Animals – Page 2

Imitation Eyes

Eyespot mimicry is used throughout nature to defend against predators

Mimicry is a useful method of disguise employed by a variety of species for both offensive and defensive reasons. Eyespot mimicry is frequently used defensively where a decoy set of eyes are used to help a vulnerable species. This is especially true of creatures lower down the food chain but you can find it higher up as well. Tigers have spots on their ears that look like eyes when they vulnerably lean over to drink water, giving the appearance that they’re still on the lookout.

Sometimes the decoy eyes serve as a scare tactic, such as in Batesian mimicry. The owl butterfly has owl-like eyes on its wings. It’s believed that in being able to flash the eyes of an owl the owl butterfly is able to scare small predator birds into thinking a large owl (who eats such birds) is present. In other species the eyespots are a distraction. In flashing a set of eyes a species can surprise & confuse a predator just long enough to escape. Some species use eyespots to draw attention away from their more critical body parts. The foureye butterflyfish for example has dark eyespots near its tail (which is less important) which draws attention away from its head (which is very important). When feeling threatened it can even swim backwards making its tail seem more like the head and vice versa.

The owl butterfly whose eyespots mimic that of an owl to frighten away predators.

The foureye butterflyfish, eyespots by its tail.

Eyes looking out, for you

The northern pygmy owl of North America has eyespots on the back of its head, helping to mislead predators into thinking they are being closely watched. In 2016 an experiment was conducted in Botswana of painting eyes on the rumps of cows to prevent lion attacks. The cows with painted eyespots were less susceptible to predation by lion attacks than normal cows, as the lions may have felt they were being watched.

Finally, for those who believe in the supernatural malevolent force of the “evil eye”, you have some options of magical defensive eyespots. The nazar (a blue & white eye-like amulet) has been used for thousands of years from Turkey through to India and elsewhere. Similarly the hamsa (which also features an eye but sitting in the palm of a hand) has been used around the Middle East for a similarly extended period of time.

Both symbols are said to attract the negative energy of evil eye attacks, and destroy/repel them. If your nazar is cracked then it’s “proof” that it has worked, and of course you’re supposed to buy a new one. After all, you have to keep your magical eyespot functional.

Venomous vs Poisonous

Venomous species are aggressively toxic while poisonous species are defensively toxic.

The difference between venomous and poisonous is a difference of evolutionary strategies. It’s a difference of offense vs. defense, actively toxic vs. passively toxic.

Venomous

Venomous species use an active strategy to inflict toxins. As such they always have some sort of toxin delivery system such as fangs, barbs, stingers, spurs, etc. as a way to inject their venom. They are predators that use venom to incapacitate their prey.

Poisonous

Poisonous species defensively pass on their toxins when they are touched or eaten. This passive approach is why toxic plants are categorized as poisonous because, well, most plants don’t actively move around trying to attack prey.

As for poisonous animals the poison is frequently secreted through their skin as in the case of the poison dart frog (who got their name because their poison was sometimes used by indigenous tribes of Central/South America to make poisonous blow darts).

Poisonous species use their toxin to deter predation. Sometimes a predator only needs to be poisoned once to learn to never attack that poisonous species again. For others, a particular poison doesn’t leave the predator with the option of a second attack as the result is death.

In Short:

Venomous: when something toxic bites/touches you
Poisonous: when you bite/touch something that is toxic

Added info: While generally mutually exclusive, there are a few species that are both venomous and poisonous. One example is the Tiger Keelback snake of East Asia. It has fangs to inject toxin but more frequently it employs a defensive strategy and stores toxin in nuchal glands. Any predator that bites into the snake’s neck will be poisoned. The toxin they use for either strategy is not produced by the snake, but rather it’s acquired by eating poisonous toads.

The Tiger Keelback is a rarity in that it is both venomous and poisonous

Lobster Immortality

Lobsters are not immortal, but are still pretty special

To point out that lobsters aren’t immortal may seem unnecessary unless you’ve previously seen internet buzz stories that lobsters might be able to live forever. Different species of lobsters have different lifespans but male European lobsters typically live around 31 years and females live around 54 years. This is far from forever. Aside from being killed by fishing, how do lobsters die?

One of the remarkable things about lobsters is that, unlike humans and most other animals, lobsters continue to get bigger as they get older. Humans get to an adult size and stop getting taller, but for lobsters there is no upper limit on how large they can grow to be. Another remarkable thing about lobsters is that they don’t show many signs of aging like we do. They don’t get weak, or slow down, or stop reproducing as they get older. Part of this longevity is how their cells divide. Unlike humans, lobsters continue to produce an enzyme called telomerase which helps repair damaged chromosomes during cell division. Having undamaged chromosomes allows lobsters to avoid the effects of old age and to keep living normal lives … until they don’t.

