2014: Did you know?
December: Did you know...
...a minimum of 5.25 trillion particles of plastic, weighing nearly 269,000 tonnes, are estimated to be floating in the world’s oceans. New researchconcludes that pieces of plastic primarily derived from food and drink packaging amass an equivalent weight of 5 ½ Titanic-sizes vessels or 1,415 Blue Whales put together, yet is mainly constituted by ‘micro-plastics’ measuring less than 5mm. More locally, 95% of dead Fulmars analysed from the North Sea have been found to have an average of 44 pieces of plastic contents in their stomachs, with one bird having 1,603 pieces.
November
Did you know that there are more Rough-legged Buzzards in the UK than we might normally expect, and more may yet arrive. This is probably due to a shortage of food in northern Europe. The lemming population has experienced a crash in southern Norway, after a high population in the early part of the year, and has been low in northern Norway. This means that birds that have had a good summer now face starvation if they don't move. Fortunately, 2014 has been a vole year here in the UK and any birds arriving here should find it a little easier, at least for now.
For help identifying Rough-legged Buzzard from Common Buzzard, watch our BTO Bird ID video here.
October
Did you know that gulls only fly in ‘V’ formation during still conditions? It is well known that flying in ‘V’ formation offers energetic benefits* to birds in the slipstream of the birds in front, providing lift amongst other things. During still conditions gulls heading off to their night time roost sites take advantage of this and habitually fly in ‘V’ formation. However, during windy conditions this breaks down and gulls flying to their night time roosts in loose flocks with no easily determined formation. Presumably in windy conditions it is easier to find lift and harder to maintain a rigid formation. Look out from mid-afternoon onwards for gulls flying off to roost in your area.
*See here for paper abstract in Nature journal.
September
Did you know that some Yellow-browed Warblers can migrate in entirely the wrong direction? One of the most frequently occurring Asian passerines in western Europe, their breeding range extends from just west of the Ural Mountains eastwards to eastern Siberia, Mongolia and northeastern China. They winter in northeastern India east through southern China to Taiwan, and south to the Malay Peninsula. In autumn, most of the breeding population probably migrates through northeastern China, filtering down to the species’ main winter quarters.
However, each year, some birds arrive in Britain and Ireland. Between mid to late September to mid November, numbers vary annually, but some years sees hundreds arriving; in 2005, for example, more than 1,450 individuals were recorded. This autumn the earliest arrival was on 10 September on mainland Shetland, with birds in scattered coastal locations from Aberdeenshire to Norfolk over the following few days.
A popular explanation is that of ‘reverse migration’, the theory being that birds have a defect in their sense of orientation, making them fly precisely in the opposite direction to that required to reach the wintering grounds in southeast Asia. Many other theories have been proposed to explain the arrival of birds in western Britain, including genetic mutation and natural dispersal. There may even have been a subtle shift in wintering range with regular dispersal proving a successful strategy and leading to overwintering in western Europe and a subsequent return migration? It has also been suggested that there may be undiscovered wintering grounds in western Europe or West Africa and the birds we see in Britain are using an established migration route.
How to find a Yellow-browed Warbler
Yellow-browed Warblers are most likely to appear when high pressure over Scandinavia causes an easterly airflow across the North Sea towards the east coast of Scotland and England. Check coastal woodlands in the east and northeast. They are very active, tiny birds, often flicking through the high canopy. Also check tit flocks carefully as Yellow-browed Warblers sometimes roam the woods with them. They have a distinctive, high-pitched ‘tsoeest’ call which often reveals their presence so it is worth familiarising yourself with this! Coal Tits give a similar call but it is lower-pitched.
August:
...that it used to be thought that the look of a Stone Curlew could cure jaundice? The striking yellow eye of the bird was thought to draw out the jaundice through its cold stare. This lead to the birds eyes often being kept covered when being sold so as only to cure those who paid for the privilege. Their large eyes enable the bird to feed during the night but no one knows why the eyes are yellow.
July
Did you know that Rooks exhibit a wide range of intelligent behaviours including complex social relationships and the ability to plan for the future by caching food. They also have problem-solving skills and they use these skills in gardens to work out how to feed from hanging feeders (see this video).
Normally a bird associated with Farmland and Woodland edge, of the 13,000 or so gardens that submit Garden BirdWatch records, almost 500 Rooks report Rooks in the winter. In our new Garden Rook survey we are hoping to learn even more about Rook behaviour, so if you have Rooks in your garden, please do take part.
