Nudibranchs, the Butterflies of the Sea, May Also Be Ruthless 'Kleptopredators'

Wilfred Hdez, Flickr // CC BY 2.0
Wilfred Hdez, Flickr // CC BY 2.0

There's nothing ruder than taking someone's food without asking—except maybe waiting until they're finished eating and consuming them whole so you can get those extra calories. As Gizmodo reports, this way of feeding, dubbed "kleptopredation," may be how at least one group of mollusks prefers to take its meals.

In their recent study published in the journal Biology Letters, European scientists explored the eating habits of nudibranchs. Nudibranchs are soft-bodied sea slugs that are sometimes called "butterflies of the sea" for their colorful appearances. The striking sea creatures are also effective carnivores, preying on sponges, anemones, and occasionally other nudibranchs.

For their experiment, the researchers placed members of a nudibranch species known as the pilgrim hervia (Cratena peregrina) in a tank with one of their favorite treats: hydroids, a relative of jellyfish. Plankton were also present for the hydroids to eat. When given a choice between the empty-stomached hydroids and hydroids that had just consumed or were in the middle of consuming plankton, the nudibranchs chose the well-nourished prey in 14 out of the 25 trials. According to the study authors, plankton can make up at least half of the nudibranch diet this way even though it's being preyed upon indirectly. This means that a nudibranch's interactions with a plankton-loving cnidarian could go beyond the basic predator-prey relationship.

Though the nudibranchs' preference for hydroids that had eaten plankton wasn't random, that doesn't automatically mean it's a case of kleptopredation. It's possible that the sea slugs simply chose the prey that looked larger, or they went after the hydroids that had just fed because the stinging cells the cnidarians use to hunt were worn out and therefore less harmful.

If more research does support the theory that the animals target full prey before giving them a chance to digest, that would add the unique predation method to the already impressive roster of nudibranch abilities.

[h/t Gizmodo]

Need to Cure of Case of Cabin Fever? Try Backyard Birding

Baltimore orioles are colorful spring migrants.
Baltimore orioles are colorful spring migrants.
Brittany Tande/iStock via Getty Images

No matter how many virtual tours and online classes you take, it's hard not to go a little stir-crazy after weeks of social distancing. If you're already sick of activities that require you to stare at a screen, consider seeking out real-life entertainment in your backyard. As Auburn Pub reports, the New York State Department of Environment Conservation is recommending that residents take up birdwatching during the COVID-19 pandemic. However, they stress that it's important to continue to practice social distancing.

Zoos, beaches, and even some national parks are currently closed to the public, but you don't have to travel far to get your daily dose of nature. Spring is in full bloom, and many bird species are currently in the midst of migrating from their winter homes down south to northern states. That means that even urban areas like New York City are becoming places for birds to nest and raise their young.

Local parks are great spots to observe birds while keeping your distance from others, but a trip off your property isn't necessary. If you have a backyard, or even just a tree on the street outside your home, you can watch birds from a patio, balcony, or through a window.

Birding is more than just a way to pass the time when activities are limited. A 2017 study from the University of Exeter found that being able to see birds around your home may reduce levels of stress, depression, and anxiety. If you use birding as an excuse to get out of the house, those benefits may be even greater as being outdoors in general has been shown to boost several facets of mental health.

If you're interested in using your time in isolation to get into birding, there are many resources online you can use. Watch this beginner's guide to birding and read these facts about the birds in your backyard before you get started.

[h/t Auburn Pub]

Beyond Tiger King: 10 Fascinating Animal Documentaries You Can Stream Right Now

A scene from Catwalk: Tales from the Cat Show Circuit (2018).
A scene from Catwalk: Tales from the Cat Show Circuit (2018).
Markham Street Films

By now, you've probably already binged Netflix's bewilderingly bonkers docuseries Tiger King (2020). If you're ready to dive deeper into the animal kingdom, there are plenty more documentaries out there. From wildcats to whales, these 10 films will take you on a cinematic adventure around the world, introducing you to captivating creatures and the people who love them.

1. The Tigers of Scotland (2017)

The Tigers of Scotland (2017) brings viewers as up close and personal as possible with a small but mighty feline: the Scottish wildcat. The film delves into the efforts to conserve the disappearing Highland tiger, as well as the history and mythology surrounding the UK’s only “big cat.”

Watch it: Netflix, Amazon, iTunes

2. Ghost of The Mountains (2017)

This 2017 Disneynature documentary will transport you to the world’s highest plateau in search of a family of snow leopards. These cats are famously tough to find, so Ghost of the Mountains offers viewers behind-the-scenes footage of what it’s like to track the elusive beasts.

Watch it: Netflix, Google Play, Youtube

3. Catwalk: Tales from the Cat Show Circuit (2018)

This delightful documentary takes you deep into the competitive cat show circuit. Both charming and at times cutthroat, the film brings viewers on a journey to see which of the many cool cats and kittens will be crowned Canada's top cat.

Watch it: Netflix

4. Kingdom of the White Wolf (2019)

Follow along as a National Geographic explorer and photographer embeds with a white wolf pack in the high Arctic. These wild wolves aren't used to seeing people, giving the filmmakers—and audience—an intimate window into the pack's daily lives and familial bonds. In addition to showcasing captivating footage of the animals, the three-part docuseries also features sweeping views of the starkly beautiful Ellesmere Island.

Watch it: Disney+, YouTube TV

5. Dogs (2018)

This docuseries, which highlights various dogs and their humans from around the world, celebrates the bond between people and their pups. But it’s more than just a montage of feel-good moments about humankind’s best friend: Each episode tells a broader tale about the human condition, crafting an emotional narrative that pulls at the heartstrings like a puppy tugging on a toy.

Watch it: Netflix

6. Dancing with the Birds (2019)

These birds will put your dad moves to shame. Watch the male avian performers shimmy, shake, and flash their feathers while attempting to woo their female mates. The documentary, narrated by Stephen Fry, offers a colorful look at the wonderfully wacky world of bird mating rituals.

Watch it: Netflix

7. Honeyland (2019)

This documentary follows Hatidze Muratova, one of the last wild beekeepers in a remote village in North Macedonia. She lives with her ailing mother, nurturing a traditional way of beekeeping passed down through the generations and striking a balance between making a living and maintaining ecological balance. But everything changes when a nomadic family settles nearby, threatening Muratova’s way of life. The resulting story is both sweet and stinging.

Watch it: Hulu, Amazon Prime, YouTube, Google Play

8. Virunga (2014)

This 2014 documentary highlights the park rangers fighting to protect the Congo’s Virunga National Park, home to the critically endangered mountain gorilla. As poaching and oil exploration threaten the park, the rangers and conservationists risk their lives to guard the rare creatures that inhabit it.

Watch it: Netflix

9. Harry & Snowman (2016)

In the 1950s, Harry deLayer bought Snowman, a run-down plow horse destined for slaughter, for just $80 at an auction. Within months, the two were taking the show jumping circuit by storm, launching both horse and rider to new heights. This documentary tells the story of the friendship the two developed, and chronicles their lives both in and out of the competitive spotlight.

Watch it: Amazon Prime

10. The Whale and the Raven (2019)

The waters around Canada’s Great Bear Rainforest are a haven for whales, who feed and find refuge in the quiet channels. With stunning visuals, this documentary highlights the tension of a community’s push to protect its wild places against the pressures of the ever-encroaching natural gas industry.

Watch it: Amazon Prime

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