|Ph.D. student, University of Chicago|
|Hormonal Correlates of Reproductive Success in Captive Goeldi's Monkeys|
|Location: Multiple U.S. Zoos|
|Species: Goeldi's monkey|
|Abstract: The Goeldi's monkey captive breeding program has had some success, but many established pairs fail to reproduce. This project aims to compare the behavior and hormonal patterns of females that reproduce and those that fail to do so. Female reproductive cycling can be monitored by assaying fecal samples to measure progesterone levels. This technique will be used to determine if females that fail to reproduce are also exhibiting abnormal reproductive cycles. To assess the impact of stress on the reproductive activity of female Goeldi's monkeys, assays will also be employed to measure the stress hormone corticosterone in collected fecal samples. The goal of this project is to identify key behavioral and hormonal features of females that reproduce successfully and to isolate causes of reproductive failure in unsuccessful pairs. This will lead to improvement of the breeding program for this species and produce results applicable to other endangered primate breeding programs.|
Project Update: November 2006
The purpose of this project is to compare the behavioral patterns and female hormonal profiles of Goeldi's monkey breeding pairs that regularly produce viable offspring ("successful pairs") with pairs that fail to do so ("unsuccessful pairs"). To date, behavioral observations have been made on five successful pairs and one previously unsuccessful female that were re-paired with a previously unsuccessful male. Fecal sample collection is currently underway for this previously unsuccessful female and two additional unsuccessful females that will be re-paired with different males in December 2006, during which time behavioral observations will take place. Sample collection is also taking place for one female who has successfully reproduced, and collection is scheduled to begin for three additional successful females that are expected to give birth in the next two months. Collection will begin shortly after the female gives birth and continue for 60 days, with behavioral observations being made concurrently.
A number of unexpected challenges have presented themselves, which has delayed the original timeline for sample collection. First, four of the pairs comprising the unsuccessful group were dissolved before samples could be collected. The female of the non-successful pair at Bergen County Zoo died before sample collection could be initiated, while females at Denver Zoo, Lake Superior Zoo, and John Ball Zoo were transferred to other institutions. However, sample collection is currently underway for two of these females so that their reproductive hormones can be followed as they are introduced to new breeding partners. Additional samples are being collected from a four-year old female at Norfolk Zoo with an interesting history. This female was paired with a hand-reared male in May 2005, and fecal samples were collected from her for six weeks following pair formation and for an additional three month period at the end of 2005 as part of another project. The pair was separated in April 2006 due to aggression. Sample collection began again in early September 2006 and continues as she is now in quarantine at Miami Zoo where she will soon be paired with another male. Additional females at Brookfield Zoo are being considered as possible subjects for the "unsuccessful pairs" group. Sample collection and behavioral observations will begin on these females in the near future.
The second problem was that a reliable marker for fecal sample identification has not been developed despite continued effort by keepers at multiple zoos. A number of markers (corn, blueberries, non-toxic beads, food coloring) have been tried with varied success. While one method will work well for one female at one zoo, I have not been able to identify a universal marker, which has made it difficult to provide appropriate guidance and supplies when recruiting new institutions to the study. While I continue to evaluate potential markers, I look forward to the results of a project that my advisor Dr. Susan Margulis, Curator of Primates at Lincoln Park Zoo, is developing along with collaborators at Lincoln Park Zoo and Cleveland Metroparks Zoo. The group is working to test a range of fecal markers in different species, which will hopefully identify a marker that can be used universally in Goeldi's monkeys or at least provide new possible markers to be tested in females that have not accepted other markers.
Sample collection is nearing completion for the first group of subjects. Thus, laboratory supplies will be purchased by the end of November 2006 so that sample processing can begin in December 2006. In summary, although the project has encountered some unexpected complications, data collection is currently underway to address the research questions of the original proposal.
This research makes up one component of my dissertation research which focuses on behavioral, hormonal, and genetic factors that contribute to variation in reproductive success within the captive Goeldi's monkey population. In addition to this project which concentrates on established pairs, I am in the final stages of completing a project examining the hormonal and behavioral changes that take place when females are placed in a breeding situation for the first time. I discovered that these females exhibit normal progesterone cycles in their natal group and throughout the quarantine period. However, as soon an unfamiliar male is introduced, progesterone activity drops dramatically and doesn't resume for six to eight weeks, even though there is not a corresponding change in the stress hormone corticosterone. I presented these findings at the 2006 meeting of the Animal Behavior Society and received considerable interest and valuable feedback. I very much look forward to comparing the profiles of these inexperienced females with those that I obtain from the females that are being re-paired after being housed in an unsuccessful breeding situation. I have also completed and presented two other research projects; one on behavioral differences among Goeldi's monkeys housed in different types of zoo environments, and another that analyzed data from the studbook to quantify variation in reproductive success due to demographic factors. These studies, in conjunction with the work on established pairs supported by the Cleveland Metroparks Zoo, will greatly increase our understanding of the reproductive biology of the Goeldi's monkey and lead to improvements in the captive breeding program so that maximum genetic diversity can be maintained in captivity for this unique, enigmatic species.