Otters are semi-aquatic mammals that require various resting and shelter locations as they move between water and land. These places have specific names that reflect their unique function. The different names for otter homes—the permanent den and the temporary resting spot—reflect the animal’s need for both secure breeding sites and flexible daytime shelters. Understanding these terms, along with those for their territorial markings and habits, offers a clearer picture of the otter’s existence.
The Primary Den: Defining the Holt
The holt is the otter’s main, subterranean den, serving as a permanent dwelling protected from predators and severe weather. This shelter is typically excavated into riverbanks, concealed beneath the root systems of large trees like ash and sycamore, or hidden within rock piles or log heaps. The construction often includes a tunnel system that may extend up to 10 meters underground, providing a safe, dry chamber.
A defining characteristic of a holt is its multiple entrances, including openings above the high-water mark and often a concealed entrance below the water’s surface. This design allows the otter to enter and exit discreetly and provides an escape route in case of a flood or disturbance. The holt is lined internally with soft materials such as grasses, reeds, and leaves to create a comfortable bedding area.
The holt’s most significant purpose is as a natal den, where female otters give birth to their pups. These natal holts are often situated far from the water, sometimes up to a kilometer away, to reduce the risk of flooding and keep the young safe. The mother raises her cubs in this secluded environment until they are old enough to swim and join her in a holt closer to the main water body.
The Secondary Shelter: Understanding the Couch
In contrast to the permanent underground holt, the couch is a temporary, above-ground resting place used for short-term shelter, resting, and grooming. Otters typically use couches during the day while traveling across their large home ranges, which can contain up to 30 different resting sites. Unlike the holt, the couch lacks extensive tunneling or multiple chambers and is simply a concealed spot.
A couch is commonly found in dense vegetation, such as reed beds, tall grass, or under bushes or scrub. These resting spots are identifiable by a patch of flattened vegetation where the otter has pressed down the material to form a slight, nest-like depression. Otters may spend a large percentage of their daytime resting periods in couches, demonstrating reliance on these flexible shelters for immediate refuge.
Rounding Out the Vocabulary: Other Otter Terms
Beyond their dwellings, otters have other specialized terms related to their habits and territorial marking. The most common sign of an otter’s presence is its feces, known as spraint. Otters deposit spraint in conspicuous locations, such as on prominent rocks, under bridges, or on small piles of scraped-up earth called “castles,” to mark territory and communicate.
Another feature of otter territory is the slide, a smooth path on a riverbank or slope used for travel and play. Otters repeatedly slide down these muddy or icy slopes on their bellies. This is believed to help them conserve energy when traveling, in addition to being a form of social activity. Finally, a group of otters is referred to by collective nouns, including a “romp,” which describes their playful nature, or a “raft” when floating together on the water.