Historical Biogeography of the Mammals of Yemen

by Derek E. Wildman
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[Editor's Note: This article was originally submitted as a field report to AIYS in Fall ,1998. For more information, see Valderrama X, Karesh W, Wildman DE, and Melnick DJ (1999) Noninvasive methods for collecting fresh hair tissue. Mol. Ecol. 9: 249-250. ]

Yemen Update 42 (2000):24-26

Derek and George, a resident of Jabal Bura‘


I conducted field research for a period of just under three and one half months in The Republic of Yemen during the summer and fall of 1997. The purpose of this research was to collect mammalian samples appropriate for genetic analysis in a biogeographic context. Under the supervision of Dr. Abdulwali Al-Aghbari (Faculty of Animal Sciences, College of Agriculture, Sanaa University), I was able to collect over three hundred samples representative of four mammalian orders (Primates, ChiropteraRodentia, and Carnivora).

The primary questions I hope to be able to answer upon the completion of laboratory and statistical analysis at my home institution (New York University, U.S.A.) are: 1) when did mammals with mostly African distributions migrate to Asia, and, 2) by which route did this migration occur. Because I am doing dissertation research in Anthropology, I focused my field research primarily on the hamadryas baboon (Papio hamadryas hamadryas). This primate is one of Yemen's largest, and most distinctive, mammals, and is of importance to studies of human evolution, behavior, and disease. Besides the baboon, I also studied a number of other mammal taxa with primarily African distributions, but which are also found in Yemen.

My research was conducted at six sites in Yemen. [For a location map, click here]. These sites were appropriate for sample collection because they comprise a north to south population sampling distribution. Two of the sites (Jabal Bura' and Jabal Iraf) are also important because they have been earmarked as protected areas by the Ministry of Agriculture's Department of Forestry. The other sites are important because I found them to be the natural habitats of my study taxa. I also collected a small number of samples from captive mammals, either live or taxidermied specimens. The following represents a site by site summary of my collection areas.


Jabal Bura' is a granite mountain located in the Tihama foothills east of Bajil. I conducted fieldwork here for approximately two weeks in July, 1997. I visited this site first because research was conducted at the same locale in 1995 by one of my American advisors, Dr. Clifford Jolly. The area of the mountain that I focused on was Wadi Rijaf (14�52.64N, 43�25.84E). I concentrated on the area of the Wadi between the elevations of 300 and 600 meters. The vegetation of this area is particularly dense for Yemen, and the steep canyon walls make cultivation difficult if not impossible. It is therefore an ideal habitat for hamadryas baboons.

I observed baboons on each day that fieldwork was conducted. At least five separate groups of baboons numbering between 20 and 50 individuals live in this area. Demographically, they appear to be quite healthy, with a large number of infants and juveniles observed. Their diet consists primarily of fruits found near the water, and seeds and leaves found farther up slope. I was able to collect 20 baboon fecal samples and 16 hair samples. I also collected two adult specimens of the murid rodent genus Acomys (the spiny rat), and one fresh fecal sample from a large, possibly felid, carnivore. This sample is suspected to be felid because local people report that leopards live in the area. One possible leopard footprint was observed, however laboratory analysis will be necessary to identify the specimen. Porcupine quills were also collected.

While the baboons were easy to see at J. Bura', they were difficult to follow because of the steep canyon walls and dense vegetation. I spent five days climbing these walls in the hopes of finding sleeping sites. While a large number of potential sites were found, I was unable to find any evidence of recent activity, e.g feces. Therefore, I am unable to state whether or not the small groups come together at night, although this seems likely due to the presence of predators such as leopards and eagles.

Because baboons are rarely shot or trapped at J. Bura' they are relatively easy to watch near the river. Indeed, my primary method of sample collection at this site was to provision the baboons with roti (bread). I constructed a corral made of sticky, plastic tape that the baboons brushed against, thereby leaving hair samples.


Jabal Iraf, which is located west of Tur Al-Bah in Lahj governate near the border of Taiz governate (13�07.15N, 44�13.18E), was visited for ten days in early August, 1997. It was interesting to note that the people living near Tur Al-Bah had constructed elaborate fences around their livestock pens in order to prevent attacks from hyaenas. The study site on Jabal Iraf is located on a high plateau at an approximate elevation of 1100 meters. This site has been proposed for protection due to the high number of endemic plant species including Juniperus. The baboons don't live in the actual forest area itself, rather they are found near Wadis with running water at slightly lower elevations.

While at Iraf I collected ten fresh baboon fecal samples, and hair and tissue from two baboons that had recently been shot by local farmers. I also collected one skull from an adult female, but unfortunately this was taken by a vulture or kite while it was being macerated on the roof of the schoolhouse where I and my field assistants slept. Because baboons are commonly shot here for crop raiding they are very wary of human presence, and run at the first sign of humans approaching. Therefore, I did not observe many baboons at this locality. On two occasions I did see groups of between twenty and forty individuals, and Dr. Al-Aghbari and Ahmed Al-Awash (of Taiz Forestry Department) observed a small group of four or five individuals. Because of the flat terrain and the ease which baboons escape from human view, I would not recommend this locality for primate behavioral research.

I also collected a number of bats and rodents from this site. Twenty bats representing two families - Rhinopomatidae (mouse-tailed bats) and Rhinolophidae (horseshoe bats) were collected from roosting sites in small caves located two wadis south of the schoolhouse where I stayed. I also collected nine specimens of Acomys, including five almost to term fetae. Of the three pregnant rodents caught, two were carrying twins, and one had only one fetus. The rodents were collected from local houses and from rock overhangs in the highest part of the forest.

Members of the families Rhinolophidae and Rhinopomatidae (from Jabal Iraf).


