Earlier spring nesting related to climate change could negatively affect the survival of pelican chicks at Chase Lake National Wildlife Refuge, N.D., according to a new U.S. Geological Survey report.
USGS scientists found that American white pelicans are migrating north to a large nesting colony at Chase Lake National Wildlife Refuge about 16 days earlier in the springtime than they did 45 years ago. The earlier migration is likely spurred by warmer spring temperatures on the pelicans’ wintering grounds and along their migration route, but ideal post-hatching weather conditions have not advanced at the nesting colony. Now, vulnerable pelican chicks face a higher risk of encountering life-threatening wet and cold conditions. (more…)
While the disappearance of Neanderthals remains a mystery, paleoanthropologists have an increasing understanding of what allowed their younger cousins, Homo sapiens, to conquer the planet. According to Ariane Burke, Professor in the Department of Anthropology at the Université de Montréal, the rapid dispersal of anatomically modern humans was not so much due to superior intelligence or improved hunting or gathering techniques, but rather to the creation of symbolic objects that allowed them to extend their social relations across vast territories.
Symbolism and social exchanges
Homo sapiens arrived in Europe some 45,000 years ago, from Africa. In less than 15,000 years, they managed to occupy the whole of Europe and Eurasia—an extremely rapid expansion. Neanderthals, on the other hand, were born of Europe, appearing on the continent more than 250,000 years ago, after their ancestors, Homo ergaster, had established there 600,000 years earlier. Though physiologically well adapted to the cold climate of the glacial and postglacial periods, why were Neanderthals not as successful as their newly landed rivals in colonizing the continent? (more…)
