Tag: Birds (pet; ornamental; prey e.g. falcons)

Animal behavior researchers at Wake Forest University have found that the highly territorial downy woodpecker interprets drumming intensity from adversaries to figure out who is or isn’t a threat.

Instead of a distinctive song, woodpeckers bang on trees with their bills to create a sound called drumming. The birds use it to communicate when they want to attract a mate or defend a territory. Wake Forest assistant professor of biology Matthew Fuxjager and his research team, which consists of graduate student Eric Schupee and several undergraduates, tested how woodpecker pairs perceived the drumming to see how it influenced territorial interaction and coordination of defensive behavior.

“Partners will actually coordinate or cooperate with how they fight depending on who they are fighting. They size up their opponent and decide whether they need to work together,” Fuxjager said. “In short, it means an intruder woodpecker with a short drum is perceived as wimpier, while a long drum signifies a tough guy intruder.”

The team conducted behavioral experiments by recording drumming sounds from males and then playing them back, manipulating them to territory holders, to see what kind of behavioral response that would elicit, said Fuxjager, who studies physiological and behavioral mechanisms of social biology, particularly in bird species. The research was conducted in the woods on the Wake Forest campus and in the surrounding Winston-Salem community

What they found is that if you present a breeding pair of woodpeckers with a longer drum from a more aggressive intruder, the pair begins to coordinate their territorial defense behavior and coordinate how they attack the intruder; whereas, a shorter drum from a weaker intruder meant that the resident pair didn’t bother to coordinate a response.

Overall, Fuxjager said these findings, recently published in the journal Behavioral Ecology and Sociobiology, provide insight into aggressive behavior in birds in general and how individuals coordinate behavior to accomplish shared goals or tasks.

“When you walk through the woods and you hear a woodpecker, most people think they are looking for food, but that’s actually a social signal they use.”

https://www.sciencedaily.com/  Science Daily

https://www.sciencedaily.com/releases/2016/03/160304163603.htm  Original web page at Science Daily

Language is one of the defining characteristics of human beings: It enables us to generate unlimited meanings from a finite number of phonetic elements. Using syntactic rules, humans are able to combine words to form phrases and sentences, and thus ascribe meaning to various things and activities. Research on communication systems suggests that non-human primates and birds, too, have evolved the ability to assign meaning to arbitrary vocal elements. But until now, the evolution of syntax has been considered unique to human language. Warning signal plus mating call means “flock together”

Evolutionary biologists at The Graduate University for Advanced Studies in Japan, the Uppsala University in Sweden and the University of Zurich are now challenging this view. For the first time, these researchers have demonstrated that Japanese great tits (Parus minor) have developed syntactic rules. These small birds are known for their large vocal repertoire, and the team discovered that they use a variety of calls and combinations of calls to interact with one another in specific situations. The combination of sounds such as the “ABC calls,” for instance, means “watch out!.” The great tits use them when a sparrowhawk or another predator is nearby — a potentially dangerous situation. By contrast, “D calls” mean “come over here,” a call the birds use after discovering a new source of food or when wanting their partner to come to the nest.

Tits frequently combine these two calls into ABC-D calls when, for instance, the birds encounter predators and join forces to deter them. When hearing a recording of these calls played in the natural order of ABC-D, the birds are alarmed and flock together. When, however, the call ordering is artificially reversed to D-ABC, the birds do not respond.

The researchers have therefore drawn the conclusion that syntax is not unique to human language: It has also evolved independently in birds. “The results lead to a better understanding of the underlying factors in the evolution of syntax. Because the tits combine different calls, they are able to create new meaning with their limited vocabulary. That allows them to trigger different behavioral reactions and coordinate complex social interactions,” says Dr. Michael Griesser, at the Institute of Anthropology at the University of Zurich. He believes these factors may well have contributed to the development of language in humans.

https://www.sciencedaily.com/   Science Daily

https://www.sciencedaily.com/releases/2016/03/160308134748.htm  Original web page at  Science Daily

Until now, scientists had observed that some large birds are sociable amongst each other. However, a new study has confirmed that this unique characteristic can also be seen among smaller birds such as the Eurasian siskin, a bird which is able to form bonds that last for a number of years as well as travel long distances in the company of these birds. This intimacy may favour reproduction in addition to facilitating the process of adjusting to a new place.

