- Class: Aves (birds)
- Order: Passeriformes
- Family: Corvidae
- Genus: Corvus
- Species: hawaiiensis
Island Icons. ‘Alalā Corvus hawaiiensis, also known as Hawaiian crows, are endemic to the Hawaiian Islands and found nowhere else in the world. Revered in Hawaiian culture, these football-sized birds with dull black feathers are social, extremely intelligent, and well-known for their raucous calls. While ‘alalā populations have experienced a sharp and drastic decline over the last century, their story is also one of hope. San Diego Zoo Wildlife Alliance and our partners are working tirelessly to protect and breed this rare crow, so that populations can fly through their home forests once again.
HABITAT AND DIET
Forest flyers. ‘Alalā once lived in dry and semi-dry forests in the South Kohala, Kona, Kaʻū, and Puna districts of the Hawaiian Islands, ranging in elevation from 1,000 to 8,200 feet. Bones of ‘alalā or a close relative have been found on Maui, indicating a wider distribution at some point in the past. The last ‘alalā in its native habitat was thought to have been confined to higher elevations in South Kona. 'Alalā became extinct in their native habitat, and the world’s only remaining individuals were brought to two conservation centers operated by San Diego Zoo Wildlife Alliance conservation scientists and our partners, in an effort to save the crows.
Adventurous eaters. ‘Alalā are omnivorous, primarily eating native Hawaiian fruits and insects, and occasionally eggs and nestlings of small birds. As fruit eaters, ‘alalā play a vital role as seed dispersers in their native ecosystem. Seeds that pass through their digestive system propagate throughout their native forests as the birds fly from tree to tree, providing more food and shelter for other wildlife and helping to maintain the islands’ rich biodiversity.
Predators old and new. ‘Alalā hide from predators among understory shrubs. Their natural predator, the ‘io (or Hawaiian hawk) is also an endangered species. Human-introduced predators like cats, dogs, rats, and mongooses caused ‘alalā populations to plummet, as well as those of many other island birds, as they did not have the necessary adaptations to avoid these larger predators.
All in the family. ‘Alalā typically form long-term pairs, but extra-pair copulations have been observed. In March, pairs begin constructing nests together. They most commonly choose ‘ōhi‘a Metrosideros polymorpha trees for their nest sites.
Breeding occurs between March and July. ‘Alalā lay one to five greenish-blue eggs at a time, though usually only two survive. Only females incubate and brood the eggs. However, males often take a lead role in feeding nestlings and fledglings. Offspring continue to be fed by their parents until they are at least eight months of age.
Loud mouths. ‘Alalā are known for their loud and varied calls. They communicate with 24 different types of vocalizations, including squeals, growls, and human-like cries.
Once common throughout their range on Hawai‘i Island, the precipitous decline of the ‘alalā began more than a century ago. Facing a perfect storm of threats from invasive predators, disease, and habitat destruction, the ‘alalā seemed destined to follow the fate of the other four native Hawaiian corvid species and disappear forever. The ‘alalā conservation breeding program was formally established in 1993 by The Peregrine Fund, then transferred to San Diego Zoo Wildlife Alliance in 2000. It is the flagship program for our Hawai‘i Endangered Bird Conservation Program, a joint partnership with the U.S. Fish and Wildlife Service and the State of Hawai‘i Division of Forestry and Wildlife.
Because ‘alalā are rare and there was little existing information about their ecology and natural behavior, conservation scientists initially faced the challenge of developing new protocols regarding the birds’ care and conservation. Specialists from wildlife care, veterinary medicine, wildlife diseases, behavioral ecology, and other areas worked together to create best practices for care and reproduction, often learning “on the fly.” Now, we are embarking on the most critical phase of ‘alalā recovery: reintroduction and reestablishment in their native habitat.
All ‘alalā remaining in the world are cared for at the Keauhou and Maui Bird Conservation Centers, managed by San Diego Zoo Wildlife Alliance's Hawai‘i Endangered Bird Conservation Program through a partnership with U.S. Fish and Wildlife Service and the State of Hawai‘i Division of Forestry and Wildlife, as well as many additional community partners. Together with its partners, San Diego Zoo Wildlife Alliance is working to increase the ‘alalā population, and is preparing mature individuals for reintroduction into their native forests.
Partnerships and collaborations are vital to success, so a multipartner working group was established. Together, we devised a reintroduction plan. First, our partners and other organizations worked to address threats to ‘alalā recovery in their habitats, including large-scale efforts to remove invasive predators and restore forest habitat. After we and our partners experienced initial challenges reintroducing ‘alalā in 2016, we reintroduced 28 young ‘alalā to the Pu‘u Maka‘ala Natural Area Reserve on Hawai‘i Island from 2017 to 2019.
Our ʻalalā conservation breeding program has resulted in an incredible increase in the population, from fewer than 20 birds in the late 1990s to more than 110 birds today. Our intensive management starts with monitoring ʻalalā breeding activity using remote cameras. In preparation for reintroducing birds that will one day reproduce in their native habitat, we are focused on developing techniques to encourage parent birds to breed completely on their own. Such behaviors are essential for the survival and establishment of ʻalalā reintroduced into their native habitat.
Our challenge continues to be providing the ʻalalā with the skills that they need to thrive and breed successfully after reintroduction. During our last series of reintroductions, our conservation team reintroduced and monitored ʻalalā in native forests on the slopes of Mauna Loa. We have learned that reintroducing birds in a social group and providing them with supplemental food results in high survival for the first year after reintroduction. We also work on enhancing predator-avoidance behaviors, to encourage the birds to respond faster to their natural predator, the ʻio, which is also endangered. Recovering these iconic Hawaiian endemic birds will continue to require innovation and collaboration, so that they will thrive in their native forests.
Our ‘Alalā Community Inquiry Program supports and engages Hawai‘i Island science teachers with scientifically relevant and culturally significant curricular activities, and empowers students to ask original questions and construct experiments for answering them. Our hope is that by engaging in scientific investigations focused on the ‘alalā, students will discover for themselves its ecological significance and be inclined to act in an environmentally responsible manner on its behalf.
By supporting San Diego Zoo Wildlife Alliance, you are our ally in saving and protecting wildlife around the globe.