The Guam Kingfisher is small by kingfisher standards. Males average only about 58g (two ounces) and 24 cm (9 inches) long, making them less than half the size of North America’s Belted Kingfisher. Both male and female Guam Kingfishers have an iridescent blue-green back, a disproportionately very large, slightly crested, rust-colored head, and a long, stout, pointed bill. Males have cinnamon-colored underparts, while the underparts of females and juveniles are whitish.

After World War II, the accidental introduction of brown tree snakes (Boiga irregularis) to Guam resulted in the extinction of nearly all of the island’s dozen species of native land bird by the late 1970’s. Biologists realized that drastic action was needed if there was going to be any hope of saving what was left of Guam’s native birds. In 1984, when the Guam Kingfisher received “Endangered” status from the U.S. Fish and Wildlife Service, fewer than 50 were estimated to remain in the wild. Twenty-one of these were captured and transported to U.S. zoos; eight more birds were imported in 1986. The last sighting of a Guam Kingfisher in the wild was in 1988.

Encouragingly, the population of Guam Rails in human care has continued to grow. The world’s population of Guam Kingfishers, and the future of the species is in the hands of zoological institutions, including the National Aviary, which is proud to participate in and contribute to the Association of Zoos and Aquariums (AZA) Species Survival Plan (SSP) for the Guam Kingfisher.

The Guam Rail is a small, ground-dwelling bird, inhabiting forests, mixed woodland and scrub, fern thickets, and grasslands. They move quickly through thickets and grasses. It is most active at dawn and dusk.

In the late 1980s, the presence of an invasive species, the brown tree-snake threatened the survival of bird species on the island of Guam. The Guam Rail was nearly driven to extinction, but biologists managed to rescue the remaining rails and bring them into human care. The species was listed as Extinct in the Wild for over 30 years. Careful coordination between zoos helped this species survive and breed in human care. Gradually, the species was released on the islands of Rota and Cocos near Guam, where released birds themselves have since successfully reproduced! In 2019, the Guam Rail became only the second bird species ever to be upgraded from “Extinct in the Wild” to “Critically Endangered.”

The National Aviary played a vital role in the reintroduction of Guam Rails. More Guam Rails have hatched at the National Aviary than at any other North American zoo. Read more about the remarkable recovery of this Critically Endangered species!

The shimmery feathers of the Hadada Ibis isn’t the only attention-grabbing feature of this bird: its loud call can be heard echoing through the Wetlands! Hadada Ibises are found in sub-Saharan Africa in a variety of habitats and often in close proximity to humans. This medium-sized ibis uses its long, curved beak to probe the ground for insects and the occasional small frog or reptile. Their populations are not globally threatened and in fact may even be increasing with the spread of agricultural development and irrigated land.

The Hamerkop is a mostly brown bird of the wetlands of Africa and Madagascar, and are known for the huge stick nests which they build – sometimes make several or more each year! Hamerkops are found in a variety of wetlands, including estuaries, and lake margins, but they also require nearby trees important for roosting and nesting. Like other marsh-dwellers, Hamerkops consume frogs, fish and large insects. This species can be locally common and is not currently considered to be threatened.

Harris’s Hawks are a deep chestnut brown with yellow markings that make them stand out. They are a very social species, and have been observed raising young and hunting—an unusual trait for a raptor species! While on the hunt, a group of Harris’s Hawks will descend on their prey and flush it. Harris’s Hawks can be found throughout Mexico and parts of the southern United States.

The Hooded Merganser is a showy diving duck with a distinctive head crest and bright eyes. The smallest of the three merganser species found in North America, the Hooded Merganser is found throughout most of the continental United States and southern Canada. The serrated edge and hooked tip of its bill helps the Hooded Merganser seize its prey, and its eyes are adapted to help it see underwater. Sometimes other duck species will lay their eggs in Hooded Merganser nests, a breeding strategy called “nest parasitism.” Hooded Mergansers, too, will lay their eggs in other bird’s nests. This species is not threatened but can be vulnerable to pesticides and contaminants and habitat degradation.

The Critically Endangered Hooded Vulture is a rather small, brown vulture, native to Sub-Saharan Africa. This species mainly occupies open woodland and savanna, but also forest edge, where if feeds on carrion and human food scraps. Unlike other vultures which mostly construct their nests on cliffs or buildings, the Hooded Vulture makes a stick nest deep within the foliage of a tree. Being smaller than the other African vultures, Hooded Vultures can rise on warm thermal air currents more quickly and so is often the first one to sight a carcass.  Vultures can remain in the air for hours, soaring gracefully with their long, broad wings on the thermals. This vulture is Critically Endangered as the result of the widespread loss of nesting trees, hunting of the vultures for food or medicine, poisoning at carcasses, and avian influenza.

