35.735 years in science communication
Knots Landing (and taking off) at RSPB Snettisham, on The Wash, North Norfolk. Evening High Tide 20th October 2018, with Mr and Mrs Sciencebase. Video and music by Dave Bradley.
Red Knot (Calidris canutus) – another bird with red in its name when it is so obviously orange. See my post on avian fake news.
This is a version of my bird report for our local village newsletter scheduled to appear in December.
At the time of writing, the summer visitors, such as the swifts, swallows, house martins, and various migratory warblers were all long gone. Indeed, it is still sunny and warm during the day, but the nights have turned decidedly damp and chilly and one friend reported early-morning frost on his car windscreen (it was 90 days until Christmas, at the time).
Well, speaking of Christmas for the birder can mean only one thing, and I don’t mean turkey, nor do I actually mean the winter visitors such as the fieldfare, redwing, hawfinch, waxwing, nor any of the other species that head south from Siberia and Scandinavia during the winter to pick the leftover fruit and berries from our season of mellow fruitfulness and find some degree of warmth even if there is another Beast from the East. No, I am talking about the Robin, Erithacus rubecula.
There is all sorts of folklore surrounding this old world flycatcher with its tremulous and flutingly melodic song and its famous breast plumage. But, its appearance on Christmas paraphernalia is somewhat puzzling given that the bird is a resident. It’s fake news that they make an appearance only at the festive end of the year and prefer snow to soil. The bird is here all year, unlike those swifts and swallows which swan off [pardon the pun] back to southern Africa as our days shorten and the temperatures fall. It never leaves.
If I remember rightly, the Robin was voted Britain’s favourite bird. Fair enough, it is a wonderful, bold species with a history of finding a home near human settlements where it will be forever watchful and dart in to catch dropped food and crumbs. They evolved alongside other foraging mammals, such as wild boar, and are quite happy to piggyback in that animal’s stamping grounds too. Despite their popularity and cute appearance they are actually rather aggressively territorial birds and quick to drive away or even attack intruders.
There is one thing about Robins that might have confused all but the most casual observer of their plumage. The species is commonly known as the robin redbreast. But, the feathers on its chest are anything but red. That “rubecula” in its scientific name is also fake news. The rubecula comes from the Latin “ruber” meaning red, same etymology as the precious stone the ruby. Same root as “rufous” meaning red. But, that redbreast is most definitely not red, it’s orange!
So, why isn’t the bird commonly known as a robin orangebreast? Well, you may well ask the same question of a host of other “reds” that are also orange, such as redshanks, red knot, red admirals, and redheads.
The answer lies in the fact that until the 1540s, English had no word for the colour orange. Anything of what we perceive as a red or orange hue was just fifty or so shades of red. It was very black and white, no grey. When the common names were given to various species and hair colouration, whether they were orange or red, it was all the same – red.
The word orange arrived on our shores with the fruit, around 1300, but was used only as the name of the fruit. The word having come from the old French “orange”, which in turn and rather indirectly comes from the Sanskrit word for an orange tree, “naranga”. It wasn’t until the 1540s that the fruity word started to be used for the colour. If there had been any usage of that hue, then in Middle English it was citrine or saffron. Robins were not even always called robins. They were officially known as redbreasts until 1971 and long before that ruddocks, with its allusion to their being ruddy. The bird name robin, of course, also screams red as in ruby, ruby, ruby, despite it coming from the forename.
At least the avian cousin of the robin, the bluethroat is a lot more obvious and trustworthy in its name. It’s a bird with a blue throat. Except of course, you do get ones with a white spot in that blue patch and others with a red spot just to add to the confusion and don’t get me started on pied, white, grey, and yellow wagtails.
They’re naming the new hide at RSPB Snettisham “Knots Landing” in honour of the bird, Calidris canutus, that flocks in vast numbers in and out over The Wash there with each turning tide.
The bird is named for King Canute (it’s not a long way from ca-nute to k-not and then dropping the k, in Dutch they’re called “Kanoeten”) because these medium-sized waders, which breed in the tundra and the Arctic Cordillera of Canada, Europe, and Russia will whoosh from the mudflats and sandbanks as the tide rises until they are ankle deep at high tide periodically forming vast flocks that shapeshift across the skies.
