Maytenus Magellanica) Seeds by Three Primarily Insectivorous Bird Species
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Anales Instituto Patagonia (Chile), 2007. 35 (1): 71-73 71 CONSUMPTION OF LEÑADURA (MAYTENUS MAGELLANICA) SEEDS BY THREE PRIMARILY INSECTIVOROUS BIRD SPECIES CONSUMO DE SEMILLAS DE LEÑADURA (MAYTENUS MAGELLANICA) POR TRES ESPECIES DE AVE PRINCIPALMENTE INSECTÍVORAS Steven M. McGehee* The temperate forests of southern Chile and 2002, McGehee et al. 2004). A description of the Argentina are home to a number of endemic bird program can be found in Anderson & Rozzi (2000) species (Rozzi et al. 2003). Many are wholly or and Anderson et al. (2002). During mistnetting principally insectivorous (Jaksic & Feinsinger 1991). operations on March 24, 2004, a Patagonian tyrant Three of these species, a furnarid and two tyrannid was seen actively perch hunting for insects in the species, are found as far south as Navarino Island Omora Park. It then fl ew into a leñadura (Maytenus in the Cape Horn Biosphere Reserve, Chile. The magellanica) tree and was seen to consume two Patagonian tyrant (Colorhamphus parvirostris) is fruits. This same Patagonian tyrant then resumed considered an insectivorous species (Johnson 1967, its perch hunting for insects. del Hoyo et al. 2004), although it has been seen On April 10, 2005 two Patagonian tyrants to take the seeds of maiten (Maytenus boaria) in were seen in the same leñadura tree. Each would sit winter (Barros 1921). The fi re-eyed diucon (Xolmis on a branch of the tree or in a fi rebush (Embothrium pyrope) is also known to be mainly insectivorous coccineum) intertwined with the leñadura. The (Lazo & Anabalon 1992), but is reported to eat Patagonian tyrants would fl y from their perch, different types of fruits and seeds in certain parts of hover and pluck the fruit, then fl y back to a branch its range (Johnson 1967, Rozzi et al. 1996, Egli & and swallow the fruit. This was done on and off for Aguirre 2000). The thorn-tailed rayadito (AphrasturaAphrastura over six hours. Twice they were seen to regurgitate spinicauda), long considered strictly an insect-eater, the fruit, open their beaks, chew the seeds and has recently been shown to consume some seeds then reswallow the food item. Usually two to three of exotic pine trees (Pinus radiata) (Estades 2001) fruits were eaten in 10-15 seconds, followed by and peck at fruits of Berberis, Ribes and Gunnera a 30 second pause that was followed by another (del Hoyo et al. 2003). Here, three instances of series of fruit plucking and eating. This continued observations of fruit-eating behavior in these bird for approximately 40 minutes. The birds would then species are reported for the subantarctic forests of fl y off and reappear approximately 30 minutes later the Cape Horn Biosphere Reserve. and repeat the fruit eating off and on for the next Since 2000, the Omora Ethnobotanical Park four hours. The Patagonian tyrants appeared to be has been conducting an ongoing mistnetting study of swallowing the fruits whole. the forest birds on Navarino Island, Chile (54º55´S: During the time the Patagonian tyrants 67º39´W) (Anderson & Rozzi 2000, Anderson et al. were eating fruits, another species considered to Parque Etnobotánico Omora - Sede Puerto Williams, Universidad de Magallanes, Puerto Williams, Chile (www.umag.cl/williams) *Current address: Center for the Study of Tropical Birds, 218 Conway Drive, San Antonio, Texas 78109 USA ([email protected]) 72 S.M. McGEHEE CONSUMPTION OF MAYTENUS SEEDS BY INSECTIVOROUS BIRDS 73 be primarily insectivorous, the diucon (Xolmis fl ying insects, were not moving due to cold climatic del Hoyo, J., A. Elliot & D.A. Christie 2004. Han- Lazo, I. & J.J. Anabalon 1992. Dinámica repro- pyrope), was seen to consume these fruits well. A conditions. Rayaditos on the other hand, may take dbook of the birds of the world. Volume 6. ductiva de un conjunto de aves Passeriformes diucon fl ew in and ate a leñadura fruit, plucking it fruits and seeds whenever the opportunity presents Lynx ediciones, Barcelona de la sabana de espinos de Chile central. while hovering and then fl ying to a nearby branch itself (del Hoyo et al. 2003). The implications for Dollenz, O. 1995. Los árboles y bosques de Ornitología Neotropical 3:57-64. and swallowing it whole. The individual repeated plant seed dispersal by principally insectivorous Magallanes. Ediciones Universidad de McGehee, S.M., R. Rozzi, C.B. Anderson, S. Ippi, R. this three times, then fl ew off. Throughout that day, birds are important to consider for the ecology of Magallanes, Punta Arenas Vásquez & S. Woodland 2004. Late summer fl ocks of 10-16 rayaditos would pass though the trees subantarctic forests, as well as general assumptions Egli, G. &J. Aguirre 2000. Aves de Santiago. presence of the Patagonian tyrant, Colorham- as well. They