The sociability of swans, geese and birds of the crow family has been studied and is well understood by scientists. These are large birds that tend to form stable, long-lasting bonds. This peculiarity, however, had not been observed in smaller birds, such is the case with the Eurasian siskin (Carduelis spinus). A study published in ‘Bird Study’ reveals that this species has a tendency to travel long distances in groups over the course of several years. Up to this time, researchers from the Natural Sciences Museum of Barcelona -the leaders of this study- had discovered that female Eurasian siskins in captivity prefer to mate with males that they know. Nevertheless, the investigators still needed to prove that these birds, when out in nature, do indeed live together for periods of time that are long enough for these specimens to interact and to get to know each other.

“In this study we show how the Eurasian siskin is able to form stable group relationships lasting for periods of several years in addition to travelling in each other’ company over distances spanning more than 1,000 km,” points out Juan Carlos Senar, lead author of this study and a scientist at the museum.

The research team used data from the ‘European Union for Bird Ringing’ (EURING) -the European institution in charge of banding and tracking birds- in order to examine the data recorded on 42,707 Eurasian siskins between 1907 and 2011. For greater accuracy, the experts limited their study to those birds that had travelled distances greater than 50 km from the place where they had been banded — a distance that exceeds the maximum number of kilometres that these birds tend to travel in a single day (10-40 km).

The findings demonstrated that Eurasian siskins can remain together in the same group for up to four years. The results also showed that they can travel with other individuals for distances up to 1,300 km. With regard to the types of groups the birds travelled in, the records confirm that they could be either single-sex or mixed-sex groups.

Senar also draws attention to the fact that “what is important is that several groups of individuals were detected travelling together for hundreds of kilometres, and that these groups included both males with females (possible partners), as well as single-sex groups, thus implying that these bonds are not only formed between mating partners, but that they can also form between groups of friends with social ties.”

Until now, some studies had confirmed a marked sociability in small birds such as the pine siskin (Carduelis pinus) and the common redpoll (Acanthis flammea). These studies, however, were conducted over the course of one winter, thus resulting in data corresponding to relatively short travel distances and a period of time of only a few months.

Senar and his team wanted to replicate these results in the Eurasian siskin by studying the journeys made during the entire biological period and throughout the lifetime of an individual. “This study conducted on the Eurasian siskin also carries the added importance of the fact that this species, unlike the European goldfinch (Carduelis carduelis) or the European greenfinch (Carduelis chloris), is nomadic, meaning that these specimens fly to a different destination each year,” indicates the scientist.

Thus, “if two individuals are recaptured together hundreds of kilometres from where they were originally captured, this is not because both were going to independently spend the winter in the same place and just happened to both be there. Rather, these two individuals would have had to purposefully travel together,” explains the researcher.

The study has also revealed that these individuals prefers to mate with others that they are familiar with — something which may be an important mechanism to aid in adjusting to new places. For this to be possible, individuals must interact with each other over long periods of time, something that, as demonstrated in this study, is also characteristic of these little birds.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2016/02/160201085012.htm  Original web page at Science Daily

Scientists have been given an extraordinary glimpse into how wild New Caledonian crows make and use ‘hooked stick tools’ to hunt for insect prey. Scientists have been given an extraordinary glimpse into how wild New Caledonian crows make and use ‘hooked stick tools’ to hunt for insect prey.

Dr Jolyon Troscianko, from the University of Exeter, and Dr Christian Rutz, from the University of St Andrews, have captured first video recordings documenting how these tropical corvids fashion these particularly complex tools in the wild.

The pair developed tiny video ‘spy-cameras’ which were attached to the crows, to observe their natural foraging behaviour.

They discovered two instances of hooked stick tool making on the footage they recorded, with one crow spending a minute making the tool, before using it to probe for food in tree crevices and even in leaf litter on the ground. The findings are reported in the Royal Society’s journal Biology Letters on Wednesday, December 23.

