Human disturbance hits narwhals where it hurts — the heart

Human disturbance hits narwhals where it hurts — the heart:

Two articles came out last week describing a weird discovery about the fascinating unicorns of the sea, Narwhals. 

In the face of threat, specifically human disturbances, Narwhals rapidly increase their heart rate and flap their flippers as fast as they can. This is not a normal response of Narwhals to predators and raises a lot of questions about how humans and human activities are impacting marine mammal environments.

Second article here.