Hawaiian Crow

The raucous cries of the Hawaiian crow once filled the forests of Hawaii. Now the imperiled species is extinct in the wild.

Resourceful and intelligent, social and gregarious, the Hawaiian crow — also known as the Alala — is well-adapted to the hot climates of the lush Pacific island for which it’s named. With few natural threats and abundant sources of food, the species once thrived in its forest habitat.

But the intrusion of outside threats in the 19th and 20th centuries brought the species to the brink of extinction.

Now conservationists are attempting to coax the crow back to life.

4 Hawaiian Crow Facts

• Once venerated by the native Hawaiians, the crow was thought to be an aumakua, meaning a family guardian spirit.

• Despite the harshness of its call, the crow is considered to be a type of songbird. It is part of the same genus as crows, ravens, and rooks.

• The word Alala in Hawaiian is associated with chants, cries, and messages.
• Crows are considered one of the world’s smartest animals!

Scientific Name

Corvus hawaiiensis, which derives from the Latin word for raven, is the scientific name for the Hawaiian crow. It belongs to the family of Corvidae, which is a type of perching songbird common in nature. Members of the family include all species of crows, jays, jackdaws, magpies, ravens, rooks, and treepies.

Evolution and Origins

The Hawaiian crow, also referred to as Alalā Corvus hawaiiensis, is a species native to the Hawaiian Islands and is not found anywhere else on the planet.

These birds are significant in Hawaiian culture, and they are recognizable by their unremarkable black feathers and football-like size. Alalā Corvus hawaiiensis are social creatures and renowned for their noisy calls, as well as their high level of intelligence.

The Hawaiian crow, also known as the ʻalalā, holds significant importance in Hawaiian mythology. According to legend, it guides souls to their eternal resting place on the cliffs of Ka Lae, which is the southernmost point of the Big Island of Hawaii.

The native priests who performed prayers and chants gave it this name because of its unique vocalization.

Appearance and Behavior

The Hawaiian crow shares similarities with many other species of Corvus. It features a thick bill, bristling throat feathers, black feet, and a dark brown to black sheen — though the wings are lighter in color than the rest of the body. The typical male crow is about 20 inches long and weighs just over a pound — about the size of a book. Females tend to be slightly smaller and lighter, but otherwise, sexual dimorphism in the species is limited. The Hawaiian crow is a social species that appear to gather in small, local flocks.

Once reviled as a baleful portent of future calamity (or simply dismissed as a nuisance and a pest), the crow is now known to possess a particularly rich and cunning intelligence. The crow’s remarkable mental acuity, which is a function of its relatively large brain-to-body size and a densely packed cluster of neurons (they appear to lack the big neocortex of primates), enables them to perform all kinds of complex tasks such as puzzle-solving and object manipulation.

The New Caledonian crow, which inhabits a chain of small Pacific islands east of Australia, is frequently studied as an exemplar of crow intelligence. It possesses many of the features that make object manipulation possible such as a straight bill and large mobile eyes. The Hawaiian crow is similar in this respect.

According to a 2016 study, tests performed in captivity demonstrate that the Hawaiian crow possesses the ability to extract food from holes with a stick. Even young birds could perform this trick without any training or input from adults, which suggests it is completely innate. This behavior would place it in the hallowed but small company of other tool-using species. Another marker of the crow’s intelligence is its remarkable memory. It is believed that the crows have evolved the capacity to remember individuals for months or even years at a time. This helps them to distinguish friend from foe.

Since the Hawaiian crow and New Caledonian crow are somewhat distantly related, it’s been suggested that tool use is an example of convergent evolution — meaning the behavior arose independently in both species. However, tool use is so novel and rare in the animal kingdom that it’s not clear why this behavior was selected at all — or why other types of birds in similar environments have not evolved it.

Given the crow’s intelligence, it’s unsurprising that the species also exhibits an immense vocal range. Their cacophonous riot of sounds, which includes screeches, howls, and burbling, conveys information to surrounding birds about the presence of nearby threats or friendly relations. Some scientists have postulated that the crow’s vocal repertoire is an example of a transmissible culture that can be passed on to and modified by future generations.

A 2017 study in the journal Animal Behavior found that the Hawaiian crow’s vocal patterns had changed while in captivity. Although they lost none of their vocal range, the birds appeared to be making fewer alarm and territorial calls. Another possibility, besides culture, is that the birds are simply responding to a lack of threats, and these calls will quickly reemerge in the wild.

Habitat

Now extinct in the wild, the Hawaiian crow was once endemic to the semi-dry forest on the south and west slopes of the Mauna Loa and Hualalai volcanoes on the largest island of Hawaii. Residing at mid-elevation around 3,000 to 6,000 feet up, they preferred the dense understory of the ohi’a and the koa trees to avoid predators. Fossils also seem to indicate that the species once occupied the island of Maui.

Diet

The omnivorous Hawaiian crow is a highly opportunistic and eclectic eater that will feed on almost anything that becomes available. Most of its diet consists of small invertebrates such as snails, arachnids, and isopods foraging from trunks, foliage, and branches.

