BIOL10004 Lecture Notes - Lecture 16: Breastfeeding, Estrous Cycle, Thought Experiment
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Curious behaviour in the queensland gulf country - Crows sometimes swoop down to the ground, pick up something, and then drop it from a height. Stunning the toads by dropping them from a height may allow crows to kill and eat the toads without getting a beak full of toxin. Gulls nest on the ground, so eggs and chicks are vulnerable to ground predators. Solution: eggs and chicks are cryptic (difficult to see) Shortly after chicks hatch, the broken, empty egg-shells are removed. Perhaps the chicks will injure themselves on the sharp edges of the shells. Perhaps the decaying membranes and fluids that remain in the eggshells are a breeding ground for disease-causing bacteria. Perhaps the white inside of the eggshell is visually conspicuous to predators. Field experiments show that the inside of the eggshell is conspicuous. Ants widespread across australia with characteris>c nest. Colonies are huge (> 100,000 individuals) and polydomous, comprising many nests.