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Fayez Nureldine/AFP/Getty Images
Fayez Nureldine/AFP/Getty Images

Starling Nests Make Huge Feasts for Pigs, Snakes, Insects, and Turkeys

Fayez Nureldine/AFP/Getty Images
Fayez Nureldine/AFP/Getty Images

The people of Australia might not celebrate Thanksgiving, but every November, plenty of animals in the northeastern part of the continent have something to be thankful for, and they gather together for a feast.

The yearly bounty comes courtesy of the metallic starling (Aplonis metallica). These glossy looking, red-eyed birds migrate from New Guinea to northeastern Australia in mid-November, where they stay through the summer monsoons to lay their eggs and raise their chicks. When they arrive at the Cape York peninsula in Queensland, they form enormous colonies, with 1000 or more birds building dome-shaped nests in the same tree. 

The activity draws plenty of attention from local wildlife. Insects, amphibians, reptiles, mammals, and other birds all crowd around the colonized trees to feed on plants that are fertilized by the starlings’ poop, and to eat starling eggs, nestlings that fall from the nests, and even other animals that are attracted to the colonies.

You can see an example of starlings congregating in a tree (likely in Cornwall, UK) in the slo-mo video below. While the entire video is worth a watch, jump to 2:05 for their spectacular departure.

In Australia, the lure of the buffet is so great—and consistent, because starlings nest in the same trees each season, and some trees will host colonies for 15 or more years in a row—that the birds’ arrival radically alters the distribution of wildlife in Cape York’s rainforests, says ecologist Daniel Natusch. The trees they colonize become “ecological hotspots,” where different species gather in great numbers. Natusch and other researchers at the University of Sydney recently described these hotspots for the first time in a paper in PLOS One [PDF], cataloging the species that show up—42 taxa, not including insects—and measuring just how “hot” they are. The small (just 32 x 45 feet) areas under the trees, the scientists say, host some of the largest and most diverse animal congregations in the world.

Natusch’s team took regular wildlife censuses for about 18 months beneath 26 starling colonies. They hung flypaper from the trees’ branches to catch flying insects; collected and sifted through soil to find other invertebrates; and used trail cameras to collect candid shots of mammals, reptiles, amphibians, and birds. They then compared these animal assemblies to the ones they found at nearby trees that didn’t house starlings.

The researchers documented 42 different species—from cattle and kookaburras to rats and pythons—beneath the starling colonies. Brush turkeys and pigs—both seen in the images below—showed up more often than any other species, and the largest gathering they recorded included 50 different individual animals. Overall, they found significantly more animals at trees with starlings than those without, and the densities of some species were 100 to 1000 times higher under the colonies than elsewhere in the rainforest. 

The communal nesting colonies of the metallic starlings attract many species, including (clockwise from upper right) scrub pythons, brush turkeys and palm cockatoos, and pigs. Lots and lots of pigs. Image Credit: © 2016 Natusch et al.

 
“To our knowledge, this system represents one of the highest-biomass and most diverse faunal aggregations in the world,” the scientists write.

It’s not hard to see why the starlings draw such a crowd. Guano from thousands of birds enriches the ground beneath the colonies with nutrients, attracting soil-dwelling invertebrates and fertilizing plants. The bugs and plants attract herbivores and insectivores, which in turn draw predators higher up on the food chain. When the monsoons come and strong winds knock nests to the ground, carnivores like dingoes and snakes also feed on fallen starling eggs and chicks. 

These hotspots are impressive, but Natusch thinks scientists could also put them to practical use. Since the colonies attract some of Australia’s most destructive invasive species, like feral pigs and cane toads, the researchers suggest that they could be sites for targeted control. When large numbers of problematic animals gather at the same tree, conservationists could capture or kill them in one swoop—giving Australia’s native wildlife one more reason to be thankful for the starlings.

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NUS Environmental Research Institute, Subnero
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Researchers in Singapore Deploy Robot Swans to Test Water Quality
NUS Environmental Research Institute, Subnero
NUS Environmental Research Institute, Subnero

There's something peculiar about the new swans floating around reservoirs in Singapore. They drift across the water like normal birds, but upon closer inspection, onlookers will find they're not birds at all: They're cleverly disguised robots designed to test the quality of the city's water.

As Dezeen reports, the high-tech waterfowl, dubbed NUSwan (New Smart Water Assessment Network), are the work of researchers at the National University of Singapore [PDF]. The team invented the devices as a way to tackle the challenges of maintaining an urban water source. "Water bodies are exposed to varying sources of pollutants from urban run-offs and industries," they write in a statement. "Several methods and protocols in monitoring pollutants are already in place. However, the boundaries of extensive assessment for the water bodies are limited by labor intensive and resource exhaustive methods."

By building water assessment technology into a plastic swan, they're able to analyze the quality of the reservoirs cheaply and discreetly. Sensors on the robots' undersides measure factors like dissolved oxygen and chlorophyll levels. The swans wirelessly transmit whatever data they collect to the command center on land, and based on what they send, human pilots can remotely tweak the robots' performance in real time. The hope is that the simple, adaptable technology will allow researchers to take smarter samples and better understand the impact of the reservoir's micro-ecosystem on water quality.

Man placing robotic swan in water.
NUS Environmental Research Institute, Subnero

This isn't the first time humans have used robots disguised as animals as tools for studying nature. Check out this clip from the BBC series Spy in the Wild for an idea of just how realistic these robots can get.

[h/t Dezeen]

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iStock
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There May Be an Ancient Reason Why Your Dog Eats Poop
iStock
iStock

Dogs aren't known for their picky taste in food, but some pups go beyond the normal trash hunting and start rooting around in poop, whether it be their own or a friend's. Just why dogs exhibit this behavior is a scientific mystery. Only some dogs do it, and researchers aren't quite sure where the impulse comes from. But if your dog is a poop eater, it's nearly impossible to steer them away from their favorite feces.

A new study in the journal Veterinary Medicine and Science, spotted by The Washington Post, presents a new theory for what scientists call "canine conspecific coprophagy," or dogs eating dog poop.

In online surveys about domestic dogs' poop-eating habits completed by thousands of pet owners, the researchers found no link between eating poop and a dog's sex, house training, compulsive behavior, or the style of mothering they received as puppies. However, they did find one common link between the poop eaters. Most tended to eat only poop that was less than two days old. According to their data, 85 percent of poop-eaters only go for the fresh stuff.

That timeline is important because it tracks with the lifespan of parasites. And this led the researchers to the following hypothesis: that eating poop is a holdover behavior from domestic dogs' ancestors, who may have had a decent reason to tuck into their friends' poop.

Since their poop has a high chance of containing intestinal parasites, wolves poop far from their dens. But if a sick wolf doesn't quite make it out of the den in time, they might do their business too close to home. A healthier wolf might eat this poop, but the parasite eggs wouldn't have hatched within the first day or two of the feces being dropped. Thus, the healthy wolf would carry the risk of infection away from the den, depositing the eggs they had consumed away in their own, subsequent bowel movements at an appropriate distance before the eggs had the chance to hatch into larvae and transmit the parasite to the pack.

Domestic dogs may just be enacting this behavior instinctively—only for them, there isn't as much danger of them picking up a parasite at home. However, the theory isn't foolproof. The surveys also found that so-called "greedy eaters" were more likely to eat feces than dogs who aren't quite so intense about food. So yes, it could still be about a poop-loving palate.

But really, it's much more pleasant to think about the behavior as a parasite-protection measure than our best pals foraging for a delicious fecal snack. 

[h/t The Washington Post]

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