Nature’s Foraging Specialists
By Safina Center Fellow Alex Chege
A herd of Grant’s Zebra seen travelling in Solio Game Reserve, Kenya. ©Alex Chege
Most animals are social and tend to congregate together in groups.
These groups make it easier for them to find mates, protect themselves against predators, enjoy the benefits of familial bonds, cooperate, and share information on where to locate foods in diverse landscapes and during unpredictable times. Though there are many benefits of grouping together, social animals face challenges with conflict and competition for fundamental resources, such as food, that are needed by each member of the group. Individuals can resolve these challenges of competition by adjusting their behaviour appropriately in response to their social and ecological environments.
More recently, scientists are finding that individuals within wild populations can become ecologically specialized, where they become more efficient in exploiting a subset of the resources used by the entire group. These individuals can employ different foraging strategies therefore becoming more efficient in taking advantage of a less competitive resource. These specialist strategies become more advantageous over their generalist counterparts that may experience greater competition in similar habitats. New reports in scientific literature suggest that individual specialization is actually quite common among different species. For example, specialization in foraging for food items has frequently been studied in marine mammals where species such as sea otters, dolphins, and orcas have been shown to contain social groups where individuals specialize in food types not used by the entire population. For example, orca groups specialize in different food types (salmon or seals) and use alternate strategies with differing degrees of communication and cooperation to hunt their respective prey choices.
The degree to which individuals are capable of specializing in nature is thought to be influenced by both habitat contexts and individual requirements. For example, if two environments vary in their available food types, then food preferences may be determined by how nutritious certain foods may be given the environmental context. An individual’s needs may also influence their chosen diet if using certain resources is based on individual nutritional requirements, or one’s unique ability, knowledge, or technologies to better capitalize on the food resource in question. For example, a recent paper published in Science Advances demonstrated that children in hunter-gatherer societies may specialize in easier to attain foods such as fruit or shellfish during their early years. Leaving childhood, they gain more complex knowledge and develop the necessary dexterity to handle more challenging-to-obtain food items.
Through social learning, juvenile vervet monkeys (pictured) learn food choices. These choices are a result of locally available easy-to-process foods and those learned through imitation of their mother’s food preferences. ©Alex Chege
In the case of vervet monkeys occupying coastal contexts, I am interested in determining to what extent do individual traits determine whether or not vervets choose to participate in exploiting marine crabs as a food source. Since individuals can differ markedly in their nutritional requirements, certain individuals may disproportionally use and benefit from exploiting these food resources. However, the ways in which both the context of local food availability and individual traits come together to determine how beneficial marine foraging strategies are in individual dietary specialization is yet to be explored in greater detail.
Scientists believe that within a population, a diversity of strategies and foraging specializations can increase the population’s resilience to disturbance - promoting ecosystem stability. This diversity, in its various forms, functions, and behaviours can also impact the degree to which new species (or animal traditions) are formed in nature as they allow organisms to adapt to varying contexts.