Walruses are large marine mammals that live in the Arctic. They are known for their long tusks, whiskers, and ability to whistle. But why exactly do walruses whistle? In this article, we’ll explore the reasons behind walrus whistling and what their whistles might mean.
What Exactly Is a Walrus Whistle?
A walrus whistle refers to the unique whistling sounds that walruses make using their vocal cords and air passages. Walrus whistles are loud, carrying noises that can be heard from over a mile away on land or underwater.
When a walrus whistles, it forcefully exhales air out of its blowhole while also vibrating its vocal cords deep inside the throat. This creates a high-pitched whistle sound, similar to the sound of a small rocket or a human whistling. However, walrus whistles have distinctive variations in tone, pitch, and duration compared to man-made whistles.
Walruses have large vocal cords and special anatomy. These allow them to produce a variety of sounds, including whistles, grunts, knocks, bell-like sounds, and more. The shape of their lips and mouth cavity helps them whistle clearly.
Whistles stand out as particularly loud and high-pitched vocal signals. They differ from knocks and grunts, which sound lower and gruff. Whistles also stand apart from the bell-like rings that walruses can make by slapping their flippers or bodies.
Why Do Walruses Whistle?
Walruses use whistling as a form of communication, dominance displays, contact calls, mating, and reproduction. It allows them to interact and identify each other over long distances despite their bulky bodies. Their whistles can carry for long distances over water.
Whistling is one of the main sounds that male walruses make. They develop this ability at a young age and continue whistling throughout their lives. Male walruses, in particular, use whistling to establish dominance and attract mates. By whistling prominently, they advertise their size and strength to females.
Male walruses often engage in “whistling contests” where they try to out-whistle each other. The lower-pitched and louder whistles tend to assert dominance in conflicts. By whistling, males can establish their presence and defend their harem of female walruses from other males.
Their whistles are also useful for contact calls between walruses on land or at sea. When separated, walruses will whistle to locate each other. The whistles help mothers find and recognize their calves. They also allow walruses resting on beaches to keep track of the herd when they enter the water.
How Do Walrus Whistles Help Walruses Communicate?
Walruses whistle to communicate information to other walruses. Their whistles can convey different meanings depending on the context and situation.
For example, a mother walrus may whistle to call her calf. Male walruses may whistle during mating displays to attract females or warn off other males.
Whistling is also used when walruses are disturbed by potential threats.
In addition, walruses also use other vocalizations, like growls, roars, etc., to communicate. They have specialized anatomical features like highly mobile lips and inflatable pharyngeal pouches behind the throat that give them the flexibility to produce a variety of sounds. This allows them to convey different meanings through their vocalizations.
Walruses live in big groups. They use whistling to communicate and stay connected. Whistling also helps them warn each other of danger and find each other. This is especially important for mothers and calves. Whistling is, therefore, a key method of communication for walruses that helps them interact and survive as a social species.
How Do Whistles Help Walrus Mothers Find and Recognize Their Calves?
Each walrus mother-calf pair develops a unique whistling “dialect”. It allows the mother to reliably identify and return to her offspring even when separated or surrounded by other walruses. This vocal communication is important for offspring survival in a challenging Arctic environment.
Some key points:
- Walrus calves start whistling at a young age, around 2-3 months old. They use whistling calls to signal their location to their mothers.
- Mother walruses and their calves develop individually distinct whistling calls. This allows the mothers to recognize the unique whistle of their own calf, among many others.
- Research has shown that walrus mothers can distinguish the whistle of their own calf from the whistles of other unrelated calves with over 90% accuracy.
- If a calf becomes separated from its mother, it will whistle loudly and repeatedly. The mother recognizes her calf’s distinctive call and uses it to navigate back to her young.
- The whistling communication works over long distances, even if the calf is out of sight in the water or amidst a large herd on land. This helps mothers locate calves in noisy, crowded environments.
Why Do Walruses Whistle More During Breeding Season?
The breeding season amplifies the importance of male whistling for competitive displays, mate selection, and reproductive access. These are key drivers that have evolved to increase whistling behavior at this crucial time.
Here are several key reasons:
- Males whistle to show they are stronger and should be the dominant walrus with the most females. Louder, lower-pitched whistles suggest greater size and strength.
- Males use extensive whistling to advertise their fitness to prospective female partners. Whistling shows off qualities sought for successful mating and siring of calves.
- Dominant males must defend their harems of females from rival males during the breeding period. Increased, aggressive whistling deters challengers from attempting to steal females.
- The whistling vocalizations of males stimulate hormonal changes in females. This brings them into estrus and readiness to mate.
- Mates recognize each other by their distinct whistles. This helps them know when to go in the water together to mate.
What Other Animals Whistle to Communicate?
Whistling helps facilitate social communication for many animals like dolphins, primates, rodents, and even some insects. It allows them to coordinate, warn each other, and stay connected within their groups.
Here are some other animals that whistle as a form of communication:
Bottlenose dolphins are well known for their signature whistles that they use to identify themselves and keep in contact with others in their pods. Each dolphin’s whistle is unique, like a name. They whistle when separated from the group or when approaching other dolphins.
Pygmy marmosets are one of the few primates known to whistle. They use whistles to communicate between family groups and also during courtship displays.
Guinea pigs commonly whistle when distressed, excited, or looking for companions. Their whistles help them stay socially connected to other guinea pigs. They may also whistle during play or when being handled.
Some caterpillars, like the walnut sphinx caterpillar, produce whistles that function as alarm calls when threatened. The whistles warn other caterpillars of danger.
Marmots whistle loudly when sensing a predator. This helps warn other marmots to take cover. They may also whistle during social interactions.
How Does Climate Change Impact Walrus Whistling?
Climate change is melting Arctic ice that walruses depend on. This is causing problems for walruses and changing their whistling. Here are some of the effects:
- Less ice means more walruses crowd together on land. At busy beaches, walrus groups can stampede. This crushes calves, so mothers whistle desperately, trying to find them.
- Walruses usually migrate and mix with others while moving between ice and land. With less ice, their groups and routes change more. Calves might not learn proper whistling to find mates when older.
- More ships can now travel in the Arctic as the ice melts. Their engine noises drown out walrus whistles, so it’s harder for walruses to connect over long distances.
- Scientists think walruses will change their whistles over time to deal with these challenges. Studying their whistling shows how they respond to the changing Arctic.
Overall, climate change is impacting where walruses can go and how they gather and communicate. This affects their important whistling behaviors. Scientists are watching to see how walrus whistling might adapt as the Arctic environment keeps changing.
What Do Scientists Still Want to Learn About Walrus Whistles?
Scientists still have many questions about how walruses whistle and what their whistles mean. Here are some of the main things they want to find out:
- Exactly how walruses make different sounds, including whistles, using their bodies. Scientists have ideas about what body parts are involved, but they need more research to fully understand.
- What do all the different types of whistles mean, and when walruses use them? Are some whistles only made by males or females, or by adults vs babies? What do certain whistles signal – alarm, mating, etc? Long studies of recordings are needed.
- How far walrus whistles can travel underwater and across different environments. Some estimates are the whistles can go 6 km in open water, but more data is required for different conditions.
- If walruses can identify other walruses just by their whistle. Early research shows mothers and calves recognize each other, but more studies with captive walruses could provide insights.
- How climate change is impacting walrus communication as ice melts and habitats get warmer. More monitoring of how they adapt whistles is key for conservation.
There are still many detailed studies required to fully understand walrus whistles. Scientists have more detective work ahead!