Male Elephant Research Articles

Male reproductive organs of the African elephant, Loxodonta africana.

Summary. Results are presented of detailed dissections of the reproductive tracts of eight adult male African elephants and of one full-term male foetus, together with additional information obtained from the examination of a number of other bulls and cows. A notable feature of the elephant's tract is the absence of a pampini-form plexus, cremaster muscle and inguinal canal; this is consistent with the intra-abdominal location of the testes. The weight of the testes and the mean diameter of the seminiferous tubules appear to be related to the size and hence the age of the animal. Active spermatogenesis was observed in all the adult testes examined. Testosterone was isolated from the testes and identified by infra-red spectroscopy ; the testicular testosterone concentrations ranged from 3 to 490 μg/100 g testis and were apparently unrelated to season, age, behavioural status or vesicular fructose concentrations. The elephant has no anatomically distinct epididymis. The wolffian duct is highly convoluted and probably several hundred metres in length. Its caudal half has an unusual histological appearance, with a very folded and extremely vascular lamina propria. The ampullae are large glandular structures, opening into the ducts of the corresponding seminal vesicles. The seminal vesicles are large, thick-walled sacs that contain up to 350 ml of a watery secretion rich in fructose. The prostate varies in shape considerably between animals, being uni- or multilobular. The bulbo-urethral glands are large, and full of a highly viscous secretion. The penis has a well-developed corpus cavernosum penis and large paired levator penis muscles on its dorsal surface. The temporal gland is apocrine in nature, with a strongly smelling serous secretion. Its secretory activity appears to be unrelated to the reproductive status of the animal or the body temperature. The mean deep body temperature was found to be 36·8° C (range 36·2 to 37·5° C). Spermatozoa, recovered within 2 to 6 hours of death from the caudal end of the wolffian duct and the ampullae, were immotile, but could be partially activated by dilution with vesicular secretion. At least two of the elephants had had a retrograde ejaculation when they were shot, and in one instance motile spermatozoa were recovered from the bladder 6 hr after death.

Molariform Teeth of Male African Elephants in Relation to Age, Body Dimensions, and Growth

This paper is based upon the teeth, body dimensions and weights of 58 male elephants ( Loxodonta africana ) collected in Uganda and represents an attempt to relate dental status to approximate age as revealed by a hypothetical growth curve. The elephant bears a successional series of six molars in each half of each jaw during its potential life of about 70 years. Molars 1, 2, 3 and 6 can be readily identified. Molars 4 and 5 are sometimes difficult to identify, but satisfactory designations appear possible by reference to the body weight of the individual. The correlation coefficient between body weight and shoulder height is 0.99. This relationship, when compared with data from an elephant of known age, makes possible the construction of a growth curve. Comparisons of the tooth data with the growth curve reveal the approximate times that the teeth appear in an individual and also their subsequent periods of usage. By knowing the approximate longevity of each tooth, one can satisfactorily estimate the ages of individual animals.

