FLEMING THEODORE H., MUCHHALA NATHAN, AND ORNELAS, J. FRANCISCO. NEW WORLD NECTAR-FEEDING VERTEBRATES: COM- MUNITY PATTERNS AND PROCESSES, CAP. 15: 163-186. En: SÁN- CHEZ-CORDERO V. y M EDELLÍN R.A. (Eds.) CONTRIBUCIONES MASTOZOOLÓGICAS EN HOMENAJE A BERNARDO VILLA, 706 p. Instituto de Biología, UNAM; Instituto de Ecología, UNAM; CONA- BIO. México, 2005. ISBN 970-32-2603-5. 15. NEW WORLD NECTAR-FEEDING VERTEBRATES: COMMUNITY PATTERNS AND PROCESSES THEODORE H. FLEMING1, NATHAN MUCHHALA1, AND J. FRANCISCO ORNELAS2 1Department of Biology, University of Miami 2Departamento de Ecología y Comportamiento Animal, Instituto de Ecología, Xalapa Abstract Resumen New World nectar-feeding vertebrates occur primarily in Los vertebrados nectarívoros del Nuevo Mundo perte- the mammalian family Phyllostomidae (subfamilies necen principalmente a las familias Phyllostomidae Glossophaginae and Phyllonycterinae with a total of (subfamilies Glossophaginae y Phyllonycterinae con un about 34 species) and the avian family Trochilidae (about total de 34 especies) y Trochilidae (cerca de 330 espe- 330 species). In this paper we compare and contrast pat- cies). En este trabajo, comparamos y contrastamos las terns and processes in the community structure of these tendencias y procesos en la estructura de comunidades two groups to identify evolutionary commonalities and de estos dos grupos e identificamos las similitudes y di- differences. Both groups show similar latitudinal trends ferencias evolutivas. Ambos grupos muestran tendencias in regional species diversity with peak diversities occur- latitudinales similares en riqueza regional de especies con ring in northwestern South America and southern Cen- picos de diversidad en el noroeste de Sudamérica y el sur tral America. Diversity at the community level shows de Centroamérica. La diversidad al nivel de comunidad parallel trends with species richness increasing as a power muestra tendencias paralelas con la riqueza de especies function of annual rainfall per site. Nectar-bat diversity incrementándose como la potencia de la precipitación ranges from 1-6 species per site; hummingbird diversity anual por sitio. La diversidad de murciélagos nectarívoros ranges from 3-28 species per site. Higher per site hum- va de 1-6 especies por sitio; la diversidad de colibríes va mingbird diversity has arisen in part from the evolution de 3-28 especies por sitio. La mayor diversidad de colibríes of distinct sets of canopy- vs. understory-feeding spe- por sitio ha surgido debido, en parte, a la evolución de cies. The major factor controlling both regional and local distintos grupos de especies que se alimentan en el dosel diversity in these groups is the species richness of their y en el sotobosque. El factor principal que controla la flowers. Hummingbird flowers have evolved more fre- diversidad local y regional en estos grupos es la riqueza quently and in a wider range of plant habits and habitats de especies de las flores. Las flores de que se alimentan than nectar-bat flowers. The two groups also show a par- los colibríes han evolucionado más frecuentemente en un allel trend regarding body size and jaw/bill length distri- espectro más amplio de hábitos y hábitat de plantas, que butions in different habitats: the largest species tend to las flores de que se alimentan los murciélagos nectarívoros. occur in dry habitats. This trend reflects differences in Ambos grupos también muestran tendencias paralelas en mean flower sizes among habitats. The density and bio- relación al tamaño del cuerpo y la distribución de la lon- mass of both nectar-feeding bats and birds tend to be gitud mandíbula/pico en diferentes hábitat: las especies low at most sites, reflecting the low energy density of más grandes tienden a ocurrir en hábitat secos. Esta ten- nectar compared with other food resources (e.g., fruit). dencia refleja diferencias en el tamaño promedio de las 164 CONTRIBUCIONES MASTOZOOLÓGICAS EN HOMENAJE A BERNARDO VILLA In both groups, seasonal migration is a prominent fea- flores entre los hábitat. La densidad y biomasa de las aves ture of community organization. Hummingbirds exhibit y murciélagos nectarívoros tienden a ser bajos en la ma- a more diverse array of foraging strategies than nectar yoría de los sitios, reflejando la baja densidad de energía bats. Whereas both groups contain species that forage del néctar comparado con otros recursos alimenticios via trap-lining, only in hummingbirds is resource defense (e.g., fruta). En ambos grupos, la migración estacional es a common foraging strategy. Island communities of these una característica prominente en la organización de la nectarivores usually contain only 2-4 species as a result comunidad. Los colibríes muestran una mayor diversi- of low floral