[pvaldes]

My first candidate would be roar sound. In any case 100 miles/ 160Km is an impressive distance.

Whales were reported communicating at a distance of 60 miles / 100Km at least and in theory sound could travel 100 miles easily in the water. Howling monkeys roars can be heard at 3 miles (4.8Km), and are seen as the loudest terrestrial mammals but low frequency sounds in Lion roars can be heard at 5 miles.

I would assume that either he was aware previously of the female territory (maybe both tigers were roaring near the frontiers of both territories while wandering); or that both tigers were attracted to the same place by an external factor (plenty of preys born in a place at a given time, or a water source).

[rightbyte]

Sounds really far fetched. Pun intented.

How would you know the direction if it could hear it in the water? Did the other tiger roar in the water otherwise I think it might be too damped.

Maybe birds that comes from that direction like sing a tiger song or something? I think birds in the jungle can do that but it is probably really local.

[pvaldes]

> How would you know the direction if it could hear it in the water?

Cetaceans have echolocation systems, for they to locate the source of sound echoes is child's play. They keep also detailed maps of its habitat in their brains and remember it for years. This probably helps to tag some directions as most probable to find another whale

Tigers detecting tigers by watching other animals behavior is not impossible, but they should be a lot of false positives. Tigers probably just wander a lot and watch carefully their territories for scents and marks of other tiger presence.

Lynx territories overlap when came from different sexes, and don't in the same sex.

[rightbyte]

> Cetaceans have echolocation systems

That's interesting. Do we have that?

My house cat is really impressive in locating mouse. She just finds them. They have to have so insane senses.

Ye. Scent marks is probably reasonable.

[pvaldes]

> Do we have that?

Yes. Is called sonar.

[rightbyte]

Heh ye and we have nightvision too. Just needs a flashlight.

[pipe2devnull]

I don’t think the person was saying the lion roar traveled through the water and that’s how they heard it.

[rightbyte]

Oh ye rereading I don't know how I made that assumption.