94 ABSTRACTS Isr. J. Zoo!.

Neve David, a Geometric-Kebaran hunter gatherer site." The Giddy Zakai Memorial Prize for the best poster presentation was awarded to E. Tauber (The Hebrew University of Jerusalem) for his work "Acoustic communication in the duetting bush cricket Phaneroptera nana (Tettigoniidae, Orthoptera)." M.G. Dembo (Tel Aviv University) and H. Shamir (Ben-Gurion University of the Negev) received honorable mentions in the poster presentation category. Profs. A. Borut and F. D. Por from the Hebrew University of Jerusalem, and Profs. E. Kochva and A. Zahavi from Tel Aviv University were awarded Honorary Life-Membership in the Zoological Society of . Special thanks to A. Ar, R. Ben-Hillel, N. Ben-Eliahu, D. Friedmann, Y. Glass, M. Goren, 0. Kerman, A. Landsman, 0. Manheim, R. Ogorek, R. Ophir, R. Szmit, 0. Shukry, T. U. Stem, A. Tyran, and D. Wool for their help in preparing and running the meeting.

ABSTRACfS

Effect of group size on number and body mass of fledglings in Arabian babblers (Turdoides squamiceps) A. ANAVA, • M. K.AM,b A. SHKOLNIK,c and A.A. DEGEN.h •Department ofLife Sciences, Ben­ Gurion University of the Negev, Beer Sheva 84105, Israel; hAnimalAdaptations and Husbandry, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel;

The Arabian babbler (Turdoides squamiceps; adult body mass = 7~75 g) is a cooperative breeding species that inhabits extremely hot and dry deserts. In Israel, it is the only bird species that lives in groups year-round. The number of birds per group ranges from 2 to more than 10. Egg laying in each group occurs in one nest, usually between February and July. Three cycles of egg laying are possible in one breeding season. All members of the group participate in activities such as nest building, incubation, and the feeding and guarding of nestlings and fledglings. Nestlings reach approximately 60% of adult body mass after 12 days and fledge at about 14 days. Mter fledging, the young usually remain huddled under plant cover, are fed by the group, and do not forage. At 3~0 days, they stray out from cover and engage in foraging, but are still provided with food from the group until the end of the second month. Adult body mass is achieved at about 10 months of age. Since all group members participate in the raising of the young, we hypoth­ esized that larger groups would have an advantage over smaller groups during the breeding season. We predicted that larger groups would produce more offspring per year, and that their offspring would grow faster, mainly during the period in which they are dependent on the group for food. The number of fledglings and their body mass in different-sized groups were compared in 1994 and 1995. The average number of fledglings per year per group(± SD) increased with group size: from 1.9 (± 1.5, n =8) for a group size of2, to 5.5 (± 3.2, n = 13) for a group size of7- ll. Body masses during the second month were 60.2g (± 1.3, n =9), 63.2g (± 2.1, n =4), and 67.7g (± 1.6, n = 8) for small (2-3 individuals), medium (4-5), and large (0!: 6) groups, respectively. The Vol. 43,1997 ABSTRACTS 95 offspring from the large groups were significantly larger than those from the small groups. After a year, however, there were no differences in body mass among the different groups: 71.5g (± 1.2, n = 11), 71.1g (± 0.9, n = 23), and 71.5g (± 1.7, n = 7) for the small, medium, and large groups, respectively.

Effect of prey availability on the foraging activity of Scorpio maurus palmatus in relation to moonlight A. BACill. Department ofLife Sciences and the Mitrani Center for Desert Ecology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel Activity of scorpions and other nocturnal animals is known to change during moonlit nights. It is usually assumed that the change in activity occurs due to a higher risk of predation from visually oriented predators. I investigated an alternative hypothesis, that a predator's activity may be reduced on moonlit nights due to a reduction in prey availability. I manipulated scorpions' prey density and monitored their foraging activity, during full-moon and moonless nights. The activity of arthropods (the prey) was also sampled. The results support the hypothesis that feeding activity may be reduced on moonlit nights due to a reduction in prey availability.

Faunal remains from , a Geometric-Kebaran hunter gatherer site G. BAR-OZ and T. DAY AN. Department of Zoology, GeorgeS. Wise Faculty ofLife Sciences, Tel Aviv University, Tel Aviv 69978, Israel The Geometric- (15,000--12,500 before present) preceded the Natufian and fol­ lowed the Kebaran culture in the southern . This sequence is usually considered a continu­ ous development. However, beginning with the advent of sedentariness during the Natufian, a change in demography and intensification of environmental exploitation occurred. The Geomet­ ric-Kebaran economy and paleoecology are key to understanding the Natufian shift in culture and economy. We studied the faunal remains from a large Geometric-Kebaran site, Neve David, at the western foot of Mount Carmel. Neve David was a rich and varied hunting site. We found 15 mammalian and 2 reptilian species, as well as 7 genera of mollusks. Among mammals, cut marks and burnt bones indicate use for consumption of at least 9 species. The economy was based on two dominant species, the gazelle (Gazella gazella) and the fallow deer (Dama mesopotamica). No evidence for selective hunting of male gazelles was found. The age distribution indicates random hunting as well. However, male fallow deer were selectively hunted, possibly as a conscious strategy. The presence of red deer (Cervus elaphus)and squirrels (Sciurus anomalus) suggests a cooler and wetter climate than at present, as does a significant reduction in the size of the hare (Lepus capensis).

Predator-prey interactions between three species of Mediterranean lobsters and the gray triggertish D.E. BARSHAW, E. SPANIER, and K.L. LAVALLI. Leon Recanati Center for Maritime Studies, University ofHaifa, 31905, Israel Various antipredator strategies were tested in three species of Mediterranean lobsters against the predatory triggerfish, Balistes carolinensis. The distribution of this fish overlaps that of the three lobster species. The Mediterranean slipper lobster (Scyllarides latus) has no antipredator adapta­ tion except its heavy carapace, its ability to cling to the substrate, and its behavior. The common