Date of Award
5-1-2010
Degree Name
Master of Science
Department
Zoology
First Advisor
Feldhamer, George
Abstract
AN ABSTRACT OF THE THESIS OF REGINA HELEN MOSSOTTI, for the Master of Science degree in ZOOLOGY, presented 23 October 2009, at Southern Illinois University Carbondale. TITLE: FEMALE REACTION TO MALE URINE SCENTS AS POTENTIAL INDICATOR OF MATE CHOICE IN CAPTIVE CHEETAHS (ACINONYX JUBATUS) MAJOR PROFESSOR: GEORGE A. FELDHAMER Genetic variation in the cheetah (Acinonyx jubatus) has become dangerously low because of dramatic population decline and fragmentation. Zoos throughout the world manage captive cheetahs with breeding programs to maximize genetic heterozygosity. Unfortunately, the zoo community has not accomplished consistent breeding success with cheetahs, possibly because of a general lack of information on sociosexual behavior. Currently, individual cheetahs are assigned mates based primarily on genetic relatedness; however, evidence from many species suggests that allowing animals to choose mates increases breeding success. When animals, primarily females, are allowed to choose mates they will often pick the best genetic match. I tested whether female cheetahs can determine their genetic relatedness to males by investigating their urine scents. Voided male urine was collected following scent marking. The female was offered scents from three different males: one from an unrelated male, a "good" mate choice (A), another from a male that was equivalent to a second cousin, an "average" mate choice (B), and one from a male that was closely related, equivalent to a brother/father, a "poor" mate choice (C). Every female was also offered "blank" gauze as a control (D). The scents were offered in a pair-wise forced choice paradigm for a total of six possible combinations. All behaviors displayed toward each scent (and their duration) were recorded. The estrous cycling of each female was monitored through fecal hormone evaluation for approximately six weeks, including the weeks during scent trials. In every pairing except C vs. D, the females spent more time overall with the better mate choice in the pair; with three of the comparisons being significantly different (A>C, t=2.38, df=11, P=0.039; A>D, t=1.88, df=11, P= 0.087 and B>D, t=2.62, df=8, P=0.045). Proximity was the most frequently observed behavior and females spent more time in proximity to the most distantly related male scent in all pairings. They spent significantly more time in proximity with A in AC pairing (t=2.25, df=10, P=0.049) and with B in the BC and BD pairings (t=6.37, df=8, P=0.0002; t=2.46, df=6, P=0.049; respectively). Sniffing was the next most frequently observed behavior, and in all pairings (except CD) females spent more time sniffing the most distantly related male's scent; but was only significantly different for A in the AD pairing (t=2.31, df=7, P=0.055). Lag time of estradiol in fecal samples varies between individuals; therefore, the affect of daily estradiol concentrations on scent choices could not be determined. This is the first mate choice study using urine with a mammalian carnivore.
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