Lost Birds of the USA


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Cable ties probably won’t stop magpie attacks – here are a few things to try instead



Stylish? No. Effective? Probably not.
Tony Wills/Wikimedia Commons, CC BY

Bill Bateman, Curtin University

Every spring in Australia is heralded by reports of magpies swooping at people. While it is of little comfort to those at the receiving end of a surprise attack, such events are actually quite rare when one considers the number of magpies across Australia, and the fact that they love to share our urban habitat with us.

According to one estimate, fewer than 10% of magpies swoop, and even fewer of these do so consistently. It is almost always males that swoop, and they only do so when they have chicks in the nest. Once the chicks are out the males seem to calm down; presumably they perceive nest-bound chicks as most vulnerable.

Swooping behaviour also seems to vary across Australia – at least according to Magpie Alert!, a website on which the public can report magpie attacks. Many more swoops have been reported in the eastern states than in Western Australia, and fewest of all in Tasmania.




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But regardless of their relative rarity, being the target of a swooping attack by a magpie can be frightening. It has resulted in injuries and, tragically this week, the death of a 76-year-old cyclist in Wollongong.

What can we do to avoid ending up on the receiving end? Is any of the advice meted out each year on avoiding attacks actually worthwhile, or backed by evidence? As with just about everything involving biology, the answer is “it depends”.

Some magpies never attack pedestrians but go for cyclists; others do the opposite. And some hold a deep animus against posties on bikes, and reserve their fury solely for them. Even more astonishingly, some magpies seem to really have it in for particular people, and will preferentially attack them.

Although Australian magpies are not related to true crows, they do share similar levels of intelligence. US researchers have shown that American crows recognise people who have trapped them to band them, give alarm calls when they next see them, and even pass on that information to untrapped birds who also sound the alarm when they see trappers.

It seems likely that Australian magpies do the same, effectively holding a grudge against particular people. Unfortunate posties, travelling the same route each day and meeting the same magpies, seem to end up on the naughty list through no fault of their own.

Cyclists do seem to invoke more extreme reactions than pedestrians, judging by the fact that magpies appear to pursue cyclists farther. It therefore stands to reason that the best response to a swooping attack while cycling would be to get off and push your bike.

You will of course be wearing a bike helmet, and as magpies swoop from behind, this will offer protection against its sharp beak.

Sadly it seems that the classic tactic of attaching cable ties to your helmet does little to deter a determined magpie, beyond the fact that some strategic placing can help keep them away from your ears. Ditto the idea of painting eyes on the back of your helmet or hat.

More reassuringly, however, magpies really only swoop in the vicinity of their nest, so once you have moved away you should be safe. If you become aware of swooping attacks in a certain area the best thing is to avoid it – even just crossing the road should be sufficient.

If you can’t do that, at least wear a hat and sunglasses; these will help reduce the chance of a determined magpie pecking a sensitive area. Turning to face magpies may also help – many birds do not appreciate being stared at, and as magpies prefer to swoop from behind, this may be a good tactic if you find yourself cornered in a park.

If you have magpies in your garden, perhaps the most appealing way of avoiding attacks is to become their best friend. Given that magpies have long memories, a few judicious offerings of mince or similar tidbits throughout the year can help you befriend them, making them much more amenable to your presence come spring.

But don’t overfeed them – it’s just a friendly bribe, not a full-blown dependency.




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If all else fails, simply console yourself with the fact that swooping season only lasts a few weeks. For the rest of the year magpies are peaceful urban nighbours who delight us with their distinctive song.

