This actually occurred in a dream last night, but I'm interested in what could come out of this. I'm not experienced with writing stories and have only read some Worldbuilding posts, so excuse me if this isn't the best! I'll give a brief introduction on what happened, but the scenario does not really lead on to anything about the black color of the animals.
In my world, humans stranded on an island find themselves in several dangerous encounters with animals. The first encounter occurs when one human is attempting to make contact with an elephant calf, but the calf is spooked when another human verbally warns his friend. In response to the alarmed calf, the cow elephant charges at the human, who barely manages to escape.
However, the situation does not end there - a panther has also responded to the calf's cry, but encounters the humans in a cave the panther is using as a shortcut to a cliffside. The panther attacks one of the humans, knocking them from the cliff and killing them.
...and so on.
TL;DR Later, the humans come to the realization that all of the animals they've encountered have black fur or skin.
- In my dream, it was daylight during both attacks. Although possible, it did not appear that the animals utilized the color for nighttime camouflage.
- I was never aware of the temperature of the island, but the foliage was green and a beach led on that it was not very cold.