Lawson, John (1674-1711), British-born early naturalist in North America, burned at the stake, about age 37,  by angry Indians near what is now Snow Hill, North Carolina.  He wrote A New Voyage to Carolina.

Lees, Andrew (1949-1994), an environmental activist, went missing while in Madagascar to make a film about a Rio Tinto Group plan to stripmine an area of coastal forest. He was later found and determined to have died, age 45, of heat exhaustion.

Leitão Filho, Hermógenes de Freitas (1946-1996), Brazilian botanist of a heart attack during field research.

Leitner, Edward F. (1812–1838), German-born physician and botanist, col­lector for Audubon and Bachman, shot by Indians, age 26, near Jupiter Inlet, Florida.

Leopold, Aldo (1887-1948), father of wildlife ecology who helped found The Wildlife Society and the Wilderness Society, died of a heart attack, age 61, while battling a wildfire on his neighbor’s property.

Lockwood, Tom E. (1941-1975),  botanist at the University of Illinois-Urbana, monographer of the genus Brugmansia, died, age 34, in an auto accident in Mexico during a field trip with students.

Löfling, Pehr (1729 – 1756),  an “apostle” of Linnaeus, he was the first naturalist to make careful observations about the flora and fauna in Venezuela, and probably the first person to bring a microscope there. Linnaeus later published the Iter Hispanicum based on Löfling’s notes.  He died on expedition there, probably of malaria or yellow fever.

Loftus-Hills, Jasper (1946?-1974) , a post-doc at the University of Michigan, from New Victoria, Australia, who died in a car accident, age 28, on a trip collecting frogs in Texas.  Eleutherodactylus jasperi is named in his honor.  Biologist Joan E. Strassman, a passenger in the vehicle, reports that they were parked at the side of the road when “a pickup truck driving along the shoulder side-swiped the car, killing Jasper instantly and throwing him far along the road into the ditch. Marty [Condon] and I only saw the taillights and felt the car rock, but did not know right away what had happened.  Afterwards was a typical Texas story of unfriendly cops, a restaurant that refused to let us in because we didn’t have shoes on, then a complete failure to prosecute the well-known local bumpkin and drunk who didn’t even have a driver’s license.”

Lothian, Norman Veitch (1889- 1925), Scottish medical entomologist with the League of Nations Malaria Commission‚ killed, age 35, in the same car accident with Samuel Darling in Beirut, while researching malaria mosquito epidemiology in the Middle East.   The Lothian Scholarship and Darling Prize for malaria research were created in their honor.

Lotter, Wayne (1966?-2017), South African conservationist who fought rampant elephant poaching in Tanzania, assassinated, age 51, in Dar es Salaam. Colleagues credited him with helping in the arrest of “1,398 poachers and ivory traffickers in recent years, 78% of whom were convicted.”

Lynn, Denis (1947-2018), marine biologist at the University of Guelph and later at the University of British Columbia, expert in the ecology of marine, freshwater, and terrestrial ciliates, hit by a large wave and carried to his death, age 71, while doing tide pool biodiversity research at the Hakai Institute in British Columbia.