The Arctic tern, a small and slender bird, is renowned for its extraordinary migratory journey, which spans from the Arctic to the Antarctic and back each year. These resilient seabirds navigate staggering distances, showcasing impressive adaptability and survival instincts in some of the Earth’s most extreme environments.
By covering roughly 25,000 miles annually, the Arctic tern embarks on the longest migration of any known animal. This article delves into 21 weird and interesting facts about these fascinating birds, exploring their unique traits, behaviors, and the remarkable journeys they undertake.
1) Arctic terns migrate over 44,000 miles per year
Arctic terns hold the record for the longest annual migration of any animal species. They travel between the Arctic and Antarctic regions each year. This journey covers distances well over 44,000 miles, round trip, depending on their exact flight path.
These birds don’t follow a straight line; their route is characterized by many detours. This adds significant mileage to their journey. For example, some individuals have been tracked traveling up to 59,650 miles in a single year.
Migration starts in the breeding season when Arctic terns breed in the northern Arctic during the summer. As temperatures drop, they commence their southbound trek to the Antarctic.
During their migration, they are often seen across various parts of the globe, stopping to rest and feed. This extensive travel ensures they experience two summers each year, maximizing daylight exposure.
2) These birds can live up to 30 years
Arctic terns are known for their impressive lifespan, typically living between 20 to 30 years.
Some individuals have even been recorded living as long as 34 years. This longevity allows them to undertake numerous migratory journeys throughout their lives.
The long lifespan of Arctic terns contributes to their ability to accumulate incredible migratory distances. By the end of their lives, some Arctic terns may have flown as much as 1.5 million miles.
Breeding for Arctic terns begins at around 3-4 years of age, ensuring they have many seasons to reproduce. Arctic terns are known to nest once every one to three years.
Their extended lifespan and breeding habits make them a fascinating subject for ornithologists and bird enthusiasts alike.
3) Arctic terns feed on fish and small marine creatures
Arctic terns have a diverse diet that mainly consists of fish and small marine creatures. Their primary food sources include fish, such as herring and cod, and various marine invertebrates.
They catch their prey by diving into the water from heights of up to 30 feet. Their sharp beaks and agile flight make them effective hunters.
These birds are known for their precision and skill in catching fish. They can also snatch prey from the water’s surface with remarkable speed.
Arctic terns often hunt in coastal regions, taking advantage of the abundant marine life. Their diet ensures they have enough energy for their long migratory journeys.
While fish make up a significant portion of their diet, they also consume crustaceans and other small sea creatures. This varied diet helps them thrive in their harsh environments.
4) They have a distinctive forked tail
The Arctic tern is known for its strikingly forked tail, which is one of its most distinctive features. This tail shape helps the bird maneuver with precision during flight.
The deeply forked tail, combined with long, pointed wings, allows for agile and energy-efficient travel. These adaptations are vital for their extensive migratory journeys.
The tail is mostly white with grey outer webs, which adds to the bird’s sleek appearance. The sharp design not only aids in flight but also plays a role in their social displays and courtship rituals.
When observing Arctic terns, the forked tail makes them easily identifiable among other sea birds. This feature is an integral part of their graceful and efficient flying capabilities.
5) Arctic terns are monogamous
Arctic terns exhibit monogamy, forming strong pair bonds that usually last for life. These birds dedicate themselves to a single partner throughout their breeding season.
Each year, Arctic terns return to the same colony to reunite with their mate. The bond formed between pairs is crucial for their successful breeding.
The pair work together to build nests out of grass and other plant materials. Both parents share the responsibilities of incubating the eggs and caring for the hatchlings.
Monogamy in Arctic terns ensures stable and cooperative parenting, which is essential for the survival of their offspring. The fidelity between the partners strengthens their effectiveness in raising young terns.
6) Known for their loud calls
Arctic Terns are recognized for their distinctive and loud calls. These calls are essential for communication within their colonies, especially during breeding season.
Their vocalizations can be described as harsh and sharp, often sounding like “kree-ar.” These sounds help the birds coordinate group activities and signal alerts.
Both male and female Arctic Terns use their calls to ward off intruders and predators. This vocal behavior ensures the safety and cohesion of their colonies.
In addition to their loud calls, Arctic Terns employ a variety of sounds during courtship displays. These acoustic signals play a crucial role in mate attraction and bonding.
Whether defending their nests or maintaining social order, loud calls are an integral part of the Arctic Tern’s behavior and survival.
7) Adults weigh about 4 ounces
Arctic Terns are small to medium-sized birds. As adults, they typically weigh between 3.0 to 4.5 ounces, which is about 86 to 127 grams.
Despite their small size, they exhibit impressive endurance. Their lightweight bodies are an adaptation that aids in their extensive migratory journeys.
