Two yellow fever outbreaks (YFOs) occurred in northeastern Argentina between November 2007 and October 2008, seriously affecting populations of two howler monkey species: the brown howler Alouatta guariba clamitans and the black howler Alouatta caraya. Both howlers live syntopically in El Piñalito Provincial Park, Misiones, where four groups (36 individuals) were studied since January 2005. The first dead howlers were found on January 20, 2008, in El Piñalito. Systematic searches found 14 dead howlers within the area (12 from the study groups and two from neighboring groups), with only two young seen on January 25, 2008, and none found since up to December 2008. In October 2008, another YFO hit howler monkey populations from El Soberbio, Misiones. Overall, 59 howlers were found dead in Misiones from November 2007 to December 2008. Thanks to the alert of the howler's death in El Piñalito, a prompt human vaccination campaign started in the area. Wild howler monkey populations from both species are in a delicate situation in Misiones, especially the brown howler, an already endangered species in Argentina and endemic to the Atlantic Forest. If we add the recurrence of YFOs to the reduction of suitable habitat to small fragments, it could be only a matter of time until howler populations disappear from the Upper Paraná Atlantic Forest in Misiones.
Most bamboos are semelparous. Their synchronous masting events occur on a cycle of 3–120 yr and represent an extremely pulsed resource for granivorous birds. Although many bird species feed occasionally on bamboo seeds, there are constraints to specializing on such a fluctuating resource and few bird species are known to specialize on bamboo seeds. Three of these bird species are endemic to the Atlantic forest of South America: the purple‐winged ground‐dove Claravis godefrida, buff‐fronted seedeater Sporophila frontalis, and Temminck's seedeater Sporophila falcirostris. All three species are irregularly recorded in the province of Misiones, Argentina. We compared the temporal and spatial patterns of records of these birds in Misiones to masting events of the five common bamboos: yatevóGuadua trinii, takuaruzúGuadua chacoensis, takuapíMerostachys claussenii, pitinga Chusquea tenella, and takuarembóChusquea ramosissima. All bird records coincided with times and places where Guadua bamboos (G. trinii and G. chacoensis) were known or estimated to have seeds. None of the bird species occurred during masting events of Merostachys or Chusquea, unless Guadua was also masting. We discuss relevant ecological and morphological features of the birds that might bear on their association with Guadua bamboos and that might be key to their conservation.
Entre Ríos Seedeaters (Sporophila zelichi), also called Zelich's Seedeaters, White‐collared Seedeaters, and Narosky's Seedeaters, are one of the rarest birds in the Neotropics. However, doubts have been raised about the validity of this species. Therefore, I evaluated the systematic status of Entre Ríos Seedeaters based on analysis of previously unpublished vocal and habitat data. I tested four hypotheses regarding the systematic status of S. zelichi: Good Species Hypothesis (valid species), Hybridization Hypothesis (hybrid S. palustris×S. cinnamomea), Color Morph Hypothesis I (morph of S. cinnamomea), and Color Morph Hypothesis II (morph of S. palustris). The songs and preferred habitat of S. zelichi are indistinguishable from those of Marsh Seedeaters (S. palustris), and the songs of both forms have exhibited similar changes from the early 1990s to 2003–2007. In contrast, the songs and preferred habitat of Chestnut Seedeaters (S. cinnamomea) differ from those of S. zelichi. Therefore, the Good Species Hypothesis is rejected by vocalization and habitat data, the Hybrid Hypothesis is undermined by the absence of shared vocal characters and limited habitat overlap of the proposed parental forms S. cinnamomea/S. palustris, and Color Morph Hypothesis I is rejected by both song and habitat data. However, Color Morph Hypothesis II is supported by both song and habitat data. Thus, I propose that S. zelichi be considered a color morph of S. palustris.
33 Vocalizations became progressively longer, but the series types shown by adults were evident 34 in juveniles at an early age. All three acoustic features of series (triad) notes studied correlated 35 with age in both sexes (duration 90% increased through development, while bandwidth 90% 36 and peak frequency decreased). LRV developed normally in juveniles acoustically isolated from 37 adults, supporting the vocal tract maturation hypothesis and possibly rejecting the vocal 38 learning hypothesis. Juveniles emmitted a higher proportion (7.4%) of abnormal vocalizations 39 than adults (0.3%), as expected in the development of any complex behavior that requires 40 practice to be mastered. The maturation of the LRV occurred well before the sexual maturation, 41 presumably due to the protracted time needed to acquire or build a burrow system long before 42 mating is possible. We propose that protracted vocal development is another component in the 43 slow developmental strategy of Ctenomys and subterranean rodents in general.
