Over the Atlas Mountains and to the land of rebbachisaurs, agamas and fennec foxes

More musings from the Morocco trip. So, we travelled over the Atlas Mountains and were soon up at the snowline. We joked about seeing lions and bears, but did see a Barbary partridge Alectoris barbara (another first) and a representative of the strikingly blue Blue tit subspecies Cyanistes caeruleus ultramarinus. If you've been keeping up with parid taxonomy you'll know that some workers now regard this blue tit of north-west Africa and the Canaries as a distinct species, the Ultramarine or Afrocanarian tit C. ultramarinus (but note that not all the blue tits of the Canaries belong to this species: another four or five are recognised from the islands... by some authors at least). Black redstart Phoenicurus ochruros and loads of Red-billed choughs Pyrrhocorax pyrrhocorax were also present (but no Alpine choughs P. graculus) [adjacent photos by Richard Hing].

Eventually we got to the arid desert regions around Ouarzazate (pronounced something like 'wazza-zat'), and we were later to go to Taouz, Merzouga and Rissani, and eventually to Er Rachidia in the east. On a few occasions we had to drive around in the desert at night, and jerboas were often seen in front of the headlights (though I failed to even get a glimpse of one, as I was sat in the back). However, during the days I spent a lot of time looking at tracks: paired, tridactyl tracks made by an animal that placed its metatarsus on the ground a lot were thought by Richard and I to be jerboa tracks (they are actually very similar to tracks produced by some passerines). At night the desert clearly comes alive with rodents and large arthropods, with beetle, jerboa and mice tracks being abundant. Feral cats were clearly wandering around the villages and hostels we stayed at: I initially followed cat tracks in the vain hope that they might have been made by a Sand cat Felis margarita, but I assume that this secretive species doesn't come close to places where people are. At Gara Sba Richard and I also spent a while tracking a small canid - we assumed that it was a Fennec fox - and we discovered many places where it had dug about in the sand, presumably in search of lizards and arthropods. The tracks and diggings were less than a day old, but we were to have a far superior encounter with a Fennec later on in the trip.

Trumpeter finches and ubiquitous wheatears

Our first field site - we referred to it throughout the trip as 'the pterosaur site' (due to a previous find) - was an escarpment just to the south of Tafrout (there are apparently several places in Morocco called Tafrout [or Tafroute] and I'm not sure which of them this was). Finding surface 'float' (eroded bone fragments that are kicking around in the sediment) was dead easy, and within a few minutes you could gather a huge pile of it. Teeth were relatively abundant (especially of sawfish and lungfish), but good ones were few. I was, however, pleased to find spinosaurine, carcharodontosaur and sauropod teeth. At the top of what seemed to be a high plateau (it was actually a valley floor, and we'd been in a deep gorge underneath it) I encountered a brown passerine with a streaked breast, rufous flanks and a distinctive song. I realised later on that it was a Desert lark Ammomanes deserti, a bird that would become extremely familiar to us as time went on [one is shown here: © Bob Loveridge]. The rufous flanks threw me but are characteristic of the Moroccan subspecies A. d. payni.

Another bird of the desert that would also become very familiar later on, the White-crowned black wheatear Oenanthe leucopyga, was also encountered here [adjacent photo © Bob Loveridge]. Initially this was a big deal, but these birds proved to be ubiquitous and a constant presence everywhere we went. They seem to seek people out, and regularly visit camps and dig sites. Like a lot of the desert birds they were surprisingly relaxed about humans and would often perch just a few metres away from you. As a result Bob got some outstanding photos. There are 16 wheatears in the European Field Guide Region (EFGR from hereon: effectively synonymous with Western Palaearctic) and it can be difficult to remember how they can be distinguished.

