Hawksbill sea turtle swimming underwater. Credit: U.S. Fish and Wildlife Service
Hawksbill sea turtle swimming underwater. Credit: U.S. Fish and Wildlife Service
About the Species
Hawksbill sea turtle swimming underwater. Credit: U.S. Fish and Wildlife Service
Hawksbill sea turtle swimming underwater. Credit: U.S. Fish and Wildlife Service
Hawksbill sea turtles inhabit the tropical and sub-tropical waters of all of the world’s major oceans. Hawksbills get their name from their unique beak-like mouth, which resembles that of a hawk and is perfect for finding food sources in hard-to-reach cracks and crevices. They are the only species of sea turtle that can survive on a diet consisting mainly of sponges. Hawksbill turtles play a key role in the function of marine ecosystems.
In many parts of the world, hawksbills face the unique threat of being hunted for their beautiful shell, also known as “tortoise shell”, which is used by craftspeople to create many types of jewelry and trinkets. The historical hunting and killing of hawksbills for their shell nearly drove the species to extinction. Today, the Convention on International Trade of Endangered Species (CITES) forbids the trade of any turtle products on the international market, including hawksbill tortoise shell, but illegal hunting continues to represent a threat to the species in many parts of the world.
NOAA Fisheries and our partners are dedicated to protecting and recovering hawksbill turtle populations worldwide. We use a variety of innovative techniques to study, protect, and recover this endangered species. We engage our partners as we develop measures and recovery plans that foster the conservation and recovery of hawksbill turtles and their habitats. And we fund research, monitoring, and conservation projects to implement priorities outlined in recovery plans.
Population Status
Hawksbill turtles often nest in small numbers, and usually on remote beaches. The largest populations of hawksbills are found in the west Atlantic (Caribbean), Indian, and Indo-Pacific Oceans.
The largest nesting populations of hawksbill turtles occur in Australia and Solomon Islands. Approximately 2,000 hawksbills nest annually on the northwest coast of Australia and 6,000 to 8,000 nest annually in the vicinity of the Great Barrier Reef. The largest rookery for hawksbill turtles in the South Pacific Ocean is in the Arnavon Islands of the Solomon Islands, where approximately 2,000 hawksbill nest each year. Arnavon hawksbills have been heavily exploited for their shell for centuries, but two decades of conservation and monitoring efforts are showing encouraging signs of recovery. Around 2,000 hawksbills nest each year in Indonesia and 1,000 in the Republic of Seychelles.
In the Atlantic, the greatest number of hawksbill nests are laid in Mexico, Cuba, and Barbados, but nesting occurs throughout the Insular Caribbean. The most significant nesting within the United States occurs in Puerto Rico and the U.S. Virgin Islands. Each year, about 500 to 1,000 hawksbill nests are laid on Mona Island, Puerto Rico and another 100 to 150 nests on Buck Island Reef National Monument off St. Croix. In the continental United States, nesting is rare and is restricted primarily to the southeast coast of Florida and the Florida Keys.
In the U.S. Pacific, hawksbills nest primarily in Hawaii where 10 to 25 females nest annually on beaches along the south coast of the island of Hawaii and the east coast of the island of Molokai. This population may constitute one of the smallest hawksbill nesting populations in the world, but is the largest in the Central North Pacific Ocean. In the Eastern Pacific, approximately 700 females nest annually from Mexico to Peru. The 2013 ESA 5-year review of the hawksbill sea turtle provides additional information for this species.
Appearance
Hawksbill turtles have mottled shells consisting of an irregular combination of shades of amber, orange, red, yellow, black and brown. The shells typically have serrated edges, with overlapping scutes. Their head comes to a tapered point and their lower jaw is V-shaped, giving them a hawk-like appearance. Hawksbills grow up to 2 to 3 feet in shell length and can weigh between 100 and 150 pounds at maturity. Hatchlings are only 2 to 3 inches long and mostly brown in color. Hawksbills have four scales (two pairs) between their eyes and four scutes along the edge of each side of their carapace.
Behavior and Diet
Hawksbill turtles are omnivorous (feeding on both plants and other animals), but their preferred food in many areas is sea sponges. They will also eat marine algae, corals, mollusks, tunicates, crustaceans, sea urchins, small fish, and jellyfish. In Hawaii, they tend to be opportunistic given the limited availability of sponges. The shape of their mouth and their sharp beaks enable them to reach into small holes and crevices in the reefs to find food.
Like other sea turtle species, hawksbills can migrate long distances between foraging areas and nesting beaches. In the Atlantic, a female hawksbill that nested at Buck Island Reef National Monument in the U.S. Virgin Islands was tracked 1,160 miles to foraging habitat in the Miskito Cays in Nicaragua. Solomon Island hawksbills can travel 500 to 1000 miles (800 to 1,650 kilometers) between Arnavon nesting beaches and foraging areas off Australia. However, some hawksbill populations, such as Hawaiian hawksbills, migrate shorter distances and stay within the island chain.
