Over the past 500 years, approximately 500 land-based animal species have gone the way of the dodo, becoming extinct as a result of human activity. In the ocean, where scientists count only 15 or so such losses, the numbers currently aren't nearly as dire.
A study of the migratory biology of bar-headed geese, during their high altitude flights across the Tibetan plateau and Himalayan Mountains, has revealed how these birds cope with flying in the relatively low-density mountain atmosphere. The study shows that the geese perform a 'roller coaster' ride through the mountains, tracking the underlying terrain even if this means repeatedly shedding hard-won altitude only to have to regain height later in the same or subsequent flight.
A see-through zebrafish and enhanced imaging provide the first direct glimpse of how blood stem cells take root in the body to generate blood. Researchers describe a surprisingly dynamic system that offers clues for improving bone marrow transplants, and for helping those transplants 'take.'