Orangutans are unique among great apes in their maturation process. As male orangutans experience puberty, specialized facial structures called “cheek pads” emerge, signaling sexual maturity. For most males, this occurs around 10 to 12 years of age, but maturity in orangutans housed with or near other adult males can be suppressed.
When this suppression occurs, the development of these cheeks pads is delayed for up to 10 years, and the animal remains in a sub-adult state. The precise mechanisms of this suppression are not fully understood.
Dr. Melissa Thompson of the University of Mexico is working with Dr. Cheryl Knott of Boston University to better characterize orangutan development both in conservation care and in the animal’s natural range. Seneca Park Zoo contributes to this project through collection of urine samples from our male orangutan Denda.
Zoo keepers have trained Denda to urinate in a collection cup in exchange for a food reward. These urine samples are then sent to Dr. Thompson who analyzes the urine for concentrations of sex hormones, especially testosterone, to track the influences these hormones have on development.
Zoo keepers also track Denda’s development so that researchers might be able to correlate hormonal changes with development in male orangutans.
A team of University of Rochester scientists led by Assistant Professor Dr. Jessica Cantlon are engaging the Zoo’s troop of Olive baboons in games of puzzle solving and decision making as part of a research initiative to evaluate learning abilities and thought process across the animal kingdom.
Humans display the unique ability to use language and symbols. However, non-human primates (prosimians, monkeys and apes) possess many complex conceptual skills despite the fact that they lack natural language abilities.
“Our research team is interested in identifying the cognitive abilities that distinguish humans from other primates as well as those that all primates share, whether human or non-human,” explains research associate Allison Barnard. “Our lab is especially interested in the origins of conceptual abilities such as math, music and logic.”
We are currently testing baboons’ abilities to:
We are interested in understanding whether baboons share some basic aspects of our human conceptual profile despite the fact that they lack language abilities, as well as what baboon cognition can tell us about child development. For example, we will examine the extent to which the conceptual abilities of young children who have not yet mastered language show similarity to the primitive abilities of baboons. Human children might be born with the same cognitive capacities as other primates, but change radically as they learn human language and culture.
We are also investigating how genetic and environmental factors have shaped particular cognitive abilities over evolutionary time. We will compare the baboons’ performance on a variety of tasks to the performance of many other animal species including great apes, lemurs, capuchin monkeys, sparrows, squirrels, mice and many more. These species are all quite different from one another yet many of them have a few things in common, such as what they eat, the sizes of their groups or where they live.
We are interested in whether certain cognitive abilities are more likely to be shared by two different species when they have something in common. By comparing cognitive abilities across all of these different species, we can determine whether a particular cognitive ability is likely to emerge in a species that has the same group size, social structure, diet, terrain or predators.
These studies will help us understand the precise causes of complex conceptual skills in animals.
For more information on how other scientists are studying primate thought processes and decision making, check out the Smithsonian Institution’s “Think Tank” at the National Zoo in Washington D.C.