The Hyacinth Macaw is a beautiful inhabitant of várzea, savanna, palm-savannas, and similar habitats adjacent to tropical forests in central and eastern South America. These intelligent and social birds are sometimes known as “gentle giants” for their gentle personalities and their large size. They are the largest macaw species, with strong beaks to match: some Hyacinth Macaws have beaks strong enough to crack open a coconut! They are especially adept at opening notoriously tough palm nuts. In response, palm trees have evolved to produce harder and harder nuts, but Hyacinth Macaws are evolving bigger beaks with each generation. Like all parrots, Hyacinth Macaws are great imitators and can mimic human speech. Fewer than 6,500 Hyacinth Macaws remain in the wild, as the species is vulnerable to the illegal pet trade, habitat loss, and hunting.

The National Aviary’s Tropical Rainforest habitat is home to two female Hyacinth Macaws, Jewel, seen on the left, and Sapphira, seen on the right.  Both Jewel and Sapphira arrived at the National Aviary in 2018 and have been getting to know each other in their shared space above the waterfall, now featuring multiple new perching areas for them to explore as they bond. Their expert care team has been observing the two closely and are delighted to see positive signs of a social bond being built between them.

This dark tern with its reddish-orange beak and feat, and striking white moustache, is a resident of the coasts of Peru and Chile where it catches fish in the Humboldt Current. The Inca Tern nests along the Pacific coast on rocky cliffs or guano islands, sometimes utilizing the old nest of a Humboldt Penguin. Reduction of nesting habitat as a result of guano harvesting may affect population dynamics. However, Inca Terns are very flexible and successful in using any kind of coverage (natural or artificial) for nesting. They can nest inside abandoned buildings and huts on guano islands, and in any pile of wood and metal slabs. Inca Tern populations may be affected by the reduction of anchovy stocks due to commercial fishing, and by reduced breeding success caused by the presence of rats and cats on some islands.

When most of us think of the canary, we think of a cheerful, bright yellow bird in a decorative cage. In reality, this common canary (Serinus canaria domestica) is the domesticated cousin of the “true” Island Canary (Serinus canaria), native to the Canary Islands just off the northwest coast of Africa.

Spanish sailors first brought the canary to Europe in 1478, where it was prized among those wealthy enough to afford one for the male canary’s silvery, twittering song. The brilliant yellow color that we associate with modern domestic canaries is the result of a genetic mutation that suppresses the melanin in the birds’ feathers, effectively “erasing” the dark banding and streaking found on wild birds. For the next century, the Spaniards controlled availability of canaries by only selling male birds to the rest of Europe. When a shipping accident in the 16th Century allowed a shipment of the birds to escape to Elba Island in the Tuscan Archipelago, the Italians were quick to take advantage of the situation. Soon canaries were being bred and sold all over the world outside of Spanish control.

The ready availability of domestic canaries made them ideal candidates when, in the late 1890’s, pioneering physiologist John Scott Haldane recommended the use of small, warm-blooded animals as “sentinels” for the build-up of toxic gases in coal mines. A build-up of toxic gases following “firedamp” and coal dust explosions was known to be what killed most miners, but reliable gas detectors were hard to come by. The flame of a “safety lamp” could be used to detect rising levels of methane and “chokedamp” (a combination of gaseous nitrogen and carbon dioxide), but no mechanical means of measuring carbon monoxide existed. With their small body size and faster metabolism, animals such as mice and canaries would succumb to a build-up of carbon monoxide more quickly than a human. Canaries came to be preferred over mice because the birds more visibly demonstrated signs of distress in the presence of even small quantities of carbon monoxide gas. This few minutes of warning gave miners time to put on protective gas masks, or even to leave the mines entirely. In their capacity as sentinels, canaries saved the lives of thousands of miners during the nearly 100 years they were in use. Today, we still use the phrase “the canary in a coal mine” when we talk about species who are biological indicators for the health of an ecosystem – species who, like the canary for the miners, begin to suffer and die as an early sign that something is wrong. Changes in the function, health, or population of these indicator species can reveal such things as the accumulation of pollutants (lamp shell brachiopods), changes in overall air quality (milkweed and some strains of white pine are sensitive to ozone), and the threat of rising ocean temperatures (corals and marine fishes worldwide).

Measuring roughly 12 inches in length, Jackson’s Three-horned Chameleons live amongst tree canopies. Their prehensile tail – or a tail adapted to grasp or hold objects – allows them to grip tree branches.

They are a dimorphic species – meaning it’s easy to tell males from females. Males are bright green-yellow and feature three, distinct horns that make them look like modern-day mini Triceratops. These horns are sometimes used to defend territories. Females notably lack these horns.

Jackson’s Three-horned Chameleons help keep insect populations in check – serving as natural pest control which benefits plants and wildlife, including birds. They also help with the propagation of forests as their movements across tree branches help seed dispersal.

This species is endemic to East Africa, however, a subspecies was accidentally introduced in Hawaii in the early 1970s and has since established a small (invasive) population on all main islands.

The Javan Pond-Heron is a wading bird found in Southeast Asia. Described as “stout,” this heron is sometimes mistaken for an egret with similar plumage. It inhabits swamps, marshes, and flooded plains, where it forages for crabs, insects, and fish by remaining motionless for long periods of time before snatching food from the water. This species is not globally threatened and its numbers may actually be increasing.