The number of occurrences of a repeating event per unit of time, such as the appearance of harbour porpoises in a fjord during a year or the number of your heartbeats per minute. The frequency of a particular sound refers to the number of soundwave vibrations created per second—high frequency sounds are more high-pitched, low frequency sounds are deeper.
Breeding season
Time in the year when females give birth to their calves or pups.






















































































































