Whether it is potentially a new species, a subspecies, a morph, a hybrid, a significant range extension for a taxon or nothing.
In most cases, that's something I'll leave for the people actually describing them. Obviously, I do have my opinions, but opinions are of little scientific value. Add to that the problems with species concepts (see e.g. Silveira and Olmos, 2007).
I'll also add that, while some info may be published freely before the actual descriptions, some info is withheld, at least sometimes intentially. While descriptions of Neotropical birds haven't had any major issues with anybody "stealing the honours" (so to speak), it is certainly not unheard of (e.g. R. Hoser & Australian snakes).
On the other hand, the “Allpahuayo Hawk” seen by the same two in Peru (Loreto: Allpahuayo) in 1993 and later in Brazil (Pará: Carajás) could well be a new species or a range extension of Leucopternis semiplumbea.
It has actually been seen more than once by what can only be described as an extremely knowledgeable and reliable ornithologist. In terms of biogeography, it is extremely unlikely that it, unless a single individual that somehow got lost and managed to cross the Andes in the process, represents the same as
L. semiplumbea (even if visually similar). Note also that the only "mystery"
Leucopternis records I am aware of in Carajás are
L. melanops - something dealt with recently in Amaral, Silveira, & Whitney, 2007.
My tapaculo list (9 birds) is not well documented. For instance I do not know when the “Apurimac Tapaculo” was first discovered.
Haven't asked and don't know, but it is at least 15 years ago.
I have only one in Venezuela (close to caracae and meridanus ?), two in Colombia: one from the East Andes (Donegan et al.) and one from the Serranía de los Yariguíes (Donegan et al. 2005), three in Peru: Apurimac, Millpo and Satipo (different from Millpo ?) and three in Brazil: one from Minas Gerais, one from the Atlantic forest and one Merulaxis (currently described by Luiz Pedreira Gonzaga and others).
Serranía de los Yariguíes has other undescribed taxa; a warbler, antpitta and hermit. The Millpo does occur near Satipo. I'm not aware of any additional new from that region. A
Scytalopus briefly caused some problems, but was later found to be
S. acutirostris.. Add to the
Scytalopus' I mentioned earlier that "something" apparently is going on within the populations presently included in
S. magellanicus. The Brazilian situation is very messy, and the Minas Gerais taxon I suspect you are referring to may already have been described (many birders that have seen
S. novacapitalis at Serra da Cipo have actually seen the "new" taxon), as Raposo
et al., 2006, suggested it is this population that actually should be referred to as
S. speluncae, whereby the "old-new" Mouse-coloured Tapaculo from the Serra do Mar region in Brazil needed a new name;
S. notorius. This has not (yet) gained widespread recognition, and one can question if they interpreted the old type correctly (if not, the inland Minas Gerais population remains undescribed). There are also a few other prob's - among others, they included the population later described as a separate species,
S. diamantinensis, in their
S. speluncae. Add to that the problem that they and the recently described
S. pachecoi have similar songs, which, following the most recent authority on tapaculo taxonomy, would mean that they're probably better considered subspecies of a single species (per BSC). They do, however, have different calls, and work that may validate this as significant for species-level taxonomy is in progress. Add to that the problem that some have suggested transferring the English name Mouse-coloured Tapaculo to the "new"
S. speluncae from inland Minas Gerais, instead referring to the coastal population as Serra do Mar Tapaculo. I'd suggest people just forget the name Mouse-coloured Tapaculo completely, and use the locality based names (Serra do Mar, Espinhaço, Diamantina & Planalto). Finished? No: There's an undescribed taxon in Bahia (also a pos. new
Heliobletus and
Tolmomyias in that state), and the northern and southern Serra do Mar Tapaculo are likely to represent different species. The issues I referred to regarding the song-types in the Slaty Brislefront are the same as the
Merulaxis you refer to.
Is it the one mentioned by Hornbuckle ?
Yes, it is the same spinetail in Venezuela I referred to. A pretty standard
Synallaxis - fairly dull with rufous crown and dark frontlet.
There is apparently one more in Peru (La Libertad), the “Chao Spinetail” (Birding-Peru website)
It is part of the
S. stictothorax complex, which needs a review. The presently published evidence only supports a single species, but that is almost certainly too little. And while we're at spinetails, there's a pos. new
Certhiaxis in Tocantins, Brazil. It is quite similar to, and found sympatrically with, the widespread
C. cinnamomea.
Is there any data somewhere on the net ?
No, the info on the owls is not on the net (haven't really searched for it, so I could be wrong, but I guess not).
Do you have more details on these ?
Hummingbird1: An
Amazilia found in the southern part of the range of the Versicoloured Emerald (which in any case needs a taxonomic review). Work in progress (but as always it may take years before actual results are published).
Hummingbird2: "Ampay Hummingbird".
Hummingbird3: A
Coeligena. Prob. just a new ssp. or aberrant population.
Hermit: Found in the Brazilian Amazon. A small, dark-throated species with a distinctive feature I'll leave for the description (which is in progress).
Potoo:
http://www.birdforum.net/showthread.php?t=93985 (post #14).
Wren1: "Mantaro/Otuto Wren"
Wren2: A
Microcerculus found in the region of the triple-border between Brazil, Peru & Colombia. The entire
M. marginatus complex needs a review.
Add to that the other Furnariids, tyrant-flycatchers, antbirds, and all the single, brief views that could be something or could be nothing - e.g. highly competent ornithologists have seen a barbet, part of the
Capito niger group, in the south-east Amazon, but I'm not aware of any further sightings, and with that level of evidence who can say what it was or for that matter exclude an escapee (even if locality suggests otherwise).
