Post by Eaglehawk on Feb 15, 2020 5:11:47 GMT
Red-breasted Nuthatch - Sitta canadensis
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Sittidae
Genus: Sitta
Species: Sitta canadensis Linnaeus, 1766
The red-breasted nuthatch (Sitta canadensis) is a small songbird. The adult has blue-grey upperparts with cinnamon underparts, a white throat and face with a black stripe through the eyes, a straight grey bill and a black crown. Its call, which has been likened to a tin trumpet, is high-pitched and nasal. It breeds in coniferous forests across Canada, Alaska and the northeastern and western United States. Though often a permanent resident, it regularly irrupts further south if its food supply fails. There are records of vagrants occurring as far south as the Gulf Coast and northern Mexico. It forages on the trunks and large branches of trees, often descending head first, sometimes catching insects in flight. It eats mainly insects and seeds, especially from conifers. It excavates its nest in dead wood, often close to the ground, smearing the entrance with pitch.
Taxonomy
In 1760 the French zoologist Mathurin Jacques Brisson included a description of the red-breasted nuthatch in his Ornithologie based on a specimen collected in Canada. He used the French name Le torchepot de Canada and the Latin Sitta Canadensis. Although Brisson coined Latin names for the species, these usually do not conform to the binomial system and none of them are recognised by the International Commission on Zoological Nomenclature. When in 1766 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition, he added 240 species that had been previously described by Brisson. One of these was the red-breasted nuthatch. Linnaeus included a brief description and used Brisson's name Sitta canadensis as his binomial name.
Like all nuthatches, the red-breasted nuthatch is assigned to the genus Sitta (Linnaeus, 1758), a name derived from sittē (σίττη), the Ancient Greek word for the Eurasian nuthatch. The specific epithet canadensis is New Latin for "belonging to Canada". "Nuthatch" is a linguistic corruption of "nuthack", referring to the bird's habit of wedging nuts into cracks in tree bark and hacking at them until they break open. "Red-breasted" is a reference to the rusty colour of the male's underparts.
The nuthatch's habit of wedging seeds into cracks and hammering them open has given rise to its common name.
In the past, the red-breasted nuthatch and four other species — the Corsican nuthatch, the Chinese nuthatch, the Algerian nuthatch and the Krüper's nuthatch — were thought to be a single species. These five make up a well-defined species group known as the "Sitta canadensis group", and are sometimes considered to be a superspecies. Within the species group, DNA studies have shown that the red-breasted nuthatch, the Corsican nuthatch and the Chinese nuthatch make up one clade and the Algerian nuthatch and Krüper's nuthatch make up a sister clade. The red-breasted nuthatch is monotypic across its extensive range.
Description
The red-breasted nuthatch is a small passerine, measuring 4.5 in (11 cm) in length, with a wingspan of 8.5 in (22 cm) and a weight of 9.9 g (0.35 oz). Its back and uppertail are bluish, and its underparts rust-colored. It has a black cap and eye line and a white supercilium (eyebrow). Sexes are similarly plumaged, though females and youngsters have duller heads and paler underparts.
Voice
The red-breasted nuthatch's call is high-pitched, nasal and weak. Transcribed as yenk or ink, they have been likened to a toy tin horn or a child's noisemaker. Its song is a slowly repeated series of clear, nasal, rising notes, transcribed as eeen eeen eeen.
Habitat and range
Though it is primarily a full-time resident of northern and subalpine conifer forests, the red-breasted nuthatch regularly migrates irruptively, with both the number migrating and the wintering locations varying from year to year. They sometimes reach northern Mexico, where they are rare winter visitors to Nuevo León, Baja California Norte and south along the Pacific slope as far as Sinaloa. In the eastern United States, its range is expanding southwards. Though formerly resident on Isla Guadalupe, an island off the western coast of Mexico, it appears to have been extirpated there, with the last known record of the species on the island dating from 1971. There is a single vagrant record for Mexico's Isla Socorro. It is an extremely rare vagrant to Europe, with two records in the western Palearctic; one bird successfully overwintered in eastern England.
