Although it is one of the widest ranged sharks, the blue shark (Prionace glauca) may be threatened by over-harvesting. They migrate seasonally, moving from cooler to warmer waters. Blue sharks sometimes circle prey before attacking and they will gather in large numbers to eviscerate whale or porpoise carcasses. They can also be found following trawling boats, stealing the caught fish. The blue shark is known as a shark species that will attack humans, but just like with any other sharks, getting bitten by one is relatively rare.
The blue coral snake (Calliophis bivirgata) is sometimes colloquially referred to as the “100-pace snake” because it is said that a human can make it 100 paces away after sustaining a bite from this animal before they die. However, there are not many recorded cases of human fatalities due to this snake, which hints that the snake gets a worse reputation than it deserves. Its typical prey is other snakes.
Beautiful and elegant, the blue crane (Anthropoides paradiseus) is native to a relatively small area in South Africa (where it is the national bird). Populations of this bird have seriously declined since the 1970s for a number of anthropogenic reasons. They face habitat loss, bioaccumulation of toxins from insecticides, and life-threatening collisions with power lines. Conservation programs are now in place to aid the recovery of this species.
Coming in an array of blues and greens, the green and black poison-dart frog (Dendrobates auratus) belongs to a family of nearly 180 species that includes some of the most poisonous amphibians in the world.
Glass sculpture of a weevil species, family Curculionidae
Photo © Vittorio Costantini
Horned blenny (Parablennius intermedius)
The smallest of the penguins is the little blue penguin (Eudyptula minor). Unlike other penguins, it spends its days in the sea and typically comes on shore during the night. In areas where little blue penguins are common (southern Australia and New Zealand), great numbers of these birds can be seen coming ashore as night falls to avoid marine predators. However, even on land they are still at risk of being attacked by land mammals.
Photo © Frank Todd
Blue sea squirts (Rhopalaea crassa) reach about 4 cm in length and are found in western Pacific waters.
In North America, the call of the eastern bluebird (Sialia sialis) is regarded as a first sign of spring.
Photo by Ken Thomas
The blue-gray gnatcatcher (Polioptila caerulea) is found throughout North and Central America, from southern Canada to Guatemala and Cuba.
Photo from the Encyclopedia of Life