There are animals designed to fill every ecological niche, and they are often specialized for a local ecosystem. Many flightless birds have a unique ability to fill a specialized niche. Penguins and ostriches are examples of that. New Zealand kiwis are an especially odd example of birds designed for a unique environment.
These flightless, nocturnal birds fill a niche in the New Zealand forests. They are about the size of a chicken, and they eat worms, insects, and berries. Kiwi feathers resemble the rough fur of some mammals rather than bird feathers. The feathers shed dirt efficiently, which is good since they live in dug-out burrows underground. Kiwis get their name from their vocalizations, which sound like “keee weee.”
Kiwis have no keel on their sternum and no tail, so they can’t fly. They do have muscular legs with four toes. (Most flightless birds in the ratite group have two or three.) They have thick, tough skin and heavy, dense bones. (Most birds have hollow bones for flying.) They have a low body temperature for a bird. Their bills have nostrils at the tip, giving them an acute sense of smell. By eating worms, grubs, and insects, kiwis maintain the ecological balance needed in the forest. New Zealand kiwis had no predators until humans introduced dogs and cats to the country.
Kiwi eggs are designed differently from other bird eggs. They are huge, being equal to 20% of the mother’s weight. It would be like a human mother having a baby one-fifth of her weight. The eggs have twice as much yolk as other bird eggs, and they contain antibacterial and antifungal materials needed for living in underground burrows. The male sits on the egg until the chick kicks its way out since kiwi chicks have no egg tooth to break the shell. The parents do not feed the chick, which lives on the extra yoke until it can follow the male outside to get worms and insects.
God’s design is different in each ecosystem, but there are always creatures that provide balance. When humans upset that balance, the result can be a disaster. New Zealand kiwis are an example of unique specialization to support the forests of that unique country. To the people of New Zealand, they are a treasure.
— John N. Clayton © 2020
Data from the NewZealand.com