Last winter was a trial for us all, and our garden birds did not have an easy
time of it either. The British Trust for Ornithology's (BTO) Garden Bird Feeding
Survey saw unprecedented numbers of birds driven into Britain's gardens in
search of food. As winter looms once again, an army of 'citizen scientists' is preparing to chart the changing fortunes of our winter visitors.

The combination of poor fruit and seed yields in the wider countryside last
autumn, and the long, cold winter that followed, brought unprecedented numbers
of birds to our gardens. Perhaps the most striking arrival was the number of Siskins visiting gardens in search of food — numbers last winter were more than double the previous five-year average — a response to very poor crops of Sitka Spruce and birch seed, which Siskins usually take in winter.

 While the stories emerging from individual winters are fascinating, it is the
quantity of information collected by the BTO's armchair birdwatchers since 1970
that has proved so important. These long-term changes hint at what the future
might hold for our gardens and their visiting bird communities. Garden
birdwatchers may be seeing less of 'common' species, such as Collared Dove, Song Thrush and Starling, which are disappearing from our gardens
quite rapidly. However, fortunes for other birds are improving with Bullfinch, Goldfinch and Great Spotted Woodpecker becoming regulars.

 As the nation hopes that this winter is not as long or cold as the last one,
a certain group of birdwatchers are probably in two minds. For those who
participate in the BTO's Garden Bird Feeding Survey (GBFS), it is time to dust
off their notebooks and start recording from the warmth of their living
rooms.

Clare Simm of the BTO Garden Ecology team shares her thoughts as to what may
happen this winter: "With an unusually late start to the breeding season this
year, and a slow move towards the warm weather, it is difficult to predict
exactly how our birds will be faring as they enter the winter months. If this
winter is anywhere near as cold as last, then we might expect a sudden influx
into gardens once the autumn seed and berry stocks are depleted. One thing is
for sure, our 'citizen scientists' will be the first to notice and tell us."

 For a free guide on what to feed your birds this winter, information on how
to become a citizen scientist with the BTO and the opportunity to contribute to
valuable work like this, email [email protected],
telephone 01842 750050 or write to GBFS, BTO, The Nunnery, Thetford, Norfolk,
IP24 2PU.

Birds might be paying more attention to road speed limits than some humans: a
new study has found that some European birds factor in average traffic speeds
when determining when they need to take off to avoid oncoming cars. In the
study, published in this week's issue of the journal Biology Letters, scientists tested whether European birds standing on the side of the road
altered their escape distances in response to how fast an approaching car was
moving or to road speed limits. The abstract can be found below:

 Behavioural responses can help species persist in habitats modified
by humans. Roads and traffic greatly affect animals' mortality, not only through
habitat structure modifications but also through direct mortality owing to
collisions. Although species are known to differ in their sensitivity to the
risk of collision, whether individuals can change their behaviour in response to
this is still unknown. Here, we tested whether common European birds changed
their flight initiation distances (FIDs) in response to vehicles according to
road speed limit (a known factor affecting killing rates on roads) and vehicle
speed. We found that FID increased with speed limit, although vehicle speed had
no effect. This suggests that birds adjust their flight distance to speed limit,
which may reduce collision risks and decrease mortality maximizing the time
allocated to foraging behaviours. Mobility and territory size are likely to
affect an individual's ability to respond adaptively to local speed
limits.
Study co-author Pierre Legagneux, a biologist at Canada's University of
Quebec in Rimouski, said the idea for the experiment occurred to him while he
was commuting to his lab in France. "I found [the commute] very boring so I had
to do something while driving, so I started to record birds flying away,"
Legagneux said. Using only a stopwatch and a notebook, Legagneux measured the
reaction times of birds that he spotted on the edge of the road while travelling
in regions where the speed limit ranged from about 12 to 70 miles per hour (20
to 110 kilometres per hour). "When the birds flew away, I started my timer and I
fixed the point where the birds were standing. And when I passed over this
point, I stopped my timer," Legagneux explained. "So I had the time elapsed, and
because I also recorded our vehicle speed, I also had the distance."

