Metaves II

The 44 Orders

Paleognaths

Galloanserae

Metaves

Pelecanae

Charadriae

Passerae

CYPSELOMORPHAE

The biggest chunk of Metaves is the Cypselomorphae. Although it is tempting to group all of the remaining nightbird families in a single order, it is hard to find convincing evidence that they are even constitute a clade (e.g., Barrowclough et al., 2006; Braun and Huddleston (2009), Mariaux and Braun, 1996; Mayr, 2002). The divisions between them are very deep, and DNA studies have not only not come to a clear conclusion about the 4 orders are related, but many have not even shown they are each other's closest relatives! The oilbirds are particularly problematic. Because of this, I have listed them in separate orders. Hackett et al. (2008) and Ericson et al. (2006a) are two of the few genetic analyses that place them all in the same clade, which is augmented by the Adopiformes. The Apodiformes may be found on the next page, with the remainder of the Cypselomorphae on this one.

In fact, the monophyly of the Cypselomorphae is only supported by analyses that include β-fibrinogen, which also support the Metaves hypothesis. When β-fibrinogen was excluded in Ericson et al. (2006a), the Cypselomorphae ended up in the Anomalogonatae. Moreover, the nighthawks did not group with the other Cypselomorphae, being closer to a clade containing the owls and others. One of Braun and Huddleston (2009) analyses also placed the nighthawks closer to the owls.

STEATORNITHIFORMES

The results of both Hackett et al. (2008) and Braun and Huddleston (2009) suggest the oilbirds and potoos are sisters, which makes sense geographically.

Steatornithidae: Oilbird

1 genus, 1 species HBW-5

NYCTIBIIFORMES

Nyctibiidae: Potoos

1 genus, 7 species HBW-5

PODARGIFORMES

The Frogmouths are sometimes divided into two families, Podargidae and Batrachostomidae. Molecular evidence indicates they are each other's closest relatives, and I think that is best indicated by placing them in a single family. One new species, the Solomon Islands Frogmouth, was recently discovered (Cleere et al., 2007). It seems to be closer to Podargus than to Batrachostomus.

Podargidae: Frogmouths

3 genera, 14 species HBW-5

CAPRIMULGIFORMES

Caprimulgidae tree The thesis by Han (2006) and the follow-up paper (Han et al., 2010) have done much to clarify the situation within the Caprimulgidae. It was clear from previous work (Mariaux and Braun, 1996; Barrowclough et al. 2006; Larsen et al. 2007) that Caprimulgus itself was paraphyletic and that the Caprimulgidae were not simply divided into Nighthawks and Nightjars. It also seemed that the Eared-Nightjars are completely separate from Caprimulgidae. Han sampled many more taxa, and has shown the general shape of the family, and provided evidence against separating some species into a separate family Eurostopodiae. Indeed, looking at Han's results, it does not appear that the wider Caprimulgidae can even be usefully divided in subfamilies. Such a division would not be particularly informative.

Han found that the Great Eared-Nightjar, formerly placed in Eurostopdus is actually closer to the rest of Caprimulgidae. The Malaysian Eared-Nightjar is morphologically similar, and we are guessing that it is closely related to the Great Eared-Nightjar. Both are moved to the genus Lyncornis. The Papuan Nightjar has sometimes been placed in Lyncornis, but it is more closely related to the other Eurostopodus. Since it's thought to be close to the Cloud-forest and Satanic Nightjars, I leave them in Eurostopodus too.

The next surprise is the Collared Nightjar, formerly Caprimulgus enarratus, which seems to be sister to the remaining nightjars and nighthawks. Han et al. (2010) established the new genus Gactornis for it.

The remaining Caprimulgidae seem to fall into 4 groups, a group of American nightjars, a group of nighthawks and American nightjars, the remaining nighthawks, and a complex group of Old World nightjars. Han (2006) examined 3 genes, while Barrowclough et al. (2006) examined another. There doesn't seem to be consensus on how these four groups fit together, and as you can see on the diagram, I am currently treating it as a unresolved polytomy.

The ordering is based on Han's (2006, 2010) overall tree, where the upper groups successively branch off.

The first group consists of Siphonorhis, Nyctiphrynus, Phalaenoptilus, and the possibly unfamiliar genus Antrostomus. This name, due to Bonaparte (1838, type species A. carolinensis), is being applied to one of the New World Caprimulgus nightjars clades. As you can see, it is rather separated from the main group of Caprimulgus.

I have split the the Mexican Whip-poor-will, A. arizonae, from the Whip-poor-will. It does not appear to even be sister to A. vociferus, being closer to the Dusky Nightjar, Antrostomus saturatus. Further, it is distinctive vocally and differs somewhat in plumage from the Whip-poor-will, having often been viewed as a separate species (e.g. Howell and Webb, 1995; Navarro-Sigüenza and Peterson, 2004).

The second group contains two nighthawk genera, Lurocalis and Nyctiprogne, an expanded Nyctidromus (gaining three former Caprimulgus nightjars), and a greatly expanded Hydropsalis, which has absorbed Eleothreptus, Macropsalis, Uropsalis and a number of Caprimulgus nightjars. Since the generic boundaries needed revision, and it is not entirely clear how the pieces fit together, it seemed best to place them all in one genus. In that case, Hydropsalis (Wagler, 1832) has priority.

The third group consists of the Chordeiles nighthawks and the Nacunda Nighthawk, Podager nacunda. It's not clear whether the Lesser Nighthawk belongs in Podager or Chordeiles. It doesn't affect the linear order. One option is to put all of them in the same genus. In that case, I think Chordeiles has priority. It was established by Swainson in part II of the “Fauna Boreali-Americana” (Richardson and Swainson), dated 1831, but apparently published Feb. 4, 1832. The genus Podager is due to Wagler from heft 3 of Isis von Oken in 1832, which is apparently the March issue. That's pretty close to Feb. 4, and some issues of Isis von Oken seem to have been published prior to their cover date. So far, I have been unable to confirm when it was actually published.

I've put the Brown Nightjar, Veles binotatus, in group four on the grounds that is a Old World species sometimes considered part of Caprimulgus. However, others have put it elsewhere (e.g., closer to Chondeiles or Lyncornis), which is also reflected in this arrangement. Han (2006) found considerable structure in the remaining Caprimulgus. As a general rule, the Asian species appear to be relatively basal in Caprimulgus. This is not reflected in the current arrangment of the species, which is fairly conventional. Note that Macrodipteryx needed to be submerged into Caprimulgus.

Finally, ABA and AOU use the name Gray Nightjar for Caprimulgus indicus. Here C. jotaka has been split from C. indicus and keeps the name Gray Nightjar while C. indicus becomes Indian Jungle Nightjar.

Caprimulgidae: Nightjars, Nighthawks

14 genera, 94 species HBW-5

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