The bird also consumes a variety of different fruits from the pilo, kolea, mamaki, and other plants. When it existed in the wild, the crow played an important role in the dispersal of seeds around its natural habitat. The seeds would pass through the bird’s digestive system and land in different locations. This would encourage and facilitate forest diversification.

Less common components of the crow’s diet include flowers, nectar, and carrion. The crow is also known to feed on the eggs and nestlings of other bird species. Evidence suggests that the crow would move seasonally around the forests with the availability of certain foods. However, the species is not migratory in nature.

Predators and Threats

The crow’s oldest natural predator is the Hawaiian hawk. A native of Hawaii, this threatened species preyed almost exclusively on crows and other smaller birds before the introduction of land animals to the island. The dense understory once provided the crow with a natural refuge from the sharp-eyed hawk. However, the loss of vegetation has made the crows easier to spot in the wild.

Once settlers arrived in Hawaii, they introduced new species such as the Asian mongoose, black rats, and feral cats, which placed additional strain on the local crow populations. The young fledglings are particularly vulnerable to predation before they can learn how to fly. Climate change, disease, habitat loss, and excessive predation may all complicate efforts to restore the species to the wild.

Reproduction, Babies, and Lifespan

The Hawaiian crow is a monogamous species that will form fiercely loyal long-term bonds with a single mate. Each year the mating season begins around March when both the males and females will participate in nest construction. A typical clutch consists of two to five eggs, but the female must incubate them all by herself.

It can take up to 22 days for the eggs to hatch and another 40 days to fledge. This is the time it takes before the bird is sufficiently developed enough to fly. However, the young birds often still rely on their parents for at least eight months, and they may remain with the family until the next breeding system to assist with foraging and defense. Out of the original clutch of eggs, only one or two birds will likely survive.

Females become sexually mature after two years, while males may take either two or three years. Hawaiian crows tend to have a long lifespan compared to other birds. They can live around 18 years in the wild, but scientists have documented a lifespan of up to 28 years in captivity.

Population

Once widespread across the island chain, the Hawaiian crow is now extinct in the wild. It is difficult to estimate exactly how many crows existed before the first wave of Polynesians arrived. Nevertheless, the bird entered a steep decline beginning in the late 19th century. By the 1990s, the total population of the Hawaiian crow fell to a low of only 20 or 30 individuals, which greatly constrained the genetic variability.

Despite several efforts to rehabilitate the species, a series of missteps and failures such as hawk predation led to setbacks in the attempts to reintroduce captive birds back into the wild. Conservationists were also hindered by the difficulties of procuring wild crows from private lands, where the birds had taken refuge. The Audubon Society actually threatened to sue the US government for its failure to protect the few remaining individuals. A more effective conservation plan was eventually implemented.

In 2002, after the last pair of Alala was officially spotted in the wild, conservationists declared the bird effectively extinct outside of captivity. The task of reviving the species fell to the Keauhou Bird Conservation Center and the Maui Bird Conservation Center, both managed by the San Diego Zoo Global Institute for Conservation Research. After some careful management, conservationists increased the captive crow numbers to more than 100 individuals.

In 2016, the first wave of Hawaiian crows was finally released into the wild, but three of the five birds quickly died — two from hawk attacks and another from environmental stress. After adjusting their strategy, scientists released 11 and 10 birds in 2017 and 2018, respectively. To bolster the chances of success, they sought to restore part of the birds’ natural habitat and control non-native predators and other disruptive species. They were also more selective about which birds they chose to introduce into the wild.

Given that most Hawaiian crows have spent their entire lives in captivity, the birds must learn all of the wild behaviors on their own, including courtship, foraging, socialization, and breeding. Fortunately, the birds have shown some signs of adapting to their circumstances with the help of conservationists.

FAQ

Why did the Hawaiian crow become extinct in the wild?

Out of all crow and raven species in the world, the Hawaiian crow is the most vulnerable to extinction. Several factors have conspired to imperil the species, all of which are interconnected and mutually reinforcing.

1) Hunting is one of the most important reasons for their extirpation from the wild. Regarded as a nuisance by local fruit and coffee farmers, the species was driven to near extinction by mass shootings. Although the state of Hawaii extended legal protection to the bird in 1931, the hunting continued apace for several more decades.

2) Habitat loss perhaps was the largest factor. Because the Hawaiian crow is specifically adapted to thrive in the island’s unique ecosystem, the loss of forests to agriculture, logging, and ranching was likely catastrophic, as it was unable to adapt.

3) For millions of years, the Hawaiian crow dealt with only a few predators in its natural habitat. But the introduction of outside species, including the previously mentioned cats and mongooses, has greatly reduced population numbers.

4) Likewise, the introduction of outside diseases such as toxoplasmosis (which is carried by cats) and possibly avian malaria has further precipitated the crow’s decline. The Hawaiian crow appears to be particularly susceptible to these diseases.

How did the crows reach Hawaii?

Evidence suggests that the crows first evolved in Asia and then radiated outward to the rest of the world. When it arrived on the Hawaiian islands, the crow adapted to the unique microclimate of its new island habitat. Based on fossil evidence, at least five crow species once occupied Hawaii. The Alala is the only one to survive in recent history.