Solenodon

The two species of solenodon were first discovered by Europeans in 1833 on the islands of Hispaniola and Cuba. They are shrew-like creatures with an even more antiquated look about them than the true shrews. Fossil evidence shows that they were in existence 30 million years ago in North America. They seem therefore to be primitive insectivores¤survivors from the past that have managed to hang on in these two islands because there are so few natural enemies there.

Solnodons are a foot long, with a tail up to 10 in. They have stout bodies with a disproportionately large head, made to look the more ungainly because of the unusually long snout. In most animals the snout forms a cushion of flesh just in front of the tips of the nasal bones. In solenodon, as in some other insectivores, there is a rod of cartilage, or gristle, in front of the nasals, supporting its unusually long snout. There are many long bristles on the face, the eyes are very small, the ears partly naked and mostly hidden in the fur. The coat is blackish to reddish brown, paler on the underside. The tail is nearly naked and so are the legs and the large feet each with five toes bearing large, strong claws. The especially large forefeet have larger and more curved claws than those on the hindfeet.

No straight path

One reason why it was so long before scientists got to know of solenodons is that they are nocturnal. They are also not very numerous. During the day they lie up in burrows, in hollow trees and logs or in caves, well out of sight. When they do come out they run on their toes with a stiff ungainly waddle, following an erratic almost zigzag course. The local people claim that

solenodons never run in a straight line. Moreover, when a solenodon is alarmed and tries to put on speed it is as likely as not to trip over its own toes or even tumble head-- over-heels. Like some of the shrews which they resemble, although they are not closely related to them, they have a poisonous saliva. The second incisor on each side in the lower jaw is grooved. Indeed, solenodon means grooved tooth. At the base of each of these incisors is a gland from which the poison runs along the groove in each tooth. When solenodons fight in captivity the light wounds inflicted are fatal.

Dying out in the midst of plenty

Solenodons eat a wide variety of animal and plant foods, such as insects, worms and small invertebrates generally, as well as small reptiles. I hey also eat roots, fruits and leaves. They root in the ground with their long snouts, dig with their stout claws or rip open rotten logs. Solenodons in captivity have been seen to bathe often and to drink only when bathing. Perhaps the long snout makes any other way difficult. For animals with such habits there is no shortage of food but solenodons are be coming. more and more rare. This is partly due to their slow rate of breeding. The female may have two litters a year of 1-3 young but she has only two teats in an unusual position¤almost on the buttocks!

Doomed

As well as having a poisonous bite a solenodon has glands in the armpits and in the groin, which give off a goat-like smell. It readily defends itself against one of its own kind, and probably attacks other animals savagely judging from the way a captive solenodon attacked a young chicken and tore it to pieces with its strong claws, before eating it. In moments of excitement it may grunt like a pig or give bird-like cries. but when pursued it stays motionless and hides its head, so it can be picked up easily. Taking all these facts together the solenodon is a slow mover, clumsy runner, with no agility in avoiding enemies and poor means of defence. As a result, once dogs and cats were taken to its island homes, and especially when mongooses were introduced, its future began to look black. Probably the only way of saving it would be to set up reserves, but this is hardly practical on (Cuba or Hispaniola today, and tomorrow may be too late. Although we speak about what solenodons in captivity have done, these are only random observations and the number of animals that have found their way to zoos is very small: at the last count in June 1969 10 Haitian solenodons were to be found in 5 zoos throughout the world. No Cuban ones are in captivity as far as is known.

class	Mammalia
order	Insectivora
family	Solenodontidae
genus & species	Solenodon cubanus Cuban solenodon S. paradoxus Haitian solenodon

Kakapo

The Kakapo (Māori: kākāpō, meaning night parrot), Strigops habroptilus (from the Greek strix, genitive strigos: owl and opsis: face; and habros: soft, and ptilon: feather), also called owl parrot, is a species of nocturnal parrot with finely blotched yellow-green plumage endemic to New Zealand. It has a distinct facial disc of sensory, vibrissa-like feathers, a large grey beak, short legs, large feet, and wings and a tail of relatively short length. A certain combination of traits makes it unique among its kind—it is the world's only flightless parrot, the heaviest parrot, nocturnal, herbivorous, visibly sexually dimorphic in body size, has a low basal metabolic rate, no male parental care, and is the only parrot to have a polygynous lek breeding system. It is also possibly one of the world's longest-living birds. Its anatomy typifies the tendency of bird evolution on oceanic islands with few predators and abundant food: accretion of thermodynamic efficiency at the expense of flight abilities, reduced wing muscles, a diminished keel on the sternum, a generally robust physique.