Dr Troscianko is a Postdoctoral Research Fellow in Exeter’s Biosciences Department based at the Penryn Campus in Cornwall, who worked on the project while at the University of Birmingham.

He said: “While fieldworkers had previously obtained brief glimpses of hooked stick tool manufacture, the only video footage to date came from baited feeding sites, where tool raw materials and probing tasks had been provided to crows by scientists. We were keen to get close-up video of birds making these tools under completely natural conditions.”

“New Caledonian crows are notoriously difficult to observe, not just because of the challenging terrain of their tropical habitats, but also because they can be quite sensitive to disturbance. By documenting their fascinating behaviour with this new camera technology, we obtained valuable insights into the importance of tools in their daily search for food.”

To obtain a ‘crow’s-eye view’ of this elusive behaviour, the two researchers developed video cameras that are attached to the crows’ tail feathers. The cameras are about the weight of a British 2-pound coin, and a tiny integrated radio beacon let the scientists recover the devices once they had safely detached after a few days. Dr Christian Rutz, Reader in the School of Biology in St Andrews, explains: “These cameras store video footage on a micro-SD card, using technology similar to that found in people’s smart phones. This produced video recordings of stunning quality.”

The team deployed 19 cameras on crows at their chosen dry forest study site, where in hundreds of hours of fieldwork, despite two brief glimpses with binoculars, they had never managed to film crows manufacturing hooked stick tools.

The team were excited to record two instances of this behaviour on footage recovered from ten birds in their latest study.

Troscianko noted: “The behaviour is easy to miss — the first time I watched the footage, I didn’t see anything particularly interesting. Only when I went through it again frame-by-frame, I discovered this fascinating behaviour. Not once, but twice!”

“In one scene, a crow drops its tool, and then recovers it from the ground shortly afterwards, suggesting they value their tools and don’t simply discard them after a single use.” According to Rutz, this observation agrees with recent aviary experiments conducted by his group: “Crows really hate losing their tools, and will use all sorts of tricks to keep them safe. We even observed them storing tools temporarily in tree holes, the same way a human would put a treasured pen into a pen holder.”

New Caledonian crows (Corvus moneduloides) are found on the South Pacific island of New Caledonia. They can use their bills to whittle twigs and leaves into bug-grabbing implements; some believe their tool-use is so advanced that it rivals that of some primates.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/12/151223141159.htm  Original web page at Science Daily

Scientists have called for a greater international collaborative effort to save the world’s migratory birds, many of which are at risk of extinction due to loss of habitat along their flight paths.

More than 90 per cent of the world’s migratory birds are inadequately protected due to poorly coordinated conservation around the world, a new study published in the journal Science today reveals.

Led by the ARC Centre of Excellence for Environmental Decisions (CEED), the research found huge gaps in the conservation of migratory birds, particularly across China, India, and parts of Africa and South America. This results in the majority of migratory birds having ranges that are well covered by protected areas in one country, but poorly protected in another.

“More than half of migratory bird species travelling the world’s main flyways have suffered serious population declines in the past 30 years. This is due mainly to unequal and ineffective protection across their migratory range and the places they stop to refuel along their routes,” says lead author Dr Claire Runge of CEED and the University of Queensland.

“A typical migratory bird relies on many different geographic locations throughout its annual cycle for food, rest and breeding. “So even if we protect most of their breeding grounds, it’s still not enough — threats somewhere else can affect the entire population,” she says. “The chain can be broken at any link.

Dr Runge explains that these birds undertake remarkable journeys navigating across land and sea to find refuge as the seasons change, from endurance flights exceeding 10,000 kilometres by bar-tailed godwits to the annual relay of Arctic terns, which fly the equivalent of the distance to the moon and back three times during their lives.

Other examples include the sooty shearwater which flies 64,000 kilometres from the Falkland Islands to the Arctic, and the tiny blackpoll warbler, which flies for three days non-stop across open ocean from eastern Canada to South America.

The CEED study found that of 1,451 migratory bird species, 1,324 had inadequate protection for at least one part of their migration pathway. Eighteen species had no protection in their breeding areas and two species had no protection at all along their whole route.

