Some of the world’s most unique animals can be found on islands. Ecosystems and predator-prey relationships on islands are more closed-off than their mainland counterparts, paving the way for some distinct adaptations—think of enormous Komodo dragons (indigenous to the Indonesian island of Komodo and surrounding islets) or tiny Key deer (indigenous to the Florida Keys). But island life isn’t always easy and even the smallest ecosystem changes can put these animals at risk.

Here are two species that have adapted to the island lifestyle, but are now under threat due to human activity and invasive species.

Kakapo

Evolving on the islands of New Zealand with few predators and plenty of space, these birds adapted to life on land in a big way. Kakapos are the only flightless species of parrot in the world—and happen to be the heaviest, too.

Without predators, kakapos safely foraged on the ground and picked fruit from trees without a need for flight. But all that changed with human settlement and introduced species such as cats, rats, and weasels. Today there are fewer than 160 kakapos left.

Solenodons

Solenodons have been on islands of their own for a very long time, both genetically and geographically. Solenodons retain primitive mammal characteristics; DNA studies indicate they diverged from other mammals about 78 million years ago. Today, there are two remaining species, each indigenous to a large Caribbean island (Cuba and Hispaniola).

Once a dominant predator on these islands, solenodons adapted an omnivorous diet and are one of the few venomous mammals in the world. Even their venomous bite, however, has not protected them from the introduction of other predators (mongoose, dogs, cats), competing foragers (rats and mice), and human development. These forces have put solenodons at risk. Both the Cuban solenodon and the Hispaniolan solenodon are currently listed as endangered species

  1. Solenodons and kakapos have adapted to make the most of their island environments. Can you think of other species that have done the same?

  2. What are the major threats to island ecosystems?

  3. There were only 18 kakapos left in 1970, but scientists were able to manage the remaining population, which grew to 123 in 2014. What do you think drove the kakapo recovery?

Noun

a modification of an organism or its parts that makes it more fit for existence. An adaptation is passed from generation to generation.

characteristic
Adjective

particular feature of an organism.

Noun

foods eaten by a specific group of people or other organisms.

distinct
Adjective

unique or identifiable.

diverge
Verb

to differ or branch in two or more different directions.

DNA
Noun

(deoxyribonucleic acid) molecule in every living organism that contains specific genetic information on that organism.

dominant
Adjective

main or most important.

Noun

community and interactions of living and nonliving things in an area.

Noun

organism threatened with extinction.

enormous
Adjective

very large.

forage
Verb

to search for food or other needs.

genetic
Adjective

having to do with genes, inherited characteristics or heredity.

geographic
Adjective

having to do with places and the relationships between people and their environments.

Adjective

characteristic to or of a specific place.

introduced species
Noun

a species that does not naturally occur in an area. Also called alien, exotic, or non-native species.

Noun

type of plant or animal that is not indigenous to a particular area and causes economic or environmental harm.

Noun

body of land surrounded by water.

islet
Noun

a very small island.

mammal
Noun

animal with hair that gives birth to live offspring. Female mammals produce milk to feed their offspring.

Noun

organism that eats a variety of organisms, including plants, animals, and fungi.

predator
Noun

animal that hunts other animals for food.

prey
Noun

animal that is hunted and eaten by other animals.

primitive
Adjective

simple or crude.

unique
Adjective

one of a kind.

venomous
Adjective

having to do with venom or organisms that secrete venom.