37 years later, killer whales are using dead salmon as hats again | Nature Trumpet

Welcome to the 71st issue of the Nature Trumpet column. In the past half month, we have collected the following natural news and research worth reading:

1) Nearly 1,000 smuggled animals finally returned home

2) 37 years later, the killer whale put on the salmon hat again

3) Crabs’ brains also feel pain

4) Wolves, carnivores, love to eat nectar

5) Cat videos can help you tell if they are in pain

6) Killer whales work closely together to hunt the world’s largest fish

Lemurs and tortoises return home

Nearly a thousand smuggled lemurs and tortoises can finally return home.

In May this year, Thai police discovered 1,117 illegally trafficked live animals and animal carcasses , the largest anti-animal smuggling operation in Thailand's history. These animals include ring-tailed lemurs, brown lemurs, spider tortoises and radiated tortoises, all of which are endangered species unique to Madagascar and listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, prohibiting the capture of any wild individuals and prohibiting international trade.

Ring-tailed lemurs became a celebrity animal thanks to the animated film Madagascar | References [1]

Fortunately, 963 of the animals are still alive, and the first group was recently repatriated to Madagascar , where they will be kept in a rescue center until their health is confirmed before being released back into the wild.

Thailand is a major transit point for wildlife smuggling, with the animals eventually being trafficked to the black markets of China and Vietnam, where they are sold as exotic pets for high profits. In this smuggling case, six people were arrested for trafficking endangered animals and could face up to 15 years in prison and a fine of 1.5 million baht (about 320,000 yuan).

Tortoises seized by Thai customs | References [1]

As the crackdown on illegal animal trafficking intensifies, more and more animals are seized. After this case, Thai customs seized another red panda and 86 other smuggled animals. However, the animals that can be seized and rescued are just the tip of the iceberg, and the actual number of smuggled animals may be much larger than this .

Dead salmon hat

Fashion is a cycle - the killer whales agree.

In 1987, a female killer whale on the west coast of the United States suddenly began to put dead salmon on her head . Within a few weeks, the salmon hat became popular among killer whales, and other killer whales followed suit. However, the trend came and went quickly. By the summer of the following year, the salmon hat was out of fashion, and almost no one had seen killer whales wearing salmon hats since then.

In 2019, drone footage captured killer whale A99 wearing a salmon hat, but it didn't become a trend | Ocean Wise

Unexpectedly, 37 years later, near Washington State, the killer whale trend has revived again - recently someone found a male killer whale numbered J27 wearing a salmon cap. Ten days later, scientists who were collecting data in the same sea area encountered another killer whale wearing a salmon cap.

Why did killer whales become so fond of wearing salmon hats? Scientists think it might be for fun . Southern Resident killer whales mainly feed on salmon, and with salmon resources plentiful recently, killer whales might want to have some fun while eating. Once one killer whale thought it was fun, other killer whales followed suit, and the salmon hat became popular.

Killer whales chasing salmon | Oregon State University / Wikimedia Commons

The salmon cap may also have a practical purpose - scientists speculate that killer whales carry dead salmon on their heads to save for later consumption or to share with other killer whales . Killer whales are highly social animals that often hunt together and share food with each other. They will also split a salmon into two or three and share it with their family. They may carry dead salmon on their heads to save them for sharing with their companions.

Crabs also feel pain

Crabs can also feel pain.

In previous studies, scientists have used painful stimuli on crabs, lobsters, etc., and they will try to avoid it. Scientists have speculated that they may feel pain, but no one knows what is happening in their brains. In a new study, researchers connected electrodes that measure brain activity to shore crabs for the first time, and then used mechanical and chemical stimulation to record the responses of the crabs' central nervous system.

Researchers connected electrodes to the crabs' brains to record their neural responses | Eleftherios Kasiouras

The results showed that after applying a painful acetic acid to the crab's soft tissue, the crab's brain activity increased significantly, indicating that there are pain receptors in the soft tissue that can send nerve signals to the brain. If mechanical stimulation is applied to the crab's body, their nerves will also have similar activities. In comparison, the nerve response caused by mechanical stimulation is stronger and lasts for a shorter time.

Under EU animal welfare laws, mammals such as cattle and sheep must be killed humanely, but crustaceans are not protected and can currently be cut up alive or slowly cooked while still alive. However, this study shows that crustaceans can also feel and respond to pain, and they also need a more humane death when they are handled and cooked.

Wolves eating nectar

It turns out that wolves also love sweets.