Bear that in mind, and we can hopefully reach a détente with our feathered (and occasionally flustered) friends. In the meantime, if you are unlucky enough to be swooped, remember to help others avoid the same fate by posting the details to Magpie Alert!.The Conversation

Bill Bateman, Associate professor, Curtin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Buffet buddies: footage reveals that fierce leopard seals work together when king penguin is on the menu



A wild leopard seal on South Georgia.
James Robbins, Author provided

David Hocking, Monash University; Alistair Evans, Monash University, and James Robbins, Plymouth University

Some people don’t like sharing their food – we all have a friend who gets cranky when you steal a chip from their plate. For wild animals, this makes sense, because any food shared is energy lost that could otherwise have been used to pursue more food.

So it was a big surprise to discover wild leopard seals feeding alongside one another while eating king penguins at South Georgia, a remote island in the southern Atlantic Ocean. On top of this, they may have even been cooperating with each other to eat these enormous seabirds.

Location of the study.
James Robbins

We report this fascinating observation in a new study published today in the journal Polar Biology.

Can’t we just all get along?

Leopard seals have a ferocious reputation as one of the top predators in the Antarctic ecosystem. They are infamously the “principal enemy of the penguin”, as immortalised in the film Happy Feet.




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But when they eat penguins, leopard seals are normally highly territorial, scaring off rivals by lunging at them with a fearsome set of teeth. Animal-mounted cameras have even revealed that leopard seals ambush each other to steal captured prey.

But that’s not what was seen when the film crew working on the Netflix documentary series Our Planet visited South Georgia. Instead, they were astonished to find wild leopard seals floating alongside one another dining together on a king penguin carcass, taking it in turns to tear off pieces of food.

Too costly to fight

Given how aggressive leopard seals normally are around food, why were these seals behaving so out of character?

Consider this: if you were at an all-you-can-eat buffet and a stranger sat at your table and began eating your food, would you chase them away or let them share with you, knowing you could easily get more afterwards?

When food is very abundant, it may well be cheaper to share than to fight. Penguin colonies offer a near-constant supply of potential prey, attracting scores of predators. In this case, up to 36 leopard seals were seen near the colony at the same time.

So if a seal paused feeding to scare or fight off a rival, there is a good chance a third seal would sneak in and steal the food. In this situation it makes more sense to focus on eating as much as possible, as fast as possible – tolerating some food theft if necessary so as to avoid wasting energy on fighting that would risk losing the prey altogether.

The seals didn’t get along perfectly all the time. We saw some aggression, but perhaps this is to be expected if they are just tolerating each other out of necessity.

Even in our observations, the seals didn’t always get along – note the prey item floating in the water where it could easily be stolen by a third seal.
Dion Poncet

Do leopard seals cooperate to eat large prey?

Another explanation for these unexpected observations is that leopard seals might be cooperating to make it easier to consume such large prey.

Unlike northern seals, leopard seals don’t have clawed paws to help them hold prey. Instead, they have paddle-like flippers with tiny claws, forcing them to vigorously thrash the prey from side to side in their teeth to tear it into pieces small enough to swallow. This energy-intensive eating style is even harder when the prey is large – like adult king penguins.

Unlike northern seals, leopard seals have a paddle-like flipper that lacks the large claws needed to hold and tear food.
James Robbins
Tools of the trade: Leopard seals use their strong front teeth to kill penguins, while the trident-shaped cheek teeth act as a sieve for trapping tiny krill.
David Hocking

Alternatively, if two animals hold the prey between them, one can act as an anchor while the other tears off a chunk of meat. This saves a lot of energy that would otherwise be wasted shaking the prey around.

Group feeding behaviours filmed using a drone, showing two leopard seals dining together on an adult king penguin.
Illustration by Kai Hagberg. Photos by Silverback Films.

This type of cooperative food processing is actually quite common among aquatic top predators, such as killer whales and crocodiles, that can’t easily hold onto food.

The unusual case of the sharing seal

This last possibility made us rethink the interpretation of a famous encounter between a wild leopard seal and National Geographic photographer Paul Nicklen. On entering the water, Nicklen was repeatedly approached by a seal that appeared to be trying to feed him a penguin in an act of unexpected altruism. But perhaps this was not a free gift, but an offer to cooperate.




