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The other turkey

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Wild Ocellated turkey, photographed in Belize by John Harshman, used with permission.

Whenever I mention turkeys on Tet Zoo, it’s unavoidable that I (generally) mention or illustrate the turkey we know best: the domestic form of Meleagris gallopavo, the North American bird typically known as the Wild turkey. It’s big, with bronzy-brown plumage, a mostly pinkish head and neck and a wiry ‘beard’ that hangs down from the chest. This remarkable, charismatic, wonderful and familiar bird (hey, I really like turkeys) has been discussed on Tet Zoo a few times: see the links below. But I have turkey-guilt. There is…. another.

It's sometimes said that domestic M. gallopavo are more elaborately feathered than wild individuals. In fact, that isn't obviously true. This is a captive individual of a wild-type M. gallopavo, photographed at Wilhelma Zoologisch-Botanischer Garten in Stuttgart, by Markus Bühler.

As you’ll know if you know your gamebirds, the second living turkey is the Ocellated turkey M. ocellata. Originally described (in 1820) as a species of Meleagris,  it was regarded in 1896 as different enough from M. gallopavo to deserve its own ‘genus’, Agriocharis. This persisted until Steadman’s (1980) study of fossil turkeys showed that the species is not distinct enough from M. gallopavo to warrant ‘generic’ rank. Historically, several fossil species have been regarded as especially close to the Ocellated turkey and hence as members of Agriocharis as well.

Remember that these decisions about whether a species warrants its own ‘genus’ or not are wholly subjective; we accept the view for now that the species should be included in Meleagris (indeed, it is very similar in many skeletal details to M. gallopavo), but this might change in future. Bocheński & Campbell (2006) noted that “the osteological differences [between M. ocellata and M. gallopavo] are larger than previously thought” (p. 48) and they essentially recommended that further study is needed.

The Ocellated turkey is endemic to the Yucatán Peninsula, meaning that it mostly occurs in Mexico but is also present in parts of Belize and Guatemala. Its plumage is brighter and more glossy green and copper than bronzy-brown; it also differs from M. gallopavo in having far whiter remiges and a blue head decorated with orange, wart-like nodules.

Rump and tail feathers (note white wing feathers as well) on an Ocellated turkey photographed in Belize. Image by John Harshman, used with permission.

Bands of small blue ocelli are present on the rump feathers and near the tips of the uppertail coverts and tail feathers. They’re most obvious, of course, when the bird fans out its tail in display (as in the photo below) and they explain the technical and common name. Prior to fanning the tail, a displaying male wags its tail from side to side. When displaying, it presses its neck against the top of its back (rather than pulling the neck into the chest, as is done in M. gallopavo) while drooping its wings.

Blue ocelli on the tail region are, elsewhere, famously seen in peafowl, and the superficial similarity between peafowl and the Ocellated turkey once led to the suggestion that the two might be especially close (Taylor et al. 2006). Today we’re confident that the Ocellated turkey really is a turkey, and for more on the probable position of turkeys within gamebird phylogeny see the previous article.

Ocellated turkey with spread tail - photo by Simon Woolley, used with permission.

The fossil turkeys

Reconstructed skeleton (with life reconstruction behind) of the California turkey, as displayed at the George C. Page Museum, LA. Artwork by John D. Dawson. Photo by Darren Naish.

Several Pliocene and Pleistocene species have been regarded as more closely related to the Ocellated turkey than to M. gallopavo: Martin & Tate (1970) recognised four fossil relatives of this species (they regarded all as part of Agriocharis): M. leopoldi, M. progenes, M. anza and M. crassipes. There are other Pleistocene fossil turkeys too, including M. alta, M. tridens and – best known of them all – the California turkey M. californica. The systematics and phylogeny of many of these species has been, and still is, controversial and unresolved. M. alta and M. tridens were both treated as synonyms of M. gallopavo by Steadman (1980) and the late Pliocene form M. progenes might be synonymous with M. leopoldi (Stidham 2011), as might M. anza.