Kakapo are critically endangered; only 91 living individuals are known, all of which have been given names.The ancestral Kakapo migrated to the islands of New Zealand in prehistory; in the absence of mammalian predators, it lost the ability to fly. Because of Polynesian and European colonisation and the introduction of predators such as cats, rats, and stoats, most of the Kakapo were wiped out. Conservation efforts began in the 1890s, but they were not very successful until the implementation of the Kakapo Recovery Plan in the 1980s. As of November 2005, surviving Kakapo are kept on four predator-free islands, Maud, Chalky (Te Kakahu), Codfish (Whenua Hou) and Anchor islands, where they are closely monitored. Two large Fiordland islands, Resolution and Secretary, have been the subject of large-scale ecological restoration activities to prepare self-sustaining ecosystems with suitable habitat for the Kakapo.

The conservation of the Kakapo has made the species well known. Many books and documentaries detailing the plight of the Kakapo have been produced in recent years, one of the earliest being Two in the Bush, made by Gerald Durrell for the BBC in 1962. Two of the most significant documentaries, both made by NHNZ, are Kakapo - Night Parrot (1982) and To Save the Kakapo (1997). The BBC's Natural History Unit also featured the Kakapo, including a sequence with Sir David Attenborough in The Life of Birds. It was also one of the endangered animals that Douglas Adams and Mark Carwardine set out to find for the radio series and book Last Chance to See.

The Kakapo, like many other bird species, has historically been important to the Māori, the indigenous people of New Zealand, appearing in many of the traditional legends and folklore.

Kakapo are large, rotund parrots; males measure up to 60 centimetres (24 in) and weigh between 2 and 4 kilograms (4.5–9 lb) at maturity.Kakapo are unable to fly, having short wings for their size and lacking the pronounced keel bone (sternum) that anchors the flight muscles of other birds. They use their wings for balance, support, and to break their falls when leaping from trees. Unlike other land birds, Kakapo can accumulate large amounts of body fat to store energy making them the heaviest parrot.

The upper parts of the Kakapo have yellowish moss-green feathers barred or mottled with black or dark brownish grey, blending well with native vegetation. Individuals may have strongly varying degrees of mottling and colour tone and intensity — museum specimens have shown that some birds had completely yellow colouring. The breast and flanks are yellowish-green streaked with yellow. Their bellies, undertail, necks and faces are predominantly yellowish, streaked with pale green and weakly mottled with brownish-grey.

Because the feathers do not need the strength and stiffness required for flight, they are exceptionally soft, giving rise to the specific epithet habroptilus. Kakapo have a conspicuous facial disc of fine feathers, resembling the face of an owl; thus, early European settlers called it the "owl parrot". Their beaks are surrounded by delicate vibrissa or "whiskers", which they use to sense the ground for navigation as they walk with their heads lowered. The mandible is mostly ivory-colored, with part of the upper mandible being bluish-grey. The eyes are dark brown. Kakapo feet are large, scaly, and, as in all parrots, zygodactyl (two toes face forward and two backward). They have pronounced claws particularly useful for climbing. The ends of their tail feathers often become worn from being continually dragged on the ground.

Females are easily distinguished from males due to some notable differences: they have a more narrow and less domed head, their beaks are narrower and proportionally longer, their ceres and nostrils smaller, their legs and feet more slender and pinkish grey, and their tails are proportionally longer. While their plumage color is not very different to that of males, the toning is more subtle, with less yellow and mottling. They tend to be more resistant and aggressive than males when handled. Nesting females are also distinguished by a brood patch on the bare skin of the belly.

Like many parrots, Kakapo have a variety of calls. In addition to the booms (see below for a recording) and chings of their mating calls, they often skraark to announce their location to other birds.

Kakapo have a well-developed sense of smell, which complements their nocturnal lifestyle. They can discriminate among odours while foraging; a behaviour reported for only one other parrot species. One of the most striking characteristics of Kakapo is their pleasant and powerful odour, which has been variously described as musky, honey-like or fruity.Given the Kakapo's well-developed sense of smell, this scent may be a social chemosignal. The smell often alerts predators to the largely defenseless Kakapo.

