||Links on the right provide access to pages,
one per bird family, which include species for which there have been recent proposals to
split. Typically, these are forms previously considered to be
subspecies, and now proposed to receive the full species status. The main purpose of
this information is to raise awareness amongst birders, not necessarily to tell them what
to tick and not tick. [ Though perhaps this could read: "It tells you what I would
consider ticking and not." ]
More than in any other area of
taxonomic discussion, differences of opinion and in the species concept applied become
prevalent here. I felt it necessary to make some choices of consistency, without
which the list of taxa here included might become almost meaningless. These choices
are explicated below. Nonetheless, there will be many instances of included taxa
that just deserve a wider discussion than what is possible here.
The split taxa are presented per family in taxonomic order. The
decision to include a split was made on the basis of the following criteria.
- The species concept applied is principally that of the Biological
Species Concept and not the Phylogenetic Species Concept. The reason is
- Since these pages are on splits worldwide and the PSC is not (yet)
applied worldwide, whereas BSC is more so at present, it seemed easier to come up with a
consistent list based on the latter than on the former.
- A wider reader community is hoped to appreciate the list in its current
- Without being able to take a firm position, I am not fully
convinced about the weaknesses of the BSC as put forward by PSC followers.
Reproductive isolation seems to be an intuitively appealing principle to base a species
notion on, and the problem of allopatry may, in the long term perhaps, turn out not to be
Discriminating between BSC and PSC splits, however, is not easy as
sources do not always unambiguously indicate which species notion is applied. In
some cases mentioned here, I know of, but have not yet read the supporting literature, and
my categorisation is then tentative at best. Species included in the main list,
which may turn out to be PSC splits (just because I am not fully informed) are
tagged with an asterisk. Also included below is a list of what I believe to be
pure PSC splits.
- Inclusion in the list here I have sought to back up by a reference to published
scientific data. Opinions matter but should not be the basis for a
split, obviously. Including just a single reference in many cases is a
simplification that may not do justice to a full body of literature. In a few cases,
I thought it wiser to include a reference to a publication with a more overview character,
either because identifying a single source was difficult, or the mentioned
publication was considered to be the best access point to other sources.
- The origins of my information for the splits are region and family handbooks, checklists
and published scientific papers, the internet occasionally, as well as personal
communications with a number of people. I intend to make and then keep the list
up-to-date, and information from the readership is elementary in the process.
The current list, as of September 21st, 2003, includes
340 splits out of the 583 potential splits for which I have (incomplete)
As ever, additional information on the issue of splits is happily received and
acknowledged. If you do send me new information, I will appreciate an
attempt to make it as complete as possible.
I am indebted to many people for sending me updates and corrections.
Rolf A. de By
Tall-grass Wetland Tapaculo
Scytalopus iraiensis, a species de-
scribed from Brazil in 1998. Art-
work © Diana Carneiro Marques.
Grouse and Allies
New World Quails
Ducks and Allies
New World Barbets and Allies
Old World Cuckoos
Barn and Grass Owls
Nightjars and Allies
Snipe and Allies
Pratincoles and Allies
Gulls and Allies
Hawks and Allies
Petrels and Allies
Tyrant Flycatchers and Allies
Ovenbirds and Allies
Fairywrens and Allies
Pardalotes and Allies
Crows and Allies
Old World Flycatchers and Allies
Starlings and Allies
Northern Creepers and Allies
Tits and Allies
Swallows and Allies
Old World Warblers and Allies
Sparrows and Allies
Finches and Allies
PURE PSC SPLITS