Friday, December 15, 2023

Cats prey on hundreds of threatened, endangered species: Study




















SPADE AND KEEP THEM INDOORS
SPADE FERAL CATS

Miranda Nazzaro
Wed, December 13, 2023


Cats prey on hundreds of threatened, endangered species, with scientists categorizing felines as part of the most “problematic invasive species in the world,” according to a new study.

In an assessment of the diet of 533 free-ranging cats — both owned and unowned cats with access to the outdoors — researchers found a total of 2,084 species eaten by cats, of which 347, or 16.65 percent, fall into the category of “conservation concern.” This includes species listed near threatened, threatened or extinct on the IUCN Red List of Threatened Species.

In the study, published Tuesday by the journal Nature Communications, researchers said cats have a “generalist diet” and described them as “opportunistic predators and obligate carnivores.” As a result of certain physiological demands in cats, the species are known to hunt for a wide variety of animals.

In total, cats eat 981 bird species, followed by 463 species of reptiles, 431 mammal species, 119 insect species, and 57 amphibians.

About 7.1 percent of bird species that are a part of cats’ diet fall on the IUCN Red List, along with about 4.9 percent of mammal species and 2.7 percent of reptiles, researchers said.

Cats have the largest impact on endangered species on islands when compared to continents, the study found. Just more than a quarter, or 25.22 percent, of all cat-consumed species on islands were species of conservation concern, while only 8.62 percent of cat-consumed species on continents fell into this category.

Researchers said they discovered records of cats eating 11 species across Australia, Mexico, the United States and New Zealand that have since been recategorized as extinct in the wild or extinct, with many due to island endemics.

“Our study sheds light on the predatory habits of one of the world’s most successful and widely distributed invasive predators,” researchers wrote, adding that cats are essentially eating most things directly in their environment and may not be as discriminate with their diet choices as one might think.

“Cats are largely eating what is present and if a species is missing in the diet analysis it is likely that the prey is either absent or rare in the surrounding environment, difficult for cats to catch and hence of low profitability, or the prey is difficult to detect (e.g., invertebrates) in scat or digesta studies,” researchers continued.

The study builds upon previous findings about cats’ impact on surrounding animals, with some groups calling for better pet ownership to control wildlife losses. An analysis released in June by the Biodiversity Council, Invasive Species Council and Birdlife Australia found more than 320 million native animals are killed by cats in Australia every year, an increase from 241 million in 2020.


In case you weren't aware, outdoor cats are stone-cold killers

CBC
Thu, December 14, 2023 

A Cuban blue cat is pictured in Havana, Cuba in 2011. A new study tallies how many species cats have been recorded to hunt or scavenge worldwide. (Desmond Boylan/Reuters - image credit)


There are differing opinions on cats' personalities and behaviour: They're affectionate, they're aloof, they love you, they hate you.

Then there's the undeniable fact of what they become when left to roam free outside: indiscriminate, stone-cold killers.

A new study has found cats roaming free prey upon almost any animal, reptile, insect, and amphibian around the world – their hunting so prolific and so successful, the authors found, that it poses a legitimate threat to global biodiversity.


"What's shocking is just the indiscriminate nature of their hunting," said Christopher Lepczyk, the paper's lead author and an ecology professor at Alabama's Auburn University.

"If there is a food source that they can obtain, they will."

Cats are seen in a hole in a wall at a park in Nanjing, Jiangsu province, China on March 29, 2018.

Cats are seen in a hole in a wall at a park in Nanjing, Jiangsu province, China on March 29, 2018. (Stringer/Reuters)

The team of scientists from Australia, New Zealand and the United States created the latest report by looking at more than 500 previous studies to better understand which animals free-ranging cats will eat globally.

The paper, published in Nature Communications, found domestic and feral roaming cats will hunt or scavenge more than 2,000 species from tiny hatchling turtles to hulking dairy cows.

Almost half of the victims were birds, followed by reptiles and mammals. Lepcyzk said they also found a surprising number of insects, including emperor dragonflies and endangered monarch butterflies.

The menu includes nearly 350 species that are threatened, vulnerable or endangered — including the little brown bat and green sea turtles. Cats proved especially lethal on islands that have evolved without as many natural predators.

"[Cats] don't have a big preference in terms of what they're eating, if it moves." said Lepczyk.

