Creature Feature #164: Dogfish

Dogfish are a Family of cartilaginous fish and are, essentially, small sharks. This Spiny Dogfish was once the most abundant fish in the world, but thanks to over-fishing he is now vulnerable to extinction in many parts of the world, populations around Europe having decreased by 95%. Male fish sport a pair of pelvic fins, known as "claspers" which he uses to grasp the female when mating. Fertilisation is internal, and the eggs are retained within the female until they hatch. This process is known as "ovoviviparity".

Creature Feature #163: Dodo

The Dodo was a large, flightless pigeon who once roamed the forests of Mauritius. His fate was sealed, alas, when sailors landed on the island in the 16th century, bringing with them rats, cats, dogs, pigs - and guns. With no natural predators, the Dodo was a fearless and curious bird, eager to investigate these new arrivals. The sailors killed the Dodo not only for their meat, but for sport. This, combined with the impact the introduced animals had on their habitat, lead to the Dodo’s demise in 1662. Its extinction was not immediately noted - indeed the bird itself was considered a hoax - but he has now become the icon of extinction and the phrase “dead as a dodo” has become cliche.

Creature Feature #162: Dingo

The origin of the Dingo is much questioned. She is a subspecies of wolf and resembles the domestic and feral dogs of southern Asia and thus it is widely theorised that she was once domesticated. She has inhabited Australia for around 4,000 years, and now can be found in desert and grassland. Here she dens down in abandoned rabbit burrows. Packs generally consist of a mated pair and their offspring. An apex predator, her main diet is rabbit and juvenile kangaroo, although larger prey may be taken through co-operative hunting. Whilst her killing of rabbits is beneficial to cattle stations, she is also known to prey on sheep and as such is both loved and loathed.

Creature Feature #161: Dik-dik

The diminutive Dik-dik are small antelopes, standing 30-40 centimetres tall. The name is derived from the alarm call, emitted by the female. Dwelling in the savannah and shrubland, Dik-diks form monogamous pairs, occupying territories of up to five hectares. They keep in contact with one another by shrill whistles. Only the male has horns, although the female is slightly larger. Beneath each eye, a naked dark spot indicates the presence of a preorbital gland, which the Dik-dik uses for scent marking. He rubs this gland against blades of grass and branches to define his territory. When other Dik-dik invade his territory, he will dash towards the intruder and the two will stop, nod furiously and turn around. This behaviour is repeated with the gap between them growing greater every time until one beats a retreat.

Creature Feature #160: Diamondback Rattlesnake

The Western and Eastern Diamondback are venomous vipers found across the USA. Inept at climbing, they are the heaviest of their kind, with the Eastern species weighing in at up to 15 kilograms and measuring up to 2.4 metres long. The Eastern inhabits woodland and prairies, whereas the Western favours the desert. During the night he shelters underground in gopher or tortoise burrows, emerging with the sun to bask and lie in wait for prey to wander by. The rattle is a series of interlocking kerotin segments, modified from the scales on the tail. This can be "shaken" by the contraction of special muscles to create a rattling noise. Diamondbacks do not always rattle before they strike, it is more of a warning to anything that is too large for them to eat that may be a potential danger to the snake.

Creature Feature #159: Diademed Sifaka

The Diademed Sifaka is the most widespread of Madagascar’s eastern sifaka species and inhabits lowland and subhumid forests. He lives in small troops - up to ten individuals - and fiercely defends his territory against rival diademed groups. Both male and female scent mark the outer perimeters of their home range. Purely vegetarian, he will consume parts of 25 different plants: flowers, seeds and verdant leaves. Breeding is seasonal, with females only being receptive a few days a year.

Creature Feature #158: Dhole

The highly social Dhole makes his home in India and Southeast Asia. He lives in large clans of up to 40 individuals, but more regularly numbering 5-12. These split into smaller packs for hunting. Dholes are pursuit hunters, relying not on speed but on endurance; they will run their selected prey animal - usually a deer or other ungulate - into exhaustion, then drag it down and disembowl it.  Female Dholes den together, raising their pups communually. Some adults will remain at the den while the others head off and hunt. At six months of age, the pups join their parents on the hunt.