Some interesting facts that science reveals

One past study theorized that giraffes more frequently consume bones as a result of nutritional stress. Seasonal changes that resulted in less foliage likely prompted the behavior, the study concluded.

Giraffes will rarely swallow much of the bones directly. Instead, they chew and suck on them using their saliva to dissolve nutrients, usually dropping the material once they're finished.

It's not just giraffes that supplement their diets with bones. Other herbivores, such as camels and cattle, also frequently scavenge the skeletal remains of animals.

Source: https://www.jstor.org/stable/3800701?seq=1#page_scan_tab_contents

Plants that went non-veg: Carnivorous plants occur in locations where the soil is too poor in minerals and/or too acidic for most plants to be able to grow.

Pitcher plants (or pitfall traps) are carnivorous plants whose prey-trapping mechanism features a deep cavity filled with liquid known as a pitfall trap.

Lyrebirds sing most in the winter (which is their breeding season). They sing to both proclaim a territory and to attract females, and these songs are not innate. Like all songbirds, lyrebirds are vocal learners. Male lyrebirds tend to learn their songs and, intriguingly, even their mimicry of other sounds, from older males rather than directly from their mimicked models.

What is clear, however, is that lyrebirds have a stunning ability to accurately mimic the sounds of the forests they inhabit. Most of their mimicry is of other avian species: calls, songs, wing beats, and beak claps, which they deliver in quick succession.

The avian sound-producing organ is the syrinx. Instead of the usual four pairs of syringeal muscles of other songbirds, lyrebirds have only three pairs. It is not known if this simplification makes them more adept at mimicry, nor is their motivation to mimic entirely clear.

While mimicry forms most of their vocal repertoire, lyrebirds also have their own songs and calls. While the “territorial” song can be melodious, the “invitation-display” call sounds mechanical to human ears. Twanging, clicking, scissors-grinding, thudding, whirring, “blick”-ing, galloping — these noisy or metallic sounds are the lyrebirds’ own and not mimicry. Nevertheless, they are often mistaken for that.

However, captive lyre birds have been found to imitate several things they hear like hammers, drills, and saws, sounds of machines and musical instruments they hear because they  are familiar with several forest sounds that have resemblance with these sounds.

Trees that exhibit rainbow colours: 

These colors are all natural. This peculiar tree is called Eucalyptus deglupta, commonly known as the Rainbow Eucalyptus, and also known as the Mindanao Gum, or the Rainbow Gum. The multi-coloured streaks on its trunk comes from patches of outer bark that are shed annually at different times, showing the bright-green inner bark. This then darkens and matures to give blue, purple, orange and then maroon tones.

 It grows naturally in New Britain, New Guinea, Ceram, Sulawesi and Mindanao. This tree is cultivated widely around the world, mainly for pulpwood used in making paper, and also for ornamental purposes. Older layers of these colors peel off, displaying the full rainbow array of hues. One theory says that each bark layer has a one-cell-thick transparent overlay. Over time, the clear layer becomes flush with different colors of tannins and the accumulation of these tannins as well as a depletion of chlorophyll may lead to the colorful bark layers. 

Goats that can climb trees and mountains :  Just some goats who’ve been climbing Argan trees in Morocco for hundreds of years

When food is scarce and when only food they get is from argan trees which produce juicy fruits, goats have to adopt in order to survive! And these challenges made them to climb even harder and taller trees as well.

Worms that eat themselves in order to survive:

Ribbon worms normally consume  crustaceans and molluscs as their main source of food.

Ribbon worm is another name for the Nemertea which are a branch of invertebrate animals. Usually less than 20 centimetres long and only a few millimetres wide, they are typically worm like creatures that also look flat. Some have been known to grow up to 60 metres long!

If food cannot be found, some ribbon worms will go ahead and eat themselves! It is claimed that they are able to consume 95% of themselves and still survive thereafter. The peculiar thing is that the ribbon worm is in fact poisonous for other animals.

Some animals can survive when eaten by their predators and can come out of their guts alive!

In 2012, biologists on an expedition to East Timor in southeast Asia spotted a brahminy blind snake wriggling out of somewhere quite unexpected: the rear end of a common Asian toad.

