As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Friday, 24 May 2019

Birds outside their comfort zone are more vulnerable to deforestation

Date:  May 9, 2019
Source:  Imperial College London
Members of the same bird species can have dramatically different responses to deforestation depending on where they live, finds a new study.
Predicting a species' sensitivity to environmental changes, such as deforestation or climate change, is crucial for designing conservation strategies.
These predictions are often based on a species' physical traits, and assume that all members of a species will respond the same.
However, members of a single species live across a large geographical range that encompasses areas with the right physical conditions for them, such as temperature and food sources.
Some populations of a species will inevitably live at the edge of their range, where conditions are less than perfect because they are either too cold or too hot. Now, in new research published this week in Nature Ecology & Evolution, a research team led by Imperial College London have investigated the effect living near the range edge has on bird species in Brazil.
By analysing 378 species detected over 211 sites spanning 2,000 km of Atlantic Forest in Brazil, the team found dramatic differences in sensitivity to deforestation between populations at the edge of the range and those nearer the 'core'.

Birds use social cues to make decisions

Date:  May 2, 2019
Source:  Oxford University Press USA
A new study in The Auk: Ornithological Advancessuggests that some birds prioritize social information over visual evidence when making breeding choices.
The quality of an environment can be difficult for a bird to assess and, therefore, continuously gathering information is a good way to stay up-to-date with breeding conditions. In this field study, researchers tested how the wild Zebra Finch (Taeniopygia guttata) is attracted to successful nest sites. They presented the Zebra Finch with different visual or acoustic cues in nest boxes, simulating the presence of small or large broods, in order to test how birds assess the quality of a potential breeding site.
When discussing the costs and benefits of social information, scientists often argue that socially acquired knowledge is less reliable and more prone to deception. The sounds made by nesting birds, however, are honest indicators of the number of chicks. Predators can use these cues to locate nests. While the calls of chicks serve as signals for the parents and siblings and (inadvertently) also as cues for predators, it is unknown whether chick calls can also function as cues for prospective breeders.
Researchers here aimed to test which social cues from the nests of Zebra Finches attract other Zebra Finches. In two separate experiments, they presented wild Zebra Finches with either acoustic cues (playback of chick calls) or visual cues (eggs) with either small or large broods. Using playbacks of chick calls or nests with unhatched eggs, respectively, allowed them to completely discern brood size from parental activity.

What drives multiple female acorn woodpeckers to share a nest?

Study explores the possible benefits of rare behavior
Date:  May 2, 2019
Source:  Cornell University
Acorn Woodpeckers live in close-knit family groups and have one of the most complex breeding systems of any bird in the world. In about 20 percent of family groups, up to 3 related females may lay eggs in the same nest. They raise the chicks cooperatively with one or more related males. This behavior is known as joint nesting or "cooperative polyandry." Only five other species of birds worldwide are known to do this. The reasons that may be driving the behavior are outlined in a study recently published in The American Naturalist.
Lead authors Sahas Barve at Old Dominion University (Cornell Ph.D. '17), and Cornell Lab of Ornithology scientist Walt Koenig, used demographic data collected during 35 years (1982-2016) at the Hastings Natural History Reservation in central coastal California. They analyzed the costs and benefits of joint nesting, hoping to explain why some woodpecker females exhibit this rare behavior.
They found that joint nesting was more common in years when Acorn Woodpecker population density was high, all the breeding territories were occupied, and opportunities for a female to nest on her own were very unlikely.

Rare Copy of World’s Most Famous Bird Book on Display in Chicago

Alex Ruppenthal | April 29, 2019 4:54 pm
The groundbreaking book “Birds of America” is now on display at the Field Museum.
The book was published between 1827 and 1838 by John James Audubon, a painter and ornithologist who in 1826 set out to illustrate every bird in North America. Audubon discovered more than 100 bird species during his 12-year mission and even drew some species that have since gone extinct, such as whooping cranes and passenger pigeons.
Audubon’s book features intricate and detailed life-size watercolor paintings of nearly every bird on the continent, and is recognized for its permanent influence on the art of wildlife illustration.
“At a time when photography was still at its infancy and not accessible for most, scientific journals heavily relied on paintings and drawings to illustrate animals,” said Diana Duncan, the Field Museum’s technical services librarian, in a statement. “Birds were not seen as art subjects, so Audubon’s unique and beautiful, life-size renderings were impactful not only in the scientific community for capturing the birds at their most natural but also in the art world.”

Rare bird of prey spotted over Santon

Monday, May 13th, 2019 4:41pm
The spell of good weather has been good for more than just gardeners it seems.
An osprey has been spotted on the Island today.
Director of Manx Birdlife Neil Morris, says he spotted the bird of prey in Santon this morning.
The raptor is considered a rarity in the Island's skies, with just one or two sightings each year of the bird as a passing migrant.
The bird was heading northwards, gaining height as it did so, and Neil described the sight as "magic!"
According to the RSPB, there is believed to be just 200-250 breeding pairs in the British Isles with Scotland considered a 'stronghold' for the species.

Starlings disappearing from Scotland and UK

'Mixed fortunes' for birds.
Published: 06:00Friday 03 May 2019
Scotland’s starling and rook populations have fallen dramatically over the past two decades, according to a new report.
Surveys show numbers of starlings north of the border were down by 28 per cent in 2017 compared to 1995, with a further 12 per cent loss in the past year.
This is part of a worrying UK-wide decline of 52 per cent since 1995.
Rook numbers in Scotland have fallen by 37 per cent over the same period.
Ornithologists do not know exactly what is driving the declines but say changes in the use of grasslands could be a major factor.
Other bird species that continue to cause concern include the greenfinch, which has declined by massive 66 per cent over the 22-year period, and the curlew, with a drop of 61 per cent.
Swifts have also experienced a major fall in numbers, with a 28 per cent decline in the past year and an overall loss of 59 per cent since 1995.
The latest figures show a much more positive picture for species, which have seen numbers soar.
Chiffchaffs have increased nearly eight-fold since 1995, while great spotted woodpeckers and blackcaps have more than quadrupled.
However, all three species were scarcer in 2018 than 2017.

Tagged hen harrier disappears on South Lanarkshire moor

7 May 2019
A young hen harrier fitted with a satellite transmitter has disappeared on a moor in South Lanarkshire.
RSPB Scotland said the bird of prey was the latest to have gone missing in suspicious circumstances in a "black hole" area of countryside.
The female harrier, named Skylar, was being monitored by the RSPB near a grouse moor south of the village of Elvanfoot.
Its tag abruptly stopped working on 7 February.
The RSPB's Dr Cathleeen Thomas said the disappearance in an area where birds of prey have previously been illegally killed followed a "depressingly familiar pattern".
She added: "Her tag was working as expected, then suddenly stopped. There have been no further transmissions, and the bird's body has not been located.
"Had she died of natural causes, we would have expected the transmitter to continue working, allowing us to recover her body. Sadly, we'll probably never know exactly what has happened to Skylar."
In 2017, a hen harrier and short-eared owl were shot and killed on a grouse moor a few miles away from Skylar's last known location.
Three more tagged hen harriers vanished in the area between June 2014 and May 2016.
Skylar was fitted with a satellite tag in July 2017 just before she fledged from her nest in Argyll.