 Legagneux and his colleague, Simon Ducatez of Canada's McGill University,
found that the birds — mainly Carrion Crows, House Sparrows and Blackbirds — took flight earlier after spotting
their car in areas where the speed limit was higher. Curiously, the birds did
not seem to pay attention to the car itself. "They reacted the same way, no
matter the speed of the car," Legagneux said.

 The scientists speculate that some combination of two things might be
happening. First, it may just be a case of natural selection in which
individuals that failed to take off quickly enough are killed. As a result, only
those birds with traits that help them successfully escape oncoming traffic go
on to reproduce. Another possibility, Legagneux said, is that the birds are
actually learning to adapt to different traffic speeds. Daniel Blumstein, a
biologist and bird behaviourist at the University of California, Los Angeles,
said he could easily see how learning might be taking place. Imagine, he said, a
scenario in which a bird is foraging next to the road and a truck drives by. "If
the truck is moving fast, the bird is going to get knocked around by the
vortices coming off that truck" said Blumstein. "So the bird, if it survives, is
going to learn very quickly that the truck produced a very adverse experience...
One or a few trials of getting knocked around may be sufficient for the bird to
learn that cars are approaching faster on certain roads than other roads."

 But why did the birds seem to ignore the speed of the scientist's car itself?
It's possible, Legagneux said, that the birds might have just learned that it's
simpler to react the same way for any given section of road. "This way, they are
not spending a lot of time being vigilant by looking at the speed of each car,"
he said. Legagneux added that the findings have implications for making roads
safer for wildlife. "If you have different speed limits for similar roads in
similar landscapes, it could be dangerous for birds because they hardly have any
cues of those changes."

awesome website displaying some of the most innovative (and crazy) of our nesting birds! Click here

In striking contrast to last week's report on the relation between feeding and the reproductive success of Great Spotted Woodpeckers, new research1 claims that feeding wild birds during the winter could harm the success of any chicks born in the following spring. Scientists carried out the study on nine sites across Cornwall, where over three years they supplemented the Blue Tit population's winter food with nothing, balls of fat, or fat enriched with vitamin E. Nest boxes at the sites were then checked the following spring to assess how the number of eggs, and the size and success of any chicks, related to the amount and type of extra food provided.

The study, published in Scientific Reports, found that when extra food was given Blue Tits produced smaller chicks, which had a lower chance of survival than the chicks that didn't receive any additional food. Dr Jon Blount of the University of Exeter, who led the research team, explained that, "Although the precise reasons why fed populations subsequently have reduced reproductive success are unclear, it would be valuable to assess whether birds would benefit from being fed all year round rather than only in winter".

Supplementing birds' sparse winter diet with commercially available food is common in the UK and USA, with more than half a million tonnes of commercial bird feed sold each year in the two countries. Vitamin E was used in the study for one test group as it is often found in bird food such as seeds and nuts. Previous studies have shown that giving wild birds additional food can have an almost immediate benefit to their survival, and can enhance future breeding success. Dr Kate Plummer of the British Trust for Ornithology, who is first author of the research, says that a possible reason for the findings is that extra food helps birds who would not otherwise have survived to breed. The poor condition of these birds means they can only raise a small number of chicks.

Whether providing food is detrimental or beneficial to wild bird populations, it is clear that more research is needed to better understand its effects. Blount concluded that "More research is needed to determine exactly what level of additional food provisioning, and at what times of year, would truly benefit wild bird populations."

The paper's abstract is as follows:

"Supplementation of food to wild birds occurs on an enormous scale worldwide, and is often cited as an exemplar of beneficial human–wildlife interaction. Recently it has been speculated that winter feeding could have negative consequences for future reproduction, for example by enabling low-quality individuals to recruit into breeding populations. However, evidence that winter feeding has deleterious impacts on reproductive success is lacking. Here, in a landscape-scale study of blue tits (Cyanistes caeruleus) across multiple years, we show that winter food supplementation reduced breeding performance the following spring. Compared to unfed populations, winter-fed birds produced offspring that weighed less, were smaller, and had lower survival. This impairment was observed in parents that had received fat only, or in combination with vitamin E, suggesting some generality in the mechanism by which supplementary feeding affected reproduction. Our results highlight the potential for deleterious population-level consequences of winter food supplementation on wild birds."

