Nycticein bats: apparently, a nice example of how assorted distant relatives can be mistakenly considered close allies on the basis of one or two characters (vesper bats part XIII)

A group of serotine-like bats that occur in North America, Cuba, tropical Africa, Asia and Australasia have often been grouped together in a 'tribe' called Nycticeini (or Nycticeiini: both spellings are used in the bat literature and I'm unsure which has proper precedence). Tate (1942) used this name for an assemblage of species grouped together due to the absence of the second upper incisor. Nycticeins also tend to have a near-horizontal dorsal border to the naked muzzle and a slow, steady flight. The name is obviously based around the generic name used for the so-called evening bats (Nycticeius) of North America and Cuba: the problem is that evening bats may well not be close to the other bats conventionally included within this group. In keeping with traditional classifications, I'll discuss all the nycticeins together here, despite the fact that new work shows them to be widely separated on the vesper bat tree [larger version of adjacent cladogram show below].

The best known nycticeins are the two evening bats (Nycticeius) of North America and Cuba: of the two, the best known is the Evening bat, Twilight bat or Black-shoulded bat N. humeralis of eastern North America [shown below; from wikipedia]. The generic name Nycticeius is used here in the most restrictive sense, since all the other currently recognised 'nycticein' species have been included within this genus at one time or another.

What might be a third Nycticeius species was named by Coenraad J. Temminck in 1840 as N. aenobarbus. Its provenance is uncertain ("Amérique méridionale" is all that was given for the type locality) and some authors have said that the only known specimen is so distinctive that it might represent a new genus, or that it actually belongs to one of the non-American nycticein genera. The name 'Temminck's mysterious bat' has even been used for the species (Wilson & Reeder 2005). The world of bat research is full of enigmas like this.

Schlieffen's twilight bat and its mysterious possible relatives (living and fossil)

Long considered to be a close relative of the evening bats is the tiny Schlieffen's bat or Schlieffen's twilight bat Nycticeinops schlieffenii of Africa and the Arabian Peninsula. It has a shorter, narrower snout and more anteriorly converging toothrows than Nycticeius, but otherwise looks superficially similar. The snout is naked and has large swollen areas on either side. Weighing 6-9 g and with a head and body length of between 40 and 56 mm, it's one of Africa's smallest bats. While often said to be a bat of savannahs, woodlands and open, arid habitats (e.g., Kingdon 1997), Schlieffen's bat is also said to be closely associated with marshes, streams and reservoirs (Johnston 2006). The 'Schlieffen' refers to Count Wilhelm von Schlieffen-Schlieffienberg.

A rather interesting 'mystery bat', reported by Kearney et al. (2010), was extremely similar to both Schlieffen's bat (though much larger) and also to the hypsugine Neoromicia capensis (this similarity might not be surprising in view of recent phylogenetic work: read on). They were unable to identify it securely, despite careful and detailed comparison of all appropriate measurements, and left it unidentified as 'Vespertilioninae sp.'. The figure below - from Kearney et al. (2010) - shows Schlieffen's bat at far left, the mystery bat in the middle, and N. capensis at far right. Close-ups of ears and tragi are also shown. Images are © Kearney, Seamark, Mateke and Hood.

A fossil bat from the Middle Miocene of Samos Island (Greece) - Samonycteris majori - has been said to be similar to both Schlieffen's bat and to the distantly related house bats (Rossina et al. 2006). More details are needed before its affinities can be more securely pinned down.

The Australian greater and lesser broad-nosed bats

Extremely similar to Nycticeius (and, as stated above, considered congeneric with it by some authors) is the Australian Greater broad-nosed bat Scoteanax rueppellii [shown above left, based on a photo in Nowak (1999)]. A large, adaptable, slow-flying species of ecotones and rainforests, it preys on large insects but is also said to eat small vertebrates. It has a rather robust skull and possesses what has been described as a 'pronounced occipital helmet' (Nowak 1999). By combining actual records with information on the favoured habitat and altitudinal preferences of this bat, Wilson (2006) was able to predict what its actual range might be: the results are interesting, as they suggest (for one thing) that the species may occur as far south as East Gippsland in Victoria, a region currently devoid of Greater broad-nosed bat records.

The four Lesser broad-nosed bats (Scotorepens), also endemic to Australia, are also very similar to the evening bats. The several species are extremely similar in morphology, and there's has been some debate as to whether they represent species or 'subspecies' (Kitchener & Caputi 1985, Baverstock et al. 1987). As suggested by the common name, the muzzle is distinctly squared-off and - as is also the case in Scoteanax - the third upper premolar is substantially reduced. Some species (like the Little broad-nosed bat S. greyii [shown above right, based on a photo in Nowak (1999)]) frequent arid areas but forage over watercourses while others (like the Eastern broad-nosed bat S. orion) are associated with rainforests.

Three other broad-nosed vesper bats similar overall to the evening bats and broad-nosed bats are the Scotoecus species, one of which is Asian (Sc. pallidus), two of which are African (pale-winged Sc. albofuscus [shown here; image by K. D. Dijkstra] and dark-winged Sc. hirundo). These are mostly bats of open woodland but Sc. pallidus inhabits semi-desert habitats. The Scotoecus bats look, again, rather like evening bats but have even broader snouts. The anterior surfaces of the canines are broad and flat; quite what this means for diet and lifestyle isn't entirely clear. Males have a particularly long penis, apparently. Most authors who have tried to classify these bats have included them within Nycticeini on account of their similarity to the evening bats, so it's somewhat surprising that molecular data puts them within Vespertilionini, and closer to pipistrelles and noctules than are particoloured bats (Roehrs et al. 2010).

