Summer Friends from Afar:

According to the Ocean Conservation Administration (OCA), there are 88 species of seabirds in Taiwan, of which 11—including little terns—are designated as protected marine wildlife. Little terns (Sternula albifrons) are the smallest birds of the tern subfamily (Sterninae). Unlike other protected terns, which mainly reproduce on Taiwan’s offshore islands, little terns do so on Taiwan proper.

The OCA says that although little terns have a stable and widespread global population and are listed by the International Union for the Conservation of Nature as a species of “least concern,” in Taiwan these summer migrants are few in number and have had low reproductive success rates. Moreover, they are severely threatened because their breeding habitats overlap with areas of human activity. Therefore, the little tern is designated a a “rare and valuable” species under Taiwan’s Wildlife Conservation Act (the second highest level of protection). Since the breeding and habitat status of little terns reflects the health of environmental factors such as coastal fish resources, coastal stability, and water quality, protecting their habitats is equivalent to protecting coastal ecosystems.

House-hunting in Taiwan

Flocks of little terns start to arrive in Taiwan around April each year and gather at estuaries to feed and to mate. Like human homebuyers, they seek out suitable places to make their nests and lay eggs. Chen Chieh-peng, former president of the Wild Bird Society of I-Lan (WBSI) who heads a little tern survey project in Yilan County, explains that these creatures require several conditions for nesting.

First, vegetation coverage cannot exceed 30%. “If there is a lot of tall grass, this will obstruct the birds’ line of sight and they will not feel safe.” Second, there must be an abundant supply of food at a river estuary. If nests are located too far from food, it is too exhausting for the adult birds to fly back and forth to feed their young. Third, there must be suitable cover. To ensure these conditions, local governments, bird societies, and non-governmental organizations prepare little tern breeding grounds before the birds arrive in Taiwan.

Chen Chieh-peng suggests that preparatory work should focus on removing plastic trash but leave behind things like driftwood and branches where the fledgling terns can find cover, protecting themselves from the sun and from predators.

Little tern chicks in a nest clamor to be fed.

Every April groups of little terns arrive in Taiwan, where they engage in courtship and search for suitable breeding grounds. (courtesy of WBSI)

Welcoming little tern chicks

In the animated film The Wild Robot, a robot protects a bird egg and accompanies the gosling Brightbill as it learns to fly. When Brightbill flies away with the rest of the geese, it is a truly touching moment, because the process of raising the chick was so difficult. Likewise, there are many challenges to overcome before a little tern egg can become an adult bird.

It takes about three weeks for a little tern egg to hatch, during which time the parents must take turns incubating the egg for virtually 24 hours a day to keep it warm and moist. Chicks can walk about one or two days after hatching, and leave their nests after a few days to find cover, but still cannot fly and are very vulnerable. Their down feathers provide little protection against heat and rain, and they depend on their parents for care and feeding. Fledglings develop their juvenile plumage after about three weeks as chicks and begin to learn to fly while they also are schooled in avoiding predators and catching fish. After three or four weeks of this training, little terns finally become fully independent.

Little tern chicks need a lot of care from their parents. For example, they depend on the adults to protect them from both rain and intense sunshine, so the parents cannot leave their nests for long.

A touching image of little tern parents raising their young. (courtesy of WBSI)

A dashing little tern with a fish in its mouth.

Building a little tern paradise

The Lanyang Estuary in Yilan County is the point of convergence of the Lanyang, Yilan, and Dongshan rivers. Offering abundant fish, it attracts many birds to take up residence, including little terns. According to a survey by the WBSI, by the end of July 2025 over 600 little tern nests had been built around the river mouth, making it a breeding hotspot for these creatures in Taiwan.

Although all little tern breeding grounds are at river mouths, the birds don’t reproduce at the same places ­every year. For example, at the Lanyang Estuary the shape of the beaches and sandbars differs from year to year. “One year we had to hire a boat, because there were 30–40 nests on a sandbar surrounded by seawater,” recalls WBSI director-­general Chen Shu-te. Because the habitat changes each year, every March, before the little terns arrive, the WBSI inspects estuaries and sandbars across Yilan County to identify likely nesting sites and put up protective fencing. The fencing has progressed from simple cordons to wire mesh with warning signs. In addition, there are surveillance cameras at larger breeding areas to keep track of conditions in real time.

In the past, because little tern breeding grounds overlap with areas of human activity, and their eggs are very small in size, there were often incidents of people accidentally stepping on eggs or driving over them with beach vehicles. There were also cases of birdwatchers getting close to nests to take photos and attracting curious onlookers to also approach, putting the little terns under stress in their breeding season. However, thanks to the erection of protective fences, patrols by volunteers, and educational efforts by local conservation organizations, the little tern breeding population in Taiwan has gradually increased in size.

There are abundant fish along Taiwan’s coasts and excellent habitats available for little terns, making the island a summer paradise for these birds.