Geographical distribution of Red-breasted nuthatch. Year-round Nonbreeding
Feeding behavior and diet
Like all nuthatches, the red-breasted nuthatch is an acrobatic species, hitching itself up and down tree trunks and branches to look for food. It goes headfirst when climbing down. It can "walk" on the underside of branches. Unlike woodpeckers and creepers, it does not use its tail as a prop while climbing. It tends to forage singly or in pairs.
The red-breasted nuthatch's diet changes depending on the season. In the summer, it eats mostly insects, occasionally even flycatching, while in the winter, it switches to conifer seeds. At feeders it will take sunflower seeds, peanut butter, and suet. It often wedges food pieces in bark crevices in order to break them up with the bill (as opposed to holding the food in their feet, like the Black-capped Chickadee does).
Breeding
The red-breasted nuthatch, like all nuthatches, is monogamous. The male courts the female with a peculiar display, lifting his head and tail while turning his back to her, drooping his wings, and swaying from side to side.
This bird excavates its own cavity nest, 1.53–37 m (5.0–121.4 ft) above ground (usually around 4.6 m (15 ft)). Excavation is by both sexes and takes one to eight weeks. The pair smears sap around the entrance hole, presumably to help deter predators. The nest is lined with grass, moss, shredded bark and rootlets. Nest building is by both sexes, but mostly by the female.
The female lays 2–8 eggs (usually 5–6), which are white, creamy or pinkish, and covered with reddish-brown speckles. The eggs measure 0.6–0.7 in (1.5–1.8 cm) long by 0.4–0.5 in (1.0–1.3 cm) wide. Incubation is by the female and lasts 12–13 days. The young are altricial and stay in the nest for 2–3 weeks, brooded by the female but fed by both sexes. Normally there is only one brood per year. Lifespan is around 6 years.
Conservation status and threats
Because of its large global range and its increasing population, the red-breasted nuthatch is rated as a species of Least Concern by the International Union for Conservation of Nature. In the Americas, it is protected by the Migratory Bird Treaty Act of 1918.
Researchers study how birds retweet news
by Courtney Brockman, University of Montana
Nora Carlson records a black-capped chickadee. She arrived at the University of Montana with an undergraduate degree in linguistics and the desire to translate bioacoustics. The nuthatch paper sprang from her UM senior thesis. Credit: University of Montana
Every social network has its fake news. And in animal communication networks, even birds discern the trustworthiness of their neighbors, a study from the University of Montana suggests.
The study, recently published in the top science journal Nature, is the culmination of decades' worth of research from UM alumni Nora Carlson and Chris Templeton and UM Professor Erick Greene in the College of Humanities and Sciences. It sheds a new light on bird social networks.
"This is the first time people have shown that nuthatches are paying attention to the source of information, and that influences the signal they produce and send along," Greene said.
Carlson, Templeton and Greene shared an interest in trying to crack the Rosetta Stone of how birds communicate and collected bird calls over the years.
Each bird species has a song, usually sung by the males, for "letting the babes know 'here I am,'" Greene said, as well as staking out real estate. Their loud and complex calls usually ring out during breeding season.
But for warning calls, each sound stands for a specific threat, such as "snake on the ground," "flying hawk" and "perched hawk." The calls convey the present danger level and specific information. They also are heard by all species in the woods in a vast communication network that sets them on high alert.
"Everybody is listening to everybody else in the woods," Greene said.
In the study, Greene and his researchers wanted to determine how black-capped chickadees and red-breasted nuthatches encode information in their calls.
In bird communication, a high-pitched "seet" from a chickadee indicates a flying hawk and causes a strong reaction—other birds go silent, look up and then dive in the bushes. Alarm calls can travel quickly through the woods. Greene said in previous experiments they clocked the speed of the calls at 100 miles per hour, which he likens to the bow wave on a ship.
