A spider that eats birds? An animal with five hands? An amphibious antelope? This week’s article features eight animal facts related to their feeding habits, physical characteristics and where they live.
The feathers of some sacred and exotic birds
Quetzals (Pharomachrus) are a very striking and colourful birds, which inhabit the forests and jungles of Central and South America. They had great cultural importance for pre-Hispanic civilisations, who considered these animals sacred. They used quetzal feathers to make ornaments for the priests of the god Quetzalcoatl, meaning ‘Feathered Serpent’. The tail feathers males can reach almost a meter in length, which is considerably longer than its body.
These very long feathers are fundamental during courtship, allowing males to attract females. However, they are not so efficient when it comes to flying. In fact, they can represent a major obstacle to survival. There is another group of long-feathered birds, that have found a solution to this problem: the widow of paradise (Vidua paradisaea). This species has tail feathers three times long than its body, but they are only present during the breeding season.
A giant spider with a very special diet
Spiders, contrary to what many people think, are not insects, but arachnids; arachnids are a group of predatory invertebrates that are characterised by having eight legs. They are common throughout the world, and are mostly terrestrial. Other examples of arachnids include mites and scorpions.
Species of spider found in the tropics tend to be larger. So much so that the planet’s largest spider, know as the Goliath tarantula (Theraphosa blondi), includes some very special prey in its diet: thanks to its large size (it can reach a diameter of 30 centimetres with its legs open), it’s capable of preying on reptiles, rodents or even small birds, which is why it is also known as the “bird tarantula”. Although its appearance may be fearsome, its sting is not deadly to humans, since the strength of its venom is similar to that of a wasp.
An animal with five hands
On the subject of spiders, did you know that, unlike an other species, spider monkeys (Ateles) can use their tail like a fifth hand? In fact, although many species of monkeys have long tails that they use to balance when climbing trees, spider monkeys have a prehensile tail (which means “capable of grasping”), which allows them hold and manipulate objects as if it were an extra hand. In addition, the tip of the tail, which is without hair, has the same level of sensitivity as their fingers.
Another advantage of having a prehensile tail is the ability of spider monkeys to hang easily from tree branches, as this tail is able to hold the entire body weight.
Big eagles that are skilled hunters
However, this prehensile tail wouldn’t be of much use to certain predators, such as some large birds of prey. Certain species of eagles have adapted to live in the jungles and forests of tropical regions, where they hunt and feed on, among other things, various species of monkeys that inhabit the tree canopies.
One of these raptors is the Philippine eagle (Pithecophaga jefferyi), a rare species that inhabits the forests of the Philippines, which is able to descend silently on its prey: usually small monkeys. The harpy eagle (Harpia harpyja) is another famous “monkey hunter”. This bird of prey with “striped pants” and a characteristic crest-like tuft of feathers on its head inhabits the forests of the tropical regions of America. Similarly, monkeys are also the most common prey of the African crowned eagle (Stephanoaetus coronatus), as well as big snakes…
And just as snakes may be preyed on by large birds of prey, there are snakes that feed exclusively on the eggs of birds.
In the arid lands of Africa there’s a genus of snakes called Dasypeltis. The sole source of food for this group of snakes are the eggs of certain species of birds. These snakes can dilate their mouths and bodies in such a way that they are able to swallow very large eggs. Once ingested, they are able to break the shell thanks to a series of spiky bones in their oesophagus, and then expel the broken fragments through their mouth.
A bird that sounds an alarm
The so-called “indicator birds” (Indicatoridae) are a set of common birds, usually of discrete plumage, that inhabit the tropical regions of Africa and Asia. They are considered climbing birds that, besides feeding on different kinds of insects, have a special fondness for bees wax! In fact, they are also commonly known as honeyguides.
The problem with eating bees wax is that they have to access the beehives to get it. Therefore, they have developed a characteristic behaviour and a series of mechanisms to encourage other species to help them in their task.
How do they do this? Well, when they spot a hive, these birds sound the alarm and attract animals, such as mice or humans. They then wait for their ‘assistants’ to break open the hives; once this is done, the indicator bird can feed not only on the wax, but also on the larvae and eggs.
Species with a built-in parachute
Now we are going from flying species, such as indicator birds, to other species that are also capable of “flying” in their own way. This time its a mammal. Although the only mammals that are truly capable of flying are bats, there are other species of marsupials that have developed a structures comparable to wings, adaptations that allow them to glide between trees.
The sugar glider (Petaurus breviceps), for example, is a nocturnal tree-dwelling marsupial, which lives in the forests of Australia, Tasmania, New Guinea and Indonesia, and has wide skin membranes which extend along its front and rear legs, forming a kind of parachute. Their long tail acts as a rudder, helping them fly in the right direction.
An amphibian antelope
From the heights of the tall trees we now descend to the deepest marshy areas, in search of a very special antelope, with unique characteristics. It should be noted that not all antelopes live in African savannas and deserts; some species, such as the sitatunga (Tragelaphus spekii), have opted for life near the water. This antelope is mostly solitary and can be found throughout Central Africa, where it lives in swampy areas with dense vegetation.
Living close to water means that this bovid has a series of adaptations that allow it to cope in the most flooded areas: for example, a long, thick coat similar to that of other aquatic mammals (such as the beaver), or long, curved hooves that are essential to avoid sinking in the mud. In fact, the sitatunga is an expert swimmer that can dive into deep water, leaving only its snout on the surface.