A black-crowned wheatear that I initially took to be a Black wheatear O. leucura turned out to be a young White-crowned black: confusingly, White-crowned blacks have black heads when young (some even retain the black head into adulthood). To distinguish the two easily you need to see the open tail: in the White-crowned black only the two central rectrices are black, while in the Black the distal tips of all of the other rectrices are black as well. A female Mourning wheater O. lugens was also seen, but no Red-rumped O. moesta or Desert wheatear O. deserti, both of which also occur in Morocco. Thank god for Mullarney et al. (1999). I also took along Heinzel et al. (1995) and had so much free time on my hands that by the end of the trip I had memorised the scientific names of all the birds of the EFGR (except the vagrants and accidentals), though I still struggle with the crakes.

Brown-necked raven Corvus ruficollis were also frequently seen in the desert [adjacent photo © Bob Loveridge], in environments that you might think of as being too barren to be home to such large corvids (though this view reflects nothing more than my Anglocentric bias, as I know full well that there are many big corvids inhabiting the deserts of the world). We initially saw ravens at great distance and I inferred from their distinctive calls that they were not plain old Northern/Common ravens C. corax. Once we got them in clear view, their relatively gracile bills (compared to those of Northern raven) and iridescent brownish neck identified them securely.

The north-east of the country was also the right region where, according to the books, you're likely to encounter Crimson-winged finches Rhodopechys sanguinea. Unfortunately we never knowingly saw this species. At the pterosaur site Richard and I did, however, get a fleeting glimpse of some small plain finches that flew away and vanished on a hillside. Their distinctive calls - they sounded like toy trumpets - meant that I was pretty sure that these were Trumpeter finches Bucanetes githagineus. We were unable to get closer to them on that day and assumed that they were some sort of super-elusive, rarely seen rarity of the remotest regions. This was to prove very much incorrect.

On the lizards

So far it's all been birds birds birds (pretty much). What about the lizards and snakes I hear you cry? Fact is we saw surprisingly little in the way of these, presumably because it was winter. At several locations fringe-toed lizards (Acanthodactylus) were fairly abundant, but everywhere we went they were of the same species (I assume A. erythrurus). Fringe-toed lizards have shovel-shaped snouts and can almost literally dive into soft sand when escaping from predators. Their elongate toe scales are obvious and look like tiny spikes, and they're perhaps best known for their habit of lifting alternate feet when standing on hot sand. There are about 32 species distributed across the Iberian Peninsula, northern Africa and southern Asia (as far east as Pakistan). Molecular work indicates that they originated in south-west Asia, and that several different lineages invaded northern Africa, with specialisation for life on soft aeolian sand habitats occurring independently as many as four times (Harris & Arnold 2000) [composite image below shows, at left, fringe-toed lizard (courtesy Richard Hing), unidentified agamas in the middle, and juvenile mastigure at far right, © Bob Loveridge].

We also saw a few agamas, though I'm not entirely sure what species they were. One had a rotund body and slender tail and reminded me of the Australian pebble dragons: you'd think it would be easy to identify but as is so often the case with lizards I was hindered by the fact that there is no field guide to north African lizards (so far as I know). Other agamids were here too, though unfortunately I only saw dead individuals: namely, mastigures, dabbs or spiny-tailed agamas (Uromastyx). I saw the first specimen while clambering down the side of a cliff and almost landed on its desiccated corpse. The yellowish mottling on its back suggested that it was most likely a Saharan mastigure U. geyri (one of about 20 species). While looking for fossils I found a second specimen, this time a baby. I assume it's a Saharan mastigure as well, but given that it lacks the markings of an adult it's not possible to be sure. Needless to say, I collected both of them and brought them home. That was pretty much it for herps. No tortoises, no anurans, and (most surprisingly) no snakes, though Nizar did briefly see a small, slim colubrid.