June
...that Great Tit females have been found to prefer males with broader black belly markings (ties)? These well-marked males produce better quality young – as well as having better survival themselves and are also known to be more dominant, aggressive and assertive than less well-marked individuals. However a recent Spanish study has found that the story is not that simple.
177 male Great Tits from a site in urban Barcelona were caught and ringed, and 324 from a woodland site 7-km out of the city, over a 16 year period. Whilst Great Tits with broad belly ties from a rural/woodland habitat have higher survival the opposite has been found in an urban population: males with smaller belly ties have better survival than well-marked individuals.
In line with the dominant personalities of well-marked birds, less well-marked males are known to be more cautious, less aggressive and ‘trap shy’ (this is taken into account in the analyses). The fact that urban males are actively being selected for these traits show a plasticity that will allow the species to adapt to new environments. Rather than being a sign of urban habitats only able to support poorer-quality birds, it is believed to show active selection for a desirable trait in this environment – of more cautious birds.
Several questions remain unanswered, however; firstly why are cautious birds at an advantage in urban habitats and have higher survival? And do urban females recognise that the males with smaller belly ties are the best mates, or is there an evolutionary trap here - with urban females still preferring males with broad belly ties?
Find out more by reading the full article: Selection based on the size of the black tie of the great tit may be reversed in urban habitats. Juan Carlos Senar, Michael. J. Conroy, Javier Quesada & Fernando Mateos-Gonzalez. Ecology and Evolution. 2014 doi: 10.1002/ece3.999
May
Chris is the only satellite-tagged Cuckoo that has provided data for three consecutive years. He has travelled a total of 47,000 km on his migration routes from Africa to the UK in the last three years. He spends 47% of his time in the Congo rainforest, 38% on migration and only 15% of his time in the UK. He’s our most sponsored Cuckoo with over 450 supporters. Find out more about why we’re celebrating Chris the Cuckoo.
April
Did you know that Golden Pheasant first appeared in Britain in 1725 and in the Brecks in 1880.The Brecks became, and still are, the stronghold for this species in Britain. There are only two viable wild populations in the world - in its native China and in Britain.The Atlas map shows a large loss in range and it is no longer found in Dumfries and Galloway, Anglesey and in parts of the south.
Paul Stancliffe has been working with the One Show to get a glimpse of these secretive birds. Watch their endeavors to film them in the Brecks which will be broadcast on Easter Monday.
March
Did you know that despite being less than the most proficient of flyers in the bird world and, with almost 90% of Red Grouse moving less than a mile from their natal territory, it is surprising that young Red Grouse acquire the power of flight at just twelve days old? The British race, scotica, doesn't turn white during the winter months, unlike the nominate lagopus, that occurs right around the northern hemisphere, with birds from all parts of this range having white winter plumage.
February
Did you know the heaviest nestbox user in the UK is actually Egyptian Goose, the males weighing in at just over 2kg (equivalent to 200 Blue Tits).
Mention nestbox birds to most people and their thoughts will typically turn to Blue Tits or House Sparrows. Some may be familiar with the important role boxes have played in the conservation of species such as Barn Owl, Kestrel and Swift, and a few may even be aware of the artificial House Martin nests than are now commercially available. But how many would think of ducks and geese?
The Egyptian Goose is one of the earliest too, with laying beginning as early as January in mild years. If you're out and about in the south of England this weekend, listen out for the honking display call (which makes up in volume what it lacks in subtlety) and look for pairs of birds standing close together in the high branches of mature trees.
Many ducks use tree cavities and boxes too, including Goldeneye, Goosander and Mandarin, the downy young leaping from the entrance soon after hatching. Goosander have been known to nest in castles within some European cities, and passers-by have watched in horror as the young plummet towards the pavement, only to see them bounce, reorient themselves and follow the mother through the streets to the nearest water body.
Boxes are a great way to provide homes for birds, but they also provide you with a fantastic opportunity to collect data for conservation. The occupant doesn't have to be as exotic as a Mandarin to make the information valuable, so if you have a box in your garden, why not monitor it for Nest Box Challenge.
January
Did you know that Wisdom could become a mum again? At 63 years old, Wisdom, a Laysan Albatross, is the oldest known living bird in the world. In 2013 she successfully fledged a chick, and even though she has reached a great old age, for a bird, it looks like she isn’t about to give up on motherhood just yet. Last year her chick hatched on 3 February, so we don’t have too long to wait to see if this year’s hatches successfully.
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