Bull Elephants Research Articles

Female-to-male sex pheromones of low volatility in the Asian elephant,Elephas maximus

In their natural ecosystems, the sexes of Asian elephants,Elephas maximus, live separately. For several weeks prior to ovulation, the urine and cervical mucus of female Asian elephants contain extractable chemical agents of low volatility that elicit a high frequency of flehmen responses from bull elephants as an integral part of mating. Subsequent to flehmen responses, male sexual arousal occurs and, if the female is available, mating results. During the course of our project to determine the agent(s) and describe the responses associated with female to male sexual communication, we have identified an unusual compound. This compound, apparently the sole component of the active fraction, was identified by mass, proton nuclear magnetic resonance, ultraviolet/visible, and infrared spectrometries as indolo-[2,1-b] quinazoline-6,12-dione (tryptanthrine). Exhaustive and repetitive bioassays established that pure authentic (synthetic) tryptanthrine was not the compound responsible for the bioresponse. Rather a coeluting minor component, also of low volatility, elicited the male bioresponse.

Chemical analysis of temporal gland secretions collected from an Asian bull elephant during a four-month musth episode

The temporal glands, modified facial apocrine sweat glands unique to elephants, release collectable secretions during an unusual physiological state termed "musth" in the Asian bull elephant (Elephas maximus). Recently we began the characterization of the chemical components of musth, especially in the temporal gland secretions (TGS), and the examination of the role of such secretions as agents for chemical communication between elephants. The present study focuses on possible correlations between testosterone levels in the serum and temporal gland secretions. We were especially interested in possible qualitative and/or quantitative changes in volatile compounds as the testosterone levels varied during a discrete musth period. Quantitative changes in TGS and serum testosterone were determined by radioimmunoassay. Qualitative and semiquantitative changes occurring in volatile composition were studied by high-resolution gas chromatography (fused silica capillary column, on column injection). Compound identification was by nuclear magnetic resonance, gas chromatography-mass spectrometry, and gas chromatography internal standards. Twenty-three major compounds and a number of minor components were identified. Androgen concentrations were correlated with TGS-specific volatiles including benzoic acid, 2-nonanone, 5-nonanol, tetradecanoic acid, and decanoic acid. The latter two compounds and (E)-farnesol, a major component of African TGS, demonstrated an inverse relationship to T levels.

Ecology of the Asian elephant in southern India. II. Feeding habits and crop raiding patterns

ABSTRACTThe Asian elephant's foraging strategy in its natural habitat and in cultivation was studied in southern India during 1981–83. Though elephants consumed at least 112 plant species in the study area, about 85% of their diet consisted of only 25 species from the order Malvales and the families Leguminosae, Palmae, Cyperaceae and Gramineae. Alteration between a predominantly browse diet during the dry season with a grass diet during the early wet season was related to the seasonally changing protein content of grasses.Crop raiding, which was sporadic during the dry season, gradually increased with more area being cultivated with the onset of rains. Raiding frequency reached a peak during October-December, with some villages being raided almost every night, when finger millet (Eleusine coracana) was cultivated by most farmers. The monthly frequency of raiding was related to the seasonal movement of elephant herds and to the size of the enclave. Of their total annual food requirement, adult bull elephants derived an estimated 9.3% and family herds 1.7% in quantity from cultivated land. Cultivated cereal and millet crops provided significantly more protein, calcium and sodium than the wild grasses. Ultimately, crop raiding can be thought of as an extension of the elephant's optimal foraging strategy.

