*Animals listed here are feral=no longer dependent on people*
Hoofed Animals (Ungulates)
- Eat native plants with no adapted defense to browsing animals
- Grazing and trampling cause bare soils and increase erosion and changing of water runoff patterns
- Open areas created by these animals effect the nutrients, moisture and light of the forest creating places unfavorable for native species and more susceptible to introduced plant seeds
- Reduced native bird and invertebrate populations with habitat loss
- Prey on Hawaiian birds, tree-dwelling and land birds
- Eat eggs including the ground nesting shearwater
- Compete with the native birds for food
- Distribute the seeds of invasives (they like them better)
- Larger birds prey on native bird chicks
- Carriers of bird diseases like avian malaria and avian pox
Here are a few examples:
Wild Boar have devastating impacts when it comes to Hawaii’s native habitat. Feral pigs root up large land areas increasing erosion and create mud wallows ideal for breeding mosquitoes that spread avian diseases. They also help spread the seeds of invasive plants into the newly tilled soil they create. Feral pigs also harbor and transmit many infectious waterborne pathogens creating concern for Hawaii’s water quality.
Rats are a big problem on the islands. They climb trees and prey on bird eggs and even adults!
Mongooses (not mongeese!) were introduced to the islands to control the rats. Only one problem: Rats are nocturnal (active during the night) and mongooses are diurnal (active during the day). So, instead of preying on rats, mongoose will eat birds, their chicks and their eggs.
Yup, cats. Undomesticated cats that live at higher elevations away from human development cause a threat our Hawaiiʻs native birds. These silent predators stalk unsuspecting prey and can even prey on flightless chicks nesting in burrows. Without wild predators to keep their population in check these year round breeders of up to 3 litters a year can multiply quickly.
Deer is one of Maui’s newest threat and growing fast due to lack of natural predators. Not only do they graze on local crops and affect Maui’s agriculture, but they can also can move up to higher native forested watershed areas and contribute to erosion, dispersal of invasive seeds, and graze and trample native flora and fauna.