This bird’s streamlined body, combined with its weight, allows it to travel efficiently over long distances. This efficiency is essential, given their migration from the Arctic to the Antarctic and back.
8) Their plumage changes with the seasons
Arctic Terns exhibit remarkable changes in their plumage throughout the year. During the breeding season, they display a striking appearance with a full black cap on their heads. This distinct black cap contrasts sharply with their white underparts and gray upperparts.
In the non-breeding season, their plumage undergoes a noticeable transformation. The black cap recedes and becomes mottled with white, giving the birds a less defined appearance. Their bill, which is red during the breeding season, fades to a darker color as well.
These seasonal changes serve practical purposes beyond just aesthetics. The shift in plumage helps them blend into different environments, providing better camouflage against predators. It also signals their breeding status to potential mates, assisting in reproductive activities.
Aside from their head, other parts of their plumage, such as their wings and tail, show subtle variations between the breeding and non-breeding seasons. This adaptability in their appearance is a testament to their survival and successful migration across vast distances.
9) Arctic terns nest in colonies
Arctic terns exhibit a strong preference for nesting in colonies. These colonies can vary in size, sometimes consisting of just a few pairs, but they can also include hundreds of nesting birds.
Colonial nesting offers several advantages for Arctic terns. One key benefit is increased protection from predators. With many birds present, there’s a collective vigilance that helps deter potential threats.
Their nests, typically shallow scrapes in the ground, are often lined with grasses and moss. Many colonies are found in treeless areas of the Arctic, which provides an open landscape that suits their nesting habits. Each pair actively defends its nesting territory from intruders, often diving and attacking those who come too close.
The communal environment also facilitates social interactions among the terns. It allows for coordinated foraging, where groups of terns can work together to locate schools of fish. This makes feeding their young more efficient.
Colonial nesting isn’t without its challenges. High density can lead to competition for prime nesting spots and potential spread of diseases. Despite these challenges, the benefits of nesting in close proximity to each other seem to outweigh the drawbacks for Arctic terns.
10) They are highly aggressive during breeding season
During the breeding season, Arctic terns display heightened aggression. They fiercely defend their nests and young from potential threats. This protective behavior ensures the survival of their offspring in the challenging Arctic environment.
Arctic terns often engage in aggressive dive-bombing tactics. They will relentlessly peck at intruders, including humans, to keep them away from their nesting sites. Their aggressive actions are a response to the high stakes of breeding survival.
This aggression is not limited to larger predators. Arctic terns also target smaller animals and other birds. Their territorial nature during breeding season is crucial for maintaining a safe environment for their chicks.
11) Arctic terns are excellent flyers
Arctic terns are among the most remarkable flyers in the bird world. Their extraordinary migratory journey takes them from the Arctic to the Antarctic and back each year. This journey covers about 25,000 miles annually.
Their long, pointed wings and streamlined bodies make them highly efficient in the air. These physical adaptations enable them to glide effortlessly over vast oceans and strong winds.
Arctic terns are known for their agility and precision in flight. They can perform intricate maneuvers to catch fish and avoid predators. Their flying skills are crucial for their survival, helping them thrive in extreme environments.
These birds have even been observed taking indirect routes, adding to their total mileage. This meandering flight path likely helps them take advantage of favorable wind patterns and food sources.
Their flying ability is not only about covering distances but also about energy conservation. Arctic terns can change their flying styles, such as switching between flapping and gliding, to save energy over long distances.
12) Their scientific name is Sterna paradisaea
The Arctic tern, known scientifically as Sterna paradisaea, is a member of the family Laridae. This name reflects its classification within a large group of seabirds.
The term “Sterna” refers to the terns, a group known for their graceful flight and long migratory patterns. “Paradisaea” highlights their near-paradisiacal presence across both the Arctic and Antarctic regions.
Sterna paradisaea is renowned for its remarkable migratory journey, covering around 25,000 miles each year between its breeding grounds in the Arctic and its wintering grounds in Antarctica. This epic voyage makes it one of the most migratory bird species on Earth.
13) The wingspan of an Arctic tern is about 30-35 inches
Arctic terns have a notable wingspan that ranges between 30 and 35 inches. This extensive wingspan aids in their impressive gliding capabilities. It allows them to travel vast distances with minimal energy expenditure.
These birds are among the most skillful fliers. Their long, narrow wings contribute to exceptional maneuverability and endurance.
The wingspan is almost twice the length of their body, emphasizing their aerodynamic efficiency. This feature supports their migratory behavior, enabling them to travel from the Arctic to the Antarctic.
14) They have red beaks
Arctic Terns are recognized for their distinctive red beaks. This vivid coloration sets them apart from many other bird species.
The bright red beak is not just a visual marker but also serves practical purposes. It aids in catching small fish and invertebrates during their extensive migrations.
The red color of the beak is believed to be linked to the bird’s diet and overall health. A vibrant red beak often indicates a well-nourished Arctic Tern.
