Couldn’t upload pictures for a few hours today, upload system down, thus the post is a bit late. Sorry!
Today, let’s have a short look at the diversity of extant dinosaurs. OK, admittedly all I can offer is theropods, and avialae, or more closely defined Aves at that. And that group has gone through a ridiculous miniaturization in the Jurassic, because of their adaptation to flight. The most obvious results are the loss of the bony tail, a huge central nervous system (they do have to process a huge lot of visual data very quickly, otherwise they’d fly right into things), the loss of the left aortic arch (us mammals retained it and lost the right one, and what a striking coincidence that mammals also underwent miniaturization during the Jurassic?), the loss of one ovary (in most families), and the development of a ridiculously large sternum with a keel on the midline and accordingly huge pectoral muscles.
Nah, that’s not bird inventions, that’s all stuff more basal dinosaurs already had.
*(Phil Manning pointed out at the Bonn conference, I should better say “archosaur-grade highly subdivided unidirectional lung”)
OK, enough text, here come the pics:
House Sparrows (Passer domesticus), using the condor aviary’s mesh fence as a resting place. Seeing the two next to each other is pretty impressive. Sparrows are far from being the smallest birds, even in Europe. Still, they are extremely common, and thus the smallest birds most people see regularly. The Bee Hummingbird (Mellisuga helenae) is the smallest bird, at a weight of 1.8 g. That’s a bit more than 0.01 per mill of the 154 kg for the largest ostriches (says wikipedia).
oh yeah, ostriches:
and thus we have three highly different main modes of locomotion in birds: terrestrial walking and running in ostriches, soaring in the condor, and flapping flight in the sparrow. Let’s add another one, surface swimming by paddling
A couple of Mandarin ducks (Aix galericulata) sleeping. Although I took this picture in the Berlin Zoo, this beautiful member of the dabbling ducks is pretty common in Berlin, with over 9,000 breeding pairs. That’s a higher number than in the wild in Japan and China! Dabbling ducks rest high in the water, and feed mainly on the surface or by dabbling. The other large behavioral group are the diving ducks, but the taxonomy of geese and ducks is something to have nightmares about, so I’ll not dive into it at all.
One thing that varies a lot in birds is overall proportions and neck length.
A Black swan (Cygnus atratus). Compare neck length to the sparrow. Many birds have fairly long necks, but hold them in a strong S-curve (see this budgie sketch in the epic “Necks lie!” post at SVPOW), but they are no match for many birds living on or in water, and quite a large number of other birds. As a general pattern, good maneuverable fliers have shorter necks, but neck length also correlates with leg length (you wanna get your beak to the ground without sitting down, maybe?).
Well, I could go on for days posting pictures of birds that are non-ordinary songbirds. I’ll stop now with one of the oddest groups: penguins!
Humboldt penguins (Spheniscus humboldti) about to enter the water.
All pictures taken at the Berlin zoos.