Field notebook
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Field notebook
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Permanent editions
Published facts keep their original date, evidence and correction trail. Drafts and withdrawn editions are never mixed into this index.
The paddlefish's long rostrum is not a shovel and not a stabiliser. It is covered in tens of thousands of electroreceptive pores that detect the faint electrical signals of individual water fleas, letting the fish feed in water too turbid to see through.
Underwater, a platypus closes its eyes, ears and nostrils. It locates prey entirely with its bill, which carries thousands of electroreceptors that detect the faint electrical fields produced by the muscles of moving invertebrates.
Turned on its back, a click beetle does not scramble. It arches, latches a spine against a notch in its thorax, releases the stored tension with a snap, and is thrown into the air legs uninvolved.
The tusk is not a horn but the animal's upper left canine, erupting through the lip and growing forward for up to three metres. Its spiral always turns the same way, and the tooth is porous, with nerve tissue reaching the surface.
The protruding canines of the harlequin tuskfish are blue in the living animal, a colour that appears to come from the enamel-like surface itself rather than from staining or from the surrounding tissue.
The drooping nose of an adult male is not only visual advertising. It acts as a resonating chamber that lowers and amplifies his calls, and nose size correlates with body mass and testis size, so the sound carries honest information about the caller.
No single common green darner completes the round trip between northern breeding ponds and the southern wintering grounds. Isotope work on wing tissue indicates that the annual cycle is carried by a relay of roughly three successive generations, none of which retraces its own outbound flight.
Analyses of prairie dog alarm calls, chiefly in Gunnison's prairie dog, show that acoustic structure varies consistently with the type of predator, and in experiments with the size, shape and colour of an approaching human. The calls carry more than a generic warning.
Hyacinth macaws open palm nuts whose shells resist considerable force, using a bill braced against a mobile upper jaw. Their favoured nuts often reach them already husked, having passed through the gut of cattle or other large grazers.
On Bass Strait islands where the only seasonal food is muttonbird chicks, tiger snakes have larger heads relative to body size than mainland snakes eating frogs. The difference is partly a plastic response to what an individual actually swallows.
The alpha wolf idea came from captive animals: unrelated adults forced together in an enclosure, who fought for status. Wild packs are almost always a breeding pair and their own offspring, and the researcher who popularised the alpha model spent decades trying to retract it.
Hunted to near extinction by the 1820s, Antarctic fur seals recovered to millions concentrated at South Georgia. The rebound is a conservation success that has become an ecological problem, as breeding seals flatten the coastal tussock grass that other species depend on.
A singing male mole cricket excavates a burrow with a bulb-shaped chamber and one or two flared openings. The shape matches the wavelength of his call, and it works as an acoustic horn that couples the sound into the air far more efficiently than his wings alone could.
Through summer workers hunt protein for larvae and are paid in sugary larval secretions. When the queen stops laying in late season that exchange ends, and hungry workers go looking for sweetness at picnics and orchards.
A fig is a hollow chamber of inward-facing flowers with one narrow entrance. The female wasp forces through it, shedding wings and antennal segments in the process, pollinates, lays eggs and dies inside.
The New Mexico whiptail has no males. It arose when a little striped whiptail and a western whiptail hybridised, producing females that lay unfertilised eggs developing into genetic near-copies of the mother. The state reptile of New Mexico reproduces without sex.
Hooded and carrion crows interbreed freely where their ranges touch, yet the mixed zone stays only tens of kilometres wide and has barely moved. Very little of the genome differs between them, and much of it concerns plumage colour.
Instead of closing with its prey, Scytodes fires two zigzagging streams of glue and venom from its fangs, pinning an insect to the surface in a few thousandths of a second before approaching to bite.
The claim that a duck's quack produces no echo circulated widely enough that acousticians tested it in a reverberation chamber. It echoes like any other sound; the echo is simply hard to pick out against the call's own fading tail.
Each guard hair is a hollow, colourless tube. It looks white because it scatters light, over black skin. The popular claim that the hairs pipe sunlight down to the skin like optical fibres was tested and found to be wrong.
When its pond dries, a greater siren burrows into the mud and seals itself in a dried skin-and-mucus cocoon, leaving only the mouth clear. Animals have been recovered alive after many months in that state.
With around ten animals left, the vaquita is assumed to be genetically finished. Genome analysis published in 2022 found the opposite: the species has been small for millennia, has already purged its most harmful mutations, and could recover if gillnetting stopped.
Bobolinks leave hayfields in Canada and the northern United States and winter in the grasslands of southern South America, a round trip on the order of twenty thousand kilometres. Individuals return to the same breeding fields across successive years.
![Photograph of Dodo: Skeleton cast and model of dodo at the Oxford University Museum of Natural History, made in 1998 based on modern research.[1][2]](/_next/image?url=https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2F5%2F50%2FOxford_Dodo_display.jpg%2F1920px-Oxford_Dodo_display.jpg%3Futm_source%3Den.wikipedia.org%26utm_campaign%3Dimageinfo%26utm_content%3Dthumbnail&w=3840&q=75)
Illustrations made the dodo look like a fat, absurd creature of no clear kind. DNA from museum material placed it firmly within the pigeons and doves, closest to the Nicobar pigeon, and its nearest relative was another extinct island bird.