For migratory bird species listed as threatened on the International Union for Conservation of Nature Red List by BirdLife International, less than three per cent have sufficient protected areas. “For example, the red-spectacled amazon — a migratory parrot of Brazil — is threatened by habitat loss,” says Dr Stuart Butchart, Head of Science at BirdLife International and a co-author of the study. “And yet less than four per cent of its range is protected, and almost none of its seasonal breeding areas in southern Brazil are covered.” The team also examined over 8,200 areas that have been identified as internationally important locations for migratory bird populations. They found that just 22 per cent are completely protected, and 41 per cent only partially overlap with protected areas.

“Establishing new reserves to protect the unprotected sites — and more effectively managing all protected areas for migratory species — is critical to ensure the survival of these iconic species,” Dr Butchart said.

Co-author Associate Professor Richard Fuller of CEED says the results highlight an urgent need to coordinate protected area designation along the birds’ full migration route. “For instance, Germany has protected areas for over 98 per cent of the migratory species that pass its borders, but fewer than 13 per cent of its species are adequately protected across their global range.

“It isn’t just a case of wealthy nations losing their migratory birds to a lack of protection in poorer nations. Many Central American countries, for example, meet the targets for more than 75 per cent of their migratory species, but these same species have less protected area coverage in Canada and USA.”

While protected areas are usually designated by each country, collaborative international partnerships and inter-governmental coordination as well as action are crucial to safeguard the world’s migratory birds. “It won’t matter what we do in Australia or in Europe if these birds are losing their habitat somewhere else — they will still perish. We need to work together far more effectively round the world if we want our migratory birds to survive into the future,” Dr Fuller says.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/12/151203150135.htm  Original web page at Science Daily

The cuckoo is not only capable of finding its way from unknown locations; it does this through a highly complex individual decision making process. Such skills have never before been documented in migratory birds. A new study shows that navigation in migratory birds is even more complex than previously assumed. The Center for Macroecology, Evolution and Climate at the University of Copenhagen led the study with the use of miniature satellite tracking technology.

In an experiment, 11 adult cuckoos were relocated from Denmark to Spain just before their winter migration to Africa was about to begin. When the birds were released more than 1,000 km away from their well-known migration route, they navigated towards the different stopover areas used along their normal route.

“The release site was completely unknown to the cuckoos, yet they had no trouble finding their way back to their normal migratory route. Interestingly though, they aimed for different targets on the route, which we do not consider random. This individual and flexible choice in navigation indicates an ability to assess advantages and disadvantages of different routes, probably based on their health, age, experience or even personality traits. They evaluate their own condition and adjust their reaction to it, displaying a complicated behavior which we were able to document for the first time in migratory birds,” says postdoc Mikkel Willemoes from the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

Previously, in 2014, the Center also led a study mapping the complete cuckoo migration route from Denmark to Africa. Here they discovered that during autumn the birds make stopovers in different areas across Europe and Africa. It was these areas the displaced cuckoos aimed for: Of the 11 birds, one flew to Poland, one to the Balkans, one to Chad and three of them flew to the Democratic Republic of Congo. From there, they followed their familiar migration route. The last five birds lost their transmitting signal.

“In order to select an individual strategy, the birds should be capable of balancing perceived gains and risks of several different scenarios. Such a task would require knowledge of the current location in relation to all of the possible goals as well as distances to each of the goals. This tells us that bird migration in general is far more complex than previously assumed,” says Mikkel Willemoes. The study was carried out in collaboration with Doñana Biological Station in Spain and the Max Planck Institute for Ornithology in Germany.

Bird relocation studies have been carried out in the past, but recent satellite technology has made it possible for the first time to track the complete migration of a relocated species and reveal individual responses.

“We have received remarkable details on the movement of adult birds. The next step is to develop smaller transmitters that will enable us to follow young cuckoos on a relocation flight. Without prior migration experience, their choices will reveal new insight on how they navigate from unknown locations” says Associate Professor Kasper Thorup from the Center for Macroecology, Evolution and Climate.