would hang from a leñadura branch about the diet of austral bird species, particularly UNORCH, Chile phus parvirostris (Darwin) on Navarino Island, and pluck a fruit and fl y away. A few would land on in extreme limits of their distribution, where their Estades, C. F. 2001. Consumo de semillas de pino Cape Horn County, Chile. Anales Instituto a nearby branch, hold the fruit against the branch ecology and behavior may be different than other (Pinus radiata) por rayaditos (Aphrastura Patagonia, (Chile) 32: 25-33. with their foot and proceed to tear off the fruit and parts of Chile. spinicauda). Boletín Chileno de Ornitología Moore, D.M. 1983. Flora of Tierra del Fuego. swallow one or both seeds. The rayaditos appeared 8: 30-31. Anthony Nelson, England. to only take one or two fruits before moving on. It ACKNOWLEDGMENTS Fjeldsa, J. & N. Krabbe 1990. Birds of the High Rozzi, R., J.J. Armesto, A. Correa, J.C. Torres-Mura is not known whether the same fl ock was passing Andes. Zoological Museum, University of & M. Sallaberry 1996. Avifauna de bosques through all-day or different fl ocks. In 2006, this tree Thanks to C.B. Anderson, R. Rozzi and C. Copenhagen, Denmark. primarios templados en islas deshabitadas produced very little fruit but 3 times on April 16th a Elphick for initiating the Omora mistnetting and bird Jaksic, F.N. & P. Feinsinger 1991. Bird assemblages del archipiélago de Chiloé. Revista Chilena rayadito was seen fl ying off with a fruit in its beak. banding program, which has been partially fi nanced in temperate forests of North and South Ame- de Historia Natural 69: 125-139. On April 15th and April 17th, 2005 in an area about by the Institute of Ecology and Biodiversity (www.ieb- rica: a comparison of diversity, dynamics, guild Rozzi, R., F. Massardo, C. B. Anderson, S. McGe- 120 meters from the initial site, rayaditos were seen chile.cl). Thanks also to R. Charlin, D. Christie and structure, and resource use. Revista Chilena hee, G. Clark, E. Ramilo, U. Calderón, C. eating fruit from another leñadura tree. This tree Á. Gutiérrez for sharing their knowledge of Chilean de Historia Natural 64: 491-510. Calderón, L. Aillapan, & C. Zárraga 2003. was observed for seven hours on the 15th and eight plants, and to S. Reid for sharing her expertise in Johnson, A.W. 1967. The birds of Chile and adjacent Guía Multi-étnica de Aves de los Bosques hours on the 17th, and only rayaditos were seen at Chilean birds. In addition thanks to D. Allan, C.B. regions of Argentina, Bolivia and Peru. Vol. Templados de Sudamérica Austral. Editorial this tree although diucons were in the area. The Anderson, B. Lickman, J. Jimenez, F. Massardo, 2, Platt Establ. Gráfi cos, Buenos Aires. Fantástico Sur. Punta Arenas. rayaditos were seen eating the fruit in this leñadura M. Sherriffs & J.C. Torres-Mura for their comments tree during the full period of observation. This tree on earlier drafts. This article is part of the ongoing produced no fruit in 2006. research and conservation programs conducted at Maytenus is a tree genus restricted to Central the Omora Ethnobotanical Park – Universidad de and South America with two species recorded Magallanes (www.umag.cl/williams & www.omora. in southern Chile and Argentina (Dollenz 1995). org). Leñadura (M. magellanica) are found from Hoste and Navarino islands north through Chile and Argentina LITERATURE CITED to 40ºS (Moore 1983). In late summer, it produces a fruit capsule of 4-6 × 4-4.5 mm containing two Anderson, C.B. & R. Rozzi 2000. Bird assemblages seeds (Moore 1983). This tree species is rather rare in the southernmost forests in the world: Me- on the northern part on Navarino Island, as feral thodological variations for determining species cows that inhabit the island frequently eat its leaves composition. Anales Instituto Patagonia, (R. Charlin, pers. comm.). The fruit of a closely Serie Cs. Nat. (Chile) 28: 89-100. related species Maytenus boaria have also been Anderson, C., R. Rozzi, C. Elphick & S. McGehee seen to be consumed by Patagonian tyrants in the 2002. El programa Omora de anillamiento de winter (Barros 1921). Diucons are also known to aves en los bosques subantárticos: estandari- eat fruits occasionally in central Chile as well (Egli zación del tamaño de los anillos apropiados & Aguirre 2000). para las aves de la Región de Magallanes. On April 10th, there was intermittent snowfall Boletín Chileno de Ornitología 9: 2-11. with all three bird species eating the leñadura Barros, R. 1921. Aves de la Cordillera de Aconca- fruit during these periods of snow lasting 10-20 gua. Revista Chilena de Historia Natural minutes. However, on April 15th and 17th it was 25:167-192 sunny each day. It is possible that the Patagonian del Hoyo, J., A. Elliot & D.A. Christie 2003. Han- tyrants and the diucons were supplementing their dbook of the birds of the world. Volume 5.