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The Damara Tern Sterna balaenarum is a rare, near‐endemic breeder along the southwestern coast of Africa. Found predominantly in Namibia, its world population was once believed to be 4000 birds. Population surveys in the northern Namib Desert have recently estimated that 12,000 adults exist. The aims of this study were to (1) determine the population status along the southern coast, thereby completing Namibian surveys, (2) assess latitudinal trends (over 10d̀) in relation to ocean upwellings for the entire coast and (3) determine breeding habitat preferences. This was completed in 1994 and 1996 using random sampling techniques. Survey squares of 1 km2, randomly plotted on 1:50,000 maps, were located in the desert with a Global Positioning System (GPS) unit and searched for breeding terns. A total of 1780 km2 was sampled in the southern desert and extrapolations indicated that about 1450 adult terns occur in this region. This gives a global population estimate of 13,500 adult Damara Terns. Significant habitat preferences were apparent with terns nesting most often on gravel plains in the north but switching to salt pans in the south. Lower salt pan temperatures in the south may account for these trends. The peak density was in central areas (23|dGS) with a decreasing density north and south along Namibia's 1470 km‐coast. This is parallel to recent findings for linear shorebird densities and macro‐invertebrate density. This suggests that primary productivity of the Benguela is highest in the central regions and not where the upwellings occur 400 km south. We propose a delayed blooming effect to account for these trends and conclude that this diminutive tern is influenced in many aspects of its life history by Namibia's cold offshore upwellings.

The conservation status of relic melanistic lizard species occurring in the Saldanha- Langebaan area has been investigated. A contact zone between one melanistic form and a closely related non-melanistic form has been examined in detail. Apart from melanis- tic populations of the girdled lizards, Cordylus niger and C. polywnus, a melanistic morphotype of the Cape legless skink, Acontias meleagris meleagris also occurs in the area. The taxonomic status of this morphotype needs to be investigated. At Mauritz Bay, north of Saldanha, the ranges of C niger and the non-melanistic C cordylus are in contact over a distance of approximately 240 m, with maximum overlap of 70 m. The melanistic populations of C. polyz.onus and A. m. meleagris have relatively large ranges in the Saldanha-Langebaan area and are not threatened by urban development. The C niger population, however, is fragmented into several subpopulations, and those in the Saldanha area, including the contact zone, will be affected if urban development is allowed to continue in the area. As relic populations of other cool-adapted, melanistic invertebrate and lower vertebrate species may also occur in the area, the key areas demarcated by C. niger should be preserved

To whom correspondence should be addressed CORDES, I.G., and P.le F.N. MOUTON. 1995. The cryptic significance of melanism in cordylid lizards: A case study of Cordylus niger and C. polyzonus. J. Herpetol. Assoc. Afr. 44: 16-21.The cryptic significance of melanism in two girdled lizard species, CordyllLS niger and C. polyzonlLS, was evaluated by comparing the melanistic forms with closely related, non-melanistic forms. A simple photographic technique involving colour transparencies and a colour densitometer, was used. The degree of correspondence between the integral density of the dorsal body surface of each lizard and its associated substrate was taken as an indication of the degree of background colour-matching. Inland, non-melanistic populations of C. cordyIlLS and C. polyzonlLS, were significantly more background colour-matched than a population of the melanistic species C. niger and a melanistic population of C. polyzonlLS, occurring at the coast. A darkly coloured C. cordyllLS population, occurring 2 Ion from the coast, was also less background colour-matched than the inland forms. The results show that the primary function of melanism in cordylid lizards is not a cryptic one. It is suggested that, although not selected for background colourmatching, a black body colour may be advantageous in the avoidance of predators, as it may blend in well with shadows when seen from a distance.

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