39 goldfish, either normal, sham operated, or forebrain ablated, were tested in the acquisition, extinction, and retention of an instrumental avoidance response with either a short or long delay between operations and testing. Forebrain removal severely impaired or prevented acquisition, greatly reduced resistance to extinction, and completely abolished a previously learned response. The deficits were permanent-an 8-wk. delay between operations and testing did not result in improved performances. Median escape latencies did not differ between groups, indicating that the deficit is specific to avoidance learning.

Reproductive patterns of wild cotton‐top tamarin (Saguinus oedipus) females located in La Reserva Forestal Protectora Serranía de Coraza‐Montes de María in Colosó, Colombia, were examined using long‐term behavioral observations and fecal steroid analysis. Using an enzyme immunoassay, we analyzed fecal samples for E1C and PdG. Comparisons of reproductive cycles of a reproductively active female and her daughters were made. An inhibition of ovarian cycles has been observed in daughters living in their families. However, daughters also exhibited normal ovarian cycling that subsequently resulted in pregnancy. Factors influencing the fertility are discussed as they relate to the reproductive strategies of wild cotton‐top tamarin females. Am. J. Primatol. 43:329–337, 1997. © 1997 Wiley‐Liss, Inc.