Animal of the Week, August 9, 2017—new grass snake, you're barred!

http://www.bbc.co.uk/news/uk-40853286 Aug 9, 2017

You can't have failed to notice the news come alive this week with reports of a new species of grass snake identified in the UK. Amazing, stunning! The new species (the barred grass snake; Natrix helvetica) can be distinguished by its less pronounced collar, more pronounced barring along its body, and less vibrant colour (khaki rather than green) compared with other grass snakes (Natrix natrix). Several news outlets reported that the addition of the new species raised the number of snake species living in the UK from three (adder, grass snake, and smooth snake) to four (those three plus the barred grass snake).

But hold on! Should you be asked, in say, a pub quiz, how many species of snake are native to the UK, the answer is still three. If, indeed, the barred grass snake is a separate species, it is the only grass snake species in the UK. The barred grass snake's range in Europe can largely be described as north of the Alps and Pyrenees and west of the Rhine, no other grass snakes are found in this area.

From the original research paper, the blue symbols show the distribution of Natrix natrix helvetica

Scientist analysed genetic samples from snake skins, roadkill, and museum specimens across the northern and eastern European rang of the grass snake. According to the research, the barred grass snake should be recognised as a distinct species from the other subspecies in the Natrix natrix group: whereas the other subspecies have substantial range overlap in which they crossbreed, interbreeding between helvetica and its neighbour natrix is very rare.

Font fans and graphic designers will find it ironic that the helvetica species is distinguished by its pronounced bars.

Animal of the Week, August 2, 2017—could krill save the world?

In the Animal of the Week archives, charismatic birds and mammals far outweigh other creatures, and invertebrates especially are fairly lightly represented. This week let's go some way to reddress that imbalance. By weight, Antarctic krill (Euphausia superba), are the single most abundant animal on Earth.

The most recent AOTW, blue whales, might be the largest animal ever to have lived, but if you were collect all the blue whales together, they might just tip the (very large pair of) scales at approaching 1 million tonnes, all the Antarctic krill in the world would weigh almost 500 times as much—which is just as well, because they are the main source of food for blue whales and numerous other species.

The total numbers of krill in this half a billion tonnes are immense—as many as 500 trillion (that's half a quadrillion) might be alive at any one time. They form swarms of immeasurable number, although the density of these swarms can reach 30 000 individuals per cubic metre. As you might expect for something that exists in such a multitude the individuals are pretty small: the bioluminescent free-swimming shrimp like creatures might reach 6 cm in length and weigh up to 2 grammes.

The importance of Antarctic krill to the world probably cannot be overstated—as well as providing the main food source of a host of whales, seals, penguins, seabirds, fish, and squid, they are thought to be key players in the global carbon cycle and, as such, probably have an important role in moderating climate. Krill migrate up and down the water column, rising to the surface to feed on microscopic plants (phytoplankton) and some animals (zooplankton) but when they are full, they stop swimming and sink while they digest their food (same). The outcome of this is that they transfer carbon from the surface of the water (trapped in photosynthesising plants) to the lower levels (as faeces and their own bodies). The krill's waste sinks to the ocean floor where it is sequestered—were the krill not dragging the carbon down, the plankton would decay in the surface waters releasing greenhouse gases to the atmosphere.

As well as providing food for a multitude of sea creatures, krill are also popular with people—in Japan and Korea krill have been consumed as food for a while, but in the past couple of decades krill oil has become a popular dietary supplement and krill products are increasingly used in aquaculture as fish food and in other pet foods. But given their role in ocean food webs and the potential impact on climate change of depleting krill numbers, we must be careful not to overexploit the remarkable creatures.

Animal of the Week, July 19, 2017—a whale of a time

A little over 6 months ago, AOTW surprised (not very) many by making an appearance in 2017. The occasion that breathed life back into the old blog was Dippy's retirement from the entrance hall at the Natural History Museum in London. Well, it seems only fitting that I should follow this up with a post on the installation of Hope, the 25 metre blue whale (Balaenoptera musculus) skeleton that now presides over the space.

Open to the public on July 14, I naturally took the day off work to go see (also it was the day before my birthday so I figured, treat yo'sel grrrl), and the visit was worth the opening-day queues. One knows whales are big, for sure, and the best way to get that impression would undoubtedly be to get up close in the wild. But few people will ever get the chance to do that, and anyone lucky enough to go on a whale-watching trip might not see more than a distant fin or tail fluke. But standing next to, or underneath, the skull of the largest mammal known to have lived is a remarkable experience.

Blue whales reach up to 30 metres in length, their skull alone reaching 6 metres, and they can weigh as much as 180 tonnes (around 90 great white sharks or 12 000 badgers). Their massive size likely evolved fairly recently to adapt to a patchy food distribution of food occurring in great densities. Blue whales can travel large distances from one patch of krill to another, and when they arrive swallow the enormous amounts of food in one go. Hunted almost to extinction in the twentieth century  as part of the whaling trade, populations are recovering, although climate change and ocean pollution could severely hamper their full recovery, so any attempt to reintroduce whaling or reduce their protection would be shortsighted in the extreme.

