Humpback Whale Song Communication
Humpback Whales create several kinds of sounds to communicate with each other. There are social sounds, communicative sounds between mothers and calves, the feeding siren done in the feeding grounds, and the classic whale songs. In the 1950′s, their singing was discovered when the United States Navy experimented with hydrophones.
Social sounds are short, quick sounds which can hardly be heard under water with the human ear. These sounds can only be picked up with special hydrophones which would have to be close to the whales and pointed directly at them. The social sounds are used to communicate, especially when they travel slowly on the surface or when resting – but not when traveling at higher speeds. The majority of this kind of communication (85%) takes place between mothers and their calves, but also whales within a group communicating with each other.
It has been defined that only Humpback males are singing. Humpback Whales (Megaptera novaeangliae) go to a depth of between 40 and 130 feet and usually get into a certain position with their head downward, and remain motionless when they sing. Unlike a pop song with a melody, a whale song is more like a string of different sounds in different pitches that can sound like humming, snoring, groaning, sighing, or chirping. Similar to classical music, a whalesong consists of different themes which develop and build over the years. The whale songs can even be heard from a distance of 100 miles or more. The whales are singing mainly in their breeding grounds or on the way from or to their feeding grounds in cooler waters.
Green Sea Turtle and Plastic
Green Sea Turtles (Chelonia mydas) have spent the past 100 million years roaming seas, but are now the poster animal for the impact of plastic pollution on endangered species. A new study from researchers indicates that global sea turtle populations are mistakenly ingesting fatal quantities of plastic debris.
The report firmly lays the blame on so-called “disposable” plastics – beer cups, water bottles and caps, grocery bags, plastic utensils – intended to be used just once and thrown away. While these plastics are cheap and convenient, they are also durable and buoyant-making for a potent and deadly combination in the water. Though only 0.2-0.3% of all plastic ends up in the ocean, last year the world threw away 7 billion pounds of PVC, recycling just one quarter of one percent.
Though plastics like these do break down from exposure to sunlight and other elements, the molecules of plastic never fully biodegrade… they just break into smaller and smaller pieces, but never completely disappear. Eventually, many of these small particles get blown or washed into tributaries that feed rivers which flow to the ocean. Here they swirl in the eddying currents forming a sort of plastic soup where they float virtually forever. Persistence of plastic debris is poignantly illustrated in the account of plastic swallowed by an albatross that had originated from a plane shot down 60 years ago 6,000 miles away. The photo above shows plastic remnants found in the stomach of one young sea turtle.
Hawaiian Endangered Species
Before It’s too Late – Hawaii Isles of Extinction is a video about Hawaii’s unique plants, birds, and animals that are under threat from habitat destruction, development, pollution, and alien pests. It takes you on an unforgettable journey to some of Hawaii’s most spectacular islands to meet some of the rarest and most critically endangered creatures on the planet.
Today, with so many native species struggling for survival, this paradise has become known as the endangered species capital of the world. This video covers challenges facing the Green Sea Turtle, Hawksbill Sea Turtle, Hawaiian Monk Seal, coral reefs, plants, and Hawaiian birds. You will see the struggle many Hawaiian species face and meet the determined people who are acting to save them before it’s too late.
Green Sea Turtle Conservation
An estimated 100 to 350 female Green Sea Turtles nest each year at French Frigate Shoals in the Northwest Hawaiian Islands. Worldwide, fewer than 200,000 nesting females are thought to remain, where once there were several million. Some of the factors contributing to their decline are hunting, fishing, marine debris, and disease.
The Green Sea Turtle (Chelonia mydas) has long been hunted for their shells to make jewelry and ornaments, their skin to make leather goods, their meat and eggs for food, and their fat for oil. As a result, Hawaiian populations experienced dramatic declines, and since sea turtles take so many years to reach sexual maturity, it has taken 20 years since the passing of the Endangered species Act to see evidence of a population recovery.