The mostly Californian species M. californica was – ironically, in view of the previous Tet Zoo article – originally described as a peacock (Miller 1909). Its fossils are very abundant at Rancho La Brea where numerous specimens died after entrapment in the tar. The idea of numerous peacocks strutting about the woodlands and savannahs of Pleistocene California, alongside dire wolves, sabre-toothed cats and ground sloths, is perhaps amusing. However, its describer – Larry H. Miller – revised his view, later suggesting that the ‘California peacock’ was an evolutionary intermediate between peafowl and the Ocellated turkey, and warranting the new name Parapavo (Miller 1916). Later authors appreciated that Parapavo was a true turkey, either equally related to both living species, or closer to one or the other. Steadman (1980) eventually concluded that it should be sunk into Meleagris.

For some fossil turkeys, material like this is all we have to go on. These are the type (and referred) elements of Proagriocharis kimballensis, from Martin & Tate (1970): a coracoid, a few tarsometatarsi, and a spur core.

Proagriocharis kimballensis from the Pliocene of Nebraska was described as the smallest and oldest turkey (Martin & Tate 1970). Steadman (1980), in his major review of fossil turkeys, sank Proagriocharis into Meleagris. Olson & Farrand (1974) reinterpreted Rhegminornis calobates Wetmore, 1943 from the Early Miocene of Florida as a very early turkey. Named for a tarsometatarsus 29.6 mm long, it must have been a tiny turkey. If it is a turkey, it fits with the general trend of increasing body size otherwise seen in the fossil turkeys of the Pliocene and Pleistocene.

Some aspects of anatomy, biology, behaviour

The turkey we know best – M. gallopavo – has a reddish dewlap, a dangling structure that hangs over the side of the bill (called the snood), and thickly wrinkled skin over the top and back of the head. The Ocellated turkey lacks a dewlap but it does have a snood – a bluish one rather than a reddish one. A reddish eye-ring is present. Posterior to the snood, and projecting upwards from the top of the head, is a blunt blue horn, sometimes with a yellowish tip. Snoods and horns are absent in females. Ocellated turkeys also differ from M. gallopavo in having slimmer, shorter, redder legs. Long curved spurs (generally longer than those of M. gallopavo: Bocheński & Campbell 2006) are present in males.  We don’t usually think of turkeys as birds that fight, but they do: google ‘fighting turkeys’ to see some great photos.

Head of that same bird from Belize again, showing horn, snood and nodules. Photos by John Harshman, used with permission.

Relatively little information is available on the behaviour and biology of the Ocellated turkey and it’s one of those animals where you tend to see the same several facts trotted out again and again. Sources often say that it doesn’t produce a proper ‘gobble’ call like the other turkey; that’s apparently not true – males produce a series of drumming noises before producing a high-pitched gobble (Taylor et al. 2006). Diet-wise, it’s a generalist, eating the leaves and seeds of a diversity of plants as well as moths, beetles and ants. Sugihara & Heston (1981) reported an observation of two adult males “feeding intensively on a column of leaf cutter ants carrying flower parts” (p. 396).

Having mentioned insects, Sugihara & Heston (1981) also reported anting behaviour in members of this species. Three adult males were seen to deliberately lower their wings onto ant nest mounds. The ants they were using – Atta cephalotes – don’t produce formic acid, so were presumably just running about among the birds’ feathers, removing parasites and such. I have no idea how widespread anting behaviour is in gamebirds – I’m aware of anecdotes reporting possible anting behaviour in domestic chickens – and it raises the question of how widespread anting behaviour is in birds as a whole. Do waterfowl and palaeognaths do it too?

Male Ocellated turkey in a tree (wild turkeys fly into trees to roost). Photo in public domain, by US Fish & Wildlife Service.

Moving on, the Ocellated turkey occurs in humid broadleaved forests as well as savannah-scrub mosaics, and it forms flocks that fluctuate in size throughout the year. During the early months of the year, males sing and fight with one another to claim dominance of a flock. As is typical for gamebirds with strong sexual dimorphism and ornate, showy males, females are solely responsible for eggs and chicks, and small groups of females and their poults may form ‘brooding flocks’ during September and October (Madge & McGowan 2002).

The small and localised nature of the population means that the species is listed as ‘Near Threatened’ and it’s thought to be in decline due to hunting pressure and habitat loss and degradation. It appears to be locally extinct in several Mexican regions. Declines that occurred during 1980 and 2000 were hypothesed by Kampichler et al. (2010) to be based on an influx of people into the region where it occurs and a concomitant increase in the obtaining of bushmeat.

