CONSERVATION OF ARABIAN GAZELLES - Nwrc.gov.sa

Table 2.7 Skeletal postcranial measurements for cenain Arabian gazelles
(data from both sexes combined).
Humerus Foreleg: Tibia: Metatarsal: Hindleg:
length hindleg femur femur skull
gazella (20) 125 78 127 100 302
dorcas ( II) 119 81 133 III 314
saudiya (I) 116 80 130 109 298
sub8utturosa (10) 125 81 127 109 290
Discussion
It is probable that, according to a Phylogenetic Species Concept, all the following taxa would be
regarded as separate species: saudiya, arabica, bilkis, erlangeri, gazella, muscatensis, and cora. The
status of marica vis-a-vis C. subgutturosa was not tested, but both morphologically (Groves &
Harrison, 1967) and genetically (Kingswood et al., this volume) there is ample reason to regard it as
pan of the same species. Similarly, there seems little doubt that isabella and other forms of G.
dorcas are con specific (Groves, 198Ib). As little other than metrical data was collected on the
Thumarnah crania, the position of this quasi-taxon on the cladogram remains somewhat hypothetical.
The status of the other taxa will be discussed in tum.
- Status of Gazellil saudiya: That Cazella saudiya is totally distinct from C. dorcas is
confirmed; as Rebholz et al. (this volume) have concluded, it is much closer to C. bennetti. It would
be difficult to propose uniting them specifically, however. Metrically, C. saudiya falls outside the
range of variation of C. bennetti, and the skull is a different shape from the similarly small-sized C. b.
karamii (Table 2.4). In addition it shares some derived states with C. subgutturosa which are not
seen in C. bennetti (Figure 2.6): nasal tip shortening, ethmoid fissure shape, greater sexual size
difference, horn length in both sexes, more hom rings. Unless the polarities of these characters are
incorrect, or there is an unsuspected degree of homoplasy, this does imply that C. bennetti and G.
saudiya may not be sister species.
A question that must be asked is whether the AI-Areen (Bahrain) breeding group,
phenetically resembling C. saudiya, is pure-bred or has been mixed with C. bennetti (see Rebholz et
al., this volume, for discussion). The only detailed evidence is the morphology (mainly craniometry)
of a female specimen made available courtesy of Dr Jaime Samour, formerly of the AI-Areen
Wildlife Park . This specimen (Table 2.4) is considerably larger than wild-collected C. saudiya in the
Natural History Museum, London (the only existing study sample), but is in proportion; compared to
C. bennetti, it has a narrow skull, especially the braincase and across the hom bases, and the nasals
are narrower posteriorly than anteriorly. The horns are extremely long, like C. saudiya, and spread
more widely than either (on average), though they would be easily within the 2-standard-deviation
limits of C. saudiya; but it must be borne in mind that the female of C. bennetti karamii, whose horns
are exceptionally widely flared for that species, is unknown . In Figure 2.5 this skull, entered as an
unknown in a Discriminant Analysis comparing C. bennetti and C. saudiya, falls within the range of
the latter, confirming its identity in shape.
There is consequently only one character in which the AI-Areen specimen falls outside the
expected range of C. saudiya: absolute size. It is possible that this is an effect of captivity (see the
discussion above on subspecies and phenotypic plasticity); it is also possible that it derives from a
population outside the known area of distribution of C. saudiya (Appendix 2. I).
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