While more study and more data is needed, molecular phylogenies indicate that the so-called nycticein bats are but distant relatives, formerly grouped together on the basis of convergently aquired similarities. On the basis of bacular morphology, evening bats have - quite surprisingly, to say the least - been regarded as plecotins while the other taxa have been suggested to be close to pipistrelles (Hill & Harrison 1987). Volleth et al. (2005) looked at the karyotypes of some of these bats and found Scotoecus at least to be similar to pipistrelles. Since then, Roehrs et al. (2010) included some of the taxa in a more inclusive molecular phylogenetic study: the evening bats seem to be part of the serotine clade, Schlieffen's bat appears to be a hypsugine, while Scotoecus is, as we just saw, a vespertilionin close to pipistrelles and noctules.

For previous Tet Zoo articles in the vesper bats series, see...

• Introducing the second largest mammalian 'family': vesper bats, or vespertilionids
• The vesper bat family tree: of myotines, plecotins, antrozoins, and all those cryptic species (vesper bats part II)
• Bent-winged bats: wide ranges, very weird wings (vesper bats part III)
• Of southern African wing-gland bats, woolly bats, and the ones with tubular nostrils (vesper bats part IV)
• The many, many mouse-eared bats, aka little brown bats, aka Myotis bats (vesper bats part V)
• Long-eared bats proper: Plecotus and other plecotins (vesper bats part VI)
• Desert long-eared bats - snarling winged gremlins that take scorpion stings to the face and just don't care (vesper bats part VII)
• Hairy-tailed bats: a tale of furry tails, red coats, cold tolerance, migration and sleeping out in the open (vesper bats part VIII)
• Robust jaws and a (sometimes) 'greenish' pelt: house bats (vesper bats part IX)
• Australasian big-eared bats, and how to (perhaps) single-handedly wipe out an entire species, 1890s-style (vesper bats part X)
• Antrozoins: pallid bats, Van Gelder's bat, Rhogeessa... Baeodon!! (vesper bats part XI)
• Putting the 'perimyotines' well away from pips proper (vesper bats part XII)

And for previous Tet Zoo articles on bats, see...

• Desmodontines: the amazing vampire bats
• Giant extinct vampire bats: bane of the Pleistocene megafauna
• Camazotz and the age of vampires
• Dark origins: the mysterious evolution of blood-feeding in bats
• A new hypothesis on the evolution of blood-feeding: food source duality involving nectarivory. Catchy, no?
• Oh no, not another giant predatory flightless bat from the future
• The most terrestrial of bats
• I stroked a pipistrelle
• Red bats
• We flightless primates
• Big animalivorous microbats
• Hidden in plain sight: discovering cryptic vesper bats in the European biota
• PROTOBATS: visualising the earliest stages of bat evolution

Refs - -

Baverstock, P. R., Adams, M., Reardon, T. & Watts, C. H. S. 1987. Electrophoretic resolution of species boundaries in Australian Microchiroptera. III. The Nycticeiini - Scotorepens and Scoteanax (Chiroptera : Vespertilionidae). Australian Journal of Science 40, 417-433.

Johnston, D. S. 2006. Nycticeinops schlieffeni. Mammalian Species 798, 1-4.

Kearney, T., Ernest C.J. Seamark, E. C. J., Mateke, C. & Hood, D. 2010. Chiroptera of Lufupa Camp, Kafue National Park, Zambia; with taxonomic notes on Epomophorus, Nycticeinops, Scotophilus and Scotoecus. African Bat Conservation News 23, 7-31.

Kingdon, J. 1997. The Kingdon Field Guide to African Mammals. Academic Press, San Diego.

Kitchener, D. J. & Caputi, N. 1985. Systematic revision of Australian Scoteanax and Scotorepens (Chiroptera: Vespertilionidae), with remarks on relationships to other Nycticeiini. Records of the Western Australian Museum 12, 85-146.

Nowak, R. M. 1999. Walker's Mammals of the World, Sixth Edition. The Johns Hopkins University Press, Baltimore and London.

Roehrs, Z. P., Lack, J. B., & Van Den Bussche, R. A. (2010). Tribal phylogenetic relationships within Vespertilioninae (Chiroptera: Vespertilionidae) based on mitochondrial and nuclear sequence data Journal of Mammalogy, 91, 1073-1092

Rossina, V. V., Kruskop, S. V., Tesakov, A. S. & Titov, V. V. 2006. The first record of Late Miocene bat from European Russia. Acta Zoologica Cracoviensia 49A (1-2), 125-133.

Tate, G. H. H. 1942. Results of the Archbold expeditions. No. 47. Review of the vespetilionine bats, with special attention to genera and species in the Archold collection. Bulletin of the American Museum of Natural History 80, 221-297.

Volleth, M., Heller, K.-G. & Fahr, J. Phylogenetic relationships of three ''Nycticeiini'' genera (Vespertilionidae, Chiroptera, Mammalia) as revealed by karyological analysis. Mammalian Biology 71, 1-12.

Wilson, D. E. & Reeder, D. M. 2005. Mammal Species of the World. A Taxonomic and Geographic Reference (Third edition). Johns Hopkins University Press, Baltimore and London.

Wilson, P. D. 2006. The distribution of the Greater broad-nosed bat Scoteanax rueppellii (Microchiroptera: Vespertilionidae) in relation to climate and topography. Australian Mammalogy 28, 77-85.