Where the rebbachisaurs roam... or don't

Later on in the trip we stayed for a few days at Gara Sba, a location famous in dinosaur lore as being the place where the diplodocoid sauropod Rebbachisaurus garasbae was discovered during the 1950s. The exact point of discovery can still be found (it looks like a children's sandpit) and there are local people who - within recent years at least - still recalled the discovery: the large size of the scapula impressing them in particular. I looked around in the vain hope that new bits might await discovery, but no such luck of course. Rebbachisaurid anatomy has become reasonably well known thanks to the description of Limaysaurus tessonei from Argentina (Calvo & Salgado 1995) and the remarkable Nigersaurus taqueti from Niger (Sereno et al. 2007), but Rebbachisaurus itself remains quite poorly known. The fact that Rebbachisauridae is phylogenetically anchored on this taxon is therefore a bit unfortunate (Taylor & Naish 2005), though Nizar tells me that there is additional material of R. garasbae still awaiting description.

Incidentally, if you've been following the literature on European rebbachisaurids (previously discussed a bit in the comments here), the latest news is Phil Mannion's report of postcranial material from the Wessex Formation of the Isle of Wight (Mannion 2008). Previously all we had to go on is teeth (Naish & Martill 2001), so well done Phil.

While driving around near Gara Sba we were amazed to see a bushy-tailed mammal running at high speed through the desert scrub. It was the elusive Fennec fox Vulpes zerda at last: we drove after it and got some excellent photos before it disappeared [adjacent photo © Bob Loveridge]. I never thought we had a chance of seeing one (let alone getting good photos), so this was pretty amazing. In fact we had the most amazing luck in seeing creatures while driving around. We never saw another fennec, but at another location a large running bird - which Bob was also able to photograph - proved to be a Houbara bustard Chlamydotis undulata (the lack of black on its neck showed that it must have been a juvenile). Bustards are now pretty rare in Morocco as they have been extensively persecuted by rich Saudi hunters. One book said that light aircraft had even been used in the pursuit of these birds, which doesn't exactly sound sporting. On another occasion we were driving across a dry playa lake when I spotted a Cream-coloured courser Cursorius cursor in flight. It alighted and again we were able to get pretty close and to take good photos (we saw a whole group of coursers later on). We also saw what I think was a Long-legged buzzard Buteo rufinus, and a characteristically pale Short-toed eagle Circaetus gallicus [composite below shows, top to bottom, Houbara bustard, Cream-coloured courser and Long-legged buzzard. © Bob Loveridge].

That'll have to do for now, but that's still not it. Still larks, finches and adventures at Camp Solifuge to come. Oh yeah, and at least something on the fossils we found :)

Refs - -

Calvo, J. O. & Salgado, L. 1995. Rebbachisaurus tessonei sp. nov. a new Sauropoda from the Albian-Cenomanian of Argentina; new evidence on the origin of the Diplodocidae. Gaia 11, 13-33.

Harris, D. J. & Arnold, E. N. 2000. Elucidation of the relationships of spiny-footed lizards, Acanthodactylus spp. (Reptilia: Lacertilia) using their mitrochondrial DNA sequence, with comments on their biogeography and evolution. Journal of Zoology 252, 351-362.

Heinzel, H., Fitter, R. & Parslow, J. 1995. Birds of Britain and Europe. Collins, London.

Mannion, P. 2008. A rebbachisaurid sauropod from the Lower Cretaceous of the Isle of Wight, England. Cretaceous Research doi:10.1016/j.cretres.2008.09.005

Mullarney, K., Svensson, L., Zetterström, D. & Grant, P. J. 1999. Bird Guide. HarperCollins, London.

Naish, D. & Martill, D. M. 2001. Saurischian dinosaurs 1: Sauropods. In Martill, D. M. & Naish, D. (eds) Dinosaurs of the Isle of Wight. The Palaeontological Association (London), pp. 185-241.

Sereno, P. C., Wilson, J. A., Witmer, L. M., Whitlock, J. A., Maga, A., Ide, O. & Rowe, T. A. 2007. Structural extremes in a Cretaceous dinosaur. PLoS ONE 2(11): e1230. doi:10.1371/journal.pone.0001230

Taylor, M. P. & Naish, D. 2005. The phylogenetic taxonomy of Diplodocoidea (Dinosauria: Sauropoda). PaleoBios 25, 1-7.