Another wild Ocellated turkey, this time from Guatemala: this one is eating ashes and has appeared in print in an article on hummingbird behaviour. Image by Sheri L. Williamson, used with permission.

Thanks to John Harshman, Markus Bühler, Simon Woolley and Sheri L. Williamson (of the excellent Life, Birds, and Everything) for providing the photos used here. For previous Tet Zoo articles on turkeys and other gamebirds, see…

Oh, remember the caption competition? This one wins, but only because a picture was created… and because I like Outkast. Well done, himitsunokare (if that is your real name).

Refs – -

Bocheński, Z. M. & Campbell, K. E. 2006. The extinct California turkey, Meleagris californica, from Rancho La Brea: comparative osteology and systematics. Natural History Museum of Los Angeles County, Contributions in Science 509, 1-92.

Kampichler, C., Calmé, S., Weissenberger, H., Arriaga-Weiss, S. L. 2010. Indication of a species in an extinction vortex: the ocellated turkey on the Yucatan peninsula, Mexico. Acta Oecologica 36, 561-568.

Madge, S. & McGowan, P. 2002. Pheasants, Partidges & Grouse, Including Buttonquails, Sandgrouse and Allies. Christopher Helm, London.

Martin, L. D. & Tate, J. 1970. A new turkey from the Pliocene of Nebraska. The Wilson Bulletin 82, 214-218.

Miller, L. H. 1909. Pavo californicus, a fossil peacock from the Quaternary asphalt beds of Rancho La Brea. University of California Publications, Bulletin of the Department of Geology 5, 285-289.

- . 1916. A review of the species Pavo californicus. University of California Publications, Bulletin of the Department of Geology 9, 89-96.

Olson, S. L. & Farrand, J. 1974. Rhegminornis restudied: a tiny Miocene turkey. The Wilson Bulletin 86, 114-120.

Sugihara, G. & Katherine Heston, K. 1981. Field notes on winter flocks of the Ocellated turkey (Agriocharis ocellata). The Auk 98, 396-398.

Steadman, D. W. 1980. A review of the osteology and paleontology of turkeys (Aves: Meleagridinae). Contributions in Science, Natural History Museum of Los Angeles County 330, 131-207.

Stidham. T. A. 2011. The carpometacarpus of the Pliocene turkey Meleagris leopoldi (Galliformes: Phasianidae) and the problem of morphological variability in turkeys. PaleoBios 30, 13-17.

Taylor, C. I., Quigley, H. B. & Gonzalez, M. J. 2006. Ocellated turkey (Meleagris ocellata). NWTF Wildlife Bulletin 6, 1-8.

Darren Naish About the Author: Darren Naish is a science writer, technical editor and palaeozoologist (affiliated with the University of Southampton, UK). He mostly works on Cretaceous dinosaurs and pterosaurs but has an avid interest in all things tetrapod. His publications can be downloaded at darrennaish.wordpress.com. He has been blogging at Tetrapod Zoology since 2006. Check out the Tet Zoo podcast at tetzoo.com! Follow on Twitter @TetZoo.

The views expressed are those of the author and are not necessarily those of Scientific American.



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  1. 1. vdinets 7:57 am 01/16/2013

    It is perhaps worth noting that this species is virtually extinct outside protected “Archeological zones”, i. e. Ancient Mayan cities popular with tourists. Tikal in Guatemala is the easiest place to see it.

    Link to this
  2. 2. naishd 7:59 am 01/16/2013

    I hadn’t realised that, thanks. Do you know if this has been stated in the literature – it’s a pretty important observation that I haven’t (yet) seen mentioned elsewhere. I can see a paper here: ‘Conservation of archaeological sites inadvertently conserves threatened gamebird’.

    Darren

    Link to this
  3. 3. vdinets 8:20 am 01/16/2013

    I haven’t seen it in scientific papers, but it is common knowledge among birdwatchers. In Tikal, you see something like ten turkeys per day on average. Outside Zonas Archeologicas, I’ve seen them only in one remote location on Mexican/Guatemalan border.