Moulting

Lobsters are invertebrates with exoskeletons. In order for a lobster to get larger as it ages it has to shed its current exoskeleton and grow a larger new one. It basically runs out of room in its shell and needs to start a new roomier one. Therein lies the problem. While there may be no physical upper limit as to how large a lobster can get, every moulting takes more energy than the time before and eventually a lobster just doesn’t have the energy to shed its exoskeleton. 10-15% of lobsters die during the moulting process because they run out of energy. For those older lobsters who just stop moulting, they begin to accumulate damage to their shells and eventually die.

An added bonus: Another question the internet seems to ask is if lobsters feel pain. Yes they do, and being boiled alive is not enjoyable for lobsters (it’s illegal to boil a lobster alive in New Zealand, Switzerland, and parts of Italy).

To end on a high note, while most lobsters are typically dark bluish greens and greenish browns, genetic mutations can produce some really spectacular looking lobsters. Similar to most animals, albinos are very rare (1 in 100 million). Unlike most other animals though, lobsters have another extremely rare coloration (1 in 100 million) where the lobster is pastel blues & subtle pinks called “cotton candy”.

Lightning Bugs

Lightning bugs glow for a variety of reasons through a chemical reaction

Lightning bugs, fireflies, glowworms, or whatever else you may call them based on where you live, are beetles (not bugs) known for their summertime bioluminescent light shows. There is a great deal of diversity among lightning bug species. Most are nocturnal (but not all), most can create bioluminescent light (but not all). In some species both the males & females can glow (but in others only one or the other can glow). They also produce different colors (light green, yellow green, red), depending on the species.

Light show

Lightning bugs have a special organ to produce light, which happens when luciferin (a chemical compound) and luciferase (an enzyme) mix. Both luciferin & luciferase are named after Lucifer, which is the Latin name for the planet Venus meaning “light bringer”, because Venus can appear just before dawn in the night sky. Only later did Lucifer also come to mean Satan.

Why lightning bugs glow varies by species as well as age. In larvae they can glow as a warning to predators telling them “I don’t taste good, don’t eat me.” In adults it’s primarily for mating purposes. Adult males puts on a light show to attract females. Females reciprocate with a glow of their own.

It’s worth noting that the females of the Photuris genus of lightning bugs are known as the “femme fatale lightning bugs” because they imitate the light pattern of other species to attract & then eat the males. Of this genus, the species Photuris pensylvanica is the state insect of Pennsylvania.

The Hippos of Pablo Escobar

In the Colombian jungle, Escobar’s hippos wander.

During his reign as the head of the Medellín Cartel drug empire, Pablo Escobar’s net worth was in the tens of billions of dollars. As such, Escobar could & did purchase a variety of extravagant items. He also spread the money around the local community. The venn diagram of these types of spending overlap with his personal zoo.

In the 1980s Pablo Escobar built a zoo for himself at his countryside estate Hacienda Napoles. He allowed schoolchildren to see the animals on class trips. After Escobar was killed, and Hacienda Napoles was confiscated by the government, most of the animals were dispersed to other (actual) zoos. All of the animals found new homes except 4 hippos which continued to thrive and today have fruitfully multiplied to over 80 hippos. These wild Colombian hippos are becoming a real problem in the region because they aren’t easily contained to just one area, they eat and poop in large quantities, they don’t have many predators, and any solution to the problem (aside from killing them, which the general public doesn’t want) costs money that the government doesn’t want to spend.

Dogie, Not Doggy

In American Western slang, a dogie is a calf (not a dog).

The 1937 film Git Along Little Dogies features the singing cowboy, Gene Autry. He and others sing a variety of classic western songs such as Red River Valley, She’ll Be Comin’ Round the Mountain, Oh! Susanna, and others. They even sing some of them as a medley with lyrics on the screen for the audience to sing along.

The movie’s title though, may leave some wondering exactly what a “dogie” is. The movie was named for a song of the same name, which existed as early as 1893. In the American West a dogie is slang for a stray or motherless calf. Nobody is exactly sure where the term came from but in the book Western Words, author Ramon Adams speculates that because small calves who are weened from their mothers too soon are unable to properly digest coarse grass, the resulting swelling of their bellies resembled a batch of sourdough starter in a sack. This became “dough-guts” and eventually just “dogies.”