In addition to red beaks, Arctic Terns have other unique features like their sleek bodies and long wings. The red beak, though, remains one of their most prominent and identifying characteristics.
15) These birds have short legs
Arctic terns have notably short legs. This adaptation helps them conserve heat in their frigid Arctic and Antarctic environments. Shorter legs minimize the surface area exposed to cold air, which reduces the amount of heat loss.
Their short legs also contribute to their distinctive flight and landing behaviors. They often hover above the ground or water before settling, reducing the need to rely on their legs for prolonged periods.
Additionally, the short legs of Arctic terns are well-suited to their lightweight bodies. This combination aids in their extraordinary migratory journeys, as less body weight translates to more efficient energy use during flight.
16) Arctic terns hover before diving for fish
Arctic terns exhibit an interesting hunting technique when they go after their primary food source, fish. Before making their dive, these nimble birds hover above the water.
This hovering action allows them to carefully observe their prey, ensuring a precise and successful catch.
Their hovering skill is facilitated by their strong, agile wings that enable them to remain stationary in the air. Once they spot a target, they dive swiftly into the water to capture it.
This method not only showcases their agility but also highlights their exceptional hunting strategy.
17) They are found in coastal regions
Arctic terns are predominantly found in coastal regions across the globe. These birds make their homes along coastlines due to the abundance of food and suitable nesting areas.
During their migration, Arctic terns can be spotted along coastal routes from the Arctic to the Antarctic. They breed in the Arctic regions and then travel vast distances to reach their wintering grounds in the Antarctic.
The preference for coastal habitats provides Arctic terns with easy access to the sea for feeding. The availability of fish and other marine life near the coastlines is crucial for their sustenance and the feeding of their young.
Nest sites are often located on small islands, beaches, and other remote coastal areas. These locations offer protection from predators and human disturbances, ensuring a safe environment for their chicks.
Coastal regions also provide ideal conditions for the social behavior of Arctic terns. These birds are known for foraging in groups and nesting in colonies, which is more feasible in the open and less cluttered coastal spaces.
In summary, the Arctic tern’s reliance on coastal regions is vital for its survival, providing essential resources and safe nesting sites throughout their migratory journey.
18) Arctic terns return to the same nesting sites yearly
Arctic terns exhibit strong site fidelity, returning to the same nesting locations each year. This behavior helps them take advantage of familiar environmental conditions and available resources.
They often nest in colonies, sometimes among other tern species. These birds choose specific sites, such as rock crevices or small ground depressions, for their nests.
Their yearly return to the same sites facilitates the formation of long-lasting pair bonds. Both parents participate in nest building and egg incubation, ensuring successful breeding and rearing of their young.
19) They are also known as sea swallows
Arctic terns are often called sea swallows due to their elegant flight and long tail streamers. This nickname reflects their graceful, swallow-like movements as they navigate the open skies.
Their shape and behavior contribute to this moniker. With slender bodies and pointed wings, they resemble swallows in both appearance and flight patterns.
These small seabirds are not only beautiful fliers but also skilled hunters. They soar over oceans and wetlands, diving to catch fish and other small marine creatures.
Sea swallows are known for their remarkable resilience and adaptability. These qualities, combined with their unique flight, further justify this charming nickname.
20) Their journey is the longest migration of any bird
The Arctic Tern holds the record for the longest migration of any bird on Earth. Every year, these birds embark on a remarkable journey that covers impressive distances.
Their annual migration takes them from their breeding grounds in the Arctic to the Antarctic, and then back again. This journey spans around 35,000 kilometers (22,000 miles) or more.
Remarkably, some Arctic Terns have been recorded traveling even greater distances. A particularly notable tern clocked in at about 59,650 miles over the course of its yearly migration. This demonstrates the extraordinary endurance and navigational skills of the species.
These birds experience two summers each year, benefiting from the abundant food available in both the Arctic and Antarctic regions. Their migration allows them to live in perpetual daylight for most of the year.
The Arctic Tern’s migration is not only the longest of any bird but also one of nature’s most incredible feats of endurance and instinctual navigation.
21) Arctic tern chicks fledge in about 21-24 days
Arctic Tern chicks usually fledge within 21 to 24 days after hatching. During this period, both parents are actively engaged in feeding and protecting their young.
Once the chicks hatch, they leave the nest within 1-3 days and find a secure place nearby to hide.
Parental care is intense, with both adults bringing food regularly. The chicks’ diet consists mainly of small fish and invertebrates, which the parents catch from nearby waters.
Around the three-week mark, the chicks start developing their flight feathers. By 21 to 24 days old, most chicks are ready to take their first flight.
Their initial flights are often clumsy, but they quickly improve their flying skills. The fledgling period is crucial for their survival and migration readiness.