Serum testosterone and musth in captive male African and Asian elephants

AbstractTestosterone concentrations in serum samples collected weekly over a 5‐year period from a young adult male Asian elephant (Elephas maximus) and a young adult male African forest elephant (Loxodonta africana cyclotis) were measured by radioimmunoassay. Testosterone profiles during this maturational period were compared between the two species and related to the occurrence of musth, a recurring physiological and behavioral condition exhibited by most mature Asian, and some African, bull elephants. Musth is characterized by secretion from the bull's temporal glands, dribbling urine, and increased aggression. Serum testosterone concentrations in the Asian bull were elevated substantially between April and September each year, coincident with the presence of temporal gland secretion, urine dribbling, and aggressive behavior. Testosterone levels from April through September averaged (± SEM) 41.2 ± 2.8 ng/ml, compared to 7.6 ± 1.0 ng/ml during the rest of the year. In contrast, the testosterone profile of the African bull showed greater variation and lower levels overall, the only pattern being a tendency for levels to be lowest from November to February (avg. 6.8 ± 1.5 vs. 10.3 ± 0.8 ng/ml during the rest of the year). Temporal gland secretion and other signs of musth were first observed in this bull in 1988, at age 17. While his testosterone profile did not show a pattern comparable to that in the Asian bull, average testosterone values were significantly greater in 1988 compared to previous years.The Asian bull showed sexual attention to preovulatory (estrous) cows whether in musth or not, and exposure to estrous cows did not appear to alter the highly consistent, annual pattern of musth as evidenced in temporal gland flow.

Conservation status of the Chila-Motichur corridor for elephant movement in Rajaji-Corbett National Parks Area, India

In the Rajaji-Corbett National Parks area, northern India, four crucial corridors for elephant movement have been identified: (1) Binj rau (Br) and (2) Chila-Motichur (C-M) across the Ganges; and (3) Malin river and (4) Kotdwar-Amsod in rugged terrain farther east. Our surveys showed that the Binj rau corridor is no longer used by elephants and those of Malin and Kotdwar-Amsod rarely. The C-M corridor is frequently used by elephant bulls during the summer, and is crucial to maintaining the genetic exchange between the elephant and tiger populations of the Rajaji-Motichur and Chila. However, the C-M corridor is much more vulnerable to human disturbance than the Malin/Kotdwar-Amsod corridors. This paper discusses problems of overgrazing, weed proliferation and lack of tree regeneration in the C-M corridor and suggests management inputs.

Urinary androstenedione and luteinizing hormone concentrations during musth in a mature African elephant

AbstractMusth has not been well documented in captive African elephants. A 37‐year‐old African bull elephant in the Kansas City Zoological Park was observed during periods of behavioral musth and non‐musth. Androstenedione and luteinizing hormone (LH) concentrations in urine were measured by radioimmunoassay. Urinary androstenedione and LH levels were significantly higher in musth urine than in non‐musth samples. A positive correlation (P > 0.001) existed between urinary LH and androstenedione concentrations. These results indicate that musth can occur in a zoo‐maintained African elephant and that urinary androgen levels are elevated during musth, possibly as the result of LH stimulation of testicular steroidogenesis.

Chemosensory responses in two species of elephants to constituents of temporal gland secretion and musth urine

This report discusses three areas of investigation: (1) The chemical components in the temporal gland secretion (TGS) of Asian (Elephas maximus) and African (Loxodonta africana) elephants were characterized by radioimmunoassay (RIA) for testosterone (T) and dihydrotestosterone (DHT) levels and by on-column capillary column gas chromatographic analysis of volatiles. An inverse relationship between TGS testosterone levels and (E)-farnesol levels was observed. (2). African elephants responded preferentially toward a particular constituent of African elephant TGS. (3) Urine from Asian bull elephants in musth was partially fractionated by high-performance liquid chromatography. Specific chromatographic regions elicited dramatic avoidance responses from female African elephants. These results support the suggestion that the TGS plays multiple chemocommunicative roles.

The Angolan Puzzle: Varied Actors and Complex Issues

Too frequently policy makers in Washington or Moscow see local or regional issues in southern Africa solely through their own, often distorted, lenses. And seen exclusively in ideological, or alternatively East-West or Cold War terms, they view their interests as inherently antagonistic. The old African maxim popular among non-aligned leaders in the early 1960’s is apropos: “When the bull elephants fight, the grass gets trampled.” Yet, unlike two elephants contesting clashing claims to territory of or sexual supremacy, southern Africa is not the territory of either of the super powers. Nor does Angola belong to other regional powers, notably South Africa. Although such states may have “interests” there. Angola is not their’s to shape.

