Readers’ wildlife photos

Reader Ephraim Heller has sent some lovely photos of humpback whales, including their recently-discovered and amazing behavior of bubble-netting.  His captions and IDs are indented, and you can enlarge the photos by clicking on them.

Pacific herring (Clupea pallasii) spend most of the year dispersed across the open North Pacific, but each spring they converge on Sitka Sound to spawn. The 2026 spawning biomass was estimated at roughly 233,000 tons of mature herring. This attracts commercial fishermen, fishing birds, Steller sea lions, gray whales, humpback whales (Megaptera novaeangliae), and… me.

Here’s a humpback whale jumping for joy:

And here is Sitka Sound, with Mount Edgecumbe (a dormant volcano) in the background:

The scientific name of humpback whales is Megaptera novaeangliae, meaning “big-winged of New England,” due to their oversized pectoral flippers and first observations off of New England. These flippers increase their agility and enable their unique behavior: bubble-net feeding. Here are views of the baleen:

Bubble-net feeding is not a fixed behavioral pattern; it is a culturally transmitted skill, and not every humpback population practices it. The behavior has been documented extensively in Southeast Alaska, and a long-term study published in January 2026 in Proceedings of the Royal Society B tracked its spread in the Kitimat Fjord System of northern British Columbia over a 20-year period (2004–2023). Of 526 individually identified whales, roughly half were observed bubble-net feeding at least once, with more than 92% of those events occurring in a group context:

The behavior gained momentum after the 2014-2016 marine heat wave (“the blob”) that reduced prey availability across the northeastern Pacific. Researchers interpret this as whales adopting a more efficient foraging strategy in response to environmental stress, and transmitting that knowledge through their social networks:

The hunt begins when a group of humpbacks locates a school of small prey — herring, krill, or juvenile salmon. One whale, often referred to as the “bubble-blower,” dives beneath the school and begins exhaling air through its blowhole while swimming in a tightening upward spiral. The released air rises as a cylindrical curtain of bubbles. Fish do not readily cross this curtain, so as the spiral contracts, the school is compressed into an increasingly dense ball:

Meanwhile, one or more other whales in the group produce “food call” vocalizations: loud, frequency-modulated cries that vibrate the swim bladders of herring, causing them to clump even more tightly together. The calls also appear to serve a coordinating function among the whales themselves, signaling when to begin the final ascent. I could occasionally hear the food calls on the deck of my observation boat:

When the prey is sufficiently concentrated, the group orients below the net and lunges upward in near-unison, mouths agape, through the center of the bubble column. At the surface, each whale engulfs thousands of fish in a single pass, then strains the water out through its baleen plates as it rolls and closes its jaws. Groups involved in a single feeding event can range from two to around 16 individuals (according to the literature), each surfacing in roughly the same position relative to the others on every lunge. It’s hard to tell exactly how many bubble-netters are in this photo, but I think it is more than 16:

Quantitative work using drone footage and bio-logging tags has found that solitary humpbacks actively adjust the number of bubble rings, net diameter, and the spacing between individual bubbles from one dive to the next. This level of fine-tuning (“manufacturing” a tool and modifying it based on conditions) contributed to a 2024 study’s argument that bubble nets qualify as tools under standard definitions. On average, a well-constructed net can increase the prey density available in a single lunge by roughly sevenfold, without measurably increasing the whale’s energetic expenditure:

No other baleen whale species does this, and biomechanics research suggests morphology is the reason. A 2025 study comparing turning performance across seven mysticete species found that bubble-net feeding humpbacks achieved centripetal accelerations that exceeded the upper limits recorded in comparable maneuvers by all six other species tested. The humpback’s large pectoral flippers generate substantial lift, which helps the animal bank inward tightly and decrease its turning radius enough to close a spiral into a true net. Other whale species, even if they could theoretically attempt the maneuver, would likely burn too much energy to make the strategy worthwhile:

My next post will include photos of other animals that come to Sitka sound to enjoy the herring feast.