    Link to this
  4. 4. naishd 8:27 am 01/16/2013

    Ok, great, thanks. I’m always slightly frustrated when it comes to the difference between “common knowledge” and “the stuff you will actually learn if you check the literature”, so this definitely needs to be written up by someone, hint hint :)

    Of course, it may be somewhere in the literature already.

    Darren

    Link to this
  5. 5. John Harshman 10:36 am 01/16/2013

    I might add that the pictures come from the eco-resort Chan Chich, which is in fact the site of an ancient Mayan community, though it hasn’t been uncovered: what you see are suspiciously geometrically arranged earthen mounds. So that would tend to confirm vdinets’ claim. Ocellated turkeys are quite common there, and they regularly forage near the guest houses. Can’t miss ‘em.

    Oh, and if anyone wants a Central American rain forest experience in fairly decadent comfort, Chan Chich is a nice place to visit. Take the boat trip by way of Lamanai; definitely worth the time.

    The snood on the bird I photographed seems to have a red tip, and you should really mention all the bright yellow and red carbuncles. Sadly, nobody was displaying that day.

    Oh, and it should be noted that M. gallopavo tail and covert feathers have a quite fancy purplish-brown iridescence if you look at them up close. Not so fancy as their cousins, but attractive nevertheless.

    Link to this
  6. 6. jbrougham 10:38 am 01/16/2013

    Awesome article, great photos. At the AMNH here we reconstructed the central pre-Columbian zocalo in Tenochtitlan for a recent exhibition. I was desperate to put ocellated turkey models in that but the evidence suggested that the Mexicas would have only raised the southern subspecies of M. gallopavo, as that was the stock from which domesticated turkeys came.

    Link to this
  7. 7. blakemathys 11:05 am 01/16/2013

    “…males produce a series of drumming noises before producing a high-pitched gobble”; I have a video of a male Ocellated Turkey displaying (trying to intimidate our rental car) here:

    http://www.youtube.com/watch?v=Aeivh2d58Ww

    Link to this
  8. 8. chris y 11:08 am 01/16/2013

    But you missed the most important bit: what do they taste like?

    Link to this
  9. 9. Neil K. 11:46 am 01/16/2013

    Awesome, love all of these turkeys, especially the Ocellated and especially especially M. californica. The introduction and widespread naturalization of M. gallopavo in California is an under-appreciated example of unintentional “rewilding.” Interestingly M. gallopavo is widely distributed across the state while M. californica was supposed to be restricted to southern California, although there is one report of M. sp. remains from a cave in Northern California. Somebody needs to relocate those fossils or find more.

    I have no idea how widespread anting behaviour is in gamebirds

    An early account of anting, or at least anting-like, behavior comes from Audubon in Birds of America regarding Wild Turkeys:

    “They roll themselves in deserted ants’ nests, to clear their growing feathers of the loose scales, and prevent ticks and other vermin from attacking them, these insects being unable to bear the odour of the earth in which ants have been.”

    Whitaker (1957) lists numerous other galliform species in her(?) literature compilation, including domestic chickens, but no waterfowl or palaeognaths.

    And Ocellated Turkeys are supposed to taste delicious. Hence the population declines perhaps (though habitat loss no doubt has something to do with it as well).

    Whitaker L 1957. A Resume of Anting, with Particular Reference to a Captive Orchard Oriole. Wilson Bulletin 69(3) 195-262.

    Link to this
  10. 10. naishd 12:02 pm 01/16/2013

    Loving all these comments, thanks loads. And the Ocellated turkey is such a beautiful bird that I will keep adding pictures I get hold of – another one still to come, just waiting for a high-res version. Neil (comment 9): to my embarrassment, I wasn’t aware of Whitaker (1957) until now, must check it out.

    On early domestic turkeys (comment 6): check out…

    Thornton, E. K, Emery KF, Steadman DW, Speller C, Matheny R. & Yang, D. 2012. Earliest Mexican turkeys (Meleagris gallopavo) in the Maya Region: implications for pre-Hispanic animal trade and the timing of turkey domestication. PLoS ONE 7(8): e42630. doi:10.1371/journal.pone.0042630

    Darren

    Link to this
  11. 11. Neil K. 12:40 pm 01/16/2013

    In case you haven’t found it, Whitaker (1957) is a available here (pdf).

