Study on the nutritional ecology of wild primates

Abstract

Nutritional ecology is a new research field, which has attracted many nutritional ecologists in recent years. The study of nutritional ecology is useful to understanding many aspects of primate behaviour and ecology, and is an especially valuable tool in primate conservation. Nutrient acquisition is an important component of ecological interactions among species, but the majority of researchers have developed theories in isolation from each other. Primate nutritional ecology not only involves the interaction between a primate’s nutrient intake and the environment, but it also involves the individual’s resultant physiological state. Environments are comprised of abiotic and biotic components, which are distributed in time and space over multiple scales. A number of key environmental features affecting nutritional interactions include temperature and the ratios and abundance of chemical elements within the water or soil. Further, individuals’ traits – including knowledge of the environment, and the size and specific behaviour linking an organism’s nutritional situation with their environment – can determine the goal of nutrition in primates. Nutritional ecology is a diverse field that encompasses physiology, ontogeny, growth, development, ecology, and more. Although the concept of nutritional ecology has developed gradually, many studies on the topic have been reviewed and it has been ultimately found that nutritional ecology has a special ability to join nutritional, ecological, and organismal information. Important challenges lie in trying to explain how organisms influence the populations, communities, and ecosystems in which they live, and what feedback exists from environmental conditions. All aspects of nutritional ecology are based on the need for individuals to acquire appropriate quantities of certain macro and micro-nutrients from their habitat. To achieve their nutritional requirements, primate species may prioritize different nutritional parameters when choosing the quantities and types of foods they consume. There are five important models and the geometric framework in nutrition (GF), which has been applied in the field of primate nutritional ecology: (i) energy maximization; (ii) nitrogen (protein) maximization; (iii) nutrient balancing; (iv) limitations of dietary fibre; and (v) avoidance or regulation of plant secondary metabolites (PSMs). All of the models can explain each of the nutritional strategies employed by wild primates. In the field, the nutritional requirements of individuals are uncertain and always changing in the short-term. Some nutritional traits that might be related to such changing requirements have been quantified by the GF models. These include the intake target (IT), the growth target (GT), the extent to which toxins are voided and excess nutrients ingested, and the strength of induced responses after being attacked. Following the growth of nutritional ecology, several nutritionally relevant measures have since been developed. However, in all of these cases, the geometric framework has been widely accepted due to its ability to connect several nutritionally relevant measures into simple geometrical models, and to also assess and analyse nutritional priorities in primates. This allows for a comparison between predicted and observed patterns, and ultimately promotes the development of this subject. This framework has been successfully applied to a range of invertebrate and vertebrate taxa. In order to assist research on nutritional ecology, we are summarizing a number of different study results on this topic. This article expands the research content of nutritional ecology as well as the major models and descriptive methods applied in primate nutritional research.