For tortoise, terrapin and turtle care and conservation
PAULINE BROWN.
Kinixys homeana (Home's hinged-back tortoise) is found in the rain forests of north-western Africa, i.e. Liberia, Ivory Coast, Cameroon, Gabon, Zaire. Its long agile legs, large eyes and secretive habits are adaptations to a forest habitat. The carapace is hinged at thejunction of the 2nd and 3rd costal plates, so that the animal can close the rear portion of the shell. Very little is known about its behaviour or diet in the wild, but it is known to eat snails. A pair was obtained in July 1989, purchased from a pet shop which had had difficulty in selling them and were happy to let them go for half the asking price.
Housing
The adults are housed in a 5ft x 2ft x 2ft vivarium with a thermostatically controlled tubular heater, plus manually controlled electric light (60w or 100w)and 20w Tru-lite. A substratum of Forest Bark is used as this seems the nearest natural substance to forest floor; chipped bark was considered but was found to be too coarse and it was thought that there might be a possible danger of chemical contamination as the manufacturer stated that it is treated with a fire retardant. There is a large water bath in one corner and 2 plants which help to provide humidity and a little more privacy. An upturned hanging-basket liner (of the papier mache type)with a doorway cut out, is provided as a house; this is light in weight and is aesthetically pleasing in a simulated forest environment.
Day temperature varies between 29-32°C; night temperature is around 21°C. Daylength varies between 10-12 hours. The humidity is usually around 90% and never less than 80%, and is provided mainly by spraying first thing in the morning, perhaps at mid-day, and early evening, so that the substrate, except inside the house, is almost continuously damp.
The vivarium is situated in a landing bedroom, so there is very little disturbance from people passing or frequent switching on and off of lights.
The tortoises are put outside at every opportunity on warm days, even if it isjust for half-an-hour and as early in the year as April, but are always brought in at night even in the hot weather last summer.
Feeding
Food is usually given fairly soon after the lighting has been switched on and when the animals have had sufficient time to warm up (usually between 10 and Ilam) or alternatively in the evening after spraying.
Although the female has half heartedly snatched at green vegetation in the garden, the only herbage known to be eaten is Chinese cabbage. Food is therefore mainly fruit; kiwi fruit, mandarin orange segments (tinned in orange juice not syrup), satsuma segments, tomato, cucumber, banana, pawpaw, melon, occasionally pineapple and mushrooms which are eaten avidly. Protein is provided perhaps once a week in the form of soaked Go-Cat biscuits (sometimes mixed with powdered eggshell), raw chicken liver and heart, raw fish, slugs, snails, caterpillars or worms. In the summer when snails are plentiful, these are fed perhaps twice a week to compensate for the lack during the winter. Vionate is lightly sprinkled over food most days.
Cuttlefish bone is constantly available, although it is rare for the male to eat it.
Behaviour
Almost directly after the morningspray, the kinixys appear from their house. The male especially spends some time (1-3 hours) basking under the electric light - the female seems much more secretive. After feeding, both retreat to the seclusion of their house, where they usually remain until early evening. (The Tru-lite is switched off first, leaving the electric bulb on for another hour or so, during which time the male will sometimes spend more time basking). There is a certain amount of nocturnal activity.
Infrequently one or both animals spend long periods (from a few hours up to 2/3 days) sitting in the water bath; this also appears to be an element of gravid behaviour (see below).
Courtship appears to be non-existent - no leg-biting or butting has been seen. As with other tortoises, the male does confront her if she starts to move but has displayed no other aggression.
Mating occurs enthusiastically throughout the year, but very little activity was observed from December to the end of March, perhaps as a consequence of egg-laying in early December and again at the end of January.
Gravid behaviour
In mid-November the female went off her food, although she ate a lot of cuttlefish bone, became very restless, and was seen trying to dig a nest in secluded areas of the vivaiium (inside the house and to the rear behind the plants). During this period she spent a lot of time sitting in the water bath (sometimes all night).
Tortoises sometimes show gravid behaviour when no eggs are present, and as nothing had happened after a couple of weeks, it was decided that perhaps a little help was needed. On December lst she was X-rayed and 2 eggs were seen. An oxytocin injection* was given and upon arrival home she was placed in the vivarium, the male having been removed, on top of a washing-up bowl containing Forest Bark, which was just of sufficient depth for a nest to be dug. As she seemed to need complete privacy, the 'house'was placed over her. She immediately started digging (11am) and by 4pm had laid two eggs and covered them.