    The case she describes is interesting as the ants preferred the Oriole were also non-formic acid producers. It’s worth noting that ants, including Atta, secrete a lot of other compounds aside from formic acid, including those with anti-microbial properties important for nest maintenance (especially in “fungal farming” leaf-cutters). So it is conceivable that the anting Ocellated Turkeys reported by Sugihara & Heston (1981) were after some other ant-produced chemical, possibly with anti-fungal or anti-bacterial properties. Not that I’m necessarily favor that to the grooming hypothesis, just throwing the idea out there. An obsession with formic acid to the exclusion of other insect produced compounds could mislead our understanding of anting behaviors.

    Link to this
  12. 12. Tz'unun 1:14 pm 01/16/2013

    Great post, Darren!

    I’m scratching my head over the claim that Ocellateds don’t gobble “properly,” as well as why the “drumming” noise (which is vocal, not produced by wing-beating or other external means) wouldn’t be considered a component of the gobble. You get a sense of how deep the “drumming” is from Blake Mathys’s video. Standing next to a displaying male, you feel this sound as much as hear it. The low-frequency component of a Wild Turkey’s gobble isn’t as prominent, at least to my ears.

    Another fascinating difference in Ocellateds is the lack of a “beard.” Instead, males draw attention to the same part of their anatomy by erecting the breast feathers into a sharp “keel” (also evident in Blake’s video). If only we had some way to learn the distribution of beards vs. “keels” (or some other display structure?) in the extinct forms!

    I second John Harshman’s comment about the iridescent beauty of Wild Turkeys. In bright sun, the plumage glows like fire agate – a vastly underappreciated and misunderstood bird.

    Link to this
  13. 13. David Marjanović 1:19 pm 01/16/2013

    Zonas Archeologicas

    arqueológicas :-)

    Link to this
  14. 14. James Robins 4:54 pm 01/16/2013

    Might I also add that this, with all it’s extraneous head gear, it’s loose skin, it’s psychedelic colour palette and it’s fantastic feathers, none of which would appear as a fossil, would make it a perfect candidate for a future edition of ‘All Yesterday’…..

    Link to this
  15. 15. vdinets 4:59 pm 01/16/2013

    David: sorry, I got my Spanish from oral communication only, and never learned to write well.

    Darren: I have a video of a male ocellated turkey in a zoo in Texas (Dallas, I think) in full display, with my wife being the muse. Should I email it to you?

    Link to this
  16. 16. Dartian 5:40 am 01/17/2013

    Darren:
    the superficial similarity between peafowl and the Ocellated turkey once led to the suggestion that the two might be especially close (Taylor et al. 2006)

    I’d be interested to know who those workers who suggested that the ocellated turkey is more closely related to peafowl than to the ‘common’ turkey were. I looked up Taylor et al. (2006), but they don’t cite any sources.

    Is there, by the way, any good explanation for why medium- and large-bodied galliforms are much more diverse in Eurasia (especially in eastern and southern Asia) than in Africa and North America? Granted, the fact that – by bird standards – galliform dispersal capabilities are relatively limited is likely to have something to do with it, but I don’t think that can be the only reason.

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  17. 17. Jerzy v. 3.0. 6:47 am 01/17/2013

    Yes, it is amazing how visible wildlife can be where there is no shooting :)

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  18. 18. naishd 10:16 am 01/17/2013

    Regarding the claim that the Ocellated turkey has been considered closely related to peafowl (comment 16), two possibilities occurred to me while writing: (1) that this is perhaps a confused reference to the confusion that existed over fossil species (like the California turkey), (2) that is refers to the fact that the Ocellated turkey is called Pavo ocelado in Spanish. In fact, isn’t ‘pavo’ used in Spanish for turkeys? I’ve seen cases in the literature were Spanish authors used the word ‘turkey’ when referring to taxa within Pavo, so maybe this confusion goes both ways.

    Why so few big-bodied gamebirds in Africa and North America? I can’t think of any good reasons outside of historical contingency (that is, the lineages concerned diversified in Eurasia but never got round to doing much in those other continents). Then again, some of the regions concerned might have had more big-bodied gamebirds in the past: remember those fossil peafowl from eastern Africa, for example.