Mark O'Shea from the University of Wolverhampton in the UK and his colleagues witnessed the unusual event by chance after finding the pair under a rock. It is the first account of prey surviving digestion by a toad and of an animal as big as a blind snake emerging from a digestive tract alive.
Larvae and small marine invertebrates can pass through some predators unharmed. But larger prey items are likely to be chewed to death as soon as they enter an animal's jaws. Even if they somehow dodge this fate, travelling down the predator's throat in one piece can be a tight squeeze.
And there are bigger problems ahead. Most prey would not be able to survive exposure to the harsh gastric acids that break down tissue in a predator's stomach. Coping with the lack of available oxygen deep in the digestive system is another challenge.
For prey swallowed by a toad or a bird, however, chances of survival might be a little higher. These animals often push food to the back of their throat before swallowing it, which may boost the odds of safe entry into the digestive system.
This almost certainly helps explain how an incredibly toxic amphibian – the rough-skinned newt – can survive being swallowed by a frog. Once it enters the frog's stomach, the newt's toxins kill the frog before its digestive juices can really get to work. Then the newt simply has to crawl back up the dead frog's throat and out of its mouth.
But the brahminy blind snake did not kill its host – and it took a much longer path, through the gut, to exit the toad.
The snake may be better equipped for the journey than most species. With a long, slender body just a few millimetres wide, it effortlessly burrows through tiny holes and crevices in its environment. Passing through the narrow confines of a toad's digestive tract should not be too much of a challenge in principle.
O'Shea thinks the snake crawled through the toad's gut instead of simply being carried through by muscle contractions that move food along.
One factor that might have made that journey easier is the toad's earlier dining habits. It may not have eaten much in the hours before it swallowed the snake, meaning the path through its gut might have been clear. If so, the trip would have been a quicker one, reducing the snake's exposure to digestive acids.
But its skin was probably the biggest lifesaver. The closely-knit, overlapping scales that help blind snakes move on land would likely block gastric juices, preventing them from reaching delicate tissues and organs. The scales of other snakes come apart slightly when they move, so would not have the same protective effect.
Almost certainly the biggest problem the blind snake had to deal with was a prolonged lack of oxygen. As an underground dweller and due to its small size, it needs less air to survive than many animals. But still, there is a limit to how little it can tolerate.
But sadly, the worm died five hours it emerged out alive!

In an experiment published in 2011, Shinichiro Wada from Tohoku University in Japan and colleagues fed tiny land snails, Tornatellides boeningi, to Japanese white-eye birds to see whether they could pass through their digestive system intact. About 15% survived the journey, which took between 20 and 120 minutes, proving for the first time that land snails can survive digestion. "Snails can endure the short digestive time without being fully exposed to the digestive juice.
The snails' resistance is likely due to their shell, which provides them with natural armour. But Wada and his colleagues found that size was also key to survival. The shells of the species they examined, roughly 2.5mm wide, were recovered from bird faeces intact whereas those of larger species were usually broken into pieces. They think the snails may also produce mucus as additional protection from the acidic environment, but that idea still needs to be tested.
Larger snails seem to occasionally survive ingestion too, though. Jasna Simonova from Charles University in Prague, Czech Republic found that land snails with shells up to 17mm in diameter sometimes emerged alive from a variety of bird species. These much larger shells were left undamaged by digestion.
Gut voyager is a species of nematode worm called Caenorhabditis elegans. Hinrich Schulenburg from the University of Kiel in Germany and his team found nematodes in the intestines of slugs collected in northern Germany. Later they were surprised to find the worms alive in the slugs' faeces.
"They seem to be taken up orally which is unusual because slugs have a grinder organ that should destroy them," says Schulenburg. "And we don't know how they survive the acidic conditions." Other types of nematodes have been found inside slugs and earthworms, but they are parasitic and usually enter through a puncture in the gut.
The team was also surprised to find that it was not just juvenile nematodes that survived the journey: adults did as well. Larvae have a tough outer layer to protect them during development, so are usually able to withstand harsher conditions than their fully formed elders.
Females of a species of seed shrimp can also survive in the gut of white sucker fish, while mussels can pass through common sea anemones and avoid being digested if their shells are sealed shut.
Survival may also be aided by digestive systems that favour high prey intake over digestive efficiency, like those of some birds. Food passes through these animals faster, and some of it might emerge unprocessed.

Male clownfish change sex when their partner dies, to take on their role of protecting territory and their fellow fish. 

A new study has revealed the lengths that female clownfish will go to in defending their homes. 

Experts from two universities in Paris have researched the behavioural, physiological and hormonal changes in anemonefish, or clownfish, over several years off the island of Moorea in French Polynesia.

Clownfish live in tropical climates on anemones where they stay their entire lives.

Male fish tend to look after the eggs and fan them while females act as security guards, issuing warning calls and even launching attacks. 

It has been known for some time that the distinctively striped orange fish, become female if their mate is eaten or dies. If the female gets predated upon or dies, the male  then changes sex with the help of hormones and becomes a reproductive female, the largest sub-adult male becomes her new mate with whom she lays eggs. 

Citations: 

1. Piraino, Stefano; F. Boero; B. Aeschbach; V. Schmid (1996). "Reversing the life cycle: medusae transforming into polyps and cell transdifferentiation in Turritopsis nutricula (Cnidaria, Hydrozoa)". Biological Bulletin. Biological Bulletin, vol. 190, no. 3. 190 (3): 302–312. JSTOR 1543022. doi:10.2307/1543022.