The name Hope, given to the skeleton, is a little cringeworthy if well intentioned. The museum hopes the whale will inspire people to be interested in the wonders of natural history and to think more about making space for the creatures with which we share the planet. Although, I can't help thinking that Whaley McWhaleface would have been a better choice.

ADDENDUM: After further consideration, I think Bluey McWhaleface is a better name than Whaley McWhaleface. That opens up naming for the whole family of skeletons—Minke McWhaleface, Righty McWhaleface, Fin McWhaleface, Killer McWhaleface, Bowie McWhaleface and, of course, Spermy McWhaleface.

Animal of the Week July 5, 2017—a bird on the move

So many modern tales in natural history are about declines, extinction, and the damage humankind does to its environment. When animals do succeed, it's because people messed up the environment and to the detriment of other species: just think of all those island species wiped out by invading rats, cats, pigs, and mongooses...but this week's animal is one that bucks the trend.

Cattle egret, Cburnett CC

The cattle egret, Bubulus ibis, has undergone perhaps the most remarkable, impressive, and natural expansion of any animal. Originally found hanging around with herds of buffalo, wildebeest, and cattle in sub-Saharan Africa and India, in just a short while this small white heron has made its way west to the Americas, south and east to Australia and, recently, north as far as the UK, where at least one and perhaps several pairs are raising chicks right now.

Naturally vagrant and prone to wandering with or in search of herds of ruminants, having crossed the Atlantic under their own steam is no small feat—they arrived on the east coast of South America in the early 1900s and by the 1970s they were quite widespread across the southern half of the USA. They reached Australia in the 1940s, presumably spreading east and south through Asia; and by the 1960s they were resident in New Zealand.

Historically recorded in the Iberian peninsula, they recolonised that region in the early 20th century and began wandering further north. Increasing numbers became frequent visitors to the UK. The first recorded breeding took place here in 2008. In the winter just gone, up to 70 birds were recorded across the country and quite a few seem to have stuck around. Perhaps they will join the great white egrets and little egrets, which have recently established themselves as breeding birds in the UK.

The expansion might well have been facilitated by human activity—if not by direct transportation then by creation of large herds of cattle. The egrets specialise in gleaning insects and small vertebrates disturbed by grazing herds and picking off ticks and other nasties from the grazers themselves, and warming climate is likely a factor in their increasing presence in the UK. Nonetheless, they seemingly do little damage to other animals, filling a niche created by the herding of cattle on scale, they don't seem to compete with native herons being far less tied to the water.

With such an impressive colonisation of the globe, I, for one, welcome our new avian overlords.

Animal of the Week May 30, 2017—what's the porpoise?

This week's Animal of the Week has been in the news lately, and for the worst
reasons. The vaquita, the world's smallest porpoise, is teetering on the brink of extinction, with as few as 30 individuals remaining.

One more step on the way too extinction

Although we think of whales and dolphins as being rather large animals, quite a few of them are in length as the average human being is tall, and the vaquita, the smallest of all the cetaceans (the family of whales, dolphins, and porpoises) is only around 1.4 m long (4' 6") and weighs only 54 kg (119 lb).

Confined to the Gulf of California, the vaquita (spanish for little cow) has probably never been especially numerous, but in 1996 when the species was listed as endangered, there were 600. By 2014 there were fewer than 100, now there are 30, maybe fewer—there are fewer vaquita than pupils in an average school class in the UK...a recently discovered dead vaquita represents more than 3% of the population.

The reason for the vaquita's precipitous and perilous decline is illegal fishing with gill nets for another endangered species, the totoaba—a fish of which the swim bladder is highly valued in Chinese cuisine. Although outlawed, fishing for totoaba with gill nets regularly ensnares vaquita, drowning them. The activity is so hard to police that conservationists now plan to capture several vaquita, and move them to a smaller bay that would be more easily protected and policed—such an endeavour has never been attempted for a cetacean. There once were talks of doing the same for the baiji, the Chinese river dolphin, but sadly efforts to save that came too late.

Let's hope they haven't come too late for the vaquita too. No-one really knows whether the vaquita will even survive being caught—some cetaceans get so stressed by human contact, even the best planned capture can be fatal—but without these efforts, the only thing that is certain is the extinction of the vaquita.

Animal of the week, February 1, 2017—Is it a mouth, is it an anus?

It's so hard to tell these days with all the crap some people speak. But is seems that the problem of telling mouthpiece from arsehole stems back over half a billion years in our evolutionary history.

This week's Animal of the Week Saccorhytus hit the headlines for being perhaps the earliest known example of the major group of animals that includes humans—the deuterostomes.

S Conway Morris / Jian Han

These tiny blighters lived among grains of sand 540 million years ago in what is now China, but was then under the sea. Despite their tiny size, they had muscles, skin, and features that place them firmly in the deuterostomes, which include all animals with backbones, alongside echinoderms (starfish and that lot), and a few other things I won't go into now. What it didn't have, which is somewhat unusual among complex animals, is an anus.

Saccorhytus likely swallowed mouthfuls of sand and algae, squashed out the water through cone like structures that scientists believe might have been precursors of gills, and then spat out waste and unwanted particles.

I won't go into the developmental biology and phylogenetics now, because I'll probably get it wrong and trying to do so will only bring back distant unhappy memories of undergraduate hangovers. But I will mention that the name deuterostome has something to do with developing the anus first and the mouth second. Saccorhytus seems to have made do with just one. When you're a millimetre long, why bother with both?


Researchers' analyses suggest that Saccorhytus was actually most closely related to a long extinct major lineage of deuterostomes and was not a direct ancestor of either humans and other vertebrates or sea cucumbers and other echinoderms, but it does give us the best indication of what the earliest members of this major grouping might have looked like—but then, perhaps it was actually very specialised and unlike other early deuterostomes in its adaptations to living a tiny life.

The mind does boggle at the number of other microscopic fossils that might have been overlooked previously and could offer clues about the evolution of major animal lineages, and anuses. It seems like 2017 might be the year to take a long hard look and really reflect on how we've ended up with the aresholes we've got.

Animal of the Week January 11, 2017 — Oh deer! Such monkey business!

If anything is likely to stir Animal of the Week out of hibernation it's unusual animal behaviour* of the kind shown by this week's animal, a particularly randy and misguided Japanese macaque (Macaca fuscata).

Credit: Alexandre Bonnefoy

Reported in the journal Primates, a low-ranking monkey, frustrated by exclusion from females of his own species during the breeding season sought release by trying it on with two separate sika deer (Cervus nippon). The first deer accepted the primate's advances: the monkey mounted the deer without penetr
ation and displayed about 15 sexual movements over 10 seconds before dismounting. [Same.] A second deer did not allow the macaque to mount.

Such interspecific sexual behaviour is rare [outside Wales] and serves no known evolutionary purpose. However, in Japan, macaques and sika deer frequently associate with each other: deer often pick up food discarded by macaques and even eat their faeces. Macaques have previously been observed grooming the deer and occasionally riding them (in an innocent sense). It's possible, that this young male, flush with a hormone surge and excluded from access to female macaques by their preference for higher ranking males confused appropriate behaviour with the other species.

Japanese macaques (also known as snow monkeys) are famed for their love of sitting in pools fed by hot springs during blizzards, they are the most northerly living non-human primates, and they exhibit interesting cultural behaviour such as the washing of food and seasoning potatoes by dipping them in saltwater. Let's not let this aberrant behaviour by one monkey bring down the rep of the whole species.


*Remember this weasel riding a woodpecker from 2015? The glory days of interspecific animal of the week.

Animal of the Week Jan 4, 2017—Deeply, Dippy

Many young children (and older children well into their "adulthood") over the past four decades have been stopped in their tracks when the first enter the Natural History Museum in London. Arrested by the hollow, timeless gaze and colossal magnificence of one of the world's most famous skeletons: Dippy the diplodocus. But as of today, no more.

After 111 years in the NHM, and 37 in the Hintze Hall (that wonderful cavernous atrium through which most visitors enter the museum), the 292 bones will be dismantled and packed up. The skeleton will be replaced, by something even more enormous: the skeleton of a blue whale. But for so many people, the departure of Dippy is a poignant change.

As a boy, I was struck by the wonder of intricate articulation, taking what seemed like hours to inspect every joint, picking out bumps, lumps, processess, textures, and, indeed, the wires that held the thing together. And later, after leaving the museum, in all my dinosaur books, the pages with the diplodocuses were always the best thumbed. I would gaze for hours at the pictures: great grey colossal hunks, but imagining, at the core of them all, the bones I had seen in the NHM. My long-lasting interest in dinosaurs, animals, zoology, and evolution, cannot solely be attributed to that skeleton, but by god it played its part. And later, when studying at the NHM, it was still a thrill for me to walk the length of the skeleton, from nose to the whipping pencil thin bones at the tip of Dippy's tail.

Of course, I've learned that the "bones" are actually casts of fossils. London's Dippy is one of ten replicas of fossils excavated in Wyoming in 1898. For all its size, Diplodocus carnegii (the species represented by the cast), which weighed around 16 tons and grew up to 25 m in length, was dwarfed by more recently described sauropod relatives: Argentinosaurus grew up to 40 m long and weighted perhaps 100 tons. But these facts do not lessen the wonder and awe inspired by that most loved fossil.

But, the departure is not the end: Dippy is going on a tour of UK museums form 2018–20, meaning more people in new settings will get to stare in wonder at the skeleton in new settings. And, well, having stood next to the skull of a blue whale, that is no less awe inspiring and much as I will remember that childhood thrill of seeing Dippy with nostalgic fondness, I can't wait to see the new Hintze Hall display.