We visited on the third weekend of October 2018, catching the late afternoon high tide on a clear day that ended with a glorious sunset and seeing flocks of several thousand Red Knots. There were a couple of thousand Oystercatcher there too and perhaps 1000 or so Golden Plover, not to mention the hundreds and hundreds of Pink-footed Geese that leave behind their feeding grounds and head out to sea to roost at dusk safe from terrestrial predators.
Sometimes entangled in your own dream…knots…you can find the non-avian sunset photos on my Imaging Storm site.
Our feathered friends, the birds, are all descended from the dinosaurs. Specifically, birds evolved from the hollow-boned theropod dinosaurs which includes the Tyrannosaurus rex. All 10500 species of bird alive today and all the many thousands of others that are extinct came from the dinosaurs. But. Didn’t the dinosaurs die out 65 million years ago when a huge asteroid hit the Earth, you ask? Well, most groups that were still around at the time did, allowing the mammals to fill the ecological niches left empty by their sudden absence. However, the lineage of those hollow-boned dinos would persist too. The question is how did they survive when their cousins died out?
Writing in the journal scientists affectionately know as PNAS, researchers explain how they have found another adaptation that could have given the ancestor of the birds an advantage when things got very tough for the other dinosaurs. They have examined the fossilized lungs of a bird ancestor, Archaeorhynchus spathula, using scanning electron microscopy and found features in the lungs of those animals that resemble those of modern birds and are thought to be an evolutionary adaptation that supported flight include unidirectional airflow in the lungs, supplementary air sacs, and lung tissue that is finely subdivided to maximize surface area and so absorption of oxygen from the atmosphere to drive the huge energy requirements of flying.
Crocodilians are the only other living creatures that have unidirectional airflow and this characteristic is now thought to have evolved even before the ancestors of the early feathered dinosaurs.
The authors also discovered among the preserved plumage of the fossil a pintail feather structure that has not been seen in other known birds of the Cretaceous period but is seen in some modern birds. The researchers suggest that all of this evidence stacks up to the fact that key avian structures were in place by the Early Cretaceous and could have been what helped the ancestors of modern birds survive the extinction of the other dinosaurs.
“Archaeorhynchus preserving significant soft tissue including probable fossilized lungs,” Xiaoli Wang et al. Proc Natl Acad Sci (2018)
Cross, or European Garden, Spider (Araneus diadematus), also known as the Crowned Orb Weaver, Diadem, Orangie, and also the Pumpkin Spider, so perhaps I should’ve held off posting this until Halloween. There is, however, another spider that has the vernacular name Pumpkin Spider.
This is a female specimen. The legs of orb-weaver spiders are specialized for spinning orb webs (although this one had spun a flat web across a small windowpane). The spider constructs its web and then hangs head down in the centre or in nearby foliage, with one claw hooked to a signal line connected to the web waiting for a disturbance as prey enters the web. The spider bites its prey and quickly envelops it in silk. Some enzymes paralyse the prey and preclude the prey biting or stinging the spider. Other enzymes begin the liquefaction (digestion) of the prey’s innards ready for consumption.
Just for the record, this is one of those spiders that cannibalises the male after mating.
I asked arachnid expert Dr Richard Pearce (@DrRichJP) about the fact that spiders seem to have extra pairs of eyes and wondering why other creatures did not follow this evolutionary route. This is what he had to say:
Spider eyes are not necessarily comparable to our own. Many spiders have poor vision. Those with good vision tend to have two primary eyes to give binocular vision (e.g. jumpers - Salticidae; wolf spiders - Lycosidae). The other eyes do not form images in the same way.
Spider photo now in my Invertebrates gallery (non-lepidoptera)
I’m always hopeful of interesting sightings along The Reedbed Trail at RSPB Ouse Fen. Saw lots of Hobbies and Terns as well as Marsh Harriers and Warblers there earlier in the year.Visited today with Mrs Sciencebase, two or three Marsh Harriers in evidence, lots of gulls, a single Kestrel, one or two Buzzard, big Lapwing flock, Grey Heron, waterfowl, Little Egret, Goldfinch, Reed Bunting, Green Woodpecker, Stone Chat pair, and the pew, pew, pew sound of Bearded Reedlings of which we saw a few but didn’t get any great shots. But, at least confirmed what I thought I heard earlier in the year and nice to know they’re colonising a local reserve. Oh, and as we were leaving, we saw a fox, other visitors with dogs unwittingly scared it into the trees.
