Frequency signatures: Horned Sungem to Huntsman Spider

Iridescent Tufts on a Hovering Engine

Hovering • Nectar-feeding • Hawking

That makes it a bimodal system: bursts of hovering feeding and still perching between them.

Horse Fly

Mud-Bound Youth, Slashing Pursuit

Burrowing • Preying • Slow-growing

That makes it a phase-change system: slow larval life in wet ground and a brief, persistent adult pursuit.

Horseshoe Crab

Spring-Tide Egg Placement

Benthic • Tide-timed • Unchanged

Because the system runs on low continuous activity punctuated by a tightly timed annual event, it is a low-frequency system.

Hottentot Teal

Lamellae Fine Enough for Plankton

Rows of fine comb-like lamellae along the inside edges of the bill • Water drawn in at the tip and pumped out at the sides by the tongue • Small invertebrates, seeds and plankton retained on the lamellae while the water passes through

Because pumping is continuous, it operates as a mid-frequency system.

House Centipede

Leg-Lassoed Sprint Capture

Running down prey • Throwing legs over it • Detaching a leg if grabbed

Because the whole body plan is arranged around speed and reaction, it operates as a high-frequency system.

House Cricket

Temperature-Set Chirp Rate

Rubbing wings • Calling all night • Slowing as it cools

Because the calling and feeding run continuously through the dark at a steady tempo, it operates as a mid-frequency system.

House Crow

Ship-Carried Commensal Spread

Working human waste • Nesting in any fork • Riding vessels to new coasts

Since the scavenging runs continuously through daylight, it operates as a mid-frequency system.

House Finch

Red That Must Be Eaten

Feeding on seeds, buds and fruit • Depositing dietary carotenoids into growing feathers at the moult • Wearing a colour that reports what was available

Since feeding and moult cycles repeat, it operates as a mid-frequency system.

House Fly

Eating by Dissolving and Sponging

Regurgitating fluid onto solid food • Dissolving it outside the body • Sponging the liquid up through channelled mouthparts

Since feeding bouts recur constantly, it operates as a high-frequency system.

House Mouse

Whisker-Guided Wall Following

Whiskers on the skirting • Running the edge • Crossing only when it must

Because the sweeping and the running are continuous through the active hours, it operates as a mid-frequency system.

House Sparrow

Grain-Adapted Human Commensalism

Feeding on spilled grain • Nesting in a building cavity • Roosting as a flock

Because the feeding and social activity run continuously, it operates as a mid-frequency system.

House Wren

Filling Every Cavity With Sticks

Packing several cavities with sticks • Offering the set to a female to choose from • Denying the same holes to every other bird

Since building is repeated through the season, it operates as a mid-frequency system.

Household Casebearer Moth

A Flat Portable Case

A flattened silk case built by the larva and covered in sand grains, dust, hair and fibre from wherever it lives • The larva living permanently inside it, extending the head and front legs to move and feeding on wool, hair and debris • Both ends left open so the animal can turn within the case and emerge from either, without ever leaving it

Because development runs across months, it operates as a low-frequency system.

Hoverfly

Mimicry That Need Not Convince

Wearing black and yellow bands resembling a wasp or bee • Being an unconvincing copy by any measurement anyone applies • Being avoided anyway by birds that will not risk finding out

Since hovering and visits recur constantly, it operates as a high-frequency system.

Human

Digestion Done Outside the Body

Food heated before eating, breaking down starches and denaturing proteins outside the gut • More energy released per mouthful and far less chewing and digestion required • A shorter gut and a larger brain becoming affordable on the same total energy budget

Because the change runs across generations, it operates as a low-frequency system.

Humboldt Penguin

Upwelling-Anchored Burrow Nesting

Diving the cold band • Returning to the same burrow • Dumping heat through bare skin

Because the diving and returning repeat at one steady daily tempo, it operates as a mid-frequency system.

Hummingbird Clearwing

A Stationary Hover on Clear Wings

Hovering • Nectaring • Darting

Because the adult system is organised around fast hover-feeding visits, it is a high-frequency system.

Hummingbird Hawk-Moth

The Hover-Hold Oscillator

Hovering • Rapid • Constantly fed

That makes it a high-frequency system: rapid, expensive and dependent on constant refuelling.

Hump Snout Lizard

Male-Enlarged Snout Ornament

Still • Perched • Ornamented

Long motionless waits, little travel and a fixed ornament in place of repeated active displays make this a low-frequency system.

Humpback Anglerfish

Bacterial Lure and Expandable Gulp

Hanging • Glowing • Weeks

Because both the long wait and the total gulp are essential, it is bimodal.

Humpback Turretfish

Rigid Box Rowed by Fins

Sculling • Armoured • Bottom-picking

That makes it a single-mode system: slow, armoured, fin-driven foraging.

Humpback Whale

A Song That Changes and Spreads

Feeding • Cooperative • Polar

That makes it a bimodal system: cooperative polar feeding and a tropical season of fasting and shared song.

Humphead Parrotfish

Coral Bite and Pharyngeal Milling

Biting • Grinding • All day

Because the biting and grinding run continuously all day at an even rate, it is a mid-frequency system.

Huntsman Spider