Most victims were small, weighing less than five kilograms, but cats scavenged the carcasses of animals much larger than they could kill themselves – like camels. The paper said the cats also ate spoiled and wasted food people left outside.

In all, the paper said the cat is among the most successful and "problematic" invasive predators in the world — a claim that's been made about cats before.

Last year, the Polish Academy of Sciences — a state-run scientific institute — classified domestic cats as an "invasive alien species,'' citing the damage they cause to birds and other wildlife.

Wojciech Solarz, a biologist at the centre, told the Associated Press there's a growing scientific consensus that domestic cats have a harmful impact on biodiversity given the number of birds and mammals they hunt and kill.

The criteria for including the cat among alien invasive species "are 100 per cent met by the cat,'' said Solarz.

Author recommends cats be kept inside

Lepczyk, 53, has spent decades researching the feline diet and the last five years compiling the database with his co-author, Jean E. Fantle-Lepczyk — who is also his wife.

He said studying what cats eat globally made him see his own cats differently. He and his wife have two: Mochi, a long haired siamese, and Ahi, an orange tabby – both named after Japanese foods found in Hawaii, where the family lived for seven years.

"Even watching my cats indoors, you can tell they're predators," he said. "They're actively interested in things that move."

A cat is seen during the International Cat Show in Minsk, Belarus on Dec. 6, 2008.

A cat is seen during the International Cat Show in Minsk, Belarus on Dec. 6, 2008. (Vasily Fedosenko/Reuters)

Despite being so lethal, a separate report from Lepczyk last year found there aren't many places in the world doing anything about roaming cats.

As an ecologist, Lepczyk keeps both his cats inside and recommends others do the same. It not only helps prolong the cat's life, he said, but it gives the animals a better fighting chance.

"It's going to be better for wildlife, but it's also going to be better for the cat," he said.

A cat-astrophe? Cats eat over 2,000 species worldwide, study finds

Jeanine Santucci, USA TODAY
Updated Fri, December 15, 2023 

The simple housecat, as it turns out, will kill and eat just about any tasty-looking creature it comes across and is a threat to biodiversity when allowed to roam outdoors, a new study found.

They don't call those paws "murder mittens" in certain corners of the internet for nothing.

study published this week in Nature Communications examined the global impact of free-ranging domestic cats' diets and found they eat more than 2,000 species of rodents, insects, birds and more, including at least 347 that are "of conservation concern."

Their proliferation around the world and disruption to ecosystems make them "amongst the most problematic invasive species in the world," the study authors write.

A new study found that cats will eat just about any animal they can get their hands – or, paws – on. They are known to eat over 2,000 species, including some that are endangered.


Why the housecat is 'problematic' to biodiversity


Cats were first domesticated over 9,000 years ago and spread by humans across the globe, the study authors write. They now inhabit every continent except Antarctica.

They are "opportunistic predators and obligate carnivores," meaning they will change their diet depending on what is available to them, and they require a diet of animal flesh. Cats also kill animals they don't consume afterward, unrelated to their diet, the study says.

Domesticated cats have disrupted many ecosystems, the study authors say. They spread novel diseases, including to humans; out-compete wild cats; prey on animals in their environments; and have caused many species to become extinct. Just the presence of cats alone in an environment can cause fear and affect native species' foraging and breeding behaviors, according to the authors.

MORE ABOUT CATS: Cats use nearly 300 unique facial expressions to communicate, new study shows

What's on your furry friend's menu when it goes out to eat?


In total, cats – unowned and owned with access to the outdoors – eat about 981 species of birds, 463 species of reptiles, 431 species of mammals, 119 species of insects and 57 species of amphibians, according to the study. The results of the study show an increase in the species that had been thought to be consumed by cats.

The most commonly identified animals in a cat's diet were the house mouse, European rabbit, black rat, house sparrow and brown rat. Cats also feast on carcasses that can be scavenged.

Useful though cats may be at deterring pests from our abodes, they are predators to several species that are near-threatened or threatened, including some that have endangered status or are extinct. More than 7% of birds, 4.9% of mammals and 2.7% of reptiles of conservation concern are on the cat's menu.

"We found records of cats consuming 11 species from Australia, Mexico, the United States of America, and New Zealand that have since been listed as extinct in the wild (EW) or extinct (EX)," the authors wrote.

The study also notes that known estimates are conservative, and the true number of species eaten by cats remains unknown.

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