How Humans Affect Hawaiian Stilts

Hunting

• Hawaiian stilts were regularly killed for sport before waterbirds became protected in 1939. A survey in 1941 indicated the Hawaiian stilt was on the brink of extinction with only 200 remaining at that time. Hunting played a key part in this.

Habitat Destruction

• Humans have destroyed much of the wetland habitat of stilts. The importance of wetlands, both for their own species and for their ecological services, has only recently been fully recognized, and in the past they were regarded primarily as soggy wasteland. The impact of "draining the swamp" for agriculture and development has been serious for wildlife. Today only about 10 percent of Hawaii's wetlands remain.

Pollution

• One of the ecological services wetlands provide is filtering out pollutants before they reach the oceans. Unfortunately this means pollutants accumulate in the wetlands themselves. Animals high up the food chain such as the Hawaiian stilts consume toxins from their prey.

Introduced Species

• Humans have introduced animals and plants all over the world, accidentally and on purpose. Very often, these species thrive in their new habitats, overwhelming native flora and fauna. For the Hawaiian stilt, some of the main problem invasive species are bullfrogs, mallards, rats, feral cats and mongooses. They either consume stilt adults, eggs or young or, as with mallards, compete with them. As with pollution, the problem of invasive species is ongoing in Hawaii.