What to do when being besieged by killer whales? Sperm whales: Let's do it together | Nature Trumpet

Welcome to the 55th issue of the Nature Trumpet column. In the past half month, we have collected the following natural news and research worth reading:

1) Being attacked by killer whales, sperm whales resorted to pooping

2) Whales also go through menopause, and grandmothers are the backbone of the family

3) Great tit gestures: You go first

4) The big thief is back, this time it's Spider

5) The Javan tiger, which was extinct for half a century, is suspected to have reappeared

6) Chimpanzees raised in small spaces are trapped in an invisible cage in their hearts

Sperm whale poop attack

In order to resist the attack of dozens of killer whales, the sperm whale used its ultimate move - a big one !

Sperm whale: Yeah, I did it | Jodie Lowe / Naturaliste Charters

Recently, in the waters near Australia, a large group of killer whales were seen besieging a group of sperm whales. Not long after, a large black bubble emerged from the sea , which looked like sperm whale blood or a wounded sperm whale. But just when everyone was feeling sad, the killer whales suddenly turned around and left .

Sperm whales: Get in a circle, everyone! Get ready to poop! | Jodie Lowe / Naturaliste Charters

The marine biologists on the ship found it strange, and after checking the video, they found that the facts were completely different - the big black bubble was actually the feces of the sperm whale! Apparently, the sperm whales have found a new way to defend themselves. They gathered in a circle, with their heads close together, and pulled together. After pulling, they used their tails to stir the feces back and forth, so that the feces formed a small underwater storm and fanned towards the killer whales.

It is understandable that the killer whales gave up so quickly and left so resolutely - who wants to stay in a pile of shit? They rushed to the fresh sea water that was not yet flooded with shit without looking back, and the sperm whales escaped with shit .

Killer whales: Folks, it's a biological weapon! Turn around now | Jodie Lowe / Naturaliste Charters

Sperm whales are much larger than killer whales, so killer whales have little chance of winning against sperm whales. However, being besieged by more than 30 killer whales would be a tough fight, and some weaker sperm whales or small whales are likely to get hurt. Therefore, sperm whales want to teach everyone a military strategy - sometimes defense does not require super strong attack power, a super pile of shit will do.

Whale menopause

Whales also go through menopause , and these older females who are no longer fertile are very important to the population.

Females of five toothed whale species can live long after they lose their reproductive ability , which is a very rare feature among mammals. These females not only live longer than other whales of the same size, but also live longer than males of the same species. For example, female killer whales can generally live to 60 to 70 years old, while male killer whales only live about 40 years.

Killer whale mother and baby | Robert Pitman

In order to increase their chances of survival, animals generally seize the opportunity to give birth to offspring. However, female whales no longer reproduce after menopause, but still consume resources. Why is this an evolutionary advantage?

Recently, scientists finally discovered the reason. Older female whales are the backbone of the family . They can shelter and raise the younger generation. Their rich life experience can lead the entire family through difficulties. Losing the ability to reproduce is to avoid competition with young females . If mothers and daughters compete for resources for reproduction, daughters may lose, or even reduce their survival rate because they cannot get enough resources. Therefore, they no longer participate in reproduction and "give way" to their daughters.

Beluga whales are also menopausal whales | Mike Johnston / Wikimedia Commons

Humans share similar social structures with whales and are the only land mammal species where females live long after they stop reproducing. Human females spend an average of 42.5% of their adult lives postmenopausal, compared with just 2% for our wild relatives, chimpanzees. Human grandmothers, like whale grandmothers, are vital to the lives of their offspring. Yet a male bias persists in medicine and in every other field of research, and older women are woefully understudied.

tit gesture

Communicating with gestures isn’t just a skill reserved for primates; birds do it, too!

Recently, a new study found that great tits can communicate with each other by flapping their wings, just like humans use gestures to convey information . Scientists studied the behavior of eight pairs of great tits and found that before they brought food back to the nest box to feed their children, they would stop on a nearby branch and one of the birds would flap its wings toward the other. Every time this happened, the other bird would enter the house first, and the bird flapping its wings would follow behind.

A great tit (Parus minor) with new prey in its mouth propels its wings to let its mate in first | References [3]

Scientists believe that when great tits flutter their wings at their mates, they are saying "you go first" . Regardless of who gets back to the nest box first, the female bird always makes this gesture more frequently, signaling the male bird to go in first, and stops waving its wings after the male bird has gone in. Occasionally, when the female bird goes in first, it will not flutter its wings at the male bird.