Migration Patterns
The Arctic Tern’s migration is a remarkable feat that sees these birds traveling vast distances annually between the Arctic and Antarctica. Their journeys are noted for being the longest in the avian world and for their impressive navigational skills.
Longest Migration Journey
Arctic Terns are renowned for undertaking the longest migration journey of any bird species. Each year, they travel from their breeding grounds in the Arctic down to the Antarctic and back again.
The round trip can cover an astonishing distance of approximately 40,000 miles (64,000 kilometers). Some terns have been tracked covering even greater distances, up to 56,000 miles (90,000 kilometers), due to their non-linear flight paths.
This extensive migration is key for their breeding and feeding, as it allows them to take advantage of the abundant food resources in both the high Arctic and Antarctic regions. The entire journey encompasses several stages, influenced by seasonal changes and environmental conditions.
Navigation Abilities
The navigational abilities of Arctic Terns are nothing short of extraordinary. Despite their small size, these birds exhibit an incredible knack for finding their way across vast oceanic expanses.
They utilize a combination of the sun’s position, earth’s magnetic field, and even their sense of smell to guide their way during the migration. Studies indicate that Arctic Terns may also rely on visual landmarks and possibly even an internal map of the earth’s magnetic topography.
Their ability to return to the same breeding and wintering grounds year after year highlights an intricate knowledge of global geography that is still not fully understood. These navigational skills are essential for their survival and reproductive success.
Behavioral Traits
Arctic terns demonstrate remarkable behaviors, from their agile hunting techniques to their fierce nesting practices. These traits are essential for their survival and reproduction in the extreme environments they inhabit.
Feeding Habits
Arctic terns are primarily piscivorous, feeding on small fish and marine invertebrates. They exhibit agile flight patterns and use their sharp beaks to snatch prey from just below the water’s surface. During feeding, a tern might hover briefly before plunging to capture fish, often targeting species such as herring and sand eels.
They also consume crustaceans and insects, especially when breeding. These birds are adept at foraging in various marine environments, utilizing different techniques depending on prey availability. Group foraging is common, and observing these coordinated efforts can be fascinating.
Breeding and Nesting
Arctic terns breed in the Arctic, choosing treeless areas for nesting. They prefer open ground close to water, such as islands and coastal areas. Nests are simple scrapes in the ground, lined with vegetation and other soft materials. Both parents share responsibilities, fiercely defending their nest from predators and intruders.
During the breeding season, mating pairs engage in elaborate courtship displays. These include aerial acrobatics and food offerings. After laying 1-3 eggs, they incubate them for about 22-27 days. After hatching, chicks are fed by both parents until they fledge approximately 21-24 days later. This cooperative effort between mates ensures the survival of their young in a challenging environment.
Habitat and Distribution
Arctic terns are ground-nesting birds that thrive in treeless areas in the Arctic. These areas offer the isolation and safety necessary for raising their young.
During the breeding season, they form large colonies in regions like Greenland, Iceland, and parts of northern Europe and North America.
Their adaptability to the Arctic environment is remarkable, with short legs to conserve heat and webbed feet for efficient swimming.
In winter, Arctic terns migrate to the Antarctic, making it one of the longest migrations in the animal kingdom. They cover approximately 71,000 kilometers (about 44,000 miles) annually.
Their migratory path takes them across various oceans and continents, demonstrating their incredible endurance and navigational skills. Arctic terns do not follow a straight north-to-south route. Instead, they meander, which is why their total migration distance is so high.
Throughout the year, they inhabit vastly different environments, from the icy Arctic to the comparatively temperate Antarctic regions. This extreme range highlights their incredible adaptability.
Conservation Status
Arctic terns face multiple threats that could impact their survival. Various conservation efforts are in place to protect and sustain their populations.
Threats to Arctic Tern
Arctic terns encounter several significant threats. Climate change is a primary concern as it affects their breeding and feeding habitats. Melting ice disrupts the availability of nesting sites and alters the distribution of their prey.
Predation by larger birds and mammals also poses a risk, especially to eggs and chicks. Human activities, including pollution and habitat destruction, further exacerbate these challenges. Commercial fishing can reduce fish populations, depriving arctic terns of essential food sources. Additionally, plastic pollution in the oceans can lead to ingestion or entanglement.
Conservation Efforts
Efforts to conserve arctic terns focus on protecting their natural habitats and mitigating human-induced threats. Several protected areas have been established in key breeding and feeding grounds. International cooperation is crucial since arctic terns traverse multiple countries and continents during migration.
Programs to monitor and study arctic tern populations help in understanding their needs and improving conservation strategies. Efforts to reduce pollution, particularly plastic waste, are also vital. Sustainable fishing practices ensure that adequate fish supplies remain available for arctic terns. Public awareness campaigns highlight the importance of preserving these remarkable birds and their environments.