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The latest discovery is a great example of how new technology can help researchers make close-hand observations of wild animals. By using a camera drone, the film-makers could fly above the animals without disturbing them, allowing them to observe behaviours that have so far gone unnoticed.

The remoteness of Antarctic ecosystems can make it hard to connect with the wildlife there, but these advances in technology are helping to provide new windows into this icy world. The Conversation

Wild leopard seal lunging at scavenging seabirds off Bird Island, South Georgia.
James Robbins

David Hocking, Postdoctoral fellow, Monash University; Alistair Evans, Associate Professor, Monash University, and James Robbins, Visiting researcher, Plymouth University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Meet the endangered Bunyip bird living in Australia’s rice paddies



Endangered species are living happily in rice fields.
Bitterns in Rice/Matt Herring, Author provided

Matt Herring, Charles Darwin University; Kerstin Zander, Charles Darwin University; Stephen Garnett, Charles Darwin University, and Wayne A. Robinson, Charles Sturt University

The debate around the Murray-Darling Basin is often sharply polarised: irrigation is destroying the environment, or water reforms are ruining farming communities.

But there is another story. In the Riverina region of southern New South Wales, a strange waterbird is using rice fields to live in and breed.

The endangered Bunyip Bird, also called the Australasian Bittern, is famous for its deep booming call – for thousands of years thought to be the sound made by the mythical Bunyip.

It’s a sound now familiar to most rice growers. In 2012, Birdlife Australia and the Ricegrowers’ Association teamed up to learn more about bitterns in rice. The total bittern population, including New Zealand and New Caledonia, is estimated at no more than 2,500 adults.




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The first question was how many bitterns are using rice crops. After surveying the birds on randomly selected farms, we crunched the numbers. Our results, just published, are staggering.

Across the Riverina, we conservatively estimate these rice crops attract 500-1,000 bitterns during the breeding season, about 40% of global population. It turns out the way rice is grown provides ideal water depths and vegetation heights for bitterns. It’s also favourable for their prey: frogs and tadpoles, fish and yabbies.

A bittern nest with chicks and eggs.
Matt Herring, Author provided

There is a growing body of global research investigating how human-made habitats can help fill the gap left by our vanishing wetlands, from ditches for rare turtles to constructed ponds for threatened amphibians. Rice fields around the world show great promise as well, with various “wildlife-friendly” farming initiatives. In California, farmers re-flood harvested fields to support thousands of migratory shorebirds and waterfowl, while in Japan consumers pay a premium for “Stork Rice” to help endangered species.




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However, rice fields are no substitute for natural wetlands, and it’s now clear both play a crucial role in sustaining the bittern population.

Satellite tracking has shown us that at harvest time bitterns disperse to some of southeastern Australia’s most important wetlands, including the Barmah-Millewa system along the Murray River, Coomonderry Swamp near Shoalhaven Heads in New South Wales, Pick Swamp in South Australia, and Tootgarook Swamp on the Mornington Peninsula near Melbourne.

Water efficiency might be bad news for the bittern

Rice farming in Australia’s Riverina has a century-long history. The amount grown varies greatly from year to year, depending on water allocations, and ranged from 5,000-113,000 hectares over the past decade. Around 80% is exported and it provides food for up to 20 million people each year.

Driven by water efficiency, many rice growers in the Riverina are switching their methods to intermittent flooding and not “ponding” the water – maintaining inundated fields – until later in the season.

A shorter ponding period will likely reduce opportunities for the bitterns to breed successfully before harvest. Another threat to bitterns is farmers switching to alternative crops and horticulture, none of which provides them habitat.

Around 40% of the global Australasian bittern population come to the Riverina’s rice fields.
Matt Herring, Author provided

During the 2017-18 irrigation season, there was more cotton grown than rice for the first time in the Riverina. It’s usually simple economics: irrigators will generally grow whatever gives them the best return per megalitre of water, with their choice having no net effect on the overall amount of irrigation water used in the system.