The British Trust for Ornithology (BTO) hopes to answer one of British ornithology's greatest mysteries using the very latest that technology has to offer in a project starting this summer. The House Martin is well known to many people; from April to September it lives cheek by jowl with those lucky enough to have this energetic little bird nest under their eaves. In recent years, however, the number breeding here in the UK has fallen by two thirds, leading to the species being Amber-listed as a bird of conservation concern and in need of help.

Though we know a lot about the breeding ecology of the House Martin in the UK, once September arrives and this enigmatic bird heads off south for the winter it virtually disappears from our radar. It is not known where in Africa House Martins winter, or how precisely they get there. If ornithologists are to start understanding what is driving the decline of the martins, then it is these questions that will need to be answered.

This summer, the BTO aims to use the latest technology to discover the routes that House Martins take to Africa and to find out exactly where they spend the winter months. BTO researchers plan to do this by fitting a tiny (shirt button-sized) device known as a geolocator to each bird. Weighing less than a gramme, the device contains a clock, a calendar and a light sensor, together with enough memory to store all of the data collected from the day it is fitted until the day it is retrieved.

By comparing daylight length, as measured by the light sensor, with the time and date recorded, scientists at the BTO are able to determine where on the planet the device was at any given time. This information will then reveal the wintering areas, together with the location of possible stopover and refuelling sites, precise migration routes and the timing of the migration through Europe and Africa.

Paul Stancliffe of the BTO commented, "I have long dreamed of being able to follow a bird like the House Martin on its migration from Britain to Africa, to get a glimpse of the places it is passing through and the places that it chooses to stay and rest for a while before continuing on its journey. It is very exciting to think that we are on the brink of new discoveries that should help these delightful birds and provide them with a more optimistic future. This technology comes at a price and we need help to secure enough of them to make the project worthwhile. Anyone interested in seeing how they might be able to help can find out more by visiting www.bto.org. Each device costs £170 and we hope to be able to fit them to at least 20 birds. We need help to support the scientists developing this project."

For more information please visit http://www.bto.org/volunteer-surveys/house-martin-survey/movements.

An international team lead by the University of Granada has found that female sparrows will invest more energy into laying eggs according to the male's ability to fill the nest with feathers which serve to insulate the chicks from the cold and keep them alive. Scientists from the University of Granada, in collaboration with the South African University of the Witwatersrand and the Percy FitzPatrick Institute at the University of Cape Town, have discovered that the female House Sparrow invests more energy into laying eggs when the male brings more feathers to the nest.

As well as feathers collected affecting the number of eggs laid, scientists have also found that the extent of the black bib patch and redness of the head on males influence females' choice of partner.

"We conducted an experiment with two types of treatments and a control group. In total, we observed the behaviour of 50 pairs of sparrows," Lola García López de Hierro, the study's main researcher, informed SINC. According to their results, carrying feathers could be a result of sexual selection by the females as they put more energy into reproduction if they have more feathers in the nest. "They provide excellent insulation and the females know that less chicks will die if the male brings more feathers," the expert stated.

The experiment was conducted in the natural environment of Dassen Island (South Africa) and this is the first time this behaviour has been documented in House Sparrows. The researchers took away and added feathers to the nests of the fifty pairs of sparrows during these birds' different mating seasons. A first stage in the treatment consisted of spending an hour observing the behaviour of the pairs with chicks less than five days old in order to register diverse variables and watch their behaviour if a series of feathers were taken away or if these feathers were left in the nest. The experiment was then repeated with chicks over ten days old. They also observed that when the females noticed there were feathers missing they animatedly called the males and the male sparrows responded by bringing more feathers and dancing around the female on his return to the nest. "We had film recordings of the nest where we gathered information on sparrow behaviour and, using a table of variables, we were able to conclude that the more feathers in the nest, the more eggs the sparrows laid," García-López de Hierro pointed out.

Ninety percent of sparrows mate for life and keep the same partner from one year to the next; however, numerous factors influence the choice of mating partner. For example, the size of the black patch on the males' chest, commonly known as the bib, indicates their biological quality. "The bigger the patch, the higher the quality, an aspect that females can easily select for," the scientist explained. Other factors that demonstrate the male's biological capacity are the redness of the head, in other words, "the more carotene they invest in the colour of their feathers, the more reproductive success they will have," and the ratio between the size of the beak and the size of the tarsus.