Keeping a close eye on the health of the birds is very important to us here at the Maui Bird Conservation Center. One valuable way we determine the health and body condition of a bird is through obtaining regular weights. (See also Zoo Hospital: What Do You Weigh?) Traditionally, we would weigh birds by catching them in a net, then transferring them to a box or a bag that could then be placed on a scale. This method required the time of multiple husbandry staff at once and subjected the birds to a certain amount of stress. Stress in birds can be dangerous, and we obviously like to keep our birds as stress-free as possible. Our solution was to convince our `alala to offer us their weight by landing on a freestanding platform that had been placed on a scale. This is called a “remote weight.”
By using positive reinforcement, the birds of our `alala flock have been conditioned to perch on a freestanding platform that holds their food pans. When individuals are fed on these platforms consistently, it adds little to no stress to move that platform onto a scale to obtain a weight. With this procedure, one staff member can obtain the weights of many birds in one day, with the birds typically unaware of what is taking place!
The younger `alala from 2010 and 2011 have become experts at retrieving rewards from the platforms and have served as good examples for other birds to watch the process. Not everyone is easily convinced, however, and some of our `alala have proven a challenge. It seems as though some of our smarter adults are also rather stubborn, and the conditioning process has developed their crafty side! One of our mature males, Laha, seems determined to prevent us from weighing him and goes to great lengths in order to obtain treats while breaking the rules.
Michelle Smith is a research associate at the Maui Bird Conservation Center, part of San Diego Zoo Global’s Hawaii Endangered Bird Conservation Program. Read her previous post, New Homes for the Growing Flock.