S-4/ECPD/ Natural Resources - Introduced Wildlife

What is an Introduced or Non-native Species?

An alien, non-native, exotic or introduced species is a biological entity that occurs in an area only because it was either purposefully or accidentally brought there by a human agent. It is important to note that not all non-native species are considered invasive.


What makes a species invasive?

Many features have been attributed to invasive species and invaded ecosystems, but none are universal and invasive species tend to have a suite of traits rather than all of them. Base Environmental manages these invasive species populations due to the direct impact on birds and marine life on MCBH. Common invasive species traits include fast growth, rapid reproduction, high dispersal ability, ability to live off of a wide range of food types, single parent reproduction (especially in plants), and, commonly, association with humans.


Low Risk

Low-risk species present a minimal risk of invasiveness and in some cases, have become naturalized. Low-risk species are non-native or introduced organisms not known to cause significant negative impacts to the natural environment or its native inhabitants and are not considered pests species.  In the technical sense, the term ‘invasion’ simply denotes the unwelcome and uncontrolled intrusion or unintended spread of an organism outside its native range with no specific reference about environmental or economic consequences.


High Risk

High-risk invasive animals are non-native species of reptiles, amphibians, mammals, insects, and birds which threaten Hawaii agriculture, land, forests, waterways, biodiversity, and economic value. These species are typically undesirable, detrimental to humans and often need to be controlled, monitored, and in some cases, eradicated. Due to their invasiveness, they have the potential to have serious impacts on the natural environments in Hawaii. A multitude of diseases are also brought in by invasive species and cross all taxa (populations of organisms) affecting plants, animals, and humans.

The Hawaiian Islands are particularly susceptible to the establishment of new high-risk invasive animal populations due to a number of factors, including: interstate and international air transportation, changes in climate, and the isolation from other land masses over a long period of time. Although there is not one specific trait or a specific set of characteristics common to all high-risk invasive species, there is a suite of traits that these species often have:

  • High rate of reproduction
  • Fast growth rate
  • Pioneer Species (able to quickly colonize areas that have been disturbed)
  • Long-lived
  • High dispersal rates
  • Single-parent reproduction
  • High genetic variability
  • Tolerant of wide range of environmental conditions
  • Broad diet
  • Lives in close association with humans

Intervention is focused on preventing the establishment of these high-risk species through the timely action to identify and eradicate incipient populations.

Common Bird Non-native Species of MCBH

Photo of a Rat   Photo of a feral cat


Photo of a Mosquito   Photo of a Mongoose


Photo of Feral Pigs   Photo of a Coqui Frog


Photo of African Snails   Photo of a Coconut Rhinoceros Beetle


Photo of a Barn Owl   Photo of a Cattle Egret


Photo of a Tropical Fire Ant   Photo of Yellow Crazy Ants


Photo of a Centipede
Marine Corps Base Hawaii