Adrian Hailey

Microhabitat separation among diurnal saxicolous lizards in Zimbabwe

Studies of niche overlap within communities of lizards have shown that separation may be along the three major dimensions of space, time and food. Space is usually the most important dimension where a range of habitats are involved; there is less information on the importance of microhabitat separation within a single habitat type. This study investigated microhabitat relationships of small diurnal lizard species occupying granitic rock habitat in Zillmbabwe. There was statistically significant niche separation among all species in both the type of rock occupied (size, shape, number of cracks, closeness to other rocks, and vegeta- tion cover) and the position of the lizard in the microhabitat (height on rock, slope angle, and distance to cover). Overlap of microhabitat was lowest between the generalist terrestrial skink Mabuya varia and all other species. The arboreal skink Mabuya striata was found on rocks at one site where the more saxicolous Mabuva quinquetaeniata was absent, due to competitor release. Overlap of microhabitat among rock specialists was lowest between the sit-and-wait foragers Aganma kirkii and Platysaurus intermedius, as in other tropical lizard communities. The high degree of microhabitat separation was attributed to the high structural complexity of the granitic rock habitat.

Changes in the Alyki Kitrous wetland in northern Greece: 1990–1999, and future prospects

The Alyki wetland in northern Greece is a site of notable herpetological and ornithological importance. A large population of the tortoise Testudo hermanni began to recover slowly (r = 0.016) between 1990 and 1999, following catastrophic habitat destruction in 1980 and slow decline from 1980–1990. Heathland vegetation showed signs of desiccation, probably due to increased drainage by the salt works, including deterioration of Crataegus, Ruscus and Asphodelus, and loss of formerly important food plants of tortoises. Activity and body mass condition of tortoises were reduced in summer in grassy heath habitats. Predation of artificial (chicken egg) tortoise nests increased, and the relative frequency of juveniles (about 1 % of samples) was lower than after severe habitat destruction or pesticide damage. These changes were attributed to an increasing population of badgers, Meles meles. Population levels of waders were lower in 1998/1999 than in 1988/1989, especially avocets (Recurvirostra avosetta) for which the site was internationally important. Breeding populations of most waders and larids also declined. Mediterranean gulls, for which Alyki was formerly the most important breeding area outside Russia, did not nest from 1990 to 1998, and nests were unsuccessful in 1999. Changes in breeding populations were due to falling lagoon levels, exposure to predators and vegetation encroachment on islet breeding sites. Midwinter waterfowl populations remained high or increased, however, as alternative feeding areas were available in the lagoon. Preservation of the habitats against development of the salt works and increasing desiccation are necessary to maintain the long-term conservation value of the Alyki site.

Fungus eating by the African tortoise Kinixys spekii

Fungi are important food for many invertebrates (Moore 1996). They are also widely consumed by small mammals (Fogel & Trappe 1978, Meserve et al. 1988), and may make up more than half of the volume of food in the stomachs of sciurid and microtid rodents in temperate forests (Maser et al. 1978). The use of fungi by vertebrates has not been investigated in the tropics, although macrofungi are common in some tropical systems, such as the miombo woodlands of southern Africa (Hogberg & Piearce 1986). The use of fungi by vertebrates other than small mammals is also little known. This paper describes a quantitative analysis of the diet and food selection of a tropical tortoise reported to feed on fungi. Most terrestrial tortoises (Testudinidae) have a predominantly or exclusively herbivorous diet (Pritchard 1979:247), and feed almost entirely on vascular plants (Hansen et al. 1976, Milton 1992, Rall & Fairall 1993). Nevertheless one group, namely the African hingeback tortoises Kinixys Bell, appears to be omnivorous. All species of Kinixys have been reported to eat fungi and/or invertebrates: K. erosa (Schweigger) and K. homeana Bell from West Africa (Blackwell 1968, Villiers 1958), K. lobatsiana Power and K. natalensis Hewitt from South