Biology
The American dipper Cinclus mexicanus is a songbird that walks on stream beds underwater hunting aquatic insects. It is the only songbird that does this. The adaptations are subtle, the textbook account is mostly right, and the open questions are about underwater sensing.
Biology
Kiwa hirsuta and its relatives live at hydrothermal vents and farm chemosynthetic bacteria on dense setae covering their claws. The bacteria oxidize sulfide and methane; the crabs wave their claws in vent fluid to feed them. Cultivation, not capture.
Biology
The Australian superb lyrebird Menura novaehollandiae produces 15-30 minute songs containing accurate reproductions of dozens of native bird species plus mechanical sounds that entered the species vocabulary in the last century. The mechanism and the cultural transmission puzzle.
Biology
Anoura fistulata is a small bat from the Ecuadorian Andes with a tongue 150 percent of its body length, the highest tongue-to-body ratio of any mammal. The tongue retracts into the chest cavity through a specialized housing.
Biology
Some bacteria grow magnetic crystals inside membrane vesicles, aligned with Earth's field. The crystals form in specialized compartments smaller than a virus, with shape and size controlled at the nanometer scale by a process nanotechnology cannot match.
Biology
Mole crickets sing from inside a Y-shaped burrow whose geometry acts as an exponential horn matched to the singer's wing frequency. The result is one of the loudest insect calls on Earth produced by a 3-centimeter animal in a 30-centimeter underground excavation.
Biology
Archerfish shoot water at terrestrial insects above the surface from below. The shot is corrected for refraction, accounts for ballistic drop, and uses jet-compression to amplify impact. Three independent physics problems solved in a 5-million-neuron brain through learned visuomotor control.
Biology
The toucan's outsized bill puzzled biologists from Darwin onward. The 2009 Tattersall et al Science paper resolved the puzzle: the bill is one of the largest thermoregulatory radiators in the animal kingdom, dissipating up to 60 percent of resting heat via active blood-flow control.
Biology
Kiwis are the only birds with nostrils at the tip of the bill, used to smell soil invertebrates from above ground. The bill tip also carries a dense mechanoreceptor array that detects prey movement through soil. The integration has no close avian parallel.
Biology
Common cuckoos lay eggs in nests of host species that raise the chick at the cost of their own brood. Hosts evolve egg recognition to reject parasites. Cuckoos evolve egg mimicry to defeat the recognition. One of the cleanest cases of measurable coevolution in vertebrate biology.
Biology
Sailfish coordinate group hunts on sardine schools using sail-display signaling and turn-taking attacks. The cooperation is more sophisticated than canonical fish-cognition accounts anticipated and was only characterized in the 2010s.
Biology
The honey possum is one of the few mammals to subsist entirely on nectar and pollen. Its specialization is so extreme that it cannot survive outside the few hundred plant species that flower in sequence across southwestern Australian heath.