Water management in the Murray-Darling Basin is complicated, with fluctuating temporary water prices and trading between catchments. Water is allocated to either agriculture or the environment, setting up a dichotomy. But we think allocations to serve a single purpose may be overly simplistic, and the way bitterns use rice offers a case study for considering multi-purpose water use.

Working closely with growers, we are identifying ways to develop cost-effective incentive programs for bittern-friendly rice growing, where a sufficient ponding period is provided, with complementary habitat on banks, in crop edges and adjacent constructed wetland refuges. The aim is to boost the bittern population with the help of rice farmers.

Bitterns can nest and feed in rice paddies, but they depend on fields being flooded.
Matt Herring, Author provided

We are also surveying consumers about their attitudes towards bittern-friendly rice. Would you pay a premium for rice products that offset additional costs to growers for bittern conservation? How do you feel about adjusting water and conservation policies?




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Bitterns are not the only threatened species that use the Riverina’s rice fields. The endangered Southern Bell Frog and Australian Painted Snipe have also adapted to rice crops, and it’s likely there are significant populations of other species too.

With 61% of Australia managed by farmers, the need to incorporate wildlife conservation on farms has never been greater. We hope our work will help address the divisive, sometimes toxic debate around water use in the Murray-Darling Basin, uniting irrigators and environmentalists.The Conversation

Matt Herring, PhD Candidate, Charles Darwin University; Kerstin Zander, Associate professor, Charles Darwin University; Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University, and Wayne A. Robinson, post doctoral research fellow, Charles Sturt University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Curious Kids: where do swallows sleep?


Nests are not for sleep. They are for babies.
Flickr/Anna Hesser, CC BY-SA

Graham Fulton, The University of Queensland

Curious Kids is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.


I would like to find out something about swallows: we have noticed that they return to the same nests each year, but there must be younger birds that have no nest. Where do they sleep until they have built their new nest? – Nefeli, age 13, Corfu, Greece.


Thank you for your question, Nefeli.

It’s true that some swallows return to the same nests each year. But what do they do there?

We need to understand what nests are really for – and they are not for sleeping. They are for putting eggs into. The eggs need protection from the weather (hot and cold, wind and rain) and from other animals that would eat them. For predators, eggs taste great!

Adult swallows must build their nests away from predators and unsafe weather conditions, such as the wind, heat and cold.
merec0/flickr, CC BY-NC

Eventually the eggs hatch, then a blind and featherless baby swallow emerges. The babies are called nestlings or sometimes chicks. So nests are not for sleeping, they are for raising a family.

The babies that hatch from the swallow’s eggs are called nestlings or chicks.
Rafael V/flickr, CC BY-NC

It is true that when an adult is sitting on eggs and nestlings, it may sleep, especially at night.

But the young swallows who don’t have a nest to return to must build their own nest (to protect and feed their babies) or sleep on a tree branch, a rock ledge of a cliff face, or inside the hollow of a tree.

When swallows sleep away from the nest they sleep in places called roosts.

So remember: nests are mostly for babies; roosts are for sleep.

A swallow might sleep in a tree.
Flickr/Corine Bliek, CC BY



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Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.The Conversation

Graham Fulton, PhD student, School of Biological Sciences, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Curious Kids: how can penguins stay warm in the freezing cold waters of Antarctica?



Emperor penguins have uniquely adapted to their Antarctic home.
Christopher Michel/flickr, CC BY-SA

Jane Younger, University of Bath

Curious Kids is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.


How can penguins and polar bears stay warm in the freezing cold waters of Antarctica? – Riley, age 8, Clarksville, Tennessee USA.


Thanks for your question, Riley. The first thing I should probably say is that while a lot of people think polar bears and penguins live together, in fact they live at opposite ends of the Earth. Polar bears live in the northern hemisphere and penguins live in the southern hemisphere.

