Field notebook
Opening the requested public page…
Field notebook
Opening the requested public page…
Permanent editions
Published facts keep their original date, evidence and correction trail. Drafts and withdrawn editions are never mixed into this index.
In many north-temperate songbirds only the male sings, and the female stays silent. The northern cardinal breaks that pattern: females sing complex, learned songs from the nest area, sometimes trading phrases with their mate in a structured exchange.
When alarmed, this small whale voids a dense cloud of reddish-brown fluid from a sac in the lower intestine. The cloud hangs in the water while the animal withdraws, a defence otherwise associated with squid and octopuses.
Nearly all insects stop moulting once they reach the adult stage. Silverfish do not. They continue shedding their cuticle after becoming sexually mature, potentially dozens of times, and can live several years doing so.
A female can shift between white and yellow to suit the flower she is hunting on, but the change is measured in weeks rather than seconds: roughly ten to twenty-five days to turn yellow, and about six days to return to white.
A widely repeated claim held that shark decline released cownose rays, which then wrecked Chesapeake shellfish. Later analysis found the ray's diet, reproduction and population history could not support the story, but culls had already been encouraged.
In the Interlake region of Manitoba, red-sided garter snakes gather in limestone sinkholes each autumn in numbers reaching the tens of thousands per den. They emerge together in spring into some of the largest mating aggregations known in any vertebrate.
A chimney swift's nest is a shallow half-saucer of twigs snapped off in flight and cemented to a vertical wall with the bird's own hardening saliva. The species has moved almost entirely from hollow trees into masonry chimneys.
The potto's neck vertebrae carry elongated spinous processes that stand close beneath a thickened patch of skin. Threatened, the animal tucks its head down and presents this ridged shield to an attacker, then butts with it rather than fleeing.
Indigenous Australian knowledge and a compilation of ranger and firefighter accounts describe black kites and two other raptors carrying burning sticks to unburnt grass, flushing prey. The behaviour is well attested by observers but has not yet been captured under controlled scientific conditions.
The jerboa's hind foot is built from three metatarsals fused into a single cannon bone, the same solution deer and cattle reached independently. It makes the limb a stiff, light lever and lets a rodent the size of a fist cover ground in erratic bounds.
Spring-run and fall-run chinook return to the same rivers months apart. Much of that difference maps to a single small region of the genome near the GREB1L gene, which means a lost early run is not easily rebuilt from a late one.
The air dome is not merely a store. Oxygen diffuses into it from the surrounding water while carbon dioxide leaves, so the bell functions as a physical gill and a spider can remain submerged for a day or more between trips to the surface.
Palaeolithic cave paintings at Chauvet in France show cave lions in careful detail, and the animals drawn are maneless, some with faint stripes near the tail. Frozen Siberian cubs are consistent with a pale, thick coat rather than a lion's ruff.
A Brazil nut pod is a woody capsule that few animals can open. Agoutis gnaw through it, eat some seeds and bury the rest, and buried seeds are effectively the only ones that become trees, so the tree's regeneration runs through a rodent's forgetfulness.
It does not prise a mussel apart in one pull. It grips both shell halves with hundreds of tube feet and holds a steady tension until the bivalve's own adductor muscle fatigues and the gap widens by a fraction of a millimetre.
Rather than chasing fish in open water, this shark forces its slender body into reef crevices at night. Several sharks often work the same hole at once, so a fish that escapes one animal frequently swims into another.
Striped like a zebra and built like a large antelope, the okapi is neither. It is the sole surviving member of the giraffe family besides the giraffe itself, and it shares the giraffe's ossicones and long prehensile tongue.
Tortoises on wet highland islands carry a domed shell that sits low over the neck. Tortoises on dry islands carry a saddleback shell flared upward at the front, which lets the neck reach vegetation held well above the ground.
When snow closes the mountain forests of central China, golden snub-nosed monkeys switch to a food almost no other primate uses. Lichens stripped from branches and bark can dominate the winter diet, sustaining troops through months with no fruit or fresh leaves.
Genetic work on invasive Atlantic lionfish points to a very small number of founding individuals, probably released or escaped aquarium stock off Florida. From that bottleneck they now occupy reefs from North Carolina to Brazil.
Gestation in the spiny dogfish runs between eighteen and twenty-four months, among the longest of any shark. Combined with slow growth and late maturity, it makes the species almost incapable of absorbing heavy fishing pressure.
The species went extinct around 1878 without its breeding grounds ever being located. Only about fifty specimens survive in museums, no eggs or nests were reliably described, and the cause of the decline has never been established.
European spongy moth females cannot fly, so the species disperses as newly hatched caterpillars that spin a silk thread and let the wind carry them. That thread is how a flightless insect crossed a continent.
Disturbed at the nest, a wryneck twists its neck through extreme angles, hisses and sways with its head flattened, a display strongly suggestive of a snake. The behaviour gave the bird its English name and, indirectly, the word jinx.