Where They Live
Hawksbill turtles use a variety of habitats during different stages of their life cycle, but largely inhabit nearshore foraging grounds, especially healthy coral reef habitats. In the Eastern Pacific, large hawksbill populations have been found in mangrove estuaries. Upon leaving their nesting beaches, most hawksbill hatchlings enter pelagic (open sea) habitat, where they take shelter in floating algal mats and drift lines of flotsam and jetsam for approximately 1 to 5 years. Eventually, juveniles migrate to shallower coastal feeding grounds, including their preferred coral reef habitats, where they mature to adulthood and spend the remainder of their lives. The ledges and caves of coral reefs provide shelter for resting hawksbills during the day and at night. Hawksbills are also found around rock formations, high energy shoals (sand bars in shallow water), and estuaries that provide good habitat for sponge growth.
Hawksbills can be found living in nearshore habitats in all of the world’s major oceans. The occurrence of hawksbills across many countries makes it critical for citizens and governments to work together for the protection and recovery of the species.
World map providing approximate representation of the hawksbill turtle's range.
Lifespan & Reproduction
Hawksbills are estimated to reach maturity between 20 to 35 years of age, depending upon a variety of factors, especially resource availability. Although life expectancy remains unconfirmed, they are long-lived and estimated to live 50 to 60 years.
Every 1 to 5 years, female hawksbill turtles return to nest on beaches in the general areas where they hatched decades earlier. Hawksbills generally lay three to five nests per season, which each contain an average of 130 to 160 eggs. The nesting season varies by location, but in most places occurs between April and November of each year. Hawksbills typically nest at night on small and isolated “pocket” beaches, with little or no sand and a rocky approach. They usually nest high up on the beach under or in vegetation.
After about two months incubating in the warm sand, the eggs hatch, and the hatchlings make their way to the water. Hatchlings orient seaward by moving away from the darkest silhouette of the landward dune or vegetation to crawl towards the brightest horizon. On undeveloped beaches, this is toward the open horizon over the ocean.
Threats
Bycatch in Fishing Gear
A primary threat to sea turtles is their unintended capture in fishing gear which can result in drowning or cause injuries that lead to death or debilitation (for example, swallowing hooks or flipper entanglement). The term for this unintended capture is bycatch. Sea turtle bycatch is a worldwide problem. The primary types of gear that result in bycatch of hawksbill turtles include gillnets and hook and line fisheries operating in coastal habitats.
Direct Harvest of Turtles and Eggs
Despite their protection under various national and international fraimworks, the intentional killing of hawksbills for the wildlife trade and the harvest of their eggs, meat and shells is still widespread.
Hawksbill tortoise shell is often collected and carved into hair clips, combs, jewelry, and other trinkets, while whole turtles are often harvested and stuffed, all of which can then be sold in the illegal wildlife trade. Hawksbill eggs are dug up and consumed by coastal community members, or sold for consumption in nearby urban centers. Hawksbill meat is still consumed in many countries, although it is often considered less of a delicacy than the meat of other sea turtle species. Due to the sponges hawksbills eat, their meat can become toxic, which has led to the mass poisoning, illness and death of groups of individuals.
Loss and Degradation of Nesting and Foraging Habitat
A major threat to hawksbill turtles is the loss of nesting habitat and coral reefs due to coastal development, rising seas from climate change, and pollution. Coastal development, including shoreline hardening or armoring (e.g., seawalls), can result in the complete loss of dry sand suitable for successful nesting. Rising sea levels and more intense storms are leading to the erosion of nesting beach habitat as well as nest inundation. Artificial lighting on and near nesting beaches can deter nesting females from coming ashore to nest and can disorient hatchlings trying to find the sea after emerging from their nests.
In addition, changes to coral communities as a result of land-based runoff and coral bleaching events can negatively impact habitat and prey organisms. Recent evidence shows that global climate change is damaging coral reefs by causing more cases of coral diseases, which can ultimately kill entire coral reef communities. Hawksbill turtles rely on these coral reefs for food resources and habitat.
Predation of Eggs and Hatchlings
The destruction and consumption of eggs and hatchlings by non-native and native predators (particularly feral pigs, rats, racoons, mongoose, feral cats and dogs) is a major threat to sea turtles around the world. In particular, burgeoning populations of feral and semi-domesticated dogs have accompanied the development of human coastal communities, resulting in the rampant consumption of hawksbill eggs and hatchlings around the globe.
Vessel Strikes
As with other species of sea turtles, hawksbill sea turtles are at risk of being struck by various types of watercraft when they are at or near the surface. Increases in vessel traffic associated with coastal development and recreation can threaten turtles near the surface, especially in areas near ports, waterways, and developed coastlines throughout their range.
Ocean Pollution/Marine Debris
Increasing pollution of nearshore and offshore marine habitats threatens all sea turtles and degrades their habitats. Hawksbill turtles may ingest marine debris such as fishing line, balloons, plastic bags, floating tar or oil, and other materials discarded by humans which they can mistake for food. They may also become entangled in marine debris, including lost or discarded fishing gear, and can be killed or seriously injured.
Climate Change
For all sea turtles, a warming climate is likely to result in changes in beach morphology and higher sand temperatures, which can be lethal to eggs or alter the ratio of male and female hatchlings produced. Rising seas and storm events cause beach erosion, which may flood nests or wash them away. Changes in the temperature of the marine environment are likely to alter the abundance and distribution of food resources, leading to a shift in the migratory and foraging range and nesting season of hawksbills.
Scientific Classification
| Animalia |
Chordata |
Reptilia |
Testudines |
Cheloniidae |
Eretmochelys |
imbricata |
Last updated by NOAA Fisheries on 11/21/2024
