Saturday 30 March 2024

Flight of the Fossil Pelicans

Dalmatian pelican
Pelicans are distinctive birds with long necks, short legs, and a remarkably long beak the bottom half of which is attached to a large extensible pouch for holding captured fish. They are also large, with even the smallest species having a 180 cm (6 foot) wingspan and the largest being half that again. They are, of course, water birds, with many living along coasts or in brackish waters, but others found in lakes and rivers far inland.

They are also not mammals, which is a timely reminder that, yes, this is the post that will be live on 1st April, when I switch things about for one post a year.

Wednesday 27 March 2024

Antelopine Antelopes: Gazelles of North Africa

Dorcas gazelle
(Brief note: My internet connection was down for three days over the weekend, which is why this post is delayed from the usual.)

One of the things that most distinguishes gazelles from other kinds of antelope is that they are adapted to dry environments. They don't come much drier than the Sahara so it should be little surprise that gazelles are relatively common here. In fact, the dorcas gazelle (Gazella dorcas) is one of the most widespread of all gazelle species, being found right across the Sahara from the Atlantic to the Red Sea, as well as further south along the Red Sea coast in Eritrea and Djibouti and across the Sinai into extreme southern Israel. In the north, it's largely restricted to the eastern parts of the Mediterranean coast, being absent from northern Algeria, Morocco, and Tunisia.

Sunday 17 March 2024

Home-grown Shovel Tuskers?

Elephants are unique and remarkable animals, looking quite unlike any other creature. They have no close living relatives among other mammals - you have to go back almost to the time of the dinosaurs to find any common ancestor with anything else. As a result, the elephant family is placed within its own order of mammals, a ranking equivalent to that given to such groups as "primates", "rodents", or "bats". With just one family, and only three living species, it isn't quite the smallest mammalian order, but it's very close.

This changes significantly if we choose to include the known extinct species. There are a great many of these, which tend to be large, heavily built creatures with elongated tusks, and, in most cases, features on their skulls that suggest they had a trunk. Indeed, this latter is the source of the official name of the order, the proboscideans. While only the elephant family survives today, at least six others are recognised to have existed in the past, and if we could see members of most of them today they'd be instantly recognisable as, if not actually elephants, at least "elephant-like".

Sunday 10 March 2024

Jiggling on the Ecotone

It might leave a slightly different message if a human did it, but leaving piles of droppings in the territory around your home can be an important signal for many mammal species. Although making such piles visible may help other animals find them, the primary signal is, as one might expect, the smell. And not just the smell of the faeces, of course, but complex chemicals mixed in with it from urine or the secretions of anal scent glands. These can allow an animal with a sense of smell more subtle than our own to glean a lot of useful information about who left the deposit - and why.

In many species, this takes the form, not of solitary deposits, but of latrines. In the zoological sense, this refers to a single location for defecating shared by many animals of the same species. The animals who use the site may belong to a particular pack or herd, all using the same communal site, but they could equally well be rivals or neighbours leaving messages for one another. How the latrines are distributed can give researchers significant clues about what those messages might be.

Sunday 3 March 2024

The Rhinos of Samos

Today, rhinoceroses are rare animals, with three out of the five species on the verge of extinction. Millions of years ago, however, not only were they much more common, but there were many more species, and with greater diversity, than we have today. 

How diverse that was depends on how broadly you interpret the word "rhino" when fitting it to formal scientific classifications. Even if we take the narrowest definition, considering only animals descended from the last common ancestor of the living animals, you can still add over two dozen species to the tally, although obviously, they weren't all alive at the same time. Adding in all the "rhinoceratoids" - anything more closely related to a rhino than to any other living animal - obviously gets you a great many more, although many of them didn't look much like the creatures we'd recognise.