Buzzard (Buteo buteo) takes flight
Bearded Reedling wouldn’t turn to the camera before flying off!
Isn’t it time to put the scientific moth trap away, they asked. Surely there are no moths flying in the autumn and winter. Well, there are definitely fewer species around now, especially if it has been really damp and chilly overnight. But, there were numerous last night feeding on the ivy blossom: Centre-barred Sallow, Large Yellow Underwing, Vine’s Rustic, Common Plume, and one or two micro moths.
In or around the trap, more Yellow Underwings (Lesser, Small, and Large), Setaceous Hebrew Character, White Point, Lunar Underwings, and a Red-green Carpet.
This morning some of those were still in attendance, but a Green-brindled Crescent (Allophyes oxyacanthae) had taken over the morning shift from the RG Carpet. This species was first curated by Linnaeus in 1758, it grows to between 35 and 45 mm according to the UKMoths page. It’s prominently green in colour, but subtly striped (the brindled part of its name). The crescent in its name refers to two white curves on its wings. It has unusually large oval and kidney marks compared with many other noctuid (owlet) moths.
It is mottled brown mainly but catch it in the right light or under the glare of a camera ring flash and its gree metallic scales will shine through. It commonly flies from September to November and is found across the UK, in woodland, hedgerows, and the suburbs, its caterpillars feeding on hawthorn (Crataegus) and blackthorn (Prunus spinosa) and other trees and bushes.
TL:DR – Barn Owls regurgitate pellets containing the indigestible bones and fur from their prey. It is possible to dissect these owl pellets and to find out what the owl has eaten from the debris.
Barn Owl (Tyto alba) hunting over Rampton, VC29If you have ever stopped to think about the gustatory habits of owls, then you have perhaps wondered what happens to all the bones and fur from the little creatures on which they predate after they eat them.
Well, avian digestive enzymes do not have the capacity to break down bones and fur and as the flesh and organs are digested those materials accumulate in the upper gastrointestinal tract forming a hairy bolus, a pellet, that ultimately the owl will regurgitate. A pellet forms after six to ten hours following a meal in the bird’s gizzard, its muscular stomach. Owls and other birds of prey bring up the indigestible material from the proventriculus, their glandular stomach. The pellet is thought not only to get rid of indigestible waste materials that would not pass downwards safely but also to scour parts of the digestive tract, including the gullet to remove detritus that might harbour pathogens.
Now, the experimental bit.
I collected an owl pellet (with the warden’s permission at WWT Welney on a recent visit and followed his instructions to soak the pellet in water for a number of hours and then to tease it apart to reveal the bones within its proventriculus, or glandular stomach.
After about an hour’s work I’d dissected the pellet to reveal a relatively large skull and separated lower jawbones of presumably a vole as well as various femurs, tibia, fibula, scapula, a few vertebrae and lots of rib bones, and perhaps another couple of much smaller skulls the extraction from the of the pellet I did not have the patience nor the equipment to pursue with the necessary care and attention to detail. I did not find any feathers nor insect exoskeletal parts or wings in this pellet. All the remains were rodent mammal.
Anyway, I am quite pleased with the produce harvested from my first owl pellet dissection. Mrs Sciencebase points out that she did the very same experiment as a biology student many moons ago.
Other birds, including the fish-eating, insect, and carrion-eating birds, grebes, herons, cormorants, gulls, terns, kingfishers, crows, jays, dippers, shrikes, swallows, and most shorebirds also produce pellets.
UPDATE: Just over 5 years later, night of 7th November 2024, 83 Cranes into roost at Welney.
There is a flock of 37 Cranes (Grus grus) at WWT Welney in Norfolk at the moment. Some of these have bred on the reserve, all of them, it seems, share their time between this site, NT Wicken Fen, Kingfisher’s Bridge Nature Reserve, RSPB Lakenheath, and the Ouse Washes.
Photos were taken from the Visitor Centre viewing platform, fully zoomed (600mm on a full-frame SLR) and cropped. The birds were about 900m away so the photos are not particularly distinct.
