DIFFERENCES IN MOTHER AND INFANTGREVY’S ZEBRA BEHAVIOREmily Paup
INTRODUCTION Grevy’s Zebra is the largest zebra species endogenous to the regions of Kenya and Ethiopia They live in grasslands where they feed primarily on grass and other legumes Females are polyandrous (Ginsberg and Rubenstein, 1990) Social setting comprises of many females and their young- there is normally no dominant male (Rubenstein, 2010) Considered endangered
HYPOTHESIS Ifyou observe a mother and infant Grevy’s zebra, the adult will display a smaller variety of behaviors, while the juvenile will display more ‘play’ and ‘locomotion’ behaviors. Prediction: There will be a significant difference in the mother and infant behaviors, particularly in play and locomotion.
METHODS Focal scan I observed the mother zebra and her male foal at the Detroit Zoo Observation periods were from 11:00-11:30AM (mother) and 11:30-12:00PM (foal) Behaviors documented: Rest Locomotion Grazing Nursing Play Kicking Cleaning Grunt (event)
BEHAVIORS Rest: the zebra is laying down and/or sleeping Locomotion: The zebra is running around Grazing: A zebra is eating grass or other vegetation Play: A zebra engages another zebra to run or jump with them Nursing: Female zebra feeds her young Kicking: Zebra rubs its back feet on the ground multiple times Cleaning: Zebra licks/nudges its own skin Grunt: Zebra lets out a loud guttural neighing noise
RESULTS CONT. My hypothesis was not supported. Although the infant did display more playing behavior, the mother displayed more locomotion. There was not a significant difference between these 2 results. Surprisingly, the mother and infant had almost identical behaviors. The difference in their grazing times was only off by about 21 seconds. After further review I found that foals and their mothers are almost inseparable during the first year of an infant’s life (Churcher, 1993). This can explain why the behaviors were almost identical.
DISCUSSION There were a couple things that did not correlate with my hypothesis and were surprising, but after further research I noticed that my data corresponded with previously documented zebra behaviors I was curious of the lack of nursing, but research shows that Grevy’s foals spend less time nursing than any other equid(Becker and Ginsberg, 1990). I think my behaviors were relatively clear, but sometimes it was hard to differentiate between locomotion and play. Even if I had thought of a better description, it would’ve been hard to distinguish between the two because of their similarity.
The only behavior I did not observe was rest- otherwise most of them were well observed. The most abundant activity was grazing, which I expected. I wouldn’t change any of my behaviors if I had to re- do this project, almost all of them were used. I would also stay with focal sampling because there were only 3 zebras total in the habitat. I would have liked to observe more than one of the mother-infant pair. Although I feel that my results probably do compare to most pairs across the population of zebras, more data could have helped to disprove or support my hypothesis.
FUN FACTS There is a large sperm competition in males because of the polyandrous sexual selection of the females. There are no cases of infanticide. A female will leave a territory if her foal is killed, therefore if another male comes to a territory with a female and her foal, he must raise the infant as his own to ensure reproductive success. They were named after the French president, Jules Grevy, in 1882 Every zebra’s stripes are unique
CONCLUSION Although my hypothesis was not supported, the data collected on the behaviors of Grevy’s zebra’s is significant. It shows that a mother and foal equid are nearly inseparable during the first year of the infant’s life. If I were to redo my ethogram, I would have chosen a different hypothesis. My new hypothesis would be that there will be no difference in the behaviors of mother and infant Grevy’s zebra, because typically mothers and their offspring are typically attached to each other during the formative years of an infant’s life.
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