Classification

The Kakapo has so many unusual features that it was initially placed in its own family, Strigopidae. However, it is now recognised as a member of the parrot family, Psittacidae. Its distinctiveness is highlighted by its classification in its own genus, Strigops; and tribe, Strigopini, in the subfamily Psittacinae. Some maintain the Kakapo in a subfamily of its own, Strigopinae.

Earlier ornithologists felt the Kakapo may be related to the Ground Parrot and Night Parrot of Australia; others pointed to the Nestorini tribe. A 2005 sex chromosome spindlin DNA sequence study confirmed affinities with the genus Nestor, which contains the Kākā and the Kea. The molecular data further suggests that the two Nestor species, and the Kakapo in its own genus, comprise an ancient group that split off from all other Psittacidae before their radiation, but fossil evidence seems to contradict this^{[citation needed]}; given the violent geological history of New Zealand (see, for example, Taupo Volcanic Zone), other explanations such as episodes of genetic drift seem better supported by evidence.

Groups of animals

The sponges (Porifera) were long thought to have diverged from other animals early. As mentioned above, they lack the complex organization found in most other phyla. Their cells are differentiated, but in most cases not organized into distinct tissues. Sponges are sessile and typically feed by drawing in water through pores. Archaeocyatha, which have fused skeletons, may represent sponges or a separate phylum. However, a phylogenomic study in 2008 of 150 genes in 21 genera revealed that it is the Ctenophora or comb jellies which are the basal lineage of animals, at least among those 21 phyla. The authors speculate that sponges—or at least those lines of sponges they investigated—are not so primitive, but may instead be secondarily simplified.

Among the other phyla, the Ctenophora and the Cnidaria, which includes sea anemones, corals, and jellyfish, are radially symmetric and have digestive chambers with a single opening, which serves as both the mouth and the anus. Both have distinct tissues, but they are not organized into organs. There are only two main germ layers, the ectoderm and endoderm, with only scattered cells between them. As such, these animals are sometimes called diploblastic. The tiny Placozoans are similar, but they do not have a permanent digestive chamber.

The remaining animals form a monophyletic group called the Bilateria. For the most part, they are bilaterally symmetric, and often have a specialized head with feeding and sensory organs. The body is triploblastic, i.e. all three germ layers are well-developed, and tissues form distinct organs. The digestive chamber has two openings, a mouth and an anus, and there is also an internal body cavity called a coelom or pseudocoelom. There are exceptions to each of these characteristics, however - for instance adult echinoderms are radially symmetric, and certain parasitic worms have extremely simplified body structures.

Genetic studies have considerably changed our understanding of the relationships within the Bilateria. Most appear to belong to two major lineages: the Deuterostomes and Protostomes, which includes the Ecdysozoa, Platyzoa, and Lophotrochozoa. In addition, there are a few small groups of bilaterians with relatively similar structure that appear to have diverged before these major groups. These include the Acoelomorpha, Rhombozoa, and Orthonectida. The Myxozoa, single-celled parasites that were originally considered Protozoa, are now believed to have developed from the Bilateria as well.

Superb Fairy-wren, Malurus cyaneus

Deuterostomes

Deuterostomes differ from the other Bilateria, called protostomes, in several ways. In both cases there is a complete digestive tract. However, in protostomes the initial opening (the archenteron) develops into the mouth, and an anus forms separately. In deuterostomes this is reversed. In most protostomes, cells simply fill in the interior of the gastrula to form the mesoderm, called schizocoelous development, but in deuterostomes it forms through invagination of the endoderm, called enterocoelic pouching. Deuterostomes also have a dorsal, rather than a ventral, nerve chord and their embryos undergo different cleavage.

All this suggests the deuterostomes and protostomes are separate, monophyletic lineages. The main phyla of deuterostomes are the Echinodermata and Chordata. The former are radially symmetric and exclusively marine, such as starfish, sea urchins, and sea cucumbers. The latter are dominated by the vertebrates, animals with backbones. These include fish, amphibians, reptiles, birds, and mammals.

In addition to these, the deuterostomes also include the Hemichordata or acorn worms. Although they are not especially prominent today, the important fossil graptolites may belong to this group.

The Chaetognatha or arrow worms may also be deuterostomes, but more recent studies suggest protostome affinities.

Yellow-winged Darter, Sympetrum flaveolum

Ecdysozoa

The Ecdysozoa are protostomes, named after the common trait of growth by moulting or ecdysis. The largest animal phylum belongs here, the Arthropoda, including insects, spiders, crabs, and their kin. All these organisms have a body divided into repeating segments, typically with paired appendages. Two smaller phyla, the Onychophora and Tardigrada, are close relatives of the arthropods and share these traits.

