Birds – Page 36 – David Bradley

Dunnock courtship

The courtship ritual of the Dunnock (Prunella modularis) is peculiar. I observed a pair on the lawn in our garden last week while I was sitting at the garden table working at my laptop. The female had raised her tail feathers and was fluttering them up and down rapidly while the male pecked repeatedly at her rear end, well her cloaca to be more specific. It went on for a minute or two until they both flew up quickly into a hedge, presumably to mate.

It’s not a ritual I’d observed before and Googled the bird to discover that female dunnocks are quite promiscuous. The pecking of the cloaca by the male is thought to stimulate rejection of sperm from a previous male’s mating and so increase the chances of the new mate fathering her offspring.

In my garden observations I could have sworn I could see something curved andÂ white protruding from the female, an egg, perhaps. So maybe the male’s pecking stimulates her to lay an egg outside the nest before he takes her back to mate. Either way,Â it’s apparently not an entirely efficient paternity-assurance strategy as genetic testing of dunnock broods has revealed that the female can lay eggs fertilised by several males.

I only had my phone to hand so this is awful footage and the voyeuristic blackbird is a distraction.

Puffins and razorbills

Apparently, puffins prefer to be deeper into rocky crevices on coastal cliff faces than razorbills (and guillemots) who cling to the edges. The puffin then has to wait until those other birds fly off, before it can get away itself to feed and socialise.

RSPB Bempton Cliffs

Sheer coincidence that we were visiting the East Riding of Yorkshire last week when the Royal Society for the Protection of Birds (RSPB) opened its new visitor centre at Bempton Cliffs. We approached the reserve on two walks first from North Landing on Flamborough Head where I photographed coble fishers landing and unloading their boat and then from the village of Speeton with its tiny Anglo-Saxon church (St Leonard’s and its flock of rarebreed Leicester Longwool sheep).

Bempton Cliffs plays host to England’s largest nesting colony of Northern Gannets (Sula bassana), graceful and quiet in flight and far more beautiful than their rather ugly name. The cliffs also host countless kittiwakes, razorbills, guillemots, fulmars and puffins as well as pigeons, rooks and herring gulls.

How did feathers evolve?

Carl Zimmer offered some insights at TED-Ed into how dinosaurs got their plumage and evolved into the flying birds, excellent birds, we see today. This is witty animation plucks up the courage to fill in the gaps.

On an entirely unrelated note, I wrote a song about flight, which you can hear on my SoundCloud page or via my Songs, Snaps and Science site.

H7N9 bird flu

Is another bird flu on the rise? Report from Nature on H7N9 type A influenza virus and reported outbreak in China.

Scientists and public health officials worldwide are on alert after China announced on 31 March that two people had died and a third had been seriously sickened from infections with a new avian flu virus, H7N9, that has never been seen before in humans.

via Novel bird flu kills two in China : Nature News & Comment.

There are numerous subtypes of flu, labelled with an H number, referring to the specific type of protein hemagglutinin and an N number, neuraminidase enzyme type. There are 17 H antigens (H1 to H17) and nine different N antigens (N1 to N9) and any combination might be possible. The newest H antigen type, identified as H17 by researchers, was isolated from fruit bats in 2012.

Bird flu, swine flu, now seal flu H3N8

US scientists have identified a new strain of influenza in New England harbor seals – H3N8. They say the strain, presumably made the species leap from birds, might now be a reservoir for an emergent human flu virus.

H3N8 is an influenza type A virus (Orthomyxoviridae) endemic in birds, equines and dogs and although highly contagious was not as such considered a risk to people. A flu outbreak in people in 1889 or 1900 was blamed on this strain but evidence suggests that it was due to H2N2. If H3N8 has mutated and evolved from an avian form into one that infects harbor seals (Phoca vitulina), there is a chance that it could now infect people. Indeed, the virus already has the relevant structure to attack a protein in the human respiratory tract.

