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Tepuis and plateaus of South America
JOrnitho: When I was translating the chapter about the Gran Chaco, I read about the plateaus where the Acatou make their nests. These geological formations reminded me from the Tepuis of Amazon. I was thinking that some species could have used the Tepuis as a refuge when the Amazon rainforest declined in the end of the Holocene, when the forest started to return to its original form, some of these species could have leaved the Tepuis and spread in the low land areas. An example could be the manakin birds (Pipridae).
Ответов - 13
Биолог: JOrnitho Well, this could be possible. Although, for sure, the number of birds that survived there would not be so large. And manakins are possible, yes.
Автор: If tepuis serve as island refugiums for wildlife in human-modified landscape, their fauna will evolve according the same principles, as the wildlife at "true" oceanic islands. So, we may expect for meeting small (sparrow-sized) corvids there. What about rock-climbing air-breathing loricariid catfishes living in streams of waterfalls? They may be mouthbrooders, and males may bring hatched posterity to areas of less intensive water flow. Aquatic plants from tepui waterfalls may be presented by liverworts like Riccia and by flowering plants of Podostemaceae family widespread in tropical zone.
JOrnitho: Биолог пишет: Although, for sure, the number of birds that survived there would not be so large. Yes. I was thinking that the survivors would also be smaller species. Автор пишет: So, we may expect for meeting small (sparrow-sized) corvids there. That would be interesting, with the tepuis being similar to an island I wonder if some birds would start to fly less. Perhaps there could have a member of the family Cuculidae that became adapted to live in the ground like the ground cuckoos (Neomorphus sp.)
Биолог: JOrnitho survivors would also be smaller species Sure! Eagle-sized birds are very unlikely there.
Автор: Биолог пишет: Eagle-sized birds are very unlikely there. Maybe, any nearly flightless herbivorous pigeons? "Continental dodos"?
Биолог: Автор nearly flightless herbivorous pigeons? "Continental dodos"? Sounds interesting!
JOrnitho: Автор пишет: Maybe, any nearly flightless herbivorous pigeons? "Continental dodos"? This would be interesting. Perhaps they could fill the niche of the Galliformes. For the terrestrial Cuculiformes, I was thinking that they could eat lizards, amphibs, small mammals and birds.
Автор: JOrnitho пишет: they could fill the niche of the Galliformes They are able to fly up to the top of tepui, and the fact of the appearing of flightless and poorly flying pigeons indicates that they can pass to ground dwelling easily. I think tepui pigeons will represent a bunch of closely related forms, one of which will be large ground-dweller. I think they'll keep an ability to fly, being poor flyers compared to forest-dwelling forms of lowlands.
JOrnitho: Автор пишет: think tepui pigeons will represent a bunch of closely related forms, one of which will be large ground-dweller. How big do you think it can be? Perhaps the size of a turkey?
Автор: JOrnitho пишет: Perhaps the size of a turkey? Sounds interesting, but it is too large. Don't forget, they must keep rather large number of the population in conditions of restricted (very much!!!) area. So, I think they will be not larger than modern crowned pigeons. They will be just heavy-built ground-nesting omnivorous pigeons with larger legs.
Биолог: Автор They will be just heavy-built ground-nesting omnivorous pigeons with larger legs. Will they still keep their unique ability to feed young with "pigeon milk"? By the way, can any pigeons in neocene develop some new features of their "pigeon milk" or will it just vanish?
JOrnitho: I was wondering if these regions would allow the evolution of medium sized predators. I think that large bird predator would reach these places by flying, but would not have evolved there. However, I think that there could have some medium sized predatory birds, maybe a species of owl that is a descendat of the genus Glaucidium.
Биолог: JOrnitho Why not? Just go ahead to describe it! Another owl is OK!
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