"Sometimes birds in the woods know five minutes before a hawk gets there," Greene said.
A harsh, intensified "mobbing call" drives birds from all species to flock together to harass the predator. When the predator hears the mobbing call, it usually has to fly a lot farther to hunt, so the call is very effective.
"The owl is sitting in the tree, going, 'Oh crap!" Greene said.
Greene calls it "social media networks—the original tweeting."
For the study with chickadees and nuthatches, the researchers focused on direct information—something a bird sees or hears firsthand—versus indirect information, which is gained through the bird social network and could be a false alarm.
The researchers set up multiple microphones throughout the woods to pick up the birds’ calls, analyze their locations and map the “acoustic landscape” of the forest. Credit: University of Montana
"In a way, it kind of has to do with fake news, because if you get information through social media, but you haven't verified it, and you retweet it or pass it along, that's how fake news starts," Greene said.
Nuthatches and chickadees share the same predators: the great-horned owl and the pygmy owl. To the small birds, the pygmy owl is more dangerous than a great-horned owl due to its smaller turning radius, which allows it to chase prey better.
"If you are eating something that's almost as big as you are, it's worth it to go after it," Greene said.
Using speakers in the woods, the researchers played the chickadee's warning call for the low-threat great-horned owl and the higher-threat pygmy owl to nuthatches. The calls varied by threat level—great-horned owl versus pygmy owl—and whether they were direct (from the predators themselves) or indirect (from the chickadees).
What they discovered about the nuthatches was surprising.
Direct information caused the nuthatches to vary their calls according to the high threat and the low threat. But the chickadee's alarm call about both predators elicited only a generic, intermediate call from the nuthatch, regardless of the threat level.
Greene said the research points to the nuthatch's ability to make sophisticated decisions about stimuli in their environment and avoid spreading "fake news" before they confirm a predator for themselves.
"You gotta take your hat off to them," Greene said. "There's a lot of intelligence there."
The research, conducted by Carlson, Templeton and Greene around Montana and Washington throughout the years, wasn't without challenges.
Most of the set up happened during winter, and nuthatches had to be isolated from chickadees to ensure the warning calls were not a response to witnessing chickadees going crazy. Often a chickadee would appear after everything was set up, and the researchers had to take everything down and try a new location.
"It's quite hard to find nuthatches without chickadees somewhere in the area," Greene said. "That was the most difficult part—to find these conditions out in the wild."
But the results were worth the work.
Greene said the nuthatch study ultimately helps researchers better understand how animal communication networks work and how different species decode information, encode info and pass it along.
"We kind of wish people behaved like nuthatches," Greene said.
phys.org/news/2020-02-birds-retweet-news.html
Journal References:
Nora V Carlson et al, Nuthatches vary their alarm calls based upon the source of the eavesdropped signals, Nature Communications (2020). DOI: 10.1038/s41467-020-14414-w
Abstract
Animal alarm calls can contain detailed information about a predator’s threat, and heterospecific eavesdropping on these signals creates vast communication networks. While eavesdropping is common, this indirect public information is often less reliable than direct predator observations. Red-breasted nuthatches (Sitta canadensis) eavesdrop on chickadee mobbing calls and vary their behaviour depending on the threat encoded in those calls. Whether nuthatches propagate this indirect information in their own calls remains unknown. Here we test whether nuthatches propagate direct (high and low threat raptor vocalizations) or indirect (high and low threat chickadee mobbing calls) information about predators differently. When receiving direct information, nuthatches vary their mobbing calls to reflect the predator’s threat. However, when nuthatches obtain indirect information, they produce calls with intermediate acoustic features, suggesting a more generic alarm signal. This suggests nuthatches are sensitive to the source and reliability of information and selectively propagate information in their own mobbing calls.