Experts have for some time recognised that emergent flu viruses need not only come from East Asia, swine flu, H1N1, being a case in point, the pandemic of 2009 emerging from South America. So, the emergence of a putative pandemic strain in the waters off New England, USA, is worrying, but perhaps not surprising.

It is worth noting that a paper in the same group of journals from 1984 reports on the emergence of an avian influenza virus (H4N5) in harbor seals in the early 1980s. There are presumably other instances so this would suggest that transfer to harbor seals from birds is not an uncommon leap.

BBC News – New flu virus found in seals concerns scientists.

Moscona et al, 2012, mBio; DOI: 10.1128/mBio.00166-12

Influenza A viruses are classified into subtypes based on the antibody response to the viral proteins hemagglutinin (HA), neuraminidase (NA). This distinction gives us the different names, e.g. H5N1, H1N1, H3N8 etc. There are 16 H and 9 N subtypes known, but only H 1, 2 and 3, and N 1 and 2 are usually found in people.

Bird flu research halted

The UK’s Guardian newspaper is reporting that researchers working to prevent the spread of bird flu and the possible millions of deaths it could cause should a pandemic occur, have suspended their research for 60 days amid fears that they might accidentally trigger the very Â epidemic they hope to stop. A letter published on Friday in the scientific journals Nature and Science and signed by scientists from around the world appeals for public debate about the security of the work.

Bird flu scientists suspend work amid epidemic fears.

Owl pellet dissection

A friend of mine is into nature conservation in a big way and one of the tools of the trade, which to the outsider may seem rather odd, is owl pellet dissection. I had a go at dissecting an owl pellet myself, here you can see the results

Owl pellets are the regurgitated remains (bones, feathers and other indigestibles) that accumulate in this bird of prey’s gizzard after it dines on small rodents and other critters. The dessicated pellets are to be found lying where they are discarded by the owl and can provide important information about what critters are being preyed on in owl territory.

The only way to get at that information, however, is to tease apart the pellet with tweezers and other implements to extract the bones from the tangle of hair and other detritus. It needs a steady hand, a keen eye, and a lot of patience. What you will find within is quite amazing though, tiny jaw bones and skulls, femurs, tibias pelvic bones and more.

Identifying which bone belongs to which creature takes even more patience, but it is possible and provides useful insights into the prevalence or otherwise of particular small mammals in a given area where owls prey.

For more on owl pellet dissection, check out this site http://www.kidwings.com/owlpellets/.

The reason I bring it up (pardon the pun) today, is that owl pellet dissection was the hot new search phrase on the sciencebase site this last month, with dozens of visitors all flapping for information on the subject. It’s not a topic that’s been searched for here before, so I thought I’d provide some background in case we have another flutter of en-raptor-ed activity.

Herring Gulls fighting

These two birds I photographed in my in-law’s garden were anything but lovebirds, although they might look like they were dancing seconds before and seconds after they were tearing each other’s feathers off and spitting blood. This didn’t seem to be a bar-room brawl between chums fighting over fishy scraps, these two were at it for a good half an hour. It has to have been a territorial or mating rights argument of some sort.

Nature really is red in beak and claw.

Human to human bird flu

The World Health Organization has expressed concern that a recent cluster of deaths associated with the H5N1 virus in Indonesia may not have originated with an animal host, suggesting the possibility of human to human transmission of the virus. However, it also cautions that the analytical evidence suggests that the virus has not mutated into a human transmissable form, which means we are not just yet on the verge of a global bird flu pandemic after all.

The news media inevitably picked up on this warning and ran with it, but thankfully the BBC saw the double-edged nature of the WHO announcement points out with some degree of rational response that many people in Indonesia, as in other southeast Asian countries, live in such close proximity to their animals and not necessarily in the most hygienic of circumstances that the likelihood of catching bird flu is much higher in such an environment.

It is the lack of a mutated form of H5N1 among these victims that means we are not yet doomed to see the feathers fly globally.