Threats to Native Wildlife

Kaua‘i is home to many species of seabirds that nest and raise their young in our mountain forests and coastal beaches. The absence of mongoose, unique in the state, has allowed many species of seabirds to survive on Kaua‘i. On other islands, where there are large populations of mongoose, seabirds are scarce or absent, except in remote reserves or offshore islets.

 A feral cat predating an endangered Hawaiian Petrel  Photo by KESRP

A feral cat predating an endangered Hawaiian Petrel

Photo by KESRP

Invasive Predators

Despite the absence of the mongoose; predation by free-roaming cats, dogs, feral pigs, and rats have a devastating effect on native seabirds. Native birds evolved without the presence of mammalian predators and thus have no developed defenses against them. Ground-nesting seabirds, such as the Newell’s Shearwater, form large breeding colonies. Each breeding pair excavate a ground burrow in which to lay their egg. Seabirds only lay one egg per year and it requires both parents to raise the chick to fledging. A single predator attack on a colony can have devastating effects on the breeding population because of this.

These predators multiply at a faster rate than seabirds. A feral cat can breed as often as every three months before it is even a year old and average 3-5 kittens per litter. A seabird, such as a Newell’s Shearwater, does not reproduce until between the age of five and six, breed only once a year, and lay one egg. These reproduction rates are inevitably problematic for our native birds.

Light attraction

The other main issue for seabirds is light attraction. When seabirds leave their nests at night, they are guided by the light of the moon out to sea. Unfortunately, light from urbanization on Kaua’i results in fallout. Fallout is when birds are attracted to artificial lights by mistake which causes them to circle the lights confused and then fall to the ground. Once grounded these birds have difficulty taking flight on their own. This makes them susceptible to predators or being hit by vehicles.

By eliminating stray light, you help reduce the number of young birds that get confused and fall to the ground, rather than flying out to the open ocean.

 A map of the brightest areas on Kaua’i  Spatial data from NOAA, map provided by KESRP

A map of the brightest areas on Kaua’i

Spatial data from NOAA, map provided by KESRP

       Stomach contents of a Laysan Albatross chick

      Stomach contents of a Laysan Albatross chick

Plastic Pollution

Pieces of plastic have been found in the stomachs of nearly all seabird species. These birds end up filling their stomachs with plastics instead of food. Sharp plastics can puncture internal organs or simply prevent birds from digesting their food. 

By refusing plastic utensils and straws at restaurants, you can help prevent plastic waste from ending up in the ocean.

Disposing of trash in proper containers helps prevent waste from entering the ocean. Recycle or dispose of monofilaments (such as fishing line) in designated disposal area or tightly closed containers.