I’m a penguin researcher so I’m going to explain here how penguins can stay warm in Antarctica.

There are four species of penguins that live in Antarctica: emperors, gentoos, chinstraps, and Adélies.

All these penguins have special adaptations to keep them warm, but emperor penguins might be the most extreme birds in the world. These amazing animals dive up to 500 metres
below the surface of the ocean to catch their prey, withstanding crushing pressures and water temperatures as low as -1.8℃.

But their most incredible feat takes place not in the ocean, but on the sea ice above it.

Surviving on the ice

Emperor penguin chicks must hatch in spring so they can be ready to go to sea during the warmest time of year. For this timing to work, emperors gather in large groups on sea ice to begin their breeding in April, lay their eggs in May, and then the males protect the eggs for four months throughout the harsh Antarctic winter.

It’s dark, windy, and cold. Air temperatures regularly fall below -30℃, and occasionally drop to -60℃ during blizzards. These temperatures could easily kill a human in minutes. But emperor penguins endure it, to give their chicks the best start in life.

Emperor penguins have special physical and behavioural adaptations to survive temperatures that could easily kill a human in minutes.
Flickr/Ian Duffy, CC BY

A body ‘too big’ for its head

Emperor penguins have four layers of overlapping feathers that provide excellent protection from wind, and thick layers of fat that trap heat inside the body.

Emperor penguins have a small beak, small flippers, and small legs and feet. This way, less heat can be lost from places furthest from their main body.
Anne Fröhlich/flickr, CC BY-ND

Have you ever noticed that an emperor penguin’s body looks too big for its head and feet? This is another adaptation to keep them warm.

The first place that you feel cold is your hands and feet, because these parts are furthest from your main body and so lose heat easily.

This is the same for penguins, so they have evolved a small beak, small flippers, and small legs and feet, so that less heat can be lost from these areas.

They also have specially arranged veins and arteries in these body parts, which helps recycle their body warmth. For example, in their nasal passages (inside their noses), blood vessels are arranged so they can regain most of the heat that would be lost by breathing.




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Huddle time

Male emperor penguins gather close together in big groups called “huddles” to minimise how much of their body surface is exposed to cold air while they are incubating eggs.

This can cut heat loss in half and keep penguins’ core temperature at about 37℃ even while the air outside the huddle is below -30℃.

The biggest huddles ever observed had about 5,000 penguins! Penguins take turns to be on the outer edge of the huddle, protecting those on the inside from the wind.

Incredibly, during this four-month period of egg incubation the male penguins don’t eat anything and must rely on their existing fat stores. This long fast would be impossible unless they worked together.

The biggest huddles ever observed had about 5,000 penguins!
Flickr/Ars Electronica, CC BY

Changing habitats

Emperor penguins are uniquely adapted to their Antarctic home. As temperatures rise and sea ice disappears, emperors will face new challenges. If it becomes too warm they will get heat-stressed, and if the sea ice vanishes they will have nowhere to breed. Sadly, these incredible animals may face extinction in the future. The best thing we can do for emperor penguins is to take action on climate change now.




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Curious Kids: is water blue or is it just reflecting off the sky?


Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.The Conversation

Jane Younger, Research Fellow, University of Bath

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A parasite attack on Darwin’s finches means they’re losing their lovesong



A Small Tree Finch from the Galápagos Islands with an enlarged nostril caused by a parasite.
Katharina J Peters, Author provided

Katharina J. Peters, Flinders University and Sonia Kleindorfer, Flinders University

A parasite known to infect beaks in some iconic Darwin finches on the Galapagos Islands is changing the mating song of male birds.

Our research, published today in Proceedings of the Royal Society B, reveals how the parasite deforms the beak. This has the effect of weakening the male bird’s mating call, and making it no longer clearly distinguishable from that of other closely related species.

