Spend enough time around whale sharks in the Galápagos and a strange pattern becomes hard to ignore: nearly every one that divers encounter here is an adult female, and a notably large one at that — many well over 12 meters (40 feet) long. That's not a quirk of a small sample size; it's a consistent, repeated observation, and researchers openly describe why it happens as one of the more important open questions in whale shark science.
Elsewhere in the world, whale shark aggregations tend to skew toward juveniles, with roughly even numbers of males and females at feeding sites. The Galápagos pattern — large, mature, overwhelmingly female — doesn't fit that template, which is exactly what makes it scientifically interesting rather than just a curiosity for divers.
The leading working idea is that this population uses Galápagos waters specifically around pregnancy or late-stage reproduction, but that remains a hypothesis under active investigation rather than a settled answer — no one has yet documented where these sharks actually give birth, anywhere in the world.
This is exactly the kind of question photo-identification and satellite tagging exist to help answer. Every tagged shark, and every photograph logged into the shared identification database, adds one more data point toward eventually explaining why this stretch of ocean draws such an unusual, specific slice of the species — and where they go before and after they're seen here.
Source: adapted from Galápagos Shark Diving's own published material on its whale shark naming and research program.