Rationale for Synonymy

The need for a modern checklist

There is a need for a complete, modern checklist which will list every genus, subgenus,species and subspecies of bird, with their higher level groupings, with specification of the author of each name, the citation of the source of the name,including its date, and,in the case of species and subspecies the type locality and distribution of the taxon. Ideally, such a checklist should also include a full synonymy.

The currently available source that comes closest to this is James L.Peters,Check-list of Birds of the World,Harvard University Press,Cambridge,Mass.,published between 1931 and 1987, with only volume 1 available in a second edition (1979) by Mayr and Cottrell. This is unique in giving full citations including type locality, for species and subspecies. However, given the many decades over which it was published, this is to some extent internally inconsistent in its treatment of families, and it includes only recent synonyms. Sometimes, it will indicate in a footnote a different Latin name as having been used in Sharpe & Lydon,1899-1909,Handlist of the Genera and Species of Birds in the British Museum.

Sibley & Monroe,1990,Distribution and Taxonomy of Birds of the World, Yale U.P. uses a new family sequence derived from DNA-DNA hybridisation, and explained in Sibley & Ahlquist,1990,Phylogeny and Classification of Birds,Yale U.P., New Haven. This lists higher level groupings,including Orders, Families,Subfamilies and Tribes; Species, and also subspecific “groups” , that is, taxa that at some time have been treated as species, or that may have a claim to species status. For species and groups, the distribution is given, as is the name and date of the author of the name. But there is no attempt to list subspecies systematically.

Howard & Moore,1994,A Complete Checklist of the Birds of the World,2nd ed.,Academic Press,London,uses the Basel sequence of families, They list orders, families, subfamilies, species and subspecies, with a brief indication of the distribution of subspecies. However, they do not list authors, citations or dates. There is also no attempt to relate its treatment of subspecies to earlier discussions.

The Handbook of the Birds of the World, currently in publication, gives Orders, Families, genera, species and subspecies, with the distribution of subspecies. It gives the name and date of the source of each genus,species and subspecies, and the name of the publication can be found in a “References of Scientific Descriptions” section at the back of each volume. However, it is not always possible to identify page number, and there is no indication of type locality. It is also very inconsistent in its discussion of the relation between its treatment of subspecies and earlier treatments. Since most persons interested in subspecies would tend to rely on Peters and Howard & Moore, it is desirable to mention all subspecies treated in those accounts, with an explanation of why those forms are not treated as subspecies in Handbook of the Birds of the World, if that is the case. Sometimes, some forms previously treated as subspecies are mentioned, with a brief explanation of why they are no longer so considered. However, this is not done systematically, and in many cases, there is no mention whatsoever of submerged subspecies.

In terms of what should be included in a synonymy, we can consult the statement of taxonomic authorities, and the practice of earlier compilers of synonymies. Ernst Mayr, 1969, Principles of Systematic Zoology, McGraw-Hill,New York, discusses synonymy on pages 273-76, and recommends a minimalist approach except in the case of monographs or first revisions:

Unfortunately, the exhaustive preparation of not only a complete synonymy but also of a listing of all references to previous publications with all possible binomial combinations (in the case of generic transfers) has become the misplaced ideal of scholarship for some taxonomists. The expense of printing endlessly repeated names and references…is altogether out of proportion with the benefits conveyed. Friedmann (1955), illustrated in Part II of Ridgway’s Birds of North America what this system leads to in a taxonomic group with a rich literature…

It has now become customary in the better-known groups of animals to list in synonymies only names that were not at all or not correctly listed in the previous standard treatments. For example, in Peters’ Checklist of Birds of the World (1931 et seq.) synonyms are not listed that can be found in previous standard works, such as Catalogue of Birds of the British Museum (1873-1892), the Handlist of Birds (1896-1910), for American species Hellmayr’s Catalogue (1918-1944), and for for Palearctic species Vaurie (1959-65). More recent checklists do not repeat synonyms correctly cited in Peters. Only genuine synonyms are listed, not mere new combinations. (1969,p.273).

One feels that a major consideration in Mayr’s position is expense. Peters’s Checklist, with minimal synonymies, comprises sixteen volumes and sells for a very large sum. However, computer databases have largely made considerations of expense and the consumption of whole forests of paper irrelevant. Mayr’s position also seems a little ingenuous in terms of the availability of earlier standard works, and in terms of the accessibility and user-friendliness of the information in them. The Catalogue of the Birds in the British Museum is not widely available. Today, the libraries of most universities, for example, do not possess a copy.

It is also not an easy source for a non-specialist to use. The forms cited correspond in general to the modern subspecific level, but often the forms do not correspond in any straightforward way with modern subspecies. A further problem is the abbreviation of both the names of authors and of the titles of both monographs and serials. For example, “Bp.Consp.Vol.Zygod.p.7(1854)” or “Forst.Descr.Anim.p.151.(1844)”. The former is :
Bonaparte,1854,Conspectus Volucrum Zygodactylorum in Ateneo Italiano,2,p.7
and the latter:
J.R.Forster,1844,Descriptiones animalium quae in itinere ad Maris australis terras per annos 1772,1773,1774 suscepto collegit,ed.Lichtenstein,p.151.