Female great tit | Alpsdake / Wikimedia Commons

Scientists speculate that primates walk on two feet, which frees their hands and allows them to develop gestures to express various meanings; birds stand on branches with two feet, and the movement of their wings can be used to communicate with each other. Before this, people have discovered that great tits have complex calls and their language has grammatical rules like humans; this new study found that their visual communication is richer than we imagined .

Spider

There are male and female thieves in the spider!

Huahua: There is a traitor among us! | References [4]

Looking at this picture, you may find that there seems to be something strange mixed in with this flower - yes, in the middle is actually a pair of Guangxi crab spiders (Thomisus guangxicus).

This male and female thief was found in the tropical rain forest of Xishuangbanna. At that time, the male crab spider was lying on the back of the female crab spider, blending in with the flowers of the harp orchid. The male's appearance is very similar to the stamen, and the female's pale yellow appearance is the same as the petals. Together, they just pretend to be a flower. This can not only deceive the eyes of bird predators, but also just sit back and wait for those insects that feed on nectar to come over, so that they can easily capture the prey.

Many animals disguise themselves as plants | Geoff Gallice / Wikimedia Commons

Using mimicry to disguise oneself, pretending to be a flower, leaf, or branch, is not uncommon in the animal world; but this is the first time that researchers have discovered that females and males work together to camouflage , which is a match made in heaven. However, some researchers believe that this may just be a routine behavior of males climbing onto females during mating, and more research is needed to determine whether this is a unique camouflage.

Javan tiger traces

The Javan tiger was thought to be extinct decades ago, but sightings are still reported from time to time, so perhaps they still exist.

Photo of a Javan tiger taken in 1938 | A. Hoogerwerf / Wikimedia Commons

The Javan tiger was once the top predator on the island of Java, but due to human hunting and habitat loss, they almost disappeared in the 1940s. The Javan tiger was last seen in 1976 and has been considered extinct since then. Currently, the only Sumatran tiger left in Indonesia is only a few hundred.

Seven Javan leopards and a Javan tiger were killed during a hunt in 1900 | Wikimedia Commons

In 2019, in West Java, Indonesia, a local resident claimed to have witnessed a Javan tiger on a plantation. Scientists found footprints and claw marks there, and collected a hair from the fence it jumped over. Recently, after genetic analysis, this hair did contain genetic information of a Javan tiger .

In 2017, someone accidentally took a photo of a suspected Javan tiger, but it was only a suspicion. In general, there is too little information to analyze, and scientists cannot be sure whether the Javan tiger still exists on this planet . They have set up more wildlife cameras on the island, hoping to capture the traces of the Javan tiger.

Photos taken by eyewitnesses in 2017 | Ujung Kulon National Park

While searching for more Javan tigers, some people are worried about making the current findings public. The disappearance of Javan tigers is closely related to human hunting, and making the news that Javan tigers may not be extinct now may encourage poachers .

Chimpanzee's Invisible Cage

Even if the zoo's activity space becomes larger, chimpanzees will still lock themselves in a small invisible cage.

Before people became more aware of animal welfare, zoo animals were often kept in captivity | Wikimedia Commons

In 2004, a South African zoo expanded the living space for eight chimpanzees from a small 10x10 meter fence to a large space of 2,500 square meters, which also includes natural environments such as grass, trees, and streams. Recently, a study analyzed the lives of chimpanzees five years after the space was renovated, and they were shocked to find that although chimpanzees would move around in the entire environment, they still preferred to stay in the previous small space .

Another strange thing about the chimpanzees is that they always form a group that is very close to each other and the size of the group is almost the same as the small enclosure before. In other words, even if they have lived in such a large space for 5 years, there seems to be an invisible barrier that keeps them in the original 10x10 meter cage .

Chimpanzee | Fabian Horst / Wikimedia Commons

Researchers believe that after a long period of confinement in a small space, chimpanzees have developed a long-term psychological disorder , similar to the psychological effect of "learned helplessness" in humans. They have been in a situation that they cannot control or resist for a long time, and even if the environment changes later, this sense of helplessness still exists.

This research shows that in order to ensure the welfare of zoo animals, people need to do more than just give them more space to move around. They also need to do more research to understand their real needs and how the environment changes their behavior and psychology .

Author: Cat Tun

Editor: Mai Mai

Image credit: Jodie Lowe / Naturaliste Charters