Reptiles are essential components of any ecosystem in which they occur — as key food sources, for example, or as top predators. (burkemuseum.org)
It found that as surface water levels decline, salinity increases and affects the availability of brine shrimp and other invertebrates — a key food source for waterbirds. (sciencedaily.com)
Before that time, Barkai says, elephants had occupied the area for hundreds of thousands of years and were likely a key food source. (scientificamerican.com)