangered |
| Virginia | Threatened |
| North Carolina | Threatened |
| South Carolina | Threatened |
| Georgia | Threatened |
| Florida | Species of Special Concern |
| Alabama | Protected |
| Mississippi | Endangered |
| Louisiana | Threatened |
| Texas | Threatened |
| California | Delisted |
| Oregon | Sensitive |
| Washington | Monitored |
| British Columbia | Blue-listed |
They remain listed as threatened, endangered, or protected in many states, especially along the Atlantic Coast. States like Maryland, Mississippi, and Texas list them as endangered or threatened. Other states designate them as species of concern for continued monitoring and management.
Threats facing brown pelicans today
While brown pelican populations have rebounded significantly from major declines in the last century, they still face a variety of threats across their range today:
Habitat degradation
Coastal wetland loss and degradation is a major issue, especially in the Gulf Coast where the majority of brown pelicans breed. Coastal development, erosion, pollution, and sea level rise all contribute to reducing nesting habitat. For example, over 1,900 square miles of coastal land has been lost in Louisiana since the 1930s.
Human disturbance
Brown pelicans are very sensitive to disturbance at nesting colonies. Increased human recreational activities near breeding sites can cause nest abandonment and breeding failure. For example, a colony in Mexico was abandoned in the 1990s after development of a nearby resort increased the amount of tourists visiting the island.
Reduced fish stocks
Overfishing and other factors have contributed to declining fish populations in some regions like the Gulf of Mexico. Lack of food availability can impact breeding success and adult mortality. Brown pelicans are also threatened by competition with commercial fisheries for food resources.
Environmental contaminants
While DDT impacts have declined, brown pelicans are still vulnerable to other pesticides, heavy metals, and oil spills. Contaminants become concentrated up the food chain and impair reproduction. In 2010, the Deepwater Horizon oil spill oiled over 600 brown pelicans found dead and over 2,000 live oiled pelicans. Even today, residual oil remains in Louisiana marshes where many brown pelicans feed.
Climate change
Sea level rise, increased storm activity, altered precipitation patterns, and ocean warming all threaten brown pelican breeding and foraging habitat. Availability of prey fish populations may also shift with ocean changes, reducing food resources in current foraging areas.
Disease
Brown pelicans are susceptible to diseases like avian influenza, West Nile virus, and Newcastle disease. Outbreaks of contagious diseases have the potential to spread rapidly through colonies, especially in cases when resting or breeding sites become overcrowded. For example, an avian influenza outbreak in Peru in 1998 reduced a breeding colony of 10,000 brown pelicans down to just 800 survivors.
Conservation actions needed
While brown pelican populations remain relatively stable as a whole, targeted conservation actions are still needed in many parts of their range to address ongoing threats. Some recommended actions include:
– Protect and restore vital coastal wetland habitats through regulation, acquisition, or restoration initiatives. Prioritize conservation of known nesting sites.
– Develop disturbance-free buffers and restrict human access around key breeding colonies. Limit development near sensitive nesting islands.
– Monitor and manage prey fish populations in important coastal and marine foraging grounds.
– Reduce pollution and contaminants through improved regulation, treatment of runoff, and spill response preparedness.
– Closely track and control disease outbreaks in breeding colonies. Reduce overcrowding where possible.
– Adjust habitat management and restoration priorities to account for potential changes in habitat use with climate change impacts.
– Continue population monitoring and research to assess trends and adjust conservation priorities over time. Maintain state and provincial threatened/endangered designations where warranted.
Conclusion
The brown pelican has undergone a major population recovery after nearing extinction in the last century. Conservation efforts including pesticide regulation and active management have successfully brought the brown pelican back from the brink. However, threats like habitat loss, human disturbance, reduced fish stocks, and environmental contaminants continue to pressure populations in many parts of their range. Ongoing conservation action and close monitoring of population trends are still needed to ensure the long-term viability of brown pelican populations across North and South America. While the brown pelican as a species is no longer at high risk of extinction, targeted management and habitat protection will be important in maintaining healthy, sustainable populations throughout their coastal range in the face of growing human pressures and climate change impacts in the future.
