Naturalists Whose Field Notes Changed Scientific Understanding

Insects and the plants they fed on Merian’s 1705 book on Suriname grew out of notes and drawings she made there. She showed different stages of an insect’s life together with its food plant. The pictures let readers follow a transformation and see the relationship between an insect and a plant on the same page.

Plant geography in the Andes Humboldt and botanist Aimé Bonpland recorded plants and measurements during their travels in tropical America. Their 1807 essay used a diagram of the Andes to place plant names at different elevations. It made the distribution of plants across a mountain something readers could see and compare at a glance.

How the paper nautilus makes its egg case In Sicily, Villepreux-Power observed living argonauts rather than relying on empty shells. Her account showed that the female makes the shell-like egg case herself. Keeping the animal in view while it went about its life helped settle a question that a collection of empty cases couldn’t answer.

Mockingbirds from different islands Darwin kept track of where he collected Galápagos mockingbirds and noticed that birds from different islands differed slightly. John Gould later confirmed that the collection contained three species. Darwin’s notes show him asking how closely related birds could take the same place in nature on neighboring islands, a question that helped shape his thinking about species.

First blooms in Concord Thoreau recorded when plants began flowering around Concord, Massachusetts, in the 1850s. Researchers comparing his dates with modern surveys found that plant groups differed in how well they shifted flowering times as temperatures rose. The plants that tracked temperature less closely were more likely to have declined locally.

Birds on opposite sides of a strait Wallace found birds on Bali that he didn’t encounter during months of collecting on nearby Lombok. He used comparisons like this one to identify a boundary between animal communities with different geographic affinities. The line named for him helps explain why distance alone tells you so little about which animals live on neighboring islands.

A record of where Yosemite mammals lived Grinnell and his colleagues recorded animals along a route that climbed through Yosemite and across the Sierra Nevada. A later team retraced the survey and found that about half of the small-mammal species it studied had shifted at least one end of their elevation range uphill. The old records made it possible to tell which species had moved and which had stayed put.

Song sparrows as individuals Nice recognized individual song sparrows by their colored leg bands and followed them across breeding seasons. She could connect where each bird lived with the fate of its nests and family. Her account of territory showed how defending a patch could help a pair raise young without interference from its neighbors.

Spring events in southern Wisconsin Leopold recorded when plants flowered and migratory birds arrived around his family’s Wisconsin retreat. His daughter Nina Leopold Bradley later kept similar records in the same area. The comparison showed that some events, including the first blooms of forest phlox, were occurring earlier.

Toolmaking in wild chimpanzees At Gombe, Goodall watched David Greybeard and other chimpanzees use plant stems to fish for termites. She also saw them strip leaves from twigs before using them. Recording that preparation showed that wild chimpanzees could make a tool as well as use one.

Mountain gorilla calls in context Fossey kept notes on individual mountain gorillas and published an account of sixteen types of calls. Her account drew on wild groups and two captive infants, and considered the circumstances in which the sounds occurred. Those details made it possible to study calls as part of a group’s daily life.