Lysergic Acid Diethylamide: Its Effects on a Male Asiatic Elephant

A saline pond in a region in Antarctia where other lakes and ponds are frozen remains unfrozen at the prevailing low temperatures. The ecology of the pond is unique. A distinctive aerobic microbial population, though restricted to this natural habitat, adapts to growth in artificial culture. The growth habit of these organisms, as seen in nature and in laboratory culture, indicates a possible relationship between growth at high salt concentration, at low temperatures, and in media of low organic content. On 11 October 1961 a field reconnaissance by Navy helicopter in the south fork of the Wright Valley (longitude 1610 10'E, latitude 77034'S), Victoria Land, Antarctica, revealed an unfrozen pond, although the ambient temperature was -240C. Wright Valley is one of several ice-free valleys in the region from which the continental icecap has receded (1). During the following 3 months several trips were made to the pond. This pond, which we named Don Juan Pond, is approximately 200 m wide and 700 m long; the average depth is 11 cm (2). Small salt deposits occur on the periphery of the pond. The valley surrounding the pond is carved out of metasediments intruded by granites and dolerites. Overlying this valley and forming the higher ridges and peaks in the area is Beacon sandstone, also intruded by dolerites. The pond was formed by moraines blocking both ends of the valley and, at its inception, was probably 10 or more meters deep. Beach lines, now poorly defined, are present 10 m above the water level on the north side of the valley. The influx of water into this basin is 7 DECEMBER 1962 limited. During the summer two small streams drain the moraine to the west. The only other source of moisture is snow falling directly into the small catchment area immediately surrounding the pond. The snowfall averages only a few inches per year. The water is beige-to-brown in color (3); this is attributable in part to pyritic particles in suspension. The pH was 5.4 and probably remains stable, since there is little or no decay of organic matter. The water temperature followed the temperature of the ambient air; from October to December it ranged from -24O to -3.00C, with no variation from surface to bottom. At no time during the period of study was the water frozen. The freezing point of freshly collected samples was -48? -+1 C. The water of Don Juan Pond was compared to the water of Barghoorn and Nichols Pond (4) and also to seawater (5) (Table 1). The specific gravity of Don Juan pond water was 1.2514, and the specific conductance was 790,000 [mho. The concentrations of dissolved solids in Don Juan pond water, in Barghoorn and Nichols pond water, and in seawater were 474,000, 132,620 and 34,480 parts per million, respectively. The salinity of Don Juan Pond was approximately 13.7 times that of seawater and 3.6 times that of Barghoorn and Nicholas Pond. Two deuterium determinations (6) of the pond water gave concentrations of 123.8 ppm and 124.0 ppm. By contrast, a deuterium determination on ocean water in the vicinity of McMurdo Sound gave a concentration of 160.0 ppm. These data, together with the fact that the pond is over 400 feet above sea level and 35 miles from the present coast, suggest a nonmarine origin for the water. The extraordinaryily high salt content is probably due to the weathering of the surrounding rocks, followed by increases in concentration through evaporation. Samples of water for microbiological studies were collected in sterile flasks and returned to the Biological Laboratories at the Naval Air Facility, McMurdo Sound, Ross Island. The water was kept for several days at -220C before laboratory study was begun. Examination of the water samples and sediments showed bacterial rods and cocci which grew in the form of colonies. Microscopic examination of bottom sediments from the pond revealed a diatom frustule, but no growing algae were present. Table 1. Minerals in solution in antarctic waters. Composition (ppm) Don Barghoorn MinJun and Seaeral Pond Pond water Ca 114,000 1,130 400 Mg 1,200 4,890 1,272 Mn <0.05 Na 11,500 33,200 10,556 S04 11 16,150 2,649 Cl 212,000 58,000 18,980

Some observations on growth and tusk weight in male and female African elephants

Summary. 1 Linear measurements, tusk weights, sex, and locality of origin are given for a series of elephants shot in Uganda. 2 Photographic records of the molar dentition have been used to assess the relative age of specimens and to put selected animals in order of age at death. Comparison with captive elephants of known age shows that wild female African elephants usually begin to breed at eight to twelve years, and examination of very old animals showed that they may be capable of breeding until extreme old age. 3 A diagram has been constructed to relate the body size and tusk size of individual animals to their position in a series arranged in order of age (according to the condition of the molar teeth), the sex being indicated in each case. The diagram includes fifty-seven animals for which all the relevant data are available and it shows that: (i) Growth is noticeably uniform within the sample. (ii) Males and females grow more slowly after puberty but continue to grow for a considerable time. Growth probably continues until late in life or until death. (iii) Males are generally bigger than females of the same age. (iv) The tusks of females usually cease to grow after puberty. (v) The tusks of males sometimes cease to grow after puberty, but more usually continue to do so. Their growth may continue at the same high rate as before puberty, or it may be slowed to a greater or lesser degree. Large tusks are evidently the product of rapid growth rather than longevity, and exceptionally large tusks are probably attributable to the survival to old age of an animal whose tusks have continued to grow at a higher rate than the average.

The Ceylon Elephant at the Oxford Museum

THERE has just arrived at the Oxford Museum the skeleton of a full-grown male Ceylon elephant. During the visit of the Duke of Edinburgh to Ceylon there were two elephant drives, or kraals, held, of which full accounts were given in the daily papers at the time. It may be remembered that at one of these kraals a large male elephant, a rogue, was driven into the terminal enclosure, together with several other smaller wild elephants. The rogue charged the tame elephants introduced amongst the wild ones, knocking them over repeatedly, and effectually preventing the process of noosing. It was at length found necessary to shoot him, in order that the remainder of the elephants might be secured.