The Ethiopian wolf is a canine species that lives in Africa at an altitude of more than 3,000 meters. There are less than 500 of them left, making it the most endangered carnivore in Africa. Recently, researchers have discovered that as a carnivore, they actually love to eat nectar.

Ethiopian wolves love nectar | Adrien Lesaffre

Researchers from the Ethiopian Wolf Conservation Program have observed that they lick the nectar of the multi-leafed torch flower , and this behavior is very common, with some individuals eating nectar from up to 30 flowers in one trip. Eating nectar is also a skill passed down from generation to generation, and adult wolves will take their pups to the flower fields to teach them how to eat.

A wolf that has just finished eating nectar, with pollen all over its mouth and nose | Adrien Lesaffre

For the leafy torch, having wolves eat its nectar is also a good thing. While eating the nectar, the wolf's mouth and nose will be covered with pollen, and when they visit the next flower, the pollen will be transferred to another flower. The interaction between the Ethiopian wolf and the leafy torch is the first known example of a large predator interacting with a plant as a pollinator .

Feline Pain Scale

You can tell whether the cat is in pain by looking at the video!

Cats are very good at hiding their pain to avoid being spotted by predators. Humans are able to express their pain directly, but cats are much more subtle. When they are in pain, they may just remain motionless or indifferent to the environment. If you don't know your cat well, you may not be able to tell that your cat is in pain at the first sight.

The cat in the video is breathing rapidly, huddled in a corner, and has lost interest in the surroundings. It seems to be in pain. | References [5]

In a new study, researchers from the University of Montreal and City University of Hong Kong recorded 60 hours of video of cats, documenting the behavior of cats of different breeds, ages and genders when they were experiencing various types of pain . These cats came to the hospital for treatment, and after a few seconds of video recording, the veterinarian would give them pain relief.

The cat in the video is curled up and hunched over, which is also a sign of pain. | References [5]

Based on these videos, the researchers created a cat pain scale, selecting 24 of the most clear and representative videos , with an average length of 33 seconds, including a series of behaviors such as restlessness, retreat and dodge, repeated licking of wounds, and pretending to sleep. Prior to this, scientists had created a cat "behavior map" containing 24 specific behaviors related to pain, and this video can correspond one-to-one with the behavior map.

The videos have been publicly released on the video website , and researchers hope that they can help cat owners and veterinarians identify cat pain more quickly so that every cat can receive timely pain relief and treatment.

Killer whale roundup

A group of killer whales in the Gulf of California have developed a strategy to deal with whale sharks - the largest fish in the world.

A stunned whale shark was flipped over by a killer whale | Kelsey Williamson

Researchers recorded four cases of killer whales hunting whale sharks and found that the killer whales cooperated skillfully and were well-trained. First, a killer whale was responsible for hitting the underside of the whale shark at high speed, knocking the whale shark unconscious, and then they worked together to turn the whale shark over with its belly facing up. At this time, the whale shark entered a state of tonic and could not move.

After the whale shark is controlled, the killer whales can easily attack the whale shark's pelvic area, causing the whale shark to bleed profusely, and then they can start to enjoy the food, including the nutritious liver. But this group of killer whales does not seem to be so keen on the liver, and the video does not record them eating the whale shark's liver.

When a whale shark flips over and becomes immobile, killer whales can attack its pelvic area | Kelsey Williamson

In the four hunts, an adult male killer whale named Moctezuma participated in three of them. Researchers speculate that Moctezuma may be the organizer of the hunt, or he may be teaching other killer whales the hunting strategy of whale sharks, but it is not certain yet.

Whale sharks are over 10 meters long, and the longest can reach 18 meters, while killer whales rarely exceed 10 meters in length. By acting in coordination , killer whales have become invincible killers in the sea, and can defeat animals that are larger than them. Researchers cannot be sure whether hunting whale sharks is a traditional skill of this group of killer whales, or a new tactic they have just developed in recent years; but this shows that whale sharks are also one of their food sources. If climate change and human influence lead to the disappearance of whale sharks, the killer whale population will also be affected.

References

[1] https://phys.org/news/2024-11-thailand-trafficked-lemurs-tortoises-madagascar.html

[2] https://www.livescience.com/animals/orcas/orcas-start-wearing-dead-salmon-hats-again-after-ditching-the-trend-for-37-years

[3] https://www.mdpi.com/2079-7737/13/11/851

[4] https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.4470

[5] https://journals.sagepub.com/doi/10.1177/1098612X241260712

[6] https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1448254/full

Author: Cat Tun

Editor: Mai Mai