When bird populations spread, long-distance pioneering populations are often backfilled by a more slowly advancing front [1-3]. The Barn Swallow Hirundo rustica, a globally distributed passerine [4, 5], expanded its breeding range an exceptional 7,000 km when it began breeding 35 years ago in its regular wintering range in Argentina [6], subsequently expanding over 500 km from its starting point [7-11]. Trans-hemispheric breeding attempts have occurred previously in related swallows [12-14], but only this colonization has lasted. Comparative studies of birds show a remarkable diversity in patterns of change in migratory habits [15-21], and these Argentine-breeding swallows might retain ancestral patterns, breeding in Argentina but returning to North America for the austral winter. Feather isotopes from these birds are consistent with the alternative possibility that they migrate no farther than northern South America [22]. Because isotopic patterns cannot definitively distinguish these alternatives, we pursued a solar geolocator study [23, 24] to do so. Data from nine tagged birds show conclusively that Barn Swallows breeding in Argentina have rapidly changed their movements to migrate no farther north in austral winter than northern South America. The phenology of the annual cycles of molt, migration, and breeding for these Argentine-breeding swallows have all shifted by about 6 months, and we suggest that stimulatory day lengths and the proliferation of nesting substrates facilitated their colonization.
Vinaceous Amazons (Amazona vinacea) are endemic to the Atlantic forest of southeastern Brazil, eastern Paraguay, and the province of Misiones in Argentina. We searched for Vinaceous Amazons throughout the western part of its range in Argentina and Paraguay during 1639 days of fieldwork from 1997 to 2006. These parrots have disappeared from most areas where they were historically recorded in these countries, and are now limited to a few sites in northeastern Paraguay and central Misiones (Argentina). We estimate the minimum remaining populations at 220 individuals in Paraguay and 203 individuals in Argentina. Important sites for the species are (1) the farming area from San Pedro to Tobuna (Misiones, Argentina) and (2) the Itaipú reserves complex and Reserva Natural Privada Itabó (Paraguay). In our surveys, Vinaceous Amazons were absent from the largest tracts of forest in Misiones, and were most often observed feeding, roosting, and nesting in small forest remnants and in agricultural areas that included forest fragments and isolated trees. Threats to amazons in these areas include nest poaching, forest clearing, and being shot as a crop pest. We confirmed 40 Vinaceous Amazons kept as pets in 35 homes between San Pedro and Tobuna. Environmental education and law enforcement are urgently needed to reduce threats in populated areas, and subsistence farmers need technical and logistical support to slow or stop the conversion of forest into cropland. Finally, additional study is needed to determine this amazon's habitat preferences, nest site requirements, and demography in different habitats. SINOPSIS. Distribución, abundancia y conservación del loro vinoso (Amazona vinacea) en Argentina y ParaguayEl loro vinoso (Amazona vinacea) es endémico del bosque Atlántico del sudeste de Brasil, este de Paraguay, y la provincia de Misiones en Argentina. Buscamos esta especie durante 1639 días de trabajo de campo de 1997 a 2006, a lo largo de la porción oeste de su distribución, en Argentina y Paraguay. A. vinacea ha desaparecido de la mayor parte de lasáreas donde ha sido registrada históricamente en estos paises, y permanece sólo en algunos pocos sitios del noroeste de Paraguay y del centro de Misiones (Argentina). Estimamos el tamaño mínimo de las poblaciones remanentes en 220 individuos en Paraguay y 203 individuos en Argentina. Los sitios importantes para la especie son: (1) la zona rural de San Pedro a Tobuna (Misiones, Argentina) y (2) el complejo de reservas de Itaipú y la Reserva Natural Privada Itabó (Paraguay). A. vinacea no fue encontrada en los tractos más grandes de bosque durante nuestras prospecciones en Misiones. Mayormente fue observada alimentándose, durmiendo y nidificando en pequeños remanentes boscosos y en hábitats antropogénicos. Las amenazas en estos hábitats incluyen robo de pichones de los nidos, deforestación, y cacería por daño a cultivos. Confirmamos la existencia de 40 ejemplares cautivos como mascotas en 35 hogares de San Pedro y Tobuna. Para reducir las amenazas se requieren urgentemente educaci...
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