Elephant Matriarch Drought Trek

An experienced matriarch remembers waterholes from decades of travel. Change her age, the drought, the heat and the herd's thirst, then watch whether the herd reaches water before the dehydration clock runs out.

Scenarios

Herd and weather

Infrasound rumble (herd cohesion)

Dehydration clock

Experiment: does a wise matriarch save the herd?

Runs 240 seeded treks per matriarch age with the settings above. Bars: measured success. Ticks: knowledge-only prediction 1 - prod(1 - p) over the holes she remembers. Unremembered holes can still be found by searching, so young matriarchs beat the prediction; the dehydration deadline and walking hours can push older matriarchs below it.

Independent numerical checks

The science

Social memory. Elephant family groups are led by the oldest females. Field studies report that herds led by older matriarchs cope better with drought. Here each waterhole has an illustrative discovery age; a matriarch of age a remembers the holes with discovery age at most a. She walks to the nearest remembered hole, marks it dry if it is, and moves on; with nothing left she explores by a random walk and notices unknown holes within the search radius.

Wet probability. p = r^(1 + 4s) for reliability r and drought severity s (illustrative law; larger s dries unreliable holes first). For a matriarch who knows every hole and has no deadline, success must equal 1 - prod(1 - p_i); the checks panel tests the Monte-Carlo run against it within 3 standard errors.

Dehydration clock. Water loss 0.04 L per kg per day (about 140 L/day for 3500 kg, a typical figure), multiplied by 1 + 0.04(T - 25) above 25 C and by 1.3 while walking. The critical deficit is set to 9.75 % of body mass (15 % of body water at 65 %); this gives roughly 2.4 days at 25 C. Illustrative threshold, not a veterinary value.

Energy. Basal rate by Kleiber: B = 70 M^0.75 kcal/day (about 35,000 kcal/day at 4000 kg). Walking adds the allometric minimum cost of transport 10.7 M^-0.316 J per kg per m (typical scaling; check against primary sources).

Infrasound. Rumbles are 14-35 Hz; at 20 Hz and 20 C the wavelength is c/f = 343/20 = 17 m. Level falls as SPL(r) = SL - 20 log10(r) - alpha r/1000 (spherical spreading plus excess attenuation alpha dB/km). The herd hears a call out to the distance where SPL equals the background noise. With alpha = 0 this is r = 10^((SL - N)/20). Real propagation depends on wind, temperature layers and ground; at night calm air typically carries calls farther, which the Night option mimics only through lower noise.

Simplifications. Flat terrain; one herd moving as a point; instant drinking; no food, no predators; follower elephants are kinematic. Waterhole positions, reliabilities, discovery ages, search radius and the source level are teaching values. To keep animals visible the 3D models are drawn up to 10 times larger when the camera is far away (map markers), and formations spread accordingly. Not a conservation or management tool.

Models. Built in Blender (named parts, baked skin, soil and mud textures) and animated as rigid parts in Three.js.