After six weeks of following empty leads, the first intersexual pig was observed on the island of Aore in Northern Vanuatu. During the following month fifty-three additional examples of this rare mammalian anomaly were documented. External descriptions and approximate ages and weights of these animals were recorded . Behavioral studies yielded indications of patterns of aggressiveness with the Intersexual pigs kept in villages. These periods often coincided with the heat cycle of a sow in the vicinity. When encountered in the bush, locals attribute an increased display of aggressiveness and strength to this intersexual condition. I was able to plot the Naravé's current distribution which is greatly reduced as compared to the original references in the early part of this century. Approximately 20% of all offspring born to the falé-ravé (intersex producing female) will themselves be intersexes. This conservative estimation is still very impressive and the abundance of these pseudohermaphrodites is equaled nowhere in the world. From local lore and description it is the dam who is the sole contributor to the intersexual condition. After studying the internal anatomies of six Naravé, the findings were consistent. With the exception of the external vulva-like organ, there were never any rudiments of female internal genitalia. There were however, generally two testes (either intra-abdominal or scrotal), seminal vesicals and bulbo-urethral glands. These animals were actually "modified" boars and more correctly termed male pseudohermaphrodites. These individual's embryonic testis had secreted their hormone during a "later" part of development than is necessary to hormonally produce a normal sexually developed male. In regard to the external genitalia, four distinct phases were identified and documented. Eleven animals were selected for blood examination of which; eight were intersexuals, two were males and one was a pregnant female. All eleven animals fell within or on the periphery of the range of cbc norms for swine. Hormonal of estradiol and testosterone were generated from each of the test animals. The ratio of estradiol to testosterone yielded numbers consistent with "maleness" from the two males as well as the eight intersexuals these results support my theory that Vanuatu's intersexual pigs are actually mal-developed boars. Although many locals insist that it is the female that is the sole contributor to the intersexual condition, (falé-ravé, mother or sister of an intersex, the soké-rave is the brother of an intersexual), a comprehensive controlled breeding program with test-crosses is necessary to corroborate this. In normal village "management" situations, chance breeding occurs and the sires are rarely known. There is a distinct possibility that two carriers for the trait (soké-ravé and falé-ravé) must come together in order to produce the abnormal condition in some males and not in others. A compliment to controlled breeding would be artificial insemination. Because of the positioning of the "penis" in all of these intersexes, normal reproduction is a physical impossibility. The possibility of electro-ejaculation and artificial insemination, using the intersex as a donor, must not be overlooked. Baker(15) stated "There appeared to be a few abnormal sperms in the testes of one of the nine individuals while all of the others examined lacked spermatogenesis altogether". With the size and appearance of the testicles on many of the mature animals, I have no reason to doubt the possibility of the presence of viable sperm. The simple solution to the genetics of the abnormality as stated by Baker(4) is probably more complex. The sex-linked inheritance conclusion as proposed by Baker is more than likely a polygenic trait with incomplete dominance (this explains the many graduations of the condition). There is also the possibility of secondary modifier genes either on the sex or autosomal chromosomes.
In accordance with Canonical Variates Analysis(5)(CVA), 51 mandibular measurements were taken on Vanuatu adult male Sus spp. specimens. As illustrated on Graph 1, most of the Vanuatu pigs plotted either in or adjacent to the feral swine target group. Specimens of S. celebensis and S. papuensis (believed by C. Groves(11) to be a hybrid between S. scrofa and S. celebensis) also plot with feral S. scrofa. What is curious and demands further study are those four specimens that do not plot within any of the target groups.
With the development of modern cytological methods of sex-determination, the Karyotype of each individual needs to be determined. There is a possibility that the chromosome number of Intersexes varies from those that have been cited in the literature. One pig intersex has been reported (Laing(6)) to have a condition comparable to Klinefelter's Syndrome in man. In many cases though animals which are chromosomally abnormal in either the autosome or sex chromosomes, are spontaneously aborted early in gestation. Considering the above, along with my investigations of the internal anatomy and the relative normal behavior of these intersexes, I would predict the presence of a chromosome number comparable to those previously documented(28)(29). Because of many of the limitations mentioned earlier in the introduction, this study can only approximate a complete examination to the study of intersexuality in Vanuatu. I hope to have set the foundation for more comprehensive studies, and that this paper will serve as a guide for those wishing to pursue this interesting phenomenon. This project should, however, bring the Naravé "mystique" up to date, and for the questions left unanswered, serve to encourage further investigation.
Special thanks to my Ni-Vanuatu crew, especially my friend Jeffry Vutilolo. Many thanks to my Sponsors, Perez Trading Company Miami, Florida and (George(cash in advance please)Davis). Ralph Regenvanu at the Vanuatu Cultural Center. Lastly for his generous assistance, Kirk Huffman I Thank You.