tinamous

Green-fronted Brilliant , Heliodoxa jacula, Reserva Reinita cielo azul, Eastern andes with bogota birding by Oswaldo Cortes
Via Flickr:
Another amazing birding tour with Bogota Birding Highland Tinamou, Spectacled Parrotlet, Moustached Puffbird, Bar-crested Antshrike, Recurve-billed Bushbird, Chestnut-crowned Gnateater, Yellow-throated Spadebill, Rufous-naped Greenlet, Cerulean and Golden-winged Warblers, Yellow-tufted Dacnis, Black-headed Brush-Finch, Yellow-browed Shrike-Vireo, White-eared Conebill, Double-banded Graytail, Thick-billed Seed-Finch, White-vented Euphonia, Black Inca, Moustached Puffbird, Parker’s Antbird, Upper Magdalena Tapaculo, Chestnut-crowned Gnateater, Yellow-throated Spadebill, Gorgeted Wood-Quail , Colombian Mountain Grackle, Brown-billed Scythebill and White-throated Spadebill.

Ornithologists once assumed early birds, and the dinosaurs they evolved from, laid white eggs. But we know that some of the most ancient groups of birds still around – including the tinamou and emu – actually lay coloured eggs, points out Mark Hauber, an animal behaviourist at Hunter College in New York.

His group has discovered the chemical origin of the avocado-green from emu’s eggs, as well as the blue of robin’s eggs, the brown of chicken’s eggs and the pinks and purples from the eggs of other birds belonging to ancient living groups. The colours come from the way that two pigments in the shell – biliverdin and protoporphyrin – blend with each other and with the calcium carbonate that makes most of the shell.

Sander’s student, Jasmina Wiemann, found the oviraptor eggs contained both biliverdin and protoporphyrin. Most protoporphyrin came from the protein layer or cuticle still coating the fossil egg, as it does in modern bird eggs. Biliverdin came mostly from the calcium carbonate, also as in modern birds. Collectively the pigment evidence suggests oviraptors had blueish-green eggs.

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Most male birds (e.g., roosters and turkeys) have a cloaca (also present on the female), but not a penis. Among bird species with a penis are paleognathes (tinamous andratites),[3]Anatidae (ducks, geese and swans),[4] and a very few other species (including flamingoes[citation needed] and chickens[5]). A bird penis is different in structure from mammal penises, being an erectile expansion of the cloacal wall and being erected by lymph, not blood.[5] It is usually partially feathered and in some species features spines and brush-like filaments, and in flaccid state curls up inside the cloaca. The Argentine Blue-bill has the largest penis in relation to body size of all vertebrates; while usually about half the body size (20 cm), a specimen with a penis 42.5 cm long is documented.

While most male birds have no external genitalia, male waterfowl (Anatidae) have a phallus. Most birds mate with the males balancing on top of the females and touching cloacas in a “cloacal kiss”; this makes forceful insemination very difficult. The phallus that male waterfowl have evolved everts out of their bodies (in a clockwise coil) and aids in inseminating females without their cooperation.[6] The male waterfowl evolution of a phallus to forcefully copulate with females has led to counteradaptations in females in the form of vaginal structures called dead end sacs and clockwise coils. These structures make it harder for males to achieve intromission. The clockwise coils are significant because the male phallus everts out of their body in a counter-clockwise spiral; therefore, a clockwise vaginal structure would impede forceful copulation. Studies have shown that the longer a male’s phallus is, the more elaborate the vaginal structures were.[6]

The Lake Duck is notable for possessing, in relation to body length, the longest penis of all vertebrates; the penis, which is typically coiled up in flaccid state, can reach about the same length as the animal himself when fully erect, but is more commonly about half the bird’s length.[7][8] It is theorized that the remarkable size of their spiny penises with bristled tips may have evolved in response to competitive pressure in these highly promiscuous birds, removing sperm from previous matings in the manner of a bottle brush.

Male and female emus are similar in appearance,[9] although the male’s penis can become visible when it defecates.[10]

The male tinamou has a corkscrew shaped penis, similar to those of the ratites and to the hemipenis of some reptiles. Females have a small phallic organ in the cloaca which becomes larger during the breeding season.[11]