CC BY
25
DeAgamis2: ВТОРОЙ МЕЖДУНАРОДНЫЙ СИМПОЗИУМ ПО АГАМОВЫМ ЯЩЕРИЦАМ
mer of 2005 and 2008 periods the abundance of Ph. guttatus varied from 3.6 and 4.1 ind/ha, respectively, on sites in inter-knoll depressions up to 34.7 and 32.9 on weakly-fixed barkhan-type hilly sands with rare motley-grass and shrubby vegetation.
The abundance of Ph. guttatus in Kalmykia was 15 - 25 ind/ha (Kireyev, 1982) and 5.9 - 99.1 ind/ha (Badmaeva, 1983). In 2000 and 2003, the abundance of Ph. guttatus in this territory varied from 1.2 to 27.8 ind/ha, with its maximum values being characteristic of the edges of semifixed hillock sands. Similar results were also obtained for small-hillock and hillock sands in the territory of Krasnyi Yar and Kharabali administrative districts of the Astrakhan region, where the abundance of Ph. guttatus varied from 13.6 to 38.5 ind/ha (1998) and from 5.3 to 35.4 ind/ha (2006). In May 2001, at similar sites of the isolated sandy massif Shkili (Akhtubinsk district, Astrakhan region) the abundance of the species was 9.7 ind/ha.
The revealed trend in the dynamics of quantitative indices is apparently due to the dynamics of abiotic factors. The indices of total solar radiation and annual precipitation level should be considered as determinants in this situation. E.g., A.A. Tishkov (1996) has shown that the modern warming in the steppe zone of the Russian Plain began at the end of the 19 century and reached its maximum within 1930 - 1940. Within 1940 - 1970, a cold spell was noted, and in the last decade of the 20 century the average annual temperatures were exceeded almost every year. Besides this gradual increase of the average annual temperatures, the climatic trend dynamics manifests itself as increased precipitation. It
is enough to point out that in the territory under survey from late 1970s till mid-1990s, the annual precipitation exceeded its rate by 50 mm, in some years - by 120 - 190 mm. By F.R. Zaydelman et al.'s data (1998), the period from 1986 till 1995 was characterized by higher moisture than the 1975 -1985 period. Moreover, in the 1990s these indices were synchronized with the reduction in the total head of livestock, which entailed the beginning of large-scale restoration of ecosystems and biodiversity reconstruction. In this period, mass invasion of turf-cereal communities towards past waste grounds and the formation of vast fallow lands in the place of agricultural fields (Neronov, 1998) were observed. Let us point out that, for Ph. guttatus, the humidization of living conditions is the determinant to limit its expansion north.
Thus, besides anthropogenic influence, clima-togenic successions causing the mesophilization of steppe vegetation etc. have became a significant mechanism of transformation of natural ecosystems. To no small degree these changes affect spatially-separated local populations of animals. As to Ph. guttatus' populations, their isolated existence leads to a sharp increase of the specificity of their morphophisiological organization and gradual (sometimes sharp) contraction of the habitat. All these processes display most obviously in the conditions of the Lower-Volga region and adjacent territories, where the species' habitat has somewhat narrowed and the trend of abundance reduction of Ph. guttatus is obvious.
Key words: Phrynocephalus guttatus, biotopi-cal distribution, abundance, Lower-Volga region.
PRELIMINARY STUDIES OF THE GENUS ACANTHOCERCUS (SAURIA: AGAMIDAE) IN THE CONTEXT OF THE ARID CORRIDOR IN AFRICA
Philipp Wagner
Zoologisches Forschungsmuseum Alexander Koenig 160 Adenauerallee, D-53113 Bonn, Germany E-mail: philipp.wagner.zfmk@uni-bonn.de
African lizards in the genus Acanthocercus are widespread in wooded savannahs from northeastern to southwestern Africa. Therefore, they are an ideal group for testing biogeographic hypotheses and evolutionary studies of arid corridor distributions and colonization events in Africa. However, to
test these hypotheses a clear systematic and phy-logenetic framework for the genus is needed but currently lacking. Constructing a phylogeny like this requires the solution of problems in different aspects of species determination, taxonomy and relationships.
156
СОВРЕМЕННАЯ ГЕРПЕТОЛОГИЯ 2010 Т. 10, вып. 3/4
DeAgamis2: 2nd INTERNATIONAL SYMPOSIUM ON AGAMID LIZARDS
In general, higher relationships in the genus Acanthocercus and its relationships to other Agami-nae genera are poorly understood, but especially the understanding of the different species and subspecies of the atricollis species group should be reviewed for the understanding of the zoogeographic history of eastern Africa. A dense sampling within the genus and to related genera is lacking but neces-
sary for testing monophyly, identifying sister taxa and distribution corridors. Herein a preliminary phy-logeny is presented to show radiations within the genus, taxonomic problems on species level and results on distribution pattern in comparison with other arid species groups in Africa.
Key words: Agamidae, Agaminae, Acantho-cercus, arid corridor, Africa.
ON THE THERMOBIOLOGY AND ACTIVITY PATTERN
OF THE LARGE HERBIVOROUS DESERT LIZARD UROMASTYXAEGYPTIA MICROLEPIS BLANFORD, 1875 AT MAHAZAT AS-SAYD PROTECTED AREA, SAUDI ARABIA
Thomas Wilms
Zoologischer Garten Frankfurt 1 Bemhard-Grzimek-Allee, D-60316 Frankfurt am Main, Germany E-mail: thomas.wilms@stadt-frankfurt.de
Field active body temperatures (Tb) and operative temperatures (Te) were assessed in a population of Uromastyx aegyptia microlepis at Mahazat as-Sayd Protected Area, Saudi Arabia to gain information on the extent and effectiveness of the thermoregulation in these animals. In summer Tb ranged between 23.2 and 47.2°C, in winter between 23.0 and 45.1°C and in spring between 25.5 and 45.9°C. There is a significant difference between respective Tb and Te distributions and all applied indices of thermoregulation suggest that U. a. microlepis is an active thermoregulator. Above ground activity, in-
ferred from Tb data, is very variable between seasons, with the highest activity level in spring. In winter the animals showed a unimodal activity profile, with the highest activity between 11:00 and 15:00. In spring and summer the lizards exhibit bimodal activity profiles with afternoon activity being generally lower than morning activity levels. At midday activity is generally significantly lowered.
Key words: Uromastyx aegyptia microlepis, thermobiology, activity profiles, field active body temperatures.
A REVIEW ON THE TAXONOMY OF THE GENERA UROMASTYX AND SAARA
Thomas Wilms 1, Philipp Wagner 2, and Wolfgang Böhme 2
1 Zoologischer Garten Frankfurt 1 Bemhard-Grzimek-Allee, D-60316 Frankfurt am Main, Germany E-mail: thomas.wilms@stadt-frankfurt.de 2 Zoologisches Forschungsmuseum A. Koenig 160 Adenauerallee, D-53113 Bonn, Germany E-mail: philipp.wagner.zfmk@uni-bonn.de, w.boehme.zfmk@uni-bonn.de
The taxonomic relationships within the genus Uromastyx Merrem, 1820 were assessed using morphological and genetic methods, resulting in the resurrection of the genus Saara Gray, 1845 for Saara
hardwickii, S. asmussi and S. loricata. A synopsis of all taxa considered to be valid within Uromastyx and Saara is provided.
Key words: Uromastyx, Saara, taxonomy.
COBPEMEHHA3 TEPnETO.nOrHtf 2010 T. 10, Bbm. 3/4
157