Death on the Ridge Road:Grant Wood and Modernization in the Midwest

“The automobile is treacherous, just as a cat is. It is tragically difficult to realize that it can become the deadliest missile, and can instantly turn … into a mad bull elephant.” So J. C. Furnas warned his readers in an article for the August 1935Reader's Digestentitled “… And Sudden Death.” Furnas's graphic description of the devastation on the highway in the wake of a crash was intended to terrify drivers into saner behavior behind the wheel. His words forced the reader to imagine the horror of accident scenes that “no artist working on a safety poster would dare depict … in full detail.”Reader's Digestprefaced the piece with a warning to the fainthearted.

Ultrastructure of spermatozoa of the Asiatic elephant (Elephas maximus).

AbstractA scanning and transmission electron microscopic study of semen collected with the aid of an artificial vagina was carried out. The ultrastructural characteristics of Asiatic bull elephants is compared with that of other mammalian species.

Mate searching behaviour of elephant bulls in a semi-arid environment

In the wet season, African elephant ( Loxodonta africana Blumenbach) bulls switched from a strategy associated with feeding to one where the travelled long distances in search of oestrous females. Bulls which associated with cows behaved quite differently from other bulls. In sparse elephant populations a bull may have a greater chance of associating with an oestrous female if he lives permanently with a group of cows (the traditional concept of the herd bull) instead of searching for receptive cows during the mating season.

Asian bull elephants: Flehmen-like responses to extractable components in female elephant estrous urine.

Flehmen-like responses (urine tests) are one of the characteristic behavioral reactions of male Asian elephants (Elephants maximus) to cow elephants in estrus. Components of the urine of estrous cow elephants were extracted with organic solvents and partially purified by chromatography and shown to evoke Flehmen-like responses when they were presented to adult bulls.

Studies on Asian elephant reproduction at the Washington Park Zoo

AbstractStudies of Asian elephant reproduction at the Washington Park Zoo in the areas of the estrous cycle, semen collection, bull elephant management and health care, pregnancy, and pheromones have yielded sufficient information to attempt repeated artificial insemination (AI) at the time of ovulation. While no pregnancy has been achieved to date, with the information now at hand AI can be expected to become a practical technique for breeding elephants in captivity.

Losing others' lands—it should make your blood boil

It was in the late 1940s that the United States finally succeeded in losing an entire country. In those years it lost China. It was an astounding feat, comparable to losing a bull elephant in a studio apartment.

The Seronera bull problem: The elephants

Summary(1) The activities of bull elephants in the vicinity of the Serengeti National Park headquarters at Seronera was monitored from 1968 to 1971.(2) Elephant bulls congregate in small groups of ever–changing composition; a dominance heirarchy cuts across group integrity.(3) Occupancy of the drainage area of the Seronera river is predictable by rainfall; changes in occupancy level are a question of duration rather than amplitude.(4) The feeding behaviour of the bulls is described. It is argued that large Acacia trees are uprooted for nutritional rather than social reasons. The effects of the bulls on the Seronera woodlands will be analysed in Part II (Croze, 1974).

Seronera bull problem: The trees

Summary(1) The impact of groups of bull elephants on the wooded–grassland of the Seronera area of the Serengeti National Park, Tanzania, is examined.(2) Elephant use of trees occurs contagiously. At use loci in the woodlands, removal of canopy–forming acacia has been as high as 6% per annum.(3) However, from a survey of the whole Seronera woodland community, the loss of large trees has been 2–5% per annum.(4) It is argued that the regeneration potential is adequate to compensate loss due to elephant activity, and that large acacia will not disappear because of elephants.(5) Management action is discussed and recommendations made.

Testicular temperature in the Southern elephant seal, Mirounga leonina (Linn).

The testes of the Southern Elephant Seal are extra-abdominal, but each is contained in a separate inguinal pouch and not in a single scrotum; they lie beneath the blubber and against the muscles of the abdomen, and it would appear that their position is fixed as there is no evidence of a tunica dartos, and the rudimentary external cremaster muscle consists of a few weak fibres arising from the obliquus internus abdominis. The testicular temperature might therefore be expected to be close to the body temperature. Two mature bull elephant seals were immobilized with succinylcholine chloride (Ling & Nicholls, 1963), and the temperature of the testes was measured by cutting through the blubber layer down to the testicular pouch and passing a thermistor probe approximately 4 cm into the testis, which represented approximately the centre of the testis.