![]() ![]() “It is thought that lions preferentially target giraffe calves in the wild, and there is anecdotal evidence of this, including observations of lions eating young giraffe carcasses and of lion claw marks on adult females (thought to be a result of them defending their calves),” said Muller. Zoe Muller, a PhD student at Bristol’s School of Biological Sciences, is the author of the study. Prior to this study, however, research has never been conducted to see how the presence of lions affects the overall giraffe population. Lions are the only predators which are a threat to giraffes on an individual basis. Researchers from the University of Bristol have found that one significant cause of this sharp decline is the fact that giraffes are living alongside their biggest predators in many protected regions. "Quantifying heritability and fitness consequences of variation in coat patterns could help us understand how and why complex coat patterns evolve in wild animals.Over the last three decades, giraffe populations have dropped by 40 percent, and there are now only an estimated 98,000 giraffes remaining in the wild. "My hope is that other scientists will use the same tools to measure mammal coat patterns to advance our understanding of what these patterns mean," said Lee. This study also highlights how modern image software and statistical methods can be used to reliably analyze complex coat patterns. "We used wild giraffes and modern imaging and analysis techniques to confirm her conclusions." Anne Innis Dagg, the first giraffe field researcher in Africa, presented evidence in 1968 that the shape, number, area, and color of spots in giraffe coat patterns may be heritable, but her analysis came from a small zoo population," said Monica Bond, graduate student in evolutionary biology and environmental studies at the University of Zürich and an author of the paper. This suggests that these traits are inherited by the calf. The study also found that two of eleven spot traits measured, circularity - how close the spot is to a perfect circle - and solidity - how smooth and complete the edges are - were significantly similar in mothers and calves. This increased survival could reflect better camouflage of these young giraffes, but it also could be related to other survival-enhancing factors, such as temperature regulation or visual communication. ![]() This study revealed that newborn giraffes with larger spots and irregularly shaped spots also had increased survival during the first few months of life. Spot patterns do not change as an animal ages, which allows researchers to identify individuals based on their unique patterns. Giraffe skin color is uniformly dark gray, but their spots are highly variable in color and shape, ranging from nearly round with very smooth edges to elliptical with jagged or lobed edges. ![]() In this study, we analyzed survival records and photos of spots of Masai giraffes, and show that spot patterns do affect juvenile survival and are heritable - they are passed from mom to baby." "Complex markings can help animals evade predators, regulate their temperature, or recognize family or individuals, all of which can affect their ability to survive and reproduce. Lee, associate research professor at Penn State and first author of the paper. "Giraffe spot patterns are complex and can be quite different among individuals, but we don't really know their purpose in the wild," said Derek E. ![]()
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