Cuckoos are particularly suitable for navigation studies, as they lay their eggs inside the nests of other bird species. Growing up without contact to siblings or biological parents, the young cuckoo has no one to follow during migration. Flying alone and at night, it relies entirely on instincts, inherent abilities and the experiences gained later in life. Now, scientists can conclude that these traits are combined into a complex individual decision making strategy.

The study is published in Scientific Reports.

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/11/151120092146.htm  Original web page at Science Daily

Wild birds will sacrifice access to food in order to stay close to their partner over the winter, according to a study by Oxford University researchers.

Scientists from the Department of Zoology found that mated pairs of great tits chose to prioritise their relationships over sustenance in a novel experiment that prevented couples from foraging in the same location. This also meant birds ended up spending a significant amount of time with their partners’ flock-mates. And, over time, the pairs may even have learned to cooperate to allow each other to scrounge from off-limits feeding stations.

The results, published in the journal Current Biology, demonstrate the importance of social relationships for wild birds — even when pursuing those relationships appears to be detrimental. Josh Firth, who led the research, said: ‘The choice to stay close to their partner over accessing food demonstrates how an individual bird’s decisions in the short term, which might appear sub-optimal, can actually be shaped around gaining the long-term benefits of maintaining their key relationships. For instance, great tits require a partner to be able to reproduce and raise their chicks.

‘Therefore, even in wild animals, an individual’s behaviour can be governed by aiming to accommodate the needs of those they are socially attached to.’

The research, which was carried out at Oxford University’s Wytham Woods site to the west of Oxford, involved the use of automated feeding stations with the ability to decide which individual birds could and could not access the food inside. Birds were allowed access based on radio frequency identification tags that were linked to the feeding stations.

In the experiment, mated pairs of birds were unable to access the same feeding stations as each other, meaning the male could only access the feeding stations that the female could not, and vice versa.

The researchers found that the birds randomly selected not to be allowed access to the same feeding stations as their partner spent significantly more time at feeders they could not access than birds that were allowed to feed together.

Josh Firth added: ‘Because these birds choose to stay with their partners, they also end up associating with their partners’ flock-mates, even if they wouldn’t usually associate with these individuals. This shows how the company an individual bird keeps may depend on their partner’s preferences as well as their own.

‘Also, when birds were going to feeding stations they couldn’t access because their mate was there, they learned over time to “scrounge” from those feeders by taking advantage of the fact the feeders remained unlocked for two seconds after recognising a bird’s identification tag. Interestingly, a relatively large amount of this scrounging was enabled by the bird’s own partner unlocking the feeding station, suggesting it may be a cooperative strategy.’

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/11/151112123150.htm  Original web page at Science Dail

We know surprisingly little about what songbirds do after the sun goes down, but past studies have provided tantalizing hints that many forest birds roost for the night in different habitat from where they spend the day. A new paper confirms that wood thrushes often move out of their daytime ranges to sleep, seeking dense areas of vegetation where they’re safe from predators. We know surprisingly little about what songbirds do after the sun goes down, but past studies have provided tantalizing hints that many forest birds roost for the night in different habitat from where they spend the day. For a study forthcoming in The Auk: Ornithological Advances, Vitek Jirinec of the College of William and Mary and his colleagues captured and radio-tagged Wood Thrushes (Hylocichla mustelina) to track their movements during both day and night. Their results, the first broad description of roosting ecology for a migratory North American songbird during breeding season, show that the birds often move out of their daytime ranges to sleep, seeking dense areas of vegetation where they’re safe from predators.

Jirinec and his colleagues tracked 47 birds on the coastal plain of southeastern Virginia during the breeding seasons of 2013 and 2014, including 37 males and 10 of their mates. They found that males were not faithful to particular roosting spots, regularly moving from night to night, and overall one third of the roosting locations were completely outside the birds’ daytime ranges. Remote sensing data showed that those nighttime roosts were located in areas with higher-than-average canopy density, and the researchers suggest that the birds could have been making these commutes in order to roost in safer sleeping spots, where they would be well-hidden from predators.

