FD: v4 (First Timers)

HARBOR SEALS:   The harbor seal will follow water turbulences caused by fish with sensitive hairs on its fins.

HARBOR SEALS:   Harbor seals are the master trackers of the sea. Their astonishing tracking abilities rival the amazing abilities of caterpillar moth on land.

HARBOR SEALS:   Unlike bloodhounds, seals don’t track scent. Rather, they track the slight disturbances in the water.

HARBOR SEALS:   A harbor seal can track another seal several hours after it has passed.

HARBOR SEALS:   The harbor seal does this tracking by turning his whiskers perpendicular to the water-turbulence trail he is following. Perpendicular means 90º. 

HARBOR SEALS:   The harbor seal is so good at underwater tracking that he can tell the type of fish he’s following from one mile away by its water trail alone!

ALULAS AND AILERONS: Ailerons help jets to reduce lift while landing. The alula feathers on birds’ wings help them with lift also while landing. They help birds to land elegantly.

ALULAS AND AILERONS: The alula feathers are attached to a tiny bone in the back of the bird’s wing. They stick out at exactly the right moment giving the bird extra lift.

ALULAS AND AILERONS: Particle image velocimetry was used to study the effect of the alula feathers. Particles were sprayed into the air where birds were landing. It was discovered that small vortices were caused that helped birds to land elegantly.

ALULAS AND AILERONS: At Oxford, scientist learned that the steppe eagle has a very fast movement of feathers across the shoulder of its tail just as it is about to land. This gives the bird extra lift.