www.nature.com/articles/s41467-020-14414-w
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Sittidae
Genus: Sitta
Species: Sitta canadensis Linnaeus, 1766
The red-breasted nuthatch (Sitta canadensis) is a small songbird. The adult has blue-grey upperparts with cinnamon underparts, a white throat and face with a black stripe through the eyes, a straight grey bill and a black crown. Its call, which has been likened to a tin trumpet, is high-pitched and nasal. It breeds in coniferous forests across Canada, Alaska and the northeastern and western United States. Though often a permanent resident, it regularly irrupts further south if its food supply fails. There are records of vagrants occurring as far south as the Gulf Coast and northern Mexico. It forages on the trunks and large branches of trees, often descending head first, sometimes catching insects in flight. It eats mainly insects and seeds, especially from conifers. It excavates its nest in dead wood, often close to the ground, smearing the entrance with pitch.
Taxonomy
In 1760 the French zoologist Mathurin Jacques Brisson included a description of the red-breasted nuthatch in his Ornithologie based on a specimen collected in Canada. He used the French name Le torchepot de Canada and the Latin Sitta Canadensis. Although Brisson coined Latin names for the species, these usually do not conform to the binomial system and none of them are recognised by the International Commission on Zoological Nomenclature. When in 1766 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition, he added 240 species that had been previously described by Brisson. One of these was the red-breasted nuthatch. Linnaeus included a brief description and used Brisson's name Sitta canadensis as his binomial name.
Like all nuthatches, the red-breasted nuthatch is assigned to the genus Sitta (Linnaeus, 1758), a name derived from sittē (σίττη), the Ancient Greek word for the Eurasian nuthatch. The specific epithet canadensis is New Latin for "belonging to Canada". "Nuthatch" is a linguistic corruption of "nuthack", referring to the bird's habit of wedging nuts into cracks in tree bark and hacking at them until they break open. "Red-breasted" is a reference to the rusty colour of the male's underparts.
The nuthatch's habit of wedging seeds into cracks and hammering them open has given rise to its common name.
In the past, the red-breasted nuthatch and four other species — the Corsican nuthatch, the Chinese nuthatch, the Algerian nuthatch and the Krüper's nuthatch — were thought to be a single species. These five make up a well-defined species group known as the "Sitta canadensis group", and are sometimes considered to be a superspecies. Within the species group, DNA studies have shown that the red-breasted nuthatch, the Corsican nuthatch and the Chinese nuthatch make up one clade and the Algerian nuthatch and Krüper's nuthatch make up a sister clade. The red-breasted nuthatch is monotypic across its extensive range.
Description
The red-breasted nuthatch is a small passerine, measuring 4.5 in (11 cm) in length, with a wingspan of 8.5 in (22 cm) and a weight of 9.9 g (0.35 oz). Its back and uppertail are bluish, and its underparts rust-colored. It has a black cap and eye line and a white supercilium (eyebrow). Sexes are similarly plumaged, though females and youngsters have duller heads and paler underparts.
Voice
The red-breasted nuthatch's call is high-pitched, nasal and weak. Transcribed as yenk or ink, they have been likened to a toy tin horn or a child's noisemaker. Its song is a slowly repeated series of clear, nasal, rising notes, transcribed as eeen eeen eeen.
Habitat and range
Though it is primarily a full-time resident of northern and subalpine conifer forests, the red-breasted nuthatch regularly migrates irruptively, with both the number migrating and the wintering locations varying from year to year. They sometimes reach northern Mexico, where they are rare winter visitors to Nuevo León, Baja California Norte and south along the Pacific slope as far as Sinaloa. In the eastern United States, its range is expanding southwards. Though formerly resident on Isla Guadalupe, an island off the western coast of Mexico, it appears to have been extirpated there, with the last known record of the species on the island dating from 1971. There is a single vagrant record for Mexico's Isla Socorro. It is an extremely rare vagrant to Europe, with two records in the western Palearctic; one bird successfully overwintered in eastern England.