Coexistence between industry and nature

Taoyuan, generally considered to have a high level of industrial development, has become a paradise for little tern breeding thanks to the concerted efforts of a local bird society, the municipal government, and an enterprise.

As early as 2014, the Wild Bird Society of Taoyuan (WBST) began tracking little tern nesting and reproduction within the city’s territory, with the major breeding grounds being at Zhuwei Fishing Port and the Guantan Industrial Zone at Datan. In 2017, the planned development of the Third LNG Terminal posed a direct threat to the Guantan breeding grounds, so the WBST approached CPC Corporation, the terminal’s developer, to explore the feasibility of protecting the little tern habitat. CPC has since allocated funds each year to commission the WBST to carry out surveys of little tern breeding and take measures to protect their breeding habitats.

According to WBST surveys, Zhuwei Fishing Port was formerly a major breeding ground for little terns, with more than 100 nests being recorded at times in past years, but by 2023 this number had fallen to single digits. Hsu Ching-yen, head of conservation and research at the WBST, relates that the breeding ground at Zhuwei has been restored by piling up silt from the harbor, and is protected by fencing But despite everyone’s best efforts to provide a habitat for the little terns, still they have stopped coming. Where did they go?

Happily, in June of 2023 little terns were sighted in Zone G3 of the Datan Algal Reef. Hsu Ching-yen notes that Zone G3 is an area of natural beach. Access is controlled by security guards, so there is little human activity there. Moreover, in recent years CPC has continually worked to protect the environment there and has maintained the wire mesh fencing around the breeding grounds while also putting concrete barriers across nearby small roads, which has greatly reduced the number of vehicles entering the area. The result is a broad and tranquil beach habitat that is attractive to little terns.

From the start of the breeding season in May to the end of July this year, more than 160 nests appeared in Zone G3, with a reproductive success rate of over 80%. Hsu tells us that under natural conditions, little terns achieve a reproductive success rate of only about 30%, but with human help it can be raised to 70–80%, which is very heartening.

Many of Taiwan’s people are birdwatchers and bird lovers who willingly do their bit to protect seabird habitats.

Hsu Ching-yen of the Wild Bird Society of Taoyuan has been delighted to see how little tern conservation measures have greatly increased the birds’ reproductive success.

Little tern eggs are small, and it is not easy for the parent birds to successfully incubate them amid a hazardous environment. Bird surveyors plant flags in the ground near nests to facilitate observation.

Collaboration among stakeholders

Little terns are the smallest birds of the family Laridae (gulls, terns, noddies, and skimmers) that are found in Taiwan. They show gregarious behavior, with flocks of the terns able to defend themselves against predators, whether by loud squawking, feigning a dive bombing attack, or even defecating on intruders. Chen Shu-te says that survey personnel are often subject to such attacks.

Though little terns can defend themselves, their reproductive success is still threatened by pressure from natural enemies, such as birds of prey and sand crabs, and disturbance by stray dogs and people. Dogs have an excellent sense of smell and can easily find hatchlings and fledglings, and these birds are powerless against canine attacks. Also, this year there has been a notable increase in the brown rat population at the Lanyang Estuary, posing a new threat that will be a focus of attention in coming years.

Yilan not only has the WBSI, but many local groups that are concerned about environmental protection. These groups often visit schools to promote conservation concepts, and before the little tern breeding season they set out decoy birds to create an environment that is attractive to the terns. Local groups in Yilan also mobilize communities to organize patrols. Chen Shu-te opines that many people simply don’t know about little terns, but after learning about them, they support efforts to build fences and protect breeding grounds. For example, a watersports coach once mistakenly brought a group into a breeding zone, but after someone from the WBSI explained the situation to him, he became a patrol volunteer the next year.

Many stakeholders are working together to protect little terns. For example, the Yilan County Government and a children’s theater group have collaborated to produce a play about the birds that is performed in schools. Meanwhile, the OCA has published an illustrated book that tells the story of the little tern’s annual migration to Taiwan. 

Migratory birds show a high degree of “site fidelity”— faithfully returning to the same spot year after year—so as long as we ensure the quality of the environment at their destinations, they will surely come back. Moreover, other birds including Oriental plovers and little ringed plovers are attracted to the same habitats as little terns. Actions to protect the little tern not only benefit this one species, but entire coastal ecosystems.

We look forward to future annual visits from little terns, our friends from afar! 

A little tern soaring through the air complements the splendor of Guishan Island. (courtesy of WBSI)

Little terns born in Taiwan learn life skills here, such as how to avoid predators and hunt for food. Once they are fully fledged, they head back south again. (courtesy of WBSI)

Wild bird societies all over Taiwan put up protective fencing around little tern breeding grounds to keep out people and stray dogs, creating a safe habitat for the birds.

Conservation actions on behalf of the little tern protect not only this species, but entire coastal ecosystems. We look forward to future annual visits from these friends from afar!