Aves mexicanus

Book Cover Stephen Moss Mrs. Morcau's Warbler

One of the curious traits shared by birders and professional ornithologists is an abiding interest in bird names, both common and scientific. With respect to common (English) names, I have previously highlighted attempts at standardization in the 1830s (here), one recognizing a woman (here), one that is obscure and obsolete (here), a recent name change (here), and an odd misnomer (here). Since 1850 dozens of books and papers have been published about the English and Latin names of birds (see list here). And a new book by Stephen Moss Mrs Moreau’s Warbler provides some delightful insights into the origins of many odd common names.

The scientific names of birds have attracted less interest, in part, I assume, because those names are regulated by the International Code of Zoological Nomenclature (ICZN). The ICZN governs the designation of type specimens, the choice of scientific names and the rules of priority.  The code’s Principle of Priority mandates that taxon names (species, genus, family, etc) are always the ones that appeared first in print. All of these taxon names can only change when taxa are lumped or split but the rule still applies to newly designated taxa. Hugh Strickland proposed that first rule in his 1842 report to the British Association that established the ICZN. Thus scientific names are not really open for discussion or change unless a mistake has been made.

Quite a few of the scientific (Latin) species names of birds come from country names. This is largely due to European explorers collecting and describing a species for the first time and naming the species after the country where the first specimen was collected. According to the current IOC World List [1], australis is the most common species epithet that looks like a country name, used for 22 extant bird species in 22 different genera (by necessity) and 10 orders of birds. But australis means ‘southern’, and not ‘Australia’, and only 8 of those species occur in Australia, the rest being found in New Zealand (3), Africa (6), south Pacific (3). south Atlantic (1), and the USA (1).

Thus the most popular country name used for species is americanus/americana with 17 extant species but here again the authors were often referring to the Americas and not specifically to the USA or even North America. I have not checked to see where the type specimens were collected but 4 of those species do not occur in the USA and 2 do not occur in North America.

Species unequivocally named after a country include indicus (17), mexicanus (14), peruvianus/peruanus (12), canadensis (8), sinica/sinensis (7), brasiliensis/brasilianus (6), portoricensis (4), and  colombianus/colombica (3) [2]. Species named after a continent include africanus/africanoides (11) and asiaticus (7). Interestingly, few species were named after European regions where those very explorers came from:  euopaeus (2), germana (1), scotica (1), brit- (0), espan- (0), ital- (0), norv- (0), and sver- (0)..

All of the species named indicus appear to occur in India, but 3 of the species named mexicanus are not really Mexican [3], and two do not even occur in Mexico—the Puerto Rican Tody (Todus mexicanus) being endemic, not surprisingly, to Puerto Rico, and the Oriole Blackbird (Gymnomystax mexicanus) which lives in northern South America.

Birds with species name mexicanus

About a month ago, Tom Sherry (Tulane University) wrote to ask if I knew anything about the history of the species name mexicanus for the Puerto Rican Tody. I didn’t, but his query prompted this post. It has taken me a couple of weeks to explore this question and it has so absorbed me that I had no time to post anything [4] on the past two Mondays as I usually do.

The scientific name of the Puerto Rican Tody dates from 1838 when the bird was described (see below) by René Primevère Lesson in a paper he wrote about some todies new to science. Lesson called the species Le Todier vert, rose et bleue and noted that it was from Puerto Rico (L’île Porto-Rico). His footnote #2 says that this is Todus portoricensis and attributed this name to Adolphe Lesson, his brother (who was a botanist). His footnote #1 refers to the previous species (probably the Jamaican Tody) on that page Le Todier vert et jaune that he calls Todus viridis or Todus mexicanus, also discovered and reported by his brother Adolphe, from Veracruz in Mexico.

First description of Puerto Rican Tody (Lesson 1838)

Now, I am by no means an expert on the rules of nomenclature but it seems to me that it is a mistake to call the Puerto Rican Tody Todus mexicanus, and that Todus portoricensis is both correct and appropriate. Dr Sherry tells me that some birders that he met on his trip to Puerto Rico wondered how the apparently mistaken scientific name came to be. Maybe it is a real mistake and there would be a case to have the scientific name changed. By any name, this is a beautiful little bird.

Puerto Rican Tody (Kevin Loughlin PHOTO)


  • Lesson RP (1838) Mémoire descriptif d’espèces ou de genres d’oiseaux nouveaux ou imparfaitement décrits. Annales des Sciences Naturelles 2(9): 166-176
  • Moss S (2019) Mrs Moreau’s Warbler: How Birds Got Their Names. New York: Faber & Faber.


  1. IOC World List: I used v 9.1 available here
  2. country or continent names: the names listed here include feminine and neutral variants (e.g. both asiaticus and asiatica). I have listed all the names that I could find that had >2 examples.
  3. not really Mexican: the Prairie Falcon (Falco mexicanus) breeds and winters in northern Mexico but 9/10 of its range is in the USA
  4. no time to post anything: not to mention attending the funerals of two colleagues, marking 48 final term papers in my history and philosophy of biology course, and trying to meet the Canadian income tax deadline

IMAGES: mexicanus species from Handbook of Birds of the World online; excerpt from Lesson’s paper from Biodiversity Heritage Library; Tody photo courtesy Kevin Loughlin (via Tom Sherry)


  1. Sweden does have one that I can think of: Bluethroat (Luscinia svecica).

    Van Hasselt’s Sunbird (brasiliana) is another weird one.

  2. What are the other “not really Mexican” birds? At the time they were described, Mexico may have reached farther north.

    Also, one mexicanus species, the House Finch, greatly expanded its range during the 20th century.

    1. As I mention in the essay, the Prairie Falcon’s range in mainly in the USA. The other species is the Oriole Blackbird (Gymnomystax mexicanus), which is restricted to the Amazon basin. Good point that in those days ‘Mexico’ was a name used for a much wider area than the present country.

  3. It may seem logical that the endemic todus from Puerto Rico be named Todus portoricencis but the oldest name that applies to to this bird is Todus mexicanus becase the collection upon which the name is based was thought to be from Mexico. Within the Spanish expedition to discover the natural history of Mexico there was a short trip to Puerto Rico. The collections gathered from this trip got mixed up with the collections from Mexico and as a result some of the new species were named with epithets related to Mexico. The zoological code of nomenclature makes Todus mexicanus the accepted name even when the name Todus portoricensis would be more appropriate.

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