Short answers, pulled from the story.
Adult humpback whales typically measure 14 to 17 meters in length and can weigh up to 40 metric tons. The longest reliably recorded female measured 18.6 meters; the longest male, 17.4 meters. Calves are born at around 4.3 meters long and 680 kilograms.
Male humpback whale songs typically last between 4 and 33 minutes, depending on the region. In Hawaii, individuals have been recorded vocalizing for as long as seven hours. Songs are produced only during the winter breeding season.
Commercial whaling drove humpback populations to around 5,000 individuals worldwide by the time the International Whaling Commission banned commercial humpback whaling in 1966. Over 200,000 were taken in the Southern Hemisphere during the 20th century alone, and North Atlantic populations fell to as few as 700 individuals. The Soviet Union concealed the full scale of its catch, reporting 2,820 kills between 1947 and 1972 when the true number exceeded 48,000.
Humpback whales eat krill, copepods, other plankton, and small schooling fish including herring, capelin, sand lances, and Atlantic mackerel. Their signature hunting method is bubble-net feeding, in which a group swims in a tightening circle below prey while releasing air from their blowholes, creating a cylinder of bubbles that concentrates the prey before the whales lunge upward with open mouths.
As of 2018, the worldwide humpback whale population is estimated at around 135,000 individuals, of which roughly 84,000 are mature. Regional estimates include around 13,000 in the North Atlantic, 21,000 in the North Pacific, and 80,000 in the southern hemisphere. The isolated Arabian Sea population numbers only around 80 individuals and is considered endangered.
Entanglement in fishing gear, collisions with ships, and noise pollution are the primary ongoing threats. NOAA recorded 88 stranded humpbacks along the Atlantic coast of the United States between January 2016 and February 2019, declaring an unusual mortality event in April 2017 with vessel interactions and entanglement identified as the leading causes. Climate change and coastal habitat destruction also affect the species.