Short answers, pulled from the story.
Three living species of elephants are currently recognised: the African bush elephant (Loxodonta africana), the African forest elephant (Loxodonta cyclotis), and the Asian elephant (Elephas maximus). African elephants were historically treated as one species, but molecular studies confirmed their status as two separate species.
Musth is a state of elevated testosterone and heightened aggression in adult male elephants. In one southern Indian population, males first enter musth at around age 15, but the condition does not become intense until past 25. Its most visible sign is a fluid discharge from the temporal gland that runs down the side of the face.
Elephants can reach 60-70 years of age in the wild. The captive male Asian elephant Lin Wang lived to 86 years.
Elephants reshape their environments in ways that many other species depend on. They uproot trees and undergrowth, turning savannah into grassland; they dig waterholes during droughts that other animals use; and they disperse seeds over great distances. At Mount Elgon, their digging through caves opens access routes for ungulates, hyraxes, bats, birds, and insects.
As of 2021, the IUCN lists African bush elephants as Endangered and African forest elephants as Critically Endangered. The Asian elephant was listed as Endangered in 2020, with a total population estimated at between 40,000 and 50,000 individuals, roughly 60% of which live in India.
The trunk is formed from the fused nose and upper lip and contains up to 150,000 separate muscle units with no bone. It can lift up to 350 kg, hold 8.5 litres of water, draw air inward at over 150 metres per second, reach items 7 metres above the ground, and function as a snorkel when the elephant is submerged. Its sense of smell may be four times more acute than a bloodhound's.