• Sitting on a California beach, you see a flock of birds flying just above the cresting waves in perfect V-formation. As they scan the waters below for fish, the leader glides upward, then turns and dives into the surf below. In quick succession, the rest of the flock shoots into the water, resurfacing moments later.

    In what might have been an uncommon sight only a few decades ago, these birds, the California subspecies of the brown pelican (Pelecanus occidentalis californicus), have recovered from the brink of extinction.

    Their success story is tied to the life and work of one of nature’s most passionate protectors, biologist Rachel Carson.

    In the 1940s and 1950s, scientists thought they had finally found the solution to one of the biggest problems to plague humanity—mosquitoes. The insect with the incessant buzz does more than just annoy you and leave the occasional itchy red bump on your arm. Mosquitoes and other insects carry diseases, including malaria, that cripple and kill thousands of people every year. Other insects kill crops and devastate agricultural yields. Chemical advances in the early 20th century provided new and powerful insecticides to battle against these pests.

    One insecticide widely used on everything from forests to parks, beaches to bedrooms, was DDT (dichlorodiphenyltrichloroethane). DDT was purported to be safe, without any side effects. Over time, this was shown to be untrue. DDT bioaccumulates, or builds up, in the fatty tissues of creatures that come into contact with it, either in their environment or their food.

    As it progresses up the food chain, DDT biomagnifies, resulting in higher predators having greater amounts of the chemical in their tissues. In birds in particular, this biomagnification had dire consequences. It caused a thinning of their eggshells. Parent birds crushed their eggs while incubating them.

    The loss of songbirds and other species was brought to the attention of Carson, who had worked for the U.S. Fish and Wildlife Service. She was upset about this phenomenon and motivated to inform the public about what was happening to our wildlife.

    With the 1962 publication of Carson’s book Silent Spring, the issue of thinning eggshells and the loss of birds was brought to the attention of the public in a major way.

    By this time, however, the populations of many species had already been drastically reduced. Due to biomagnification, top predatory birds like hawks, eagles, and pelicans were devastated. The brown pelican was becoming increasingly rare throughout its North American range.

    Larry Schweiger, the president and CEO of the National Wildlife Federation, believes Carson’s work was a turning point for birds, including the brown pelican.

    “My personal view is that Rachel Carson's book really woke up the public to what scientists had been saying for some time, and that was the decline of certain bird species including the California brown pelican,” he says.

    Schweiger says Silent Spring helped influence the creation of the Environmental Protection Agency in 1970, the Endangered Species Act in 1973, and the ban on DDT in 1972. The Endangered Species Act ordered the creation of a Species Recovery Plan and extreme protection of any species listed. The brown pelican was one of the first species to be protected.

    “What [Carson] did do was she sparked an awakening that swept across America, and that awakening triggered an upwelling that really took several years after her death [in 1964] to come to fruition,” Schweiger says.

    As a result of the DDT ban, careful species management, and protection, the brown pelican has recovered. In 2009, the U.S. Fish and Wildlife Service removed the brown pelican from the federal list of endangered species, and the California Fish and Game Commission removed the subspecies from the state’s list.

    Today, the U.S. Fish and Wildlife Service estimates that 650,000 brown pelicans exist globally, and a healthy breeding population of more than 140,000 birds thrives along the Pacific coast.

    Taking Flight
    Found in warm coastal marine environments, the brown pelican can often be spotted following fishing boats and hanging around piers for handouts.

    Read It!
    Check out a summary of the Endangered Species Act of 1973 or read the real thing.

    Lasting Effects
    The largest source of DDT in the United States was the Montrose Chemical Corporation in Los Angeles County. Over 1,700 metric tons of DDT was discharged from the factory through the sewage treatment plant and into the Pacific Ocean. The former site of the chemical plant remains contaminated to this day.

    Listening to Nature
    The key thing about Rachel Carson is that she and her mother used to spend time in western Pennsylvania hiking and being in nature. She had a deep connection with nature, so she learned to listen to nature.
    Larry Schweiger, president and CEO, National Wildlife Federation

  • Term Part of Speech Definition Encyclopedic Entry
    bald eagle Noun

    white-headed bird of prey native to North America.

    ban Verb

    to prohibit, or not allow.

    beach Noun

    narrow strip of land that lies along a body of water.

    Encyclopedic Entry: beach
    biomagnification Noun

    process in which the concentration of a substance increases as it passes up the food chain.

    bird Noun

    egg-laying animal with feathers, wings, and a beak.

    chemical Noun

    molecular properties of a substance.

    crop Noun

    agricultural produce.

    Encyclopedic Entry: crop
    DDT Noun

    (dichloro-diphenyl-trichloroethane) toxic chemical used as an insecticide but illegal for most uses in the U.S. since 1972.

    Endangered Species Act Noun

    (1973) U.S. legislation that protects endangered species when they are threatened by human activity.

    extinct Adjective

    no longer existing.

    extinction Noun

    process of complete disappearance of a species from Earth.

    food Noun

    material, usually of plant or animal origin, that living organisms use to obtain nutrients.

    Encyclopedic Entry: food
    food chain Noun

    group of organisms linked in order of the food they eat, from producers to consumers, and from prey, predators, scavengers, and decomposers.

    Encyclopedic Entry: food chain
    influential Adjective

    important; having the ability to lead the opinions or attitudes of others.

    insect Noun

    type of animal that breathes air and has a body divided into three segments, with six legs and usually wings.

    mosquito Noun

    insect capable of piercing the skin and sucking the blood of animals.

    pelican Noun

    large marine bird with a big bill.

    pest Noun

    harmful or annoying person or thing.

    plague Verb

    to consistently bother, torment, or annoy.

    rare Adjective

    unusual or uncommon.

    reduce Verb

    to lower or lessen.

    scientist Noun

    person who studies a specific type of knowledge using the scientific method.

    songbird Noun

    bird with a recognizable vocal pattern.

    tissue Noun

    cells that form a specific function in a living organism.

    wildlife Noun

    organisms living in a natural environment.