7/30/2014

We took a boat on an excursion from Haines to Juneau on one amazing day.  On the way back, we came across a group of 12 or more Humpback Whales doing a rarely seen feeding practice called 'bubble netting' and is described here:

Feeding and predation[edit]

A group of 15 whales bubble net fishing near Juneau, Alaska

Humpback whale lunging in the center of a bubble net spiral.

A whale off Australia on the spring migration, feeding on krill by turning on its side and propelling through the krill

Humpbacks feed primarily in summer and live off fat reserves during winter.^[33] They feed only rarely and opportunistically in their wintering waters. The humpback is an energetic hunter, taking krill and small schooling fish such as Atlantic herring, Atlantic salmon,capelin, and American sand lance, as well as Atlantic mackerel, pollock, and haddock in the North Atlantic.^[34][35][36] Krill and copepodshave been recorded as prey species in Australian and Antarctic waters.^[37] Humpbacks hunt by direct attack or by stunning prey by hitting the water with pectoral fins or flukes.

A humpback straining water through its baleen after lunging.

The humpback has the most diverse feeding repertoire of all baleen whales.^[38] Its most inventive technique is known as bubble net feeding; a group of whales swims in a shrinking circle blowing bubbles below a school of prey. The shrinking ring of bubbles encircles the school and confines it in an ever-smaller cylinder. This ring can begin at up to 30 metres (98 ft) in diameter and involve the cooperation of a dozen animals. Using acrittercam attached to a whale's back, researchers found that some whales blow the bubbles, some dive deeper to drive fish toward the surface, and others herd prey into the net by vocalizing.^[39] The whales then suddenly swim upward through the "net", mouths agape, swallowing thousands of fish in one gulp. Plated grooves in the whale's mouth allow the creature to easily drain all the water initially taken in.

A study published in the April 26, 2013 issue of Science documents a new form of bubble-net feeding called lobtail feeding among a population of whales in the Northern Atlantic Ocean. This technique involves the whale slapping the surface of the ocean with his tail between one and four times before creating the bubble net.^[40] Using network-based diffusion analysis, the authors argue that the whales in this group learned the behavior socially from other whales in the group over a period of 27 years in response to a change in the primary form of prey.^[41]

We saw this happening 4 times in a 30 minutes period...amazing!!  Here are a few of my pictures:

This has been one amazing trip!!