5 Things About Capybaras

5 Things About Capybaras

Land and Water

As semi-aquatic animals, capybaras have interdigital membranes which form partial webbing of the toes, granting more leverage for faster swimming and diving. Their sharp claws provide a substantial grip to climb out of river banks. Furthermore, on land, having a digitigrade foot structure (only toes on the ground) entails enhanced quietness - as well as less surface area to lift, promoting quicker strides alongside agility at the expense of stability - they can gallop a little over 20mph.

Capybaras can hold their breath for 5 minutes; possibly over - likely due to apnea where the heart beats decrease - coinciding with lower temperature underwater. If the water is shallow enough, they can sleep almost fully submerged for increased coverage, except for their nose poking out.

Temperature

They are often sedentary near water in humid, tropical climate zones, which may partly be why they have evolved sweat glands (though fur makes them lack effectiveness) where most other rodents don't. Otherwise, they can roll in mud for cooling.

They also can't run at top speed for too long - only for around 100-200m due to fatigue and hyperthermia, where enzymes denature over 40 degrees celsius. A sharp bite with the incisors is the only defence mechanism if running is no longer an option or there is no water to dive into for whatever reason.

Groups and Hierarchy

Capybaras are seen typically in groups of 10-20, including a dominant male, subordinate males, infants, but mostly females. In larger groups of up to 100 individuals, there is higher potential for selfish herding to succeed against predators, where adults protect the pups on the inside. Smaller groups lacking formation, might be likelier to utilise barking vocalisations can signal the herd to submerge to avoid predation. The dominant male will usually emit said sound more than any other individual.

Despite the heavier females, the 'alpha' male will commonly possess the most mass of all the competition, with an enlarged 'morillo' scent gland found on top of the snout. A social hierarchy established by mass could infer its invariability for subordinate males for numerous months and even years. Although the 'alpha' has the most entitlement to females, he still gets cucked often by subordinates.

Interspecific Interactions

Capybaras are seemingly the most tranquil animal on the planet, being content to relax around, swim with or be a ride/chair for other rodents, domestic dogs plus cats, chelonians, lagomorphs, monkeys, birds and presumably rarely, even caiman - a natural predator.

These symbiotic relationships give way to mutualism (both parties benefit) and commensalism (one party benefits). Animals such as little monkeys or birds forage for bugs or ectoparasites like ticks - simultaneously cleaning the capybara's fur/skin. Other birds can hunt from the capybara's back, remaining stationary on top where any slow movement offers more time to observe with a higher view, or walk close next to it for a stealthy ambush.

Caecotrophy

Caecotrophy involves passing digesta through the gastrointestinal tract twice after consuming the caecotroph via coprophagia - eating own excrement. Caecotrophs are distinguishable from regular oval-shaped faeces that are left alone more, since they are paste-like and are generally eaten directly from the anus. It functions so capybaras can eat pounds of food a day (potentially over 8 pounds for the heaviest) without losing the caecal microbes responsible for fermentation after getting expelled.

The process 'recycles' lost nutrients to maximise absorption because the cellulose from forage is hard to digest. Due to caecal contents, caecotrophs have higher nourishment value, returning needed caecal microbes, protein, vitamins and minerals, than the standard excrement. Consequently, capybaras may need less protein supplementation than most other animals in captivity.

As their closest relative are guinea pigs, it is inferable that a similar 'colonic separation mechanism' exists within capybaras. Needed micro-organisms in the caecum mucous get trapped to retain them (accumulating via microbial reproduction), so fermentation can occur over long periods. Any less digestible material gets egested for caecotrophy, compensating for lacking the required digestive efficiency.