    Darren

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  19. 19. vdinets 10:20 am 01/17/2013

    Dartian: I am not sure this is true for Africa, which has a long list of Francolinus spp., all of them medium-sized, plus five spp. of guineafowl and the Congo peacock. There is less diversity on genus level (despite the recent split of Francolinus), but that can be easily explained by the fact that African rainforests are less extensive and have probably contracted into small refugia in the past, while in tropical Asia most larger-bodied galliforms live in rainforests or monsoon forests (the latter totally absent from mainland Africa).

    As for North America, the diversity pattern is, indeed, weird. Odontophorids never evolved any large forms; Cracids are mostly medium or large, but haven’t expanded north of S Texas; birds formerly known as Tetraonidae are actually more diverse than in Eurasia (11 spp. vs. 9), but other Phasianidae haven’t diversified, even though introduced ones do really well (at least 5 non-Tetraonid Phasianid species have established, while, interestingly, numerous attempts at introducing European Tetraonids have failed).

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  20. 20. vdinets 10:34 am 01/17/2013

    Self-correction: there is a narrow belt of what could be called monsoon forest along the coast of E Africa, from Kenya to ZAR, but it has mostly species-level endemism and is probably relatively young. Eastern Arc forests could also be called “monsoon forests” with some stretch, and they have an endemic species (Udzungwa partridge) with Asian connections.

    BTW, two African species have recently been shown to be Odontophorids. Isn’t that cool?

    Cohen et al. 2012. Phylogenetic affinities of evolutionarily enigmatic African galliforms: the Stone Partridge Ptilopachus petrosus and Nahan’s Francolin Francolinus nahani, and support for their sister relationship with New World quails. Ibis 154 (4): 768–780.

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  21. 21. naishd 10:44 am 01/17/2013

    vdinets (comment 19): good point on the francolins. We mustn’t forget that there are over 40 species. Regarding the splitting of Francolinus of tradition, remember that the names concerned are not new (Pternistes Wagler, 1832, Peliperdix Bonaparte, 1856, Scleroptila Blyth, 1849), but rather have been resurrected from synonymy following realisation that francolins are far from monophyletic.

    Darren

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  22. 22. Dartian 12:11 pm 01/17/2013

    Vladimir:
    I am not sure this is true for Africa, which has a long list of Francolinus spp., all of them medium-sized

    Oh, I should have been more specific. I don’t consider francolins to be ‘medium-sized’ in this context. Francolins and partridges may be regarded as being medium-sized by general bird standards, but by galliform standards they are ‘small’. (By the same criteria, quail are ‘very small’, whereas turkeys, peafowl, argus pheasants, and capercaillies are ‘large’.). By ‘medium-sized’ galliform I mean something typically weighing about one kilogram (give or take a couple hundred grams); i.e., about the size of a junglefowl, a black grouse, or a (ring-necked) pheasant.

    My point is that, apart from a modest radiation of guineafowl and Afropavo, at least among the extant avifauna of Africa there is nothing comparable to the diversity of various mid- to large-sized ‘pheasants’ in tropical and temperate Asia. I’d be interested to know if that’s just a quirk of history or if there’s some deeper biological reason behind it.

    two African species have recently been shown to be Odontophorids. Isn’t that cool?

    Crikey! I had no idea. If those results hold up, ‘cool’ is an understatement!

    Link to this
  23. 23. vdinets 12:38 pm 01/17/2013

    Dartian: many francolins (i. e. Natal and Cape f.) weigh close to 1 kg. I think Jackson’s francolin can be even heavier.

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  24. 24. naishd 12:48 pm 01/17/2013

    I can’t find any mass data for Jackson’s francolin (I just checked Madge & Burn and they say “no data”) but males of its close relative Erckel’s francolin can exceed 1.1 kg. For most other francolins, males are somewhere between c. 250 and 600 g.

    Darren

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  25. 25. vdinets 12:52 pm 01/17/2013

    BTW, pheasants are not the only forest group with lots of diversity in Asia and only a handful of taxa (but not recent colonizations!) in Africa. Chevrotains, broadbills, some warblers (don’t remember which ones – there’s been so much re-shuffling), arboreal pigeons, some Angyosperms… And savanna taxa tend to show the opposite pattern.