Even a person such as myself, who has spent years systematically going through the references in the Catalogue still regularly finds unknown and puzzling abbreviated names and titles. These abbreviations were doubtless developed to save space and paper, but again, with a computer database, it would seem more approriate to go for intelligibility, and not use such abbreviations. This does not necessarily mean giving a full bibliographic citation every time a source is mentioned, such as:
Linnaeus,C.(1758) Systema Naturae per Regna Tri Naturae,secundum classes, ordines,genera,species cum characteribus,differentiis, synonymis, locis.Editio decima, reformata.

Still, Linnaeus,1758,Systema Naturae,editio decima,tom.1,pars 1 is better than Linn.Syst.Nat.(1758), as the former will unambiguously assist the student trying to track down the original source.

Another doubtful assumption in Mayr's position appears to be that the previous synonymy will always take one back to the synoymy before that. The reality, as anyone who has tried to track bird names back through earlier sources will readily understand, is that one not infrequently finds blank walls. Take the following citation:
Glaucidium pumilum pumilum Ridgway,1914,Bulletin of the U.S.National Museum,50,pt.6,p.781,in key.

What does this refer to? There is no mention of the name pumilum in Peters. Or take
Palæornis peristerodes in Salvadori,1891,Catalogue of the Birds in the British Museum,20,Psittaci,p.460.
There is no reference to this name in any later synonymy.

The practices desirable in synonymies is also discussed by R.E.Blackwelder, 1967, Taxonomy, Wiley & Sons, New York, particularly on pages 302 -303. He begins:

In a formal sense, the synonyms in zoological nomenclature include only such names as are acceptably published - what the 1961 Code calls “available”. In actual practice, a synonymy generally includes more than just a list of the “acceptable” names and their bibliographic references. It will also include (1) any names that have been printed (but not acceptably) and may thus be mistaken for real zoological names, (2) expressions which are not names but have been attached to the taxon in question, (3) misidentifications, which are uses of wrong names for a species, and (4) bibliographic histories for all of these. It is a commomplace error to speak of “the synonymy” and “the synonyms” of a name, meaning only its rejected synonyms. This does no harm so long as it does not obscure the fact that all the names applied to a taxon are synonyms, from which one is determined under the Code to be the currently acceptable one.” (1967,p.302).

He continues discussing different forms of synonymy:
The most complete synonymy will quote exactly every citation of each name in the literature, with bibliographic reference and annotations.(1967,p.302).
This was the goal aimed at in the Catalogue of the Birds in the British Museum and also in Hellmayr’s Catalogue of the Birds of the Americas and Adjacent Islands and in Ridgway’s Catalogue of the Birds of North and Middle America. However, it can lead, for example, to pages of citations accompanying a single name such as Cuculus canorus.

Thus is seems more feasible to follow Blackwelder’s later advice:

In the case of widespread species, especially variable ones to which many names have been applied, it is often practicable to list only the original reference to each name or name form.(1967, p.303).

There is also the question of what constitutes different forms, particularly where subspecific names are abbreviated in lists. Ridgway takes the most extreme position on this, citing as different forms, for example:

Platycercus elegans elegans
P[latycercus] e[legans] elegans and
[Platycercus elegans] elegans

We believe that all these forms should be treated as equivalent, and cite only the earliest one, though we would use brackets to indicate the exact form in which the name is cited.

A specific exception to the principle of citing only the first occurrence is where a name is first cited as a nomen nudum, and later as a valid name. To clarify such cases we will give both citations, annotating the first as a nomen nudum.

We cite early Non-Latin names, as the citations of early authors such as Linnaeus, J.F.Gmelin and Vieillot are often based on the non-Latin names of authors such as D’Aubenton, Latham, and Azara.

We have tried to include all forms of names for a species. For example, if we have Aptenodytes papua Forster,1776, we will also cite Aptenodyta papua Bonnaterre,1790. But if a later author gave Aptenodyta papua, we will not generally cite it.

A practice that we specifically reject is that followed at least sometimes by Ridgway, where the citation for a species in an early checklist, such as Coues, is cited under every race with the notation ‘(part)’. Since this appears to provide no additional information, especially where it does not even involve reference to a type from a specific location, we will not include such citations.

We will follow Ridgway in trying to provide type locations for names which relate to a type, and in specifying the status of New Names which involve a different name. However, with the reassignment of species names to different genera by authors such as Lesson, G.R.Gray, and Bonaparte, or the citation of names in systematic lists such as Mathews, 1927, Systema Avium Australasianarum, Peters, Checklist of Birds of the World, Howard & Moore, or Handbook of the Birds of the World, we will cite the name and citation, but without any type locality specified.