Foraging energetics in patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus): Implications for reproductive seasonality

Abstract

The patas monkeys (Erythrocebus patas) in Kala Maloue, Cameroon, have their birth season in the mid‐dry season, whereas closely related, sympatric tantalus monkeys (Cercopithecus aethiops tantalus) have their birth season in the wet season. To evaluate the optimality of a species‐specific birth season, I estimated the daily intake of available energy and gross protein, and energy expenditure for one individual of each sex of each species between respective birth and mating seasons. The monkeys obtained a larger amount of available energy and gross protein in the birth season than in the mating season. No significant seasonal differences in energy expenditure between the birth and mating season were found. Thus, the birth season appears to be timed to the season when the monkeys can obtain more surplus energy and protein. Interspecific differences in the optimality of birth season were attributed to widely exploitative foraging, supported by the patas’ high locomotive ability, which may enable them to obtain more energy from seeds of Acacia seyal and gums of A. sieberiana, and more protein from grasshoppers and seeds of A. seyal in the mid‐dry season than the tantalus monkeys. A review of preceding studies suggests that the availability of seeds of Acacia fruiting during the dry season may exert the dominant influence on timing of birth not only in patas but also in savanna monkeys (Cercopithecus aethiops), which include the tantalus monkeys. Am. J. Primatol. 52:169–185, 2000. © 2000 Wiley‐Liss, Inc.

Home‐range characteristics and the influence of seasonality on female reproduction in white‐handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand

“…In these cases, the majority of females conceived only after they accumulated sufficient fat reserves to meet the physiological demands of ovulation (Bercovitch and Strum, 1993). The same relationship between food availability and conception has been found in the nonseasonally breeding Gilgil baboon (Bercovitch and Harding, 1993),in Erythrocebus patas, Cercopithecus aethiops tantalus (Nakagawa, 2000), and in one large New World primate, Alouatta caraya (Rumiz, 1990), highlighting the high energetic demands required prior to conception (Bercovitch, 1987).…”

Female reproductive parameters and fruit availability: factors determining onset of estrus in Japanese macaques

“…In contrast, females of many nonhuman primates seem to take advantage of the period of maximum food availability for the increased nutritional demands of birth, lactating, and weaning [Portman, 1970]. In the tropics, birth peaks have been observed during the rainy season, when food availability is maximized [Bronson, 1985;Lindburg, 1987;Rutberg, 1987], or during the mid-dry season, when patas monkeys (Erythrocebus patas) in Kala Malue obtained more energy and gross protein than during the rainy season [Nakagawa, 2000]. Seasonal food availability is a factor that has also been related to birth seasonality in New World monkeys [Di Bitetti & Janson, 2000].…”

“…Annual fluctuations in food abundance undoubtedly affect the time of female fecundity and reproduction. In Old World monkeys, birth seasons and birth peaks [Butynski, 1988;Lindburg, 1987;Nakagawa, 2000], conception periods [Koenig et al, 1997], and a high lactational burden [Lee, 1987], all coincide with high food abundance. One of the factors that influence the extent of birth seasonality in New World monkeys is diet [Di Bitetti & Janson, 2000].…”

Professor Masao Kawai, a pioneer and leading scholar in primatology and writer of animal stories for children

“…These bands consist of several single-male units along with all-male groups, an organization considered to be analogous to regional communities composed of several human families (Kawai 1979a). Nakagawa (2015) developed an idea proposed by Isbell et al (1998) and discussed the benefit of the long limbs that evolved in genus Homo on the basis of my findings and on observations of patas monkeys (Nakagawa 1999(Nakagawa , 2000a(Nakagawa , 2003. The first fieldwork on patas monkeys was, in fact, done by a member of the KUPRI team in Cameroon directed by Prof. Kawai (Nakagawa 1989).…”

“…Specifically, I cannot forget him talking in his office about the importance of comparative studies. There is no doubt that this conversation led me to make intraspecies comparisons of Japanese macaques (Macaca fuscata) (Nakagawa 1998(Nakagawa , 2010Nakagawa et al 1996Nakagawa et al , 2015 and patas monkeys (Erythrocebus patas) (Nakagawa 2008), as well as interspecies comparisons between patas and tantalus monkeys (Chlorocebus tantalus) (Nakagawa 1999(Nakagawa , 2000a(Nakagawa , b, 2003.…”