Geographical distribution of Red-breasted nuthatch. Year-round Nonbreeding
Feeding behavior and diet
Like all nuthatches, the red-breasted nuthatch is an acrobatic species, hitching itself up and down tree trunks and branches to look for food. It goes headfirst when climbing down. It can "walk" on the underside of branches. Unlike woodpeckers and creepers, it does not use its tail as a prop while climbing. It tends to forage singly or in pairs.
The red-breasted nuthatch's diet changes depending on the season. In the summer, it eats mostly insects, occasionally even flycatching, while in the winter, it switches to conifer seeds. At feeders it will take sunflower seeds, peanut butter, and suet. It often wedges food pieces in bark crevices in order to break them up with the bill (as opposed to holding the food in their feet, like the Black-capped Chickadee does).
Breeding
The red-breasted nuthatch, like all nuthatches, is monogamous. The male courts the female with a peculiar display, lifting his head and tail while turning his back to her, drooping his wings, and swaying from side to side.
This bird excavates its own cavity nest, 1.53–37 m (5.0–121.4 ft) above ground (usually around 4.6 m (15 ft)). Excavation is by both sexes and takes one to eight weeks. The pair smears sap around the entrance hole, presumably to help deter predators. The nest is lined with grass, moss, shredded bark and rootlets. Nest building is by both sexes, but mostly by the female.
The female lays 2–8 eggs (usually 5–6), which are white, creamy or pinkish, and covered with reddish-brown speckles. The eggs measure 0.6–0.7 in (1.5–1.8 cm) long by 0.4–0.5 in (1.0–1.3 cm) wide. Incubation is by the female and lasts 12–13 days. The young are altricial and stay in the nest for 2–3 weeks, brooded by the female but fed by both sexes. Normally there is only one brood per year. Lifespan is around 6 years.
Conservation status and threats
Because of its large global range and its increasing population, the red-breasted nuthatch is rated as a species of Least Concern by the International Union for Conservation of Nature. In the Americas, it is protected by the Migratory Bird Treaty Act of 1918.
Researchers study how birds retweet news
by Courtney Brockman, University of Montana
Nora Carlson records a black-capped chickadee. She arrived at the University of Montana with an undergraduate degree in linguistics and the desire to translate bioacoustics. The nuthatch paper sprang from her UM senior thesis. Credit: University of Montana
Every social network has its fake news. And in animal communication networks, even birds discern the trustworthiness of their neighbors, a study from the University of Montana suggests.
The study, recently published in the top science journal Nature, is the culmination of decades' worth of research from UM alumni Nora Carlson and Chris Templeton and UM Professor Erick Greene in the College of Humanities and Sciences. It sheds a new light on bird social networks.
"This is the first time people have shown that nuthatches are paying attention to the source of information, and that influences the signal they produce and send along," Greene said.
Carlson, Templeton and Greene shared an interest in trying to crack the Rosetta Stone of how birds communicate and collected bird calls over the years.
Each bird species has a song, usually sung by the males, for "letting the babes know 'here I am,'" Greene said, as well as staking out real estate. Their loud and complex calls usually ring out during breeding season.
But for warning calls, each sound stands for a specific threat, such as "snake on the ground," "flying hawk" and "perched hawk." The calls convey the present danger level and specific information. They also are heard by all species in the woods in a vast communication network that sets them on high alert.
"Everybody is listening to everybody else in the woods," Greene said.
In the study, Greene and his researchers wanted to determine how black-capped chickadees and red-breasted nuthatches encode information in their calls.
In bird communication, a high-pitched "seet" from a chickadee indicates a flying hawk and causes a strong reaction—other birds go silent, look up and then dive in the bushes. Alarm calls can travel quickly through the woods. Greene said in previous experiments they clocked the speed of the calls at 100 miles per hour, which he likens to the bow wave on a ship.
