Black bears are found only in North America and have a relatively impressive population base - double that of all other bear species combined. Despite the common name, their coats vary from light cinnamon to dark charcoal, variants thought to have evolved from different regional geographical pressures. Black bears are full of curiosity and have complex family relationships which result from the slow maturation of cubs. During this time, mothers impart vital hunting and navigational skills to their offspring.
Did you know?
Black bears are highly efficient hibernators; they can sleep for up to seven months without eating or drinking.
Friday, August 29, 2014
Black bear
Black bears are found only in North America and have a relatively impressive population base - double that of all other bear species combined. Despite the common name, their coats vary from light cinnamon to dark charcoal, variants thought to have evolved from different regional geographical pressures. Black bears are full of curiosity and have complex family relationships which result from the slow maturation of cubs. During this time, mothers impart vital hunting and navigational skills to their offspring.
Did you know?
Black bears are highly efficient hibernators; they can sleep for up to seven months without eating or drinking.
Territorial
Territorial animals actively defend the area in which they live and more importantly on which they depend for resources. If the animal doesn't advertise its ownership and defend it from members of its own species, it isn't territorial. Often, advertising takes the form of scent marking the territory boundaries as a clear marker for others to stay away. Challenges and disputes can be resolved in a number of ways, not always violently. In addition to these 'traditional' territories, the males of some non-territorial species - such as wildebeest - establish temporary mini-territories in the mating season to impress the females.
Peacock butterfly
Peacock butterflies are certainly one of the most eye-catching creatures in the UK. Flitting between nectar-rich flowers of gardens and parks all summer long, come winter they seem to disappear. In fact they just fold up their wings and blend into a hollow tree or wooden shed, emerging in spring to lay eggs on nettle plants. The four stunning eyespots on the wing, resembling the tail feather pattern of the peacock, are there to frighten away or divert predators. Male peacock butterflies will defend a territory in summer, harassing any females that happen to pass through.
Metamorphosis
Metamorphosis is when a species changes body shape and structure at a particular point in its life cycle, such as when a tadpole turns into a frog. Sometimes, in locusts for example, the juvenile form is quite similar to the adult one. In others, they are radically different, and unrecognisable as the same species. The different forms may even entail a completely new lifestyle or habitat, such as when a ground-bound, leaf-eating caterpillar turns into a long distance flying, nectar-eating butterfly.
Chinese giant salamander
Chinese giant salamanders are the largest of the world's salamanders and can reach 1.8m in length. Despite this, their tadpoles are only 3cm long.
Asian giant salamanders
Asian giant salamanders are the largest salamanders in the world, and species are found in China and Japan. These impressive animals grow to around 1.5m long.
Salamanders
Salamanders are amphibians, although they may look lizard-like in appearance. Salamander species vary in size from under 3cm to about 180cm in length. No matter what their size, they need to stick to moist or wet environments, or they will dehydrate.
Amphibians
Amphibians include frogs, salamanders and caecilians. A typical amphibian has a larval stage spent in water during which it breathes through gills, and an adult stage that is less tied to water when they rely on lungs. However, there are some species that skip the tadpole stage and others that keep their gills throughout their life.
Vertebrates
Chordates include all the vertebrates and some invertebrate allies that possess, for part or all of their lives, a structure called a notochord. The notochord is a stiff rod that helps support the body and runs parallel to the main nerve cord. In the vertebrates, these have evolved into the spinal column, which is reinforced and protected by cartilage or bone. The allied invertebrates in the chordates phylum include members that only have the notochord for part of their life: the sea squirts, lancelets and hagfish.
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