The PI proposes to study the effects of social interactions, urine simuli and a chemosensory sampling behavior, flehmen, in the synchronization of reproductive cycles among sable antelope. There are three goals of the proposal. First, the estrous cycles of female antelopes will be characterized in order to determine the relationships between behavioral estrus, ovulation, and hormone changes monitored in blood and feces. Part of the goal here is also to understand more completely the physiological and behavioral processes that follow artificially induced ovulation. Second, this method of inducing ovulation will be used to desynchronize one female in a group from the other members of the group so that they can study the cycles of the females following this procedure, particularly to see if the cycles become synchronized again, either by changes in the odd female or the remaining members of the group. Third, the role of flehmen behavior in causing changes in cycles will be investigated by housing females alone and exposing them to urine that they can contact, urine that they cannot contact, or water and monitoring endocrine changes by analysis of hormones in feces. The PI makes the case that the sable antelope is an especially interesting species for this kind of analysis.

I agree that this sounds like a very interesting system and that the facility at Front Royal is an ideal one at which to study this system. The investigators have also had considerable experience with this species and with the techniques necessary for the study. The case could perhaps have been made more strongly by providing more detailed information about the degree of synchrony in the captive herds; the proposal would also have been clearer if this had been done. Apparently captive herds are not as synchronous as wild herds (p. 5), but no information is provided on just how synchronous they are in either place. In the second study, however, it seems to be assumed that at the start all females will be sychronized.

Study 1 seems to be a good, relatively straightforward study of endocrine changes and correlated behavioral changes. One weakness is that the two groups (one exposed to males, one in all female groups) cannot both have blood samples taken, I assume because the female group would then come in proximity with the male. But this also means that the parallel or lack of it between the two groups cannot be studied in as much detail. Study 2, on re-establishing synchrony, does suffer from a design problem - if the effect depends on whether it is a dominant or a subordinate female that is desynchronized from the group, then there should ideally be two sets of experiments, one in which dominants are desynchronized & one in which subordinates are. This possibility is acknowledged, but nothing is said about how it will be dealt with, whether dominants or subordinates are to be selected for desynchronization, etc. There is also a troubling use of language that suggests that the goal of females is to be synchronized - (e.g., her ability to manipulate her estrous cycle) - as if this were a strategy of each female. If the advantages and disadvantages of synchrony, or the advantages and disadvantages of differing strategies, were examined a bit more thoroughly a more balanced approach might be attained.

The third experiment does not test what the PI says it is designed to test. The stated goal is whether direct contact with urine is required for females to shom entrainment to the estrous cycle of a conspecific urine donor. What is tested is whether contact with urine is sufficient to cause a change in the estrous cycle, in the absence of other stimuli from females. Also, I do not agree with the proposed interpretation of this experiment. Although it has been hypothesized that the vomeronasal system may be specialized for responsiveness to large molecules that must be contacted it is not the case that it cannot respond to volatiles. There are several experiments that indicate that it is in fact responding to volatiles in rodents, and this should not be ruled out without a test in ungulates. In fact, this experiment is apparently nicely designed to determine if this is true in this system, although the details of how urine will be covered are not given.