"Sometimes birds in the woods know five minutes before a hawk gets there," Greene said.
A harsh, intensified "mobbing call" drives birds from all species to flock together to harass the predator. When the predator hears the mobbing call, it usually has to fly a lot farther to hunt, so the call is very effective.
"The owl is sitting in the tree, going, 'Oh crap!" Greene said.
Greene calls it "social media networks—the original tweeting."
For the study with chickadees and nuthatches, the researchers focused on direct information—something a bird sees or hears firsthand—versus indirect information, which is gained through the bird social network and could be a false alarm.
The researchers set up multiple microphones throughout the woods to pick up the birds’ calls, analyze their locations and map the “acoustic landscape” of the forest. Credit: University of Montana
"In a way, it kind of has to do with fake news, because if you get information through social media, but you haven't verified it, and you retweet it or pass it along, that's how fake news starts," Greene said.
Nuthatches and chickadees share the same predators: the great-horned owl and the pygmy owl. To the small birds, the pygmy owl is more dangerous than a great-horned owl due to its smaller turning radius, which allows it to chase prey better.
"If you are eating something that's almost as big as you are, it's worth it to go after it," Greene said.
Using speakers in the woods, the researchers played the chickadee's warning call for the low-threat great-horned owl and the higher-threat pygmy owl to nuthatches. The calls varied by threat level—great-horned owl versus pygmy owl—and whether they were direct (from the predators themselves) or indirect (from the chickadees).
What they discovered about the nuthatches was surprising.
Direct information caused the nuthatches to vary their calls according to the high threat and the low threat. But the chickadee's alarm call about both predators elicited only a generic, intermediate call from the nuthatch, regardless of the threat level.
Greene said the research points to the nuthatch's ability to make sophisticated decisions about stimuli in their environment and avoid spreading "fake news" before they confirm a predator for themselves.
"You gotta take your hat off to them," Greene said. "There's a lot of intelligence there."
The research, conducted by Carlson, Templeton and Greene around Montana and Washington throughout the years, wasn't without challenges.
Most of the set up happened during winter, and nuthatches had to be isolated from chickadees to ensure the warning calls were not a response to witnessing chickadees going crazy. Often a chickadee would appear after everything was set up, and the researchers had to take everything down and try a new location.
"It's quite hard to find nuthatches without chickadees somewhere in the area," Greene said. "That was the most difficult part—to find these conditions out in the wild."
But the results were worth the work.
Greene said the nuthatch study ultimately helps researchers better understand how animal communication networks work and how different species decode information, encode info and pass it along.
"We kind of wish people behaved like nuthatches," Greene said.
phys.org/news/2020-02-birds-retweet-news.html
Journal References:
Nora V Carlson et al, Nuthatches vary their alarm calls based upon the source of the eavesdropped signals, Nature Communications (2020). DOI: 10.1038/s41467-020-14414-w
Abstract
Animal alarm calls can contain detailed information about a predator’s threat, and heterospecific eavesdropping on these signals creates vast communication networks. While eavesdropping is common, this indirect public information is often less reliable than direct predator observations. Red-breasted nuthatches (Sitta canadensis) eavesdrop on chickadee mobbing calls and vary their behaviour depending on the threat encoded in those calls. Whether nuthatches propagate this indirect information in their own calls remains unknown. Here we test whether nuthatches propagate direct (high and low threat raptor vocalizations) or indirect (high and low threat chickadee mobbing calls) information about predators differently. When receiving direct information, nuthatches vary their mobbing calls to reflect the predator’s threat. However, when nuthatches obtain indirect information, they produce calls with intermediate acoustic features, suggesting a more generic alarm signal. This suggests nuthatches are sensitive to the source and reliability of information and selectively propagate information in their own mobbing calls.
www.nature.com/articles/s41467-020-14414-w