Page 7 - Gateways_2017_Fall

Closed-Circuit Courtship

SCIENCE A Species Survival Plan (SSP) of the Association of
Zoos and Aquariums (AZA) is a multizoo conservation
program through which the breeding of species
in zoos is managed to maintain a healthy, genetically diverse pop-
ulation. When an animal is part of an SSP, it is paired with a mate
that is a good genetic match to ensure it has healthy offspring. The
SSP doesn’t leave much to chance, introducing animals to spe-
cific mates chosen for them by experts who study these species
extensively. But what if there is another way to match animals?
During a study conducted here at Brookfield Zoo, we let some of
our female birds choose their own mate for the first time. Five blue-
gray tanager and five red-capped cardinal females each selected a
mate from three preselected males, all of whom had equal genetic
value. The males were placed in an enclosure that allowed them to
hear their competitors but, to keep from driving the other males away,
not interact with one another. These enclosures guaranteed that the
males were able to compete for the females’ attention, just like in
their natural habitats, but did not allow them to physically interact.
Each female was given time to inspect her potential mates
and watch their mating dances. Recordings of these interactions
and a tracking device that was fitted around the ankle of
each female and that monitored her movements allowed
our animal care specialists to “peep” in on their choices.
After the “choice” portion of the study in the spring, each female
was paired with the male she spent the most time watching.
During the summer and through the beginning of fall, they are
nesting and, we hope, producing offspring. Nest success rate is one
way to monitor these new pairs. Another is through stress levels,
determined via hormone analysis by our on-site endocrinology
staff. Close comparison of these two factors, along with the
behavior of the animals, will help staff understand if arranging
matches or allowing an animal to choose its own mate leads
to better animal welfare and greater reproductive success.
As always, our goal is to ensure the health and safety of
the species in our care while promoting their breeding.

Above top: Dr. Lance Miller, senior director of animal
welfare research, keeps an eye on 40 day/night infrared
cameras that monitor the behavior of red-capped
cardinal and blue-gray tanager pairs. BLUEGRAY
Above middle: A female blue-gray tanager sits above TANAGERS
a reader that allows scientists to automatically track
the amount of time she spends in front of three males.
Inthebackground is a male in a nearbyhabitat.

BROOKFIELD ZOO | FALL 2017 7