diversity. dad de estrategias de alimentación que los murciélagos nectarívoros. En tanto ambos grupos muestran especies Key words: glossophagine bats, hummingbirds, commu- que se alimentan estableciendo rutas de forrajeo, sólo en nity diversity, morphological diversity, migration los colibríes la defensa de recursos es una estrategia de alimentación común. Comunidades de islas de estos nectarívoros incluyen comúnmente de 2-4 especies como resultado de una baja diversidad floral. As is well known, Bernardo Villa-R’s favorite mam- Palabras clave: murciélagos glosofaginos, colibríes, diver- mals are bats, which were the subject of his doctoral sidad de comunidades, diversidad morfológica, migración. thesis (Villa-R. 1966). In one of his early publica- tions (Martinez and Villa-R. 1940), he described a new species of bat, Leptonycteris yerbabuenae (Phyllostomidae, Glossophaginae), which was col- Schuchmann 1999). The major adaptive radiation of lected near Yerbabuena in his home state of extant lineages apparently began in the early Miocene Guerrero. This bat, which has since been called L. (about 18 Mya) (Bleiweiss 1998a). This radiation sanborni and then L. curasoae (Arita and Humphrey produced seven major species groups (one hermit 1988), has been the subject of intense study in and six nonhermit groups) containing a total of Mexico and Arizona for several decades (Ceballos about 330 extant species (Bleiweiss et al. 1997). Al- et al. 1997; Cockrum 1991; Fleming and Nassar though their place of origin is currently unknown 2002; Hayward and Cockrum 1971). A common (Bleiweiss 1998a), it was likely in the Andean re- member of one of two nectar-feeding subfamilies gion of northern South America (Rahbek and Graves of the Phyllostomidae, it is responsible for polli- 2000). Early hummingbirds probably lived in tropi- nating the flowers of many species of columnar cacti cal lowland habitats; at least two major radiations and paniculate agaves, among other species of night- of nonhermits have occurred in the Andean uplands blooming “bat” flowers. (Bleiweiss 1998b). Hermits are found primarily in Don Bernardo’s early interest in nectar-feeding lowland tropical habitats of tropical America. bats has inspired us to review the community ecol- Nonhermits occur in a wide variety of habitats ogy of Leptonycteris and its relatives and to com- throughout North, Central, and South America and pare this ecology with that of hummingbirds the West Indies. (Apodiformes, Trochilidae), the other major group The chiropteran family Phyllostomidae first ap- of nectar-feeding vertebrates in the New World. pears in the fossil record in the Miocene when many Both groups contain species of small, agile fliers with of its extant lineages, including the Glossophaginae relatively large energy budgets (compared with in- and Phyllonycterinae (sensu Wetterer et al. 2000), like- sects) and large carrying capacities for pollen. Be- ly first evolved. Compared with hummingbirds, the cause they are highly mobile, cognitively advanced, adaptive radiation of nectar-feeding phyllostomids has and long-lived, these animals are effective pollina- been rather modest. Subfamily Glossophaginae con- tors of many kinds of widely dispersed tropical and tains 13 genera and about 31 species classified in two subtropical plants. Of these two groups, humming- tribes (Glossophagini and Lonchophyllini); subfam- birds are evolutionarily older, having split from ily Phyllonycterinae contains two genera and three swifts (Apodidae) in the Paleocene nearly 60 Mya species (Wilson and Reeder 1993). Glossophagines (Bleiweiss 1998a). Hummingbirds occur in two sub- are found throughout the lowlands and uplands of families (Phaethornithinae, the hermits, containing the neotropics, including the West Indies. Phyllonyc- six genera and 34 species and Trochilinae, the terines are restricted to the Greater Antilles and the nonhermits containing 96 genera and 294 species; Bahamas. NEW WORLD NECTAR-FEEDING VERTEBRATES: COMMUNITY PATTERNS AND PROCESSES 165 Nectar-bats and hummingbirds are often consid- cipal habitats: dry (annual rainfall < 1000 mm) and ered to be each other’s temporal ecological ana- non-dry (annual rainfall ≥1000 mm). We classified logues. But is this really true? How many ecological hummingbirds in one of three principal habitats: dry similarities do these two groups share? Despite vast- (xeric environments, including tropical dry forest), ly different evolutionary histories and morphologi- open forest (temperate pine and oak woodlands, clear- cal backgrounds, have these two groups converged ings, open habitats), or wet forest (tropical rain for- in their community attributes and ecological func- est, cloud forest). To quantify the morphological tion? Here we compare and contrast