Another cause of sea turtle death is from the unfortunate entanglement in longlines, driftnets, coastal gill nets and other discarded fishing gear. Commercial shrimpers use nets that trap and drown thousands of sea turtles each year. In 1992, regulations were finalized to require turtle excluder devices (TEDs), that keep turtles out of the nets.
Marine debris can prove deadly when sea turtles get entangle or they ingested it. Ingested plastics can clog the turtle’s digestive system and release toxic substances, causing them to starve or be poisoned. An infectious disease known as fibropapilloma is also a problem in Hawaii’s population. Fibropapilloma causes the growth of a large bulbous tumor on their soft tissue, which often spreads to many parts of the body, ultimately leading to their death. While the exact cause of the disease is not known, scientists suspect that a virus, parasite, or the effects of marine pollution may be involved.
Green Sea Turtles in Hawaii, are fully protected under both the federal Endangered Species Act and under Hawaii state law. Government agencies have formed a recovery team to help restore Hawaii’s green sea turtle population to previous levels. The goals of the recovery team are to identify research, management, and enforcement for effective sea turtle conservation in the islands as well as promoting sea turtle protection through public education programs.
National Public Lands Day 2010
National Public Lands Day 2010 celebrates, inspires, encourages, educates, and reminds us about how fortunate we are to be able to enjoy America’s natural wonders through outdoor recreation. Saturday, September 25, 2010 is the nation’s largest hands-on volunteer effort to improve and enhance the public lands Americans enjoy.
On this day in 2009 volunteers:
- Removed around 900,000 lbs of trash
- Collected around 20,000 lbs of invasive plants
- Built and maintained around 1,320 miles of trails
- Planted around 100,000 trees, shrubs and other native plants
- Contributed around $14 million to improve public lands
On Kauai, Kilauea Point National Wildlife Refuge is celebrating National Public Lands Day with a special program for Nene Awareness, and free admission. This is a great opportunity to spend time with family and discover maritime history, learn about native coastal plants, and migratory seabirds. Nene are one of the unique species that reside at Kilauea Point National Wildlife Refuge, and people can find out more about this endangered bird through interpretive tours, exhibits, and ranger-led activities.
The Nene was designated state bird of Hawaii in 1957, and has endured a long struggle against extinction. Conservationists have been breeding the bird in captivity in hopes of preserving the declining population and successfully re-establishing them in their native habitat. They have been successful with more than 800 nene on Kaua‘i and about 1,950 nene statewide in their effort to restore habitat and give this species a real chance to make a comeback.
Hawaiian Birds – Hawaiian Coot
The Hawaiian Coot (‘Alae Ke‘oke‘o) is a water bird endemic to Hawaii. There are currently an estimated 2,000 to 4,000 coots living in the main Hawaiian Islands of Maui, Oahu, the Big Island, Molokai, and Kauai, and it is federally listed as an endangered species.
The male and female Hawaiian Coot (Fulica alai) look alike, and are about 15 inches long, mostly dark gray or black on top, with white undertail feathers. The bill is ivory white (ke‘oke‘o meaning white), as is the bulbous frontal shield (or frontal knob). A very small percentage have frontal shields that are bluish white, yellow, or red. Their legs are light gray, and feet are lobed rather than webbed.
‘Alae Ke‘oke‘o are found in fresh and brackish-water marshes, ponds, taro fields, and wetlands. Most likely, they were more widely distributed in early Hawaii when cultivation of taro was much more extensive, and coastal fishponds were more numerous. Historical records do not indicate there ever were a large number of coots, yet the bird was significant in Hawaiian mythology and folklore and some early accounts report large populations on Kaua‘i.
Hawaiian coots are generalists and feed from grazing on land, or dabbling from the surface of the water, or diving for food. Food items include seeds, leaves, aquatic plants, snails, crustaceans, insects, tadpoles, and small fish. Photo by Jack Jeffrey