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  26. 26. Dartian 3:05 am 01/18/2013

    The fact that a couple of francolin species (out of dozens) reach the same size as an average domestic chicken does not negate my main point: that larger galliforms are far less diverse in Africa than they are in Asia. Before I’m willing to dismiss that as a mere quirk of history (to use my previous turn of phrase), I’d like to at least consider other explanations. Is there perhaps something in the African environments generally that is unfavourable for large, ground-living, conspicuous (at least the males), mainly herbivorous birds?

    -Is predation pressure more severe in Africa than it is in Asia? Perhaps that’s true in savanna habitats, but, to me at least, it seems unlikely to be the case in the African rainforests (the diversity of mammalian predators, in particular, is much lower in African than in Asian rainforests) or in montane habitats.

    -Do large galliforms face competition from some other birds (or perhaps other vertebrates) in Africa? Bustards come to mind (large, ground-living, largely ground-living), but they prefer more open habitats than large galliforms usually do, so one wouldn’t expect competition between these two bird groups to be particularly hard.

    -Is there a lack of galliform-suitable habitats in Africa? Again, that seems unlikely to be the case if we consider the entire continent. For example, why do the African mountains and montane forests lack any mid- to large-sized galliforms comparable to such Asian taxa as (for example) Tragopan, Lophophorus, Pucrasia, and Catreus?

    Surely there are other possible explanations too, but I hope this will suffice to show along which lines, IMO, questions such as ‘Why are there no (or so few) pheasants in Africa?’ should be approached.

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  27. 27. Dartian 4:54 am 01/18/2013

    (large, ground-living, largely ground-living)

    Oops, that wasn’t supposed to be from the Department of Redundancy Department. I meant to write: “(large, ground-living, largely herbivorous)”.

    Regarding potential galliform competitors, by the way; I mentioned bustards as one possible example, but I want to emphasise that bird competitors need not necessarily be birds themselves. For example, Corlett (2007) has suggested that competitive exclusion (though it’s unclear in which direction) may explain why there are so many species of squirrels and so few species of parrots in tropical Asia.

    Reference:
    Corlett, R.T. 2007. What’s so special about Asian tropical forests? Current Science 93, 1551-1557.

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  28. 28. vdinets 9:01 am 01/18/2013

    Dartian: African mountains are relatively small and isolated (although that’s where those larger francolins are found). African rainforests have lower overall diversity, and are often claimed to have contracted into small refugia in the past. African monsoon forests are tiny and probably recent. Mountains of Asia, on the other hand, cover a huge area and are outstanding in overall biodiversity. I think this is sufficient to explain the difference.

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  29. 29. John Scanlon FCD 9:32 am 01/18/2013

    Regarding competition between parrots and squirrels, it could be pretty tough if the cute, fluffy, herbivorous squirrels are anything like their marsupial counterparts:

    New threat to endangered parrots in Tasmania.

    Link to this
  30. 30. Dartian 11:56 am 01/18/2013

    Vladimir:
    African rainforests have lower overall diversity, and are often claimed to have contracted into small refugia in the past.

    But so did tropical Asian rainforests too (e.g., Wurster et al., 2010), so forest area fluctuations by themselves don’t seem like a sufficient explanation. (And it’s not at all certain that such fluctuations would decrease (in this case) galliform diversity anyway. At least on a continental scale, for most taxa – including birds – evidence suggests that the historical existence of ecological refugia typically increases, rather than decreases, overall biodiversity.)

    Reference:
    Wurster, C.M., Bird, M.I., Bull, I.D., Creed, F., Bryant, C., Dungait, J.A.J. & Paz, V. 2010. Forest contraction in north equatorial Southeast Asia during the Last Glacial Period. PNAS 107, 15508-15511.

    Link to this
  31. 31. vdinets 4:18 pm 01/18/2013

    Dartian: the fact is, Asian forests have incredibly high diversity, while African forests do not. Perhaps there were many nice, large, wet refugia in Asia, but only a couple of small, semi-dry ones in Africa? Having so many large montane areas in Asia and only one in Africa (Albertine Rift mountains, where about a half of African forest biodiversity is concentrated) might be a good reason for that.

    Link to this

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