In early January the same behaviour (sitting in water bath, lack of appetite and frequent chewing of the cuttlefish bone) was seen. As soon as nest digging was evident, the same procedure was followed and this time the eggs (2) were laid quickly, within about 2 hours, and without recourse to veterinary aid (January 23rd).
*Thanks are due to my vet, Gareth Hately, who administered exactly the right dosage just enough to'tickle her up'- his words') to enable the eggs to be laid properly. Often the effects of oxytocin are so immediate that the eggs are laid on the way home from the vet and consequently broken.
Incubation and after-care
The first clutch of eggs was placed in damp, sterilised Forest Bark, covered to a depth of about half an inch, in a 1 litre plastic ice-cream container with holes pierced in the bottom to allow for some passage of air. This was then placed in an incubator (Hova-bator) set at 30.5°C and the surface lightly sprinkled with water every other day. The two further eggs were placed in the same container as there was plenty of room to do this without disturbing those laid previously. Average egg size was 36.6mm x 33mm.
In February, during severe weather, theincubator temperature dropped at some point during the night to around 26°C, although it is unlikely that this was for more than 8 hours and evidently had no deleterious effect.
In the evening of april 8th, after 127 days incubation, a piece of eggshell was seen on the surface and careful examination revealed a glimpse of tortoise shell. By next morning the hatchling (since named'Uki') had fully emerged.
It was placed in a small vivarium at temperatures of about 30°C (day) and 270C (night) which has been gradually reduced to 21°C.
Vivarium conditions are as follows. There is a heat pad which occupies about half of the floor area, over which a metal grid has been placed. A Polythene sheet is laid over the entire floor area, on top of which is Forest Bark which forms the substratum. When needed, heating is aided by an electric light bulb, the wattage of which is varied to compensate for fluctuating external temperatures; a 20w Tru-Lite is always provided during the day. Daylength is about 10 hours.
At first it was necessary to use the heat pad to maintain the night temperature but this has proved to be unnecessary during the summer months and no heating is needed. However it will probably be essential to use a coloured (blue) electric bulb to supplement night heating in the winter months.
A shallow water bath is placed on the heat pad area, and curved pieces of bark under which the hatchling can hide help to simulate a forest floor.
Again, spraying is carried out 3 times daily, and a couple of small plants help to maintain humidity and provide cover.
Uki is put in the garden in a small pen with plenty of plant cover when the shade temperature is 21°C, though only for about an hour, unless there is a marked rise in temperature when he is then outside for 4/5 hours. Food taken so far includes worms, very small slugs and snails, a tiny amount of mackerel, chicken liver and heart, boiled egg and minced beef (all uncooked); tomato, melon and mushroom have also been eaten, particularly the latter, plus a little kiwi fruit. Although pawpaw, mango, banana, orange, cucumber and some green vegetation (clover, cabbage, lettuce, dandelion, watercress) have been offered none has so far been eaten. Live food is definitely preferred to anything else and the hatchling quickly learn that the lively end of a worm is to be tackled first.
Unlike the parents, which have long, fairly narrow shells which broaden slightly posteriorly, the hatchling is flat and round (and looks more like a terrapin in shape) with a spinose margin to the shell; it does not appear to have an 'egg tooth'. Again, in contrast to the parents, both of which have a dark colouring to the carapace, the hatchling is dull ochre with slightly darker spotting. It merges well with the dead sycamore leaves in the vivarium. There is no indication of the hinge, which presumably will develop later as with Kinixys belliana.
At about 2 months, a colour pattern began to show as small spots of cream at the lower anterior corners along the junction of the costal and marginal plates.
16 April 91 21 July 91
Weight llg 3lg
Length of carapace 38.lmm 55mm
Width of carapace 39mm 5imm
‘Uki’ is believed to the first Kinixys homeana to be hatched in this country. The remaining egg unfortunately proved to be infertile.
REFERENCE
Pritchard, P.C.H. (1979). Encyclopaedia of Turtles. TFH Publications. p.454.
Testudo Volume Three Number Three 1991