In terrestrial environments, predator body size is largely correlated with prey body size. The opposite is found for many predators in the marine environment – baleen whales in particular comprise some of the world’s largest mammals and yet they feed on something far smaller (plankton). The leopard seal is unusual in that it feeds both at the top and at the bottom of the food chain, consuming large prey, such as penguins and other seals, and small prey, such as krill, an abundant basal component of the Antarctic food web. While leopard seals are well known as raptorial predators with a ‘grip and tear’ feeding styles, a large portion of their diet (krill) is too small to be eaten in this way. For this, they use filter feeding to separate the krill from seawater.
How can the dead help the living? This is a question a lot of fossil-fanatics have bent a lot of time towards over recent years, partially due to a desire to make palaeontology ‘relevant’ as a modern science, and secondly to help guide our efforts in conservation biology. A new series, edited by my supervisor Dr. Phil Mannion and others, focusses on the way we interpret palaeobiodiversity, biodiversity in the fossil record, for different groups and the issues and solutions facing the field. The final article in the volume struck me in particular.
How can fossils help us to protect these now and in the future? Source.
Seabirds are well adapted to acquire their prey. Those that feed on bivalves close to the surface have short, strong bills to break into shells and access molluscan meat, and those that feed on bivalves buried deeper in the sand have much longer, slender bills to access their prey. The association between bill morphology and the prey type of different bird species is a frequently cited example of niche differentiation, where animals living in close proximity have evolved distinct feeding strategies which prevent them from being in direct competition with each other (known as resource partitioning).
The fossil record is brutally frustrating; it mostly preserves only vestiges of deaths long past as body fossils, with occasional glimpses of life being gleaned from their surroundings and any trace fossils, or activity fossils that we might find. One question palaeontologists have long been seeking the answer for is how good were dinosaurs as parents? Modern birds are descended from dinosaurs, and are pretty awesome parents in their nesting, brooding, and raising of their chicks from birth until they can quite literally fly the nest. But birds are the only extant group of dinosaurs out of three major lineages.
Partial skeleton of an oviraptorid dinosaur brooding over a nest of eggs. Source.