Frequency signatures: Rufous Potoo to Sand Goby
Each card gives a species’ behavioural archetype, its frequency — how often it commits effort and how long each commitment lasts — and a waveform tracing that rhythm.
Frequency signatures
Each waveform traces one species’ working rhythm — where it spends effort, and where it waits. 2,327 species, A–Z; showing 1,801–1,824.
Rufous Potoo
Motionless Dead-Leaf Roost by Day
Motionless • Cryptic • Solitary
That makes it a bimodal system: prolonged daytime stillness and short, fast nocturnal sallies.
Rufous-sided Crake
Narrow Body Between Marsh Stems
Skulking • Probing • Calling
That makes it a single-mode system: steady, concealed foraging within dense marsh vegetation.
Rufous-tailed Jacamar
A Predator That Learns the Pattern
Sallying • Testing • Remembering
That makes it a mid-frequency system: repeated attempts from a fixed perch, progressively refined.
Rugose Hermit Crab
Grinding the Shell Thinner
A shell occupied on land, where its full weight must be carried rather than supported by water • The interior worn away and remodelled by the crab so the walls become thinner and the internal volume larger • A shell that is lighter to carry and roomier to grow in than the same shell would be for a marine crab
Because the remodelling runs over months, it operates as a low-frequency system.
Russian Desman
Hydrodynamic Snout Array
Rhythmic • Probing • Forager
This produces a mid-frequency system: a rhythmic cycle of steady, information-led searching and retreat, built around continuous tactile sampling rather than rare deep reserves or explosive attacks.
Russian Tortoise
Burrow-Extended Shell Refuge
Three months up • Feeding hard • Nine months down
Because everything the animal does is slow, compressed and metered against a very short season, it operates as a low-frequency system.
Rusty-spotted Cat
Small-Body Fast Turnover
Small • Hungry • Nightly
Because the animal's whole existence is a rapid repeating cycle of hunting and eating, it is a high-frequency system.
Sable Antelope
Kneeling to Sweep Behind the Shoulder
Grazing • Watching • Dropping to the knees and sweeping
Steady grazing with rare violent events makes this a mid-frequency system.
Sac Spider
Nightly Rounds From a Silk Pocket
Roaming • Nocturnal • Grappling
The system is bimodal: nightly roaming for food and daytime retreat into silk.
Sacred Ibis
Decurved Bill Probe
Probing • Walking • Sampling
That makes the ibis a mid-frequency system: rhythmic and repetitive, gathering information by contact rather than at a distance.
Sacred Kingfisher
Flying Head-First at a Termite Mound
Perched • Dry-country • Watching
That makes it a bimodal system: a patient perched watch and a violent repeated construction phase.
Saddle-billed Stork
A Stork That Will Not Flock
Walking a wetland alone • Striking • Holding a very large territory
Solitary and unhurried, this is a low-frequency system.
Sahara Spiny-tailed Lizard
Darkening to Absorb the Sun
Emerging dark, almost black, in the cold morning to absorb solar radiation quickly • Lightening through the day to yellow, orange or red as body temperature rises • Reflecting rather than absorbing once the target temperature is reached
Because the cycle runs daily, it operates as a mid-frequency system.
Saiga Antelope
Dual-Season Nasal Chamber
Filtering • Dusty • Summer
Because the same system is reconfigured by context rather than running one way, it is an adaptive system.
Sailfin Tang
Doubling in Height on Demand
Swimming with the enormous dorsal and anal fins folded flat against the body • Erecting both simultaneously when threatened or challenged, roughly doubling the apparent body depth • Turning side-on so the expanded outline faces the other animal directly
Because displays recur, it operates as a mid-frequency system.
Saimaa Ringed Seal
Snowdrift Lair Excavation
Lair-bound • Insulated • Winter
Because the lair winter and the open-water year are both essential and run at different rates, it is a bimodal system.
Sally Lightfoot Crab
Ten Legs on Wet Vertical Rock
Sprinting • Adhering • Multi-directional
That makes it a high-frequency system: continuously fast and continuously adhering.
Salmon Shark
Heat-Exchanger Muscles in Near-Freezing Water
Cruising • Diving • Migratory
That makes it a bimodal system: continuous warm-bodied cruising and fast pursuit at prey concentrations.
Salmon-crested Cockatoo
A Signal That Changes In A Second
Decades of pairing • Slow breeding • Instant signalling
Everything about the system is low-frequency except the one channel that had to be fast.
Saltwater Crocodile
Tide-Timed Ambush
Floating • Waiting out the wrong tide • Riding the right one
Because an overwhelmingly cheap waiting state exists to fund rare and enormous releases of power, this is a bimodal system.
Sambar Deer
A Call the Forest Uses
Detecting a stalking predator by scent, sound or sight while browsing alone • Giving a loud repeated metallic bell call that carries far through dense forest • Other deer, langurs and peafowl responding to that call as reliable information
Because alarms are occasional, it operates as a low-frequency system.
San Cristobal Lava Lizard
Island-Sealed Push-Up Signature
Basking • Displaying • Island-sealed
Steady daily cycles of basking, feeding and signalling within a held territory make this a mid-frequency system.
Sand Cat
Fur-Padded Sand Listening
Nocturnal • Listening • Digging
Because returns come from many modest captures repeated nightly, it is a mid-frequency system.
Sand Goby
Fanning Eggs Under a Shell
Excavating sand from beneath a bivalve shell to make a chamber • Attracting a female to lay on its underside • Fanning the clutch with the pectoral fins continuously until it hatches
Since fin beats repeat continuously, it operates as a mid-frequency system.