Personality Plants in a Can
Yes, you can garden in a can. Select a plant and a can to reflect your personality. For example, if you are a chocolate lover, grow chocolate mint in a Yoohoo can. If you are a ham all the time, grow thyme in a ham tin.
Click on the image and print the complete directions, including
a picture of these finished plants in a can.
Delighting in Dolphins
Everyone loves dolphins! Known for their playful behavior, unique "smiles" and uncanny intelligence, these agile marine mammals have fascinated people since ancient times. They've saved sailors, helped find bombs buried deep under the sea, and even provided loving therapy for humans in need. This month, we'll dive deep into dolphin life and lore.
Props and Preparations
- Print the complete discussion below for the facilitator, including discussion questions.
- Print a copy of the pictures in this article to pass around during the discussion.
- Play this informative YouTube video about dolphins prior to or after your presentation.
Delighting in Dolphins
The people of ancient Greece, one of the first great seafaring nations, had many myths about dolphins and glorified this sea creature throughout their culture. The word dolphin comes to us from the Greek word delphis, very similar to delplys, meaning “womb.” Perhaps this is an allusion to the fact that the dolphin is a mammal that gives birth to live young and suckles them with milk.
One of the most famous Greek myths involving the dolphin is the story of the god Dionysus. Dionysus, disguised as a human, was traveling aboard a ship when the crew decided to sell him into slavery rather than deliver him safely to his destination. When Dionysus learned of their plot, he drove the crew mad with hallucinations, and they jumped into the sea. They repented as they were drowning, and Dionysus took pity on them and changed them into dolphins so they could survive in the sea.
This ancient myth is often cited as the reason that, even to this day, Greeks are appalled at the thought of killing a dolphin. Dolphins were once human and, it seems, retain many human characteristics, such as the way they care for their young and for each other.
The Dolphin Family
Dolphins are part of a family of toothed whales that includes orcas, or killer whales, and pilot whales. Most dolphin species are found in tropical and temperate oceans throughout the world, although there are four species that live in rivers. They all eat fish, squid, and crustaceans.
The bottlenose dolphin is the most common of all 36 species. They’re the dolphins you’re most likely to see when you visit an aquarium or marine animal facility. They are also the species that scientists have used in most intelligence and behavior testing. They’re playful, easy to train, and seem to be more interested in approaching humans in the wild than the other dolphin species are. Flipper, star of the 1960s movies and television series of the same name, was a bottlenose dolphin.
While the bottlenose has been known for many years, in 2011 scientists recognized a new species of dolphin living around Australia. The Burrunan dolphin—Burrunan is an Aboriginal name meaning “large sea fish of the porpoise kind”—is currently found in only two areas of the world: Port Phillip Bay around Melbourne and about 100 miles away in the coastal lakes of Gippsland.
How Smart Are Dolphins?
Many people believe the dolphin’s trainability is an indication of its intelligence, but scientists aren’t so sure. It’s difficult and expensive to test the intelligence of dolphins in the wild; researchers know that captive dolphins respond differently depending on their surroundings and might not be representative of the behavior of those in the wild.
Dolphins do have a very large brain. And they have a greater brain-to-body weight ratio—something that scientists agree is important in determining intelligence—than any mammal except humans. Their brain ratios are twice that of any of the great apes. And, with two hemispheres and a heavily convoluted surface, the appearance of their brains is strikingly similar to that of human beings.
But there’s more to intelligence than just brain size and appearance or even the ability to learn complex behaviors. The most important reason scientists think dolphins possess great intelligence is the way dolphins communicate with each other.
Do Dolphins Have Language?
Dolphins make sounds for two purposes: navigation and communication. Navigational sounds are clicks produced in their nasal passages just below their blowholes. They help dolphins detect an immense amount of information about their surroundings. Communication sounds, on the other hand, are a sophisticated collection of high-pitched whistles and squeals that the dolphins produce in their larynx or voice box. Scientists who study the whistles say they are single tones used only to communicate with other dolphins, and squeals are used to express alarm or excitement.
But all animals use sounds and behaviors to communicate with each other, so the big question is: do dolphins really have a language? According to some studies, dolphin communication follows the same basic patterns as human-based language. Recent findings also indicate that dolphins use a signature whistle to identify themselves and that other dolphins in their family group, or pod, will imitate the whistle to call or find them. Unfortunately, until we can fully understand and duplicate their language, human-dolphin communication will remain limited.
Dolphins in Danger
As with many wild creatures, the biggest threat to their existence comes from humans. In fact, research suggests that over 95 percent of dolphin deaths in the wild are directly attributable to human-related causes. Some of the greatest threats to dolphins include increasing captivity, loss of food supply due to global warming, chemical pollution of the oceans, noise pollution, and traumatic injuries due to accidental capture in nets or collisions with ships and rotor blades. In addition, the dolphin is caught for food by fishers from some countries, including Japan, Peru, and other Latin American countries.
But the outlook for dolphins is far from bleak. Many fine national and international organizations are dedicated to helping this unique mammal survive and thrive in the world’s oceans and rivers.
Dolphin Q & A
How deep can a dolphin dive?
Up to 1,000 feet.
How fast can dolphins swim?
Up to 25 miles per hour. That’s about three times as fast as the fastest humans.
How long do dolphins live?
The average lifespan is about 17 years. However, some observed in the wild have lived 50 years.
What is a group of dolphins called?
Can dolphins see well in the water?
Yes, due to the unique light-gathering ability of their retina.
How high in the air can a dolphin leap?
Up to 20 feet in the air.
What is the largest member of the dolphin family?
The killer whale, or orca, is the largest member. It can reach 30 feet in length.
What is the name for the tail of a dolphin?
Are all dolphins hairless?
No, the Boto River dolphin retains a small amount of hair into adulthood.
Do dolphins have a well-developed sense of smell?
No, dolphins have a very poor sense of smell.
- The dolphin is the only mammal that naturally gives birth with the tail first instead of the head.
- Young dolphins remain with their mother for two or three years.
- A dolphin has about 100 teeth. They use them for catching prey, not chewing. All prey is swallowed whole.
- Dolphins rarely hunt alone. Most feeding methods involve cooperation with other pod members.
- Scientists don’t know why, but dolphins can tolerate and recover from deep wounds. They heal rapidly, and even very deep wounds do not cause hemorrhaging or infection.
- Except for humans, dolphins have few natural enemies.
- The ancient Greeks thought a dolphin riding in a ship’s wake was a sign of good luck.
- Dolphin calves are born underwater, and within seconds, their mothers rush them to the surface for their first breath of air.
- Dolphins are known for spy-hopping—rising vertically out of the water to survey their surroundings.
- Dolphins, along with whales and porpoises, are considered descendants of land mammals who became aquatic about 50 million years ago.
- If you live near an aquarium with dolphins, plan a field trip to see them.
- Rent and watch Flipper, The Day of the Dolphin, or Dolphin Tale and discuss the portrayal of dolphins in each.
- Read Leo Szilard’s The Voice of the Dolphin or So Long, and Thanks for the Fish from Douglas Adams’ The Hitchhiker’s Guide to the Galaxy.
- Find out more about dolphin conservation.
- Links to stories to read aloud about dolphins saving people’s lives.