Thula, a village approximately fifty kilometers northwest of Sanaa was visited for four days in August 1997. The purpose for visiting this site was to collect rodents not found in typical baboon habitats. Thula lies at the base of a sandstone prominence at an approximate altitude of 1600 meters (15�34.44N, 43�53.99E). Eight murid rodents including PraomysArvicanthis, and Mus were collected from local houses and cultivated fields. While no baboons are present at Thula, I was informed by a local resident that large numbers can be found at the Al-Murkha area approximately twenty-five kilometers northwest of the village. It was also reported that a large number of bats could be found in caves near the village.


Wadi Mawr, north of At-Tur near Hajja was visited for two days in early September. I had planned to stay at this site for a longer period, but successful results allowed me to schedule an extra trip to Jabal Sabir (see below). We stayed at the schoolhouse in the small village of Al-Matha (15�44.19N, 43�25.22E). The vegetation of the area is typical of the Tihama foothills. Myself and Dr. Al-Aghbari were accompanied by two colleagues from the Hajja Dept. of Forestry office. The Wadi Mawr area was chosen over the hills near Wadi Sharas because the baboons appeared to be more difficult to follow at the latter locale.

After enquiring about possible baboon sleeping sites near the village, we were led to a cliff about three kilometers downstream on the Wadi directly east of Al-Matha. This cliff, about thirty meters high is the sleeping site for at least 200 hamadryas baboons. I collected approximately 150 baboon fecal and hair samples from this site. The schoolhouse where we stayed was also the sleeping sight for molossid bats, two of which were collected.

In the two days I was at this site I observed multiple groups of baboons on both sides of the wadi aforementioned. The large number of samples collected meant I did not have to stay at this site any longer. However, the facts that there are so many baboons here, and that they are easily followed, makes Wadi Mawr an ideal site for primate behavioral research. Furthermore, the baboons did not bark or run when we arrived, suggesting that they are not shot often.


This mountain near Taiz was visited because it has been reported to me by a driver for Universal Tours (Abdul Hamid Al-Kideer) that the baboons of J. Sabir were phenotypically different from most Yemeni baboons. This was confirmed on September 15th and 16th, 1997. Myself, Dr Al-Aghbari, and Jillian Schwedler, a colleague from New York University, concentrated our efforts on the highest (above 2500 meters) elevations of the northeast side of the mountain. In this area, I observed approximately 200 baboons on September 15, and approximately 40 on September 16.

The baboons are notable for three obvious phenotypic reasons. 1) They are larger than most hamadryas baboons with adult males appearing to be as large as 50 kilograms. 2) The adults maintain the brown fur seen typically in juvenile hamadryas baboons. 3) The tips of the tails of all age classes and sexes of these baboons are covered with white hair. While I was only able to collect three samples (one of which is a partial skeleton) from Jabal Sabir, I look forward to examining their genetic composition. These baboons are also considered to be crop pests, and are shot often, and quite wary of humans. I also collected one fox fecal sample and a raptor hairball which probably contains rodent hairs.


This area was sampled in mid-September because, geographically, it falls between sites like Jabal Bura' and Jabal Sabir. There are a large number of baboon populations found in the hills on both sides of the road between Dhamar and Hammam Ali. After scouting four potential sites along this road, I decided that the area near the small village of Ethar would most likely bear results. With the assistance of local residents it was determined that the far side of the small mountain just south of the village had a baboon sleeping site (14�39.12N, 44�12.54E).

We found this site, and while no baboons were observed, I did manage to collect approximately forty fecal and hair samples. I also observed that the baboons from this area eat prickly pear cactus pads. I also collected one fresh carnivore fecal sample. On our walk back to the village we stopped at a cave used for straw storage and collected one rhinolophid bat specimen.


A number of other samples were collected . These samples, were from captive animals or taxidermied specimens so locality data is suspect. Captive baboon samples were collected that are supposedly from Jabal Raymah, Hatarish, Sa'da, and near Taiz. Carnivores samples, including AcionyxHyaenaFelis caracal, and Panthera leo were also collected.

Remains of baboon shot near Jabal Iraf.


This research represents the first attempt to study Yemen's mammalian fauna from a genetic perspective. When the Yemeni samples are combined with samples from Africa and Saudi Arabia already present in our laboratory I am confident that much can be said about the zoogeographic history of the region.

The situation regarding the baboons of Yemen is less dire than I had been led to believe. There appear to be large and healthy populations present throughout Yemen. If these populations are to be maintained steps must be taken to prevent the baboons from raiding crops. Otherwise they will be shot. The most important measure is to protect areas of land from human cultivation. This will allow the baboons areas where they can subsist on native vegetation.

While my research went much better than expected (I collected five times the expected number of baboon samples), much work still needs to be done before an adequate picture of Yemeni mammalian diversity can be painted. A much more comprehensive sampling of the mammalian fauna, especially in the Eastern portion of the country, should be undertaken concomitant with protection of natural habitats and ecozones. However, it can still be stated with confidence that Yemen has the most diverse mammalian fauna on the Arabian peninsula. Preservation of this diversity can only serve to benefit the Yemeni people in the future.

Since my return to New York I have focused primarily on laboratory work. This work consists of genetic and phylogenetic analysis primarily. I have presented preliminary results from this analysis at the 1998 annual meeting of the Society for the Study of Evolution. I am also preparing a manuscript based upon collecting techniques I developed in Yemen. This manuscript will be submitted to the American Journal of Primatology. I anticipate a sizable number of publications as well as my dissertation to emerge from this study. I will forward the AIYS copies of every publication related to this study. Finally, I hope to work in Yemen again in the future and am currently discussing the preparation of a large scale phylogeographic project including the flora and fauna of the Horn of Africa and the Arabian peninsula.

[All photos supplied or taken by Derek Wildman.]

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