Small mammals in the diet of barn owls, Tyto alba (Aves: Strigiformes) along the mid-Araguaia river in central Brazil

Rocha, Rita Gomes; Ferreira, Eduardo; Leite, Yuri Luiz Reis; Fonseca, Carlos; Costa, Leonora Pires

doi:10.1590/s1984-46702011000600003

Cited by 36 publications

(27 citation statements)

References 21 publications

(16 reference statements)

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“…No obstante, el conocimiento del estado de estas invasiones es fragmentario, restringido a ciertos países (Jaksic & Yáñez 1983, Bonino & Soriguer 2004, Guichón et al 2005, Shepherd & Ditgen 2005, Scheibler & Christoff 2007, Baldini et al 2008, Galetti et al 2009, Pérez Carusi et al 2009, Rocha et al 2011 y escasamente representado en la bibliografía. De hecho, pocos países de la región tienen un inventario claro de las especies de mamíferos exóticos presentes y menos aún del estado de sus invasiones y de sus impactos.…”

Section: Introductionunclassified

Mamíferos invasores en Uruguay, historia, perspectivas y consecuencias

Pereira-Garbero¹,

Barreneche²,

Laufer³

et al. 2013

Rev. chil. hist. nat.

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RESUMENRelevar la presencia de especies exóticas y conocer sus atributos ecológicos es un importante insumo para la conservación de la biodiversidad. A través de una revisión bibliográfi ca y de colecciones científi cas, se recabaron datos de dieta, tamaño corporal, historia y estatus de invasión de los mamíferos exóticos reportados en Uruguay. Se realizaron modelaciones de nicho para cada especie en base a modelos de