The pigeon is a very common bird and is also a type of poultry that humans greatly favor. In fact, pigeons have accompanied humans for thousands of years.
Pigeons are often thought to navigate and find their way using the Earth’s magnetic field, the position of the Sun, and even infrasound waves.
There are many types of pigeons, which are widely distributed around the world. In New Zealand, located in the Southern Hemisphere, there is a very special pigeon species known as the New Zealand wood pigeon.
The New Zealand wood pigeon is quite large compared to its relatives in other regions. An adult New Zealand wood pigeon can weigh between 650 grams to nearly 1 kilogram and has a body length of over 50 cm.
The Kereru, also known as the New Zealand wood pigeon, is famously dubbed “the drunks of the sky” due to their preference for eating overripe fruits that fall to the ground, leading to inebriation, loss of balance, and awkward movements that can even result in them falling from high branches.
The New Zealand wood pigeon has colorful plumage that looks very beautiful. In the past, hunters hunted the New Zealand wood pigeon in large numbers for their meat and beautiful feathers. Subsequently, New Zealand enacted laws to protect the wood pigeon, placing it on the list of wildlife that needs protection, making any act of killing them illegal.
Currently, despite being legally protected, the population of wood pigeons in New Zealand has not significantly increased. One reason is that the New Zealand wood pigeon has a low reproductive rate. A female wood pigeon can only lay one egg at a time and it takes 28 days for the egg to hatch under the careful care of the mother. After hatching, the young pigeons must go through a long learning process before they can live independently without their parents.
In summer, when fruits ripen quickly, local residents often find “drunk” wood pigeons lying on the ground, and sometimes they have to take them to health centers to “sober them up.”
On the other hand, the New Zealand wood pigeon often places itself in very dangerous situations as they frequently become intoxicated due to their gluttonous nature. They commonly eat fruits, leaves, buds, flowers, and more. They have a particular liking for very sweet, overripe fruits that have fallen to the ground and enjoy sunbathing after a hearty meal.
Under high temperatures, the fruits in their stomachs ferment quickly, producing alcohol that makes the New Zealand wood pigeon easily “drunk” from the alcohol generated in this process.
Although widely distributed in both forest and urban environments, the population of this bird has significantly decreased since the European colonization and the introduction of invasive mammal species.
Once intoxicated, the mind of the New Zealand wood pigeon becomes dizzy, sometimes unable to maintain body stability, causing them to sway from side to side on branches. Local residents often see intoxicated wood pigeons falling from trees to the ground, where they continue to sleep.
This situation is genuinely dangerous. Although local residents do not exploit this drunkenness to catch them, feral cats, stoats, rats, and marsupials take advantage of this opportunity and prey on them.
After eating, these pigeons often sunbathe while digesting their food. This behavior can lead to the fermentation of fruits in their stomachs, especially in warm summer weather, which can cause intoxication.
New Zealand and its nearby counterpart, Australia, is an incredibly unique area on the planet. The ecosystem on this tectonic plate is distinct, and the food chain here is also very different from other continents.
Originally, the native New Zealand wood pigeon had few natural enemies, so they would not face any danger from frequent drunkenness. However, with increased human activity, many animal species from other continents, such as feral cats, stoats, and rats, have made their way to New Zealand’s islands, and these invasive species have inadvertently become natural enemies of the New Zealand wood pigeon.
In addition to preying on intoxicated New Zealand wood pigeons, these natural enemies also attack newly hatched pigeons and pigeon eggs, posing a serious threat to the reproduction of the New Zealand wood pigeon.
The New Zealand wood pigeon primarily eats fruits, favoring native fruits, but also consumes leaves, flowers, and buds.
In fact, the New Zealand wood pigeon is a very important species for maintaining the local ecosystem. For example, New Zealand has a type of berry called karaka, and its tree is a crucial part of New Zealand’s coastal forests. Because the berries are relatively large, ordinary birds can only peck at them to eat but cannot help the tree disperse its seeds. However, the New Zealand wood pigeon, being larger, can swallow both the fruit and its seeds whole.
After the New Zealand wood pigeon eats the berries, it will excrete the seeds onto the ground, where these seeds can then take root and germinate naturally, helping this tree complete its life and reproductive cycle.
