1. Feeding ecology of western lowland gorillas in the Nouabalé-Ndoki National Park, Congo

   • Tomoaki Nishihara

   OriginalPaper Pages: 151 - 168

2. Do the old aged females experience a long post-reproductive life span?: The cases of Japanese macaques and chimpanzees

   • Yukio Takahata
   • Naoki Koyama
   • Shigeru Suzuki

   OriginalPaper Pages: 169 - 180

3. Tool-use by chimpanzees (Pan t. troglodytes) in the Lopé Reserve, Gabon

   • Caroline E. G. Tutin
   • Rebecca Ham
   • Dorothea Wrogemann

   OriginalPaper Pages: 181 - 192

4. Tool-use for catching ants by chimpanzees at Bossou and Monts Nimba, West Africa

   • Yukimaru Sugiyama

   OriginalPaper Pages: 193 - 205

5. A within-group gang attack on a young adult male chimpanzee: Ostracism of an ill-mannered member?

   • Toshisada Nishida
   • Kazuhiko Hosaka
   • Miya Hamai

   OriginalPaper Pages: 207 - 211

6. Play behaviour and its effects on social development of common chimpanzees (Pan troglodytes)

   • Nicola Markus
   • David B. Croft

   OriginalPaper Pages: 213 - 225

7. Culturally-transmitted feeding behaviour in primates: Evidence for accelerating learning rates

   • Louis Lefebvre

   OriginalPaper Pages: 227 - 239

8. Birth seasonality in cotton-top tamarins (saguinus oedipus) despite constant food supply and body weight

   • William C. McGrew
   • Joanne Webster

   OriginalPaper Pages: 241 - 248

9. Serum levels of prolactin during the ovarian cycle, pregnancy, and lactation in the common marmoset (Callithrix jacchus)

   • Makoto Moro
   • Ryuzo Torii
   • Yoshikuni Tanioka

   OriginalPaper Pages: 249 - 257

10. Urine washing and related behaviour in wild moustached tamarins,Saguinus mystax (callitrichidae)

    • Eckhard W. Heymann

    Short Communication Pages: 259 - 264

11. Factors determining tool-using ability in two captive chimpanzee (Pan troglodytes) colonies

    • Linda Brent
    • Mollie A. Bloomsmith
    • Stanley D. Fisher

    Short Communication Pages: 265 - 274

12. Hand preference in the Sifaka (propithecus verreauxi coquereli) during feeding in captivity

    • Angela M. Mason
    • Linda D. Wolfe
    • Jeffery C. Johnson

    Short Communication Pages: 275 - 280

13. Sharing of sleeping sites betweenAotus vociferans with other mammals in the Peruvian Amazon

    • Pablo E. Puertas
    • Rolando Aquino
    • Filomeno Encarnacion

    Research Report Pages: 281 - 287

14. Observations onChiropotes albinasus from the Rio dos Marmelos, Amazonas, Brazil

    • Stephen F. Ferrari

    Research Report Pages: 289 - 293

15. Book review

    • Michael A. Huffman

    BookReview Pages: 295 - 295