A changed song can have an important effect on the male finch’s ability to find a mate.




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It’s another factor that could contribute to declining numbers of these already threatened birds on the Pacific archipelago, about 1,000km off the coast of South America.

A family song to impress

A male finch learns the mating song from his father, and produces the same song for the rest of his life.

It’s a simple tune consisting of one syllable repeated 3 to 15 times, depending on what species of finch he belongs to. Larger-bodied finch species produce a slower song with few syllable repeats, and smaller-bodied finch species produce faster song with many syllable repeats.

Whatever species of finch you belong to, hitting the high notes is important – because females prefer males who can produce such vocally challenging songs.

In the case of the Medium Tree Finch (Camarhynchus pauper), a critically endangered species that only occurs on Floreana Island of the Galapagos Islands, its species-typical song has a bright resonance that rings across the forest canopy.

Medium Tree Finch.
Author provided35.5 KB (download)

An accomplished male singer that can hit the high notes is quickly swooped up by a female looking to pair with a proficient singer.

The ‘Vampire’ parasite

The Vampire Fly – a suggested name for the parasite Philornis downsi given its blood feeding habits from dusk until dawn – was first discovered in a Darwin’s finch nest in 1997.

The parasitic Philornis larvae in a finch nest.
Sonia Kleindorfer, Author provided

Since then, the devastating impacts of its larval feeding habits on nestling birds have been coming to light. The adult fly is vegetarian, but the females lay their eggs into bird nests and their larvae feed on nestling bird beaks from the inside out.

Many Darwin’s finch species now have beaks with massively enlarged nostrils because of damage the feeding fly larvae have caused during the nestling stage. We discovered that a changed beak apparatus measurably affects the song of Darwin’s tree finches with consequences for pairing success.

A Medium Tree Finch male with extremely enlarged nostrils is unable to hit the high notes.

Medium Tree Finch with enlarged nostrils.
Author provided32.2 KB (download)

We found the same pattern in Small Tree Finches (C. parvulus) with enlarged nostrils.

Male finches that produce song with a narrower frequency bandwidth, because their song has a lower maximum frequency, have poor quality song. These males are less likely to be chosen by females, a pattern we documented in both the Medium Tree Finch and the Small Tree Finch.

Also, the song of Medium Tree Finches with enlarged nostrils sounds like the song of the Small Tree Finch.

Small Tree Finches.
Author provided29 KB (download)

When species merge

But confusion among the species and their mating songs may not necessarily be a bad thing for the future survival of individual finches – though it could herald the collapse of species lineages.

Previously, we discovered evidence of hybridisation in Darwin finches. This is where two separate species of finch breed which could potentially produce a new species, phase out one of the species, or cause the collapse of the two existing species into one.

We observed hybridisation driven by female Medium Tree Finches pairing with male Small Tree Finches.

When a female Medium Tree Finch inspects male Small Tree Finches in the forest, she pairs with one who produces high quality song, even if that male is from another species.

A Tree Finch with a normal beak and nostril size, so no infection from the parasite.
Katharina J Peters, Author provided

This female choice seems to be paying dividends, because hybrid pairs with greater genetic diversity also sustained fewer of the parasitic larvae in the nest. And that could lead to fewer birds with infected beaks.




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There are concerted efforts underway to develop control and eradication methods for P. downsi on the Galapagos Islands, building on a collaborative relationship between the Charles Darwin Foundation and the Galapagos National Parks. The Philornis downsi Action Group is an international consortium of concerned scientists working to develop biological control methods.

Our new research is an important step towards understanding how this invasive fly may be changing the evolutionary pathway of Darwin’s finches by literally changing the beak of the finch.The Conversation

Katharina J. Peters, Postdoctoral fellow, Flinders University and Sonia Kleindorfer, Professor of Animal Behaviour, Flinders University

This article is republished from The Conversation under a Creative Commons license. Read the original article.