Maternal and antipredator behavior of Thomson’s gazelles
Parents with dependent offspring face interesting challenges in optimizing their behavior to maximize their reproductive success. They must meet all the same requirements as non-parents – getting enough to eat, avoiding predation – while also protecting and providing for one or more vulnerable, needy offspring. Thomson’s gazelles are a great system in which to study maternal decision-making, behavior, and trade-offs for several reasons:
- First, both adults and fawns are under intense predation pressure. Adults are preyed on by all large East African carnivores, including lions, hyenas, cheetahs, leopards and wild dogs. Infants are preyed on by all of these species in addition to smaller predators such as jackals, baboons, large birds of prey, and warthogs (yes, warthogs!).
- Second, gazelle mothers are subjected to high energetic demands. For ungulates (hoofed mammals), early lactation is typically the most energetically-demanding reproductive stage due to rapid infant growth rates that are fueled almost entirely by the mother’s milk. Female tommies can become pregnant shortly after giving birth, which means they are often fueling the gestation of their next fawn while producing milk for their current one.
- Finally, gazelle engage in an interesting strategy of maternal care known as “hiding”. Rather than accompanying their mother more or less constantly after birth (as horses and rhinos do), hider infant spend most of their first days or weeks of life hidden in vegetation apart from their mothers. While they are hidden, they are relatively safe from detection by predators. Hider mothers return to retrieve their infants several times per day so that they can nurse and play. Infant active periods are relatively short compared to hiding periods, and the infant alternates between hidden and active states for the duration of the hiding phase, which lasts for approximately two months in Thomson’s gazelle.
Working within this system, I carried out the following studies as part of my dissertation research:
- Maternal tactics for preventing predation of newborn fawns
- Maternal vigilance behavior relative to fawn activity – coming soon!
- Changes in maternal and fawn behavior during the transition out of the hiding phase
- Maternal response to a simulated predator attack – coming soon!