Sensory Ecology | Field Projects International

Sensory Ecology


Detailed Description

Action heroes are usually defined by having some exceptional ability, like ultra-sensitive hearing or x-ray vision. In reality, you don’t have to be a superhero to have heightened sensory perceptions. Sometimes, all you just need is a good enough reason to evolve a characteristic – and usually that reason is improved fitness. Primates have evolved a number of adaptations to process their surroundings, relying on olfaction, taste, vision, and audition. Disentangling the extent to which each species relies on each of these areas of sensory perception can be complicated, particularly in the wild.

We are tackling this subject among Neotropical primates through multiple projects, each based on the ability of the primate to produce a signal and that of conspecifics or heterospecifics to detect it.

Project 1: Sight, smell or taste?

Neotropical primates they have an interesting sex-linked, color vision phenomenon.  Excluding howler monkeys, male platyrrhines are all dichromatic, meaning they lack the ability to see all three primary colors.  On the other hand, about half of all the females have trichromatic vision, just like most humans (with a few exceptions).  We can design experiments in the field that test which senses primates use to select ripe fruit, and we would expect the dichromatic females to adopt similar foraging strategies as the males, but the trichromatic females should behave differently if variation in vision does in fact influence foraging efficiency. We predict that a dichromatic primate that has trouble seeing the color differences between ripe and unripe fruit might compensate by honing another skill, such as olfaction or taste. At our site, our mark-recapture program utilizes feeding platforms to habituate primates to traps, and this phenomenon provides us with the perfect opportunity to test trade-offs in sensory perception in the wild.

Project 2: Alarm Call Awareness

The evolution of language is a fascinating aspect of human biology that can be used as a benchmark for the study of nonhuman primate communication. In the wild, primates have complex vocal repertoires that conspecifics understand, but what of heterospecifics? Can an emperor tamarin understand the vocalizations of a saddleback? Does a specific vocalization mean the same thing to both species? Or can each only understand a word or two of the other’s phrasebook? At our site, we have a population of sympatric tamarins that are exposed to multiple predators in the presence of which they make alarm calls. Each type of alarm call – aerial, terrestrial, or predator-specific – evokes a different suite of behaviors in tamarins nearby. Disentangling these conversations in the context of predator-prey interactions is the goal of this project. We will be conducting playback-experiments at rare and specific intervals in order to examine the ability for each species to respond to the other’s alarm calls.

Project 3: Scent-marks as Signals

Primates communicate using olfactory signals in two ways, via scents produced by their scent glands and those deposited in their urine.  Combinations of these secretions are applied on substrates in a variety of ways, can be directed towards others, and can code for a range of information such as age, sex, development status and sexual proceptivity. In this project we are interested in determining which signals animals emit and how they are received.

In addition, we are also looking at a different kind of signal – skin pigmentation. Primate coat colors can vary subtly across their lifetimes and during the year. Other portions of their anatomy, including scent-glands and genitalia, can also change in color in correlation with changes in developmental status.

Research assistants on this program will delve into these interesting topics while learning to carry out experiments on individually identifiable primate groups.  Generally speaking, experiments are conducted in  the morning or afternoon at several different locations, and data entry follows in the afternoon or evening.  Free time is scheduled into each week for assistants to pursue other interests and sightseeing activities (oxbow lakes with river otters, palm swamps with anacondas, canopy tower, and tagging along with other FPI research programs).

At the end of this program, you will be able to:

  • Design an experiment
  • Record focal behavioral data
  • Work with video recording equipment
  • Complete basic video edits
  • Understand relational databases
  • Perform basic behavioral data analyses
  • Recognize all 11 species of primate at Los Amigos
  • Distinguish species specific vocalizations
  • Gain a general knowledge about rainforest ecology


We are currently recruiting participants with the following requirements.  If you are uncertain if you are eligible, contact us to confirm.

  • Must be at least 18 years of age by the time the training program begins
  • Demonstrate a grounding or strong interest in physical anthropology, animal behavior, zoology, or psychology
  • Previous field experience is not required, but previous research experience (either outdoors or in the laboratory) will be a plus
  • Must be able to justify why this program is important to you and what you hope to gain from it
  • Able to provide a letter of recommendation from a source that can substantiate the your competency and any skills
  • Unafraid of insects, reptiles and the jungle in general
  • Must be in good physical condition, with the capability to walk 4 miles a day while carrying field equipment
  • Participants will not be discriminated against for medical conditions they might have if we determine that being on this project will not pose an immediate risk to their health.
  • Willingness to adjust your schedule to primate daily activity patterns. This can require waking up early, sometimes by 5 am, and going to bed early.
  • Due to the nature of the work and weather constraints, participants MUST be willing to be flexible about their days off. Assistants will typically have one-two days off per week; however we cannot guarantee a set schedule and breaks are normally divided into half-days.
  • Participants must sign waivers of liability for this project and for the field station before their participation in the project is finalized
  • Participants must be willing to maintain long hours in the field, but also return to complete data entry in the evening.
Quick Info

Program dates: June 11 – July 31, 2018
Start dates: June 11, June 15, July 9
Minimum commitment: 3 weeks
NEW Application deadline: April 20, 2018, or until full
Program fee: $1350; $450 each additional week

Primary Investigators

This project began in 2014, and the primary investigators working on it include Mrinalini Watsa, Amanda Melin, Kaelyn Dobson, Lais Moreira, and Gideon Erkenswick. They represent Washington University in Saint Louis, Iowa State University, the University of Missouri-St. Louis, and the University of Toronto.

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