The ecdysozoans also include the Nematoda or roundworms, the second largest animal phylum. Roundworms are typically microscopic, and occur in nearly every environment where there is water. A number are important parasites. Smaller phyla related to them are the Nematomorpha or horsehair worms, and the Kinorhyncha, Priapulida, and Loricifera. These groups have a reduced coelom, called a pseudocoelom.

The remaining two groups of protostomes are sometimes grouped together as the Spiralia, since in both embryos develop with spiral cleavage.

Platyzoa

The Platyzoa include the phylum Platyhelminthes, the flatworms. These were originally considered some of the most primitive Bilateria, but it now appears they developed from more complex ancestors.

A number of parasites are included in this group, such as the flukes and tapeworms. Flatworms are acoelomates, lacking a body cavity, as are their closest relatives, the microscopic Gastrotricha.

The other platyzoan phyla are mostly microscopic and pseudocoelomate. The most prominent are the Rotifera or rotifers, which are common in aqueous environments. They also include the Acanthocephala or spiny-headed worms, the Gnathostomulida, Micrognathozoa, and possibly the Cycliophora. These groups share the presence of complex jaws, from which they are called the Gnathifera.

Lophotrochozoa

The Lophotrochozoa include two of the most successful animal phyla, the Mollusca and Annelida.The former, which is the second-largest animal phylum, includes animals such as snails, clams, and squids, and the latter comprises the segmented worms, such as earthworms and leeches. These two groups have long been considered close relatives because of the common presence of trochophore larvae, but the annelids were considered closer to the arthropods, because they are both segmented. Now this is generally considered convergent evolution, owing to many morphological and genetic differences between the two phyla.

The Lophotrochozoa also include the Nemertea or ribbon worms, the Sipuncula, and several phyla that have a fan of cilia around the mouth, called a lophophore. These were traditionally grouped together as the lophophorates.but it now appears they are paraphyletic, some closer to the Nemertea and some to the Mollusca and Annelida. They include the Brachiopoda or lamp shells, which are prominent in the fossil record, the Entoprocta, the Phoronida, and possibly the Bryozoa or moss animals.

Animal

Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and independently. Animals are also heterotrophs, meaning they must ingest other organisms for sustenance.

Most known animal phyla appeared in the fossil record as marine species during the Cambrian explosion, about 542 million years ago.

The word "animal" comes from the Latin word animale, neuter of animalis, and is derived from anima, meaning vital breath or soul. In everyday colloquial usage, the word usually refers to non-human animals. The biological definition of the word refers to all members of the Kingdom Animalia. Therefore, when the word "animal" is used in a biological context, humans are included.

Origin and fossil record

Animals are generally considered to have evolved from a flagellated eukaryote. Their closest known living relatives are the choanoflagellates, collared flagellates that have a morphology similar to the choanocytes of certain sponges. Molecular studies place animals in a supergroup called the opisthokonts, which also include the choanoflagellates, fungi and a few small parasitic protists. The name comes from the posterior location of the flagellum in motile cells, such as most animal spermatozoa, whereas other eukaryotes tend to have anterior flagella.

The first fossils that might represent animals appear towards the end of the Precambrian, around 610 million years ago, and are known as the Ediacaran or Vendian biota. These are difficult to relate to later fossils, however. Some may represent precursors of modern phyla, but they may be separate groups, and it is possible they are not really animals at all. Aside from them, most known animal phyla make a more or less simultaneous appearance during the Cambrian period, about 542 million years ago.

It is still disputed whether this event, called the Cambrian explosion, represents a rapid divergence between different groups or a change in conditions that made fossilization possible. However some paleontologists and geologists would suggest that animals appeared much earlier than previously thought, possibly even as early as 1 billion years ago.

Trace fossils such as tracks and burrows found in Tonian era strata in India indicate the presence of triploblastic worm like metazoans roughly as large (about 5 mm wide) and complex as earthworms. In addition during the beginning of the Tonian period around 1 billion years ago (roughly the same time that the trace fossils previously discussed in this article date back to) there was a decrease in Stromatolite diversity which may indicate the appearance of grazing animals during this time as Stromatolites also increased in diversity shortly after the end-Ordovician and end-Permian rendered large amounts of grazing marine animals extinct and decreased shortly after their populations recovered.

However some other scientists doubt that these fossils are authentic and have suggested these trace fossils are just the result of natural processes such as erosion.