Add nests into the mix and things become even more interesting. Nesting females spent the night in the nest cup–not surprising, since female Wood Thrushes are exclusively responsible for incubating eggs and nestlings. While nests were active, males didn’t stick around at night, continuing their usual routine of moving to safer roosting spots that were often outside their daytime territories. However, once a nesting attempt ended (either because the nestlings reached independence or because they were killed by a predator) males roosted side-by-side with their mates, inside their daytime range. Rather than being motivated by romance or loyalty, males were probably guarding their mates to prevent other males from surreptitiously mating with them in the dark.

Tracking birds at night led to some adventures. “Thankfully many of our study birds were in large forest tracks or chose not to roost near human dwellings, but there were still a considerable number of individuals who did just that,” says Jirinec. “Although I had the necessary permits, explaining that to homeowners at 2 a.m. after they spotted a guy creeping around their property, antenna at hand, was not what I was about to try. Therefore, in those instances, I followed the radio signal entirely in the dark, feeling my way around the forest very slowly and turning on my headlamp only at the last instance to confirm bird position, then quickly absconding with my precious roosting data as newspaper headlines like ‘Graduate student shot in the buttocks by Colonial Williamsburg resident’ swirled in my mind.”

“This is an important study that uses robust data collection from extensive radio-tracking to answer a simple question that has important conservation implications: how often do Neotropical migrants use different habitats for roosting and day-time activity on their breeding grounds?” adds Kara Belinsky of the State University of New York, New Paltz, an expert on the behavior and ecology of thrushes. “The use of different roost habitat should inform conservation plans for this declining species–we will need to protect high-quality roosting habitat as well as high-quality nesting and daytime habitat if we want to slow the decline of this species, and the same is also likely to be true for many of the other Neotropical migrants we care about.”

http://www.sciencedaily.com/   Science Daily

http://www.sciencedaily.com/releases/2015/10/151021185056.htm  Original we page at Science Daily

This is it, kids: official permission to stop listening to what your parents tell you–but only if you’re a bird. Many animal parents spend time teaching their young about how to find food and avoid danger, and this usually gives a big boost to their offspring. In a Commentary forthcoming in The Condor: Ornithological Applications, however, Vladimir Dinets of Louisiana State University makes the case that when environmental conditions change, relying on their parents’ way of doing things can actually hinder, not help, young cranes.

Only one remaining population of Whooping Cranes is completely descended from wild birds raised by their parents. On both their breeding grounds in Canada and their wintering grounds in Texas, they’re very picky about what habitat they use, sticking to a certain type of wetland, and each generation teaches its young to do the same; historically, this type of habitat must be where they’ve had the most success. However, when captive-reared Whooping Cranes, free of their parents’ hang-ups, were released in Louisiana, they moved into a wide variety of human-modified habitats like agricultural fields and suburban ponds, and their flexibility has helped them succeed.

“Many animals learn some of their behavior, such as avoiding humans and choosing the right habitat, from their parents. This learning is called ‘cultural transmission of behavior.’ Usually it’s a good thing for the young,” explains Dinets. “But in our rapidly changing world, this learning of ‘traditional’ behavior can make the young animals less adaptable, for example, if they have to survive in human-modified habitats with lots of human disturbance. Animals that learn to survive by themselves, without parental guidance, might do better in such places, as illustrated by the success of the Whooping Crane reintroduction program in Louisiana.”

The Commentary goes on to describe similar results from captive-raised, reintroduced populations of storks in Japan, ibises in Spain, and geese in Hawaii–again and again, birds raised without their parents’ guidance don’t share their ancestors’ reluctance to forage and nest near humans. “Dinets challenges managers of reintroduction programs to reconsider the effects of pre-release management techniques,” adds George Archibald, co-founder of the International Crane Foundation. “This wide-ranging description of the results from an array of species will help researchers ponder future directions. As someone involved in the study of the restoration of crane populations via captive management and releases, I am acutely aware of the complexities of avian behavior and of the need for continual improvement of practices.”

http://www.sciencedaily.com/  Science Daily

http://www.sciencedaily.com/releases/2015/10/151021185100.htm  Original web page at Science Daily