The Southern Birds

It’s winter again and every year at that time the night sky clears up and lets us admire its wonders. So put the kettle on, take your scarf, beanie and gloves, stretch your neck, and let’s brave the cold night air, look up and gaze at the distant stars.

Birders will spend a considerable amount of time looking for all the avian diversity occurring in the area. From buttonquails running through the grass to vultures soaring at high altitudes, there are enough of them to do some proper neck-muscle exercise during the daytime. At night, owls and nightjars are taking over, but if you keep your head up, there are also a few birds that you cannot miss, as long as you know what you are looking for. Of course, we are no longer talking about birds of flesh and colourful feathers here, but constellations hid amongst the thousands of visible stars. If you can connect the right dots, you can uncover their secrets and stories.

Let’s start with the ancient ones.
When the night starts and it is just getting dark enough to see the sky clearly, look in the direction of the north, and right above you, you will see Corvus, the raven or crow. It is a small constellation, almost box-shaped, and honestly, not really looking like a crow… It was described by the Greco-Egyptian astronomer (and many more titles) Ptolemy, during the second century. Its story is linked with Apollo. A crow was fetching water for the god of music (among many other things) but stopped on his way to eat fig. He then lied to Apollo and said a water snake (hydra) kept him from the water, holding the snake in his talon as a proof. Apollo saw the lie and flung them in the sky, condemning the crow to be thirsty forever. As a result, you find the crow (Corvus) close to but out of reach of the cup (Crater), both along with the water snake (Hydra).

Let’s now turn towards the east and wait a bit longer. As we get closer to 21:00, we can see another bird described by Ptolemy rising in the sky: Aquila, the eagle. A much bigger constellation that actually looks more like a bird, and where shines Altair, the 12^th brightest star in the night sky. It represents the eagle carrying Zeus’ thunderbolt. During Ptolemy’s lifetime, the Romans also identified it as Vultur Volans, the flying vulture, another fitting name for the African sky. Close to it was also Vultur cadens, the falling vulture! We now call it Lyra.

As we keep waiting, past midnight comes Cygnus, the Swan, with Deneb, the 19^th brightest star in the night sky. Also described by Ptolemy, the origin of the name is however a bit more confusing. It could be different incarnations of Zeus, or Orpheus after his murder, or several characters of the Greek mythology named Cygnus. Being a prominent constellation of the northern hemisphere, especially in Summer and Autumn, Cygnus is also called the Northern Cross, in reference to our Southern Cross, but this one doesn’t help to find the north! Together with the two “vultures” (actually Aquila and Lyra), they also refer to the Stymphalian birds, voracious birds defeated by Hercules during his 6^th labour.

But even if we can also see these birds from the southern hemisphere, let’s leave them and their ancient stories for other, more specific constellations: The Southern Birds, that you will only be able to admire from our side of the equator, in what we call the southern sky, the southern half of the celestial sphere.
These birds are Pavo, the peacock, Grus, the Crane, Tucana, the toucan, and Phoenix.

Interestingly, those constellations were first identified, or established, by someone who actually never saw them! Petrus Plancius, that was his name, was a Dutch astronomer from the 16^th century who studied the southern sky from information that was only reported by navigators. In 1589 he already collaborated with the cartographer Jacob Floris van Langren to make a celestial globe showing the few southern features known at that time. Building on this experience, he trained Pieter Dirkszoon Keyser, chief navigator of the first Dutch voyage to the East Indies, to make celestial observations. Together with a colleague named Frederick de Houtman, they cataloged 135 stars. He died only one year after his departure, but his notes came back to Plancius when the ship eventually returned to Holland. From these notes, Plancius made a new 35cm celestial globe in 1597 or 1598, with 12 new constellations appearing from the 135 cataloged stars, named after animals described in natural history books and traveler’s journals of that time. And That’s how we ended up with exotic birds in our southern sky.

Pavo, Grus, and Tucana were never described in ancient astronomy and were, in the late 16^th century, completely new. Grus was also briefly named Phoenicopterus, the flamingo, in the early 17^th century, but eventually, the crane remained the official name. Tucana was identified as a toucan by Plancius but appeared as an “Indian Magpie” in the original notes he received, a designation for a bird with a large and long bill, most likely a kind of Hornbill, since the expedition was going to the East Indies (now called South-east Asia), and toucans are found in America. But Plancius had the last word eventually, even if he never saw the constellation himself, nor went to the East Indies or Southern America, and Tucana remained as the official name. Pavo could be linked to Greek mythology, as Argus (or Argos), the builder of the ship Argo, was turned into a peacock by the goddess Juno and placed in the sky next to his ship. Indeed, the constellations that we now call Puppis, Carina, and Vela (the poop deck, the keel, and the sails) used to be known collectively as Argo Navis (the ship Argo) by the Greeks. However, it seems like Plancius was refereeing to the Green peacock, newly observed by the explorers of the 16^th century, instead of the Blue peacock known by the Greeks.

On the contrary, Phoenix is obviously linked with mythology, as there is no real immortal bird living on earth, even in the most remote part of the East Indies. But the main difference with its fellow southern birds is that this constellation had been described in ancient astronomy. The Arab astronomers already knew it, but under several forms, as it was described as young ostriches, an eagle, or even a boat by the river Eridanus.

Strangely the Southern Birds do not include another constellation representing a bird, in the southern sky, and also part of the 12 new constellations established by Plancius. It is Apus, the bird-of-paradise. Interestingly, its name means “without feet” in Greek, as the only specimen available in the West at that time was missing its feet and European naturalists thought the bird didn’t have any. It is a very small constellation though, and later in the 18^th century, it was even amputated some if its tail by Louis-Nicolas de Lacaille, who took those stars to make the constellation Octans. But that is for another story!

Another neglected southern bird is Columba, the dove. It was also named by Plancius, but a bit earlier in 1592, in reference to the dove that told Noah that the great flood was receding. This one is a bit further from the other birds, as it is found close to Canis Major and Orion, more visible in the summer sky than during winter.

And that’s it for the birds of the southern sky, even if they are not all entitled as Southern Birds! Brought back from a dead man’s notes and revealed by another man who never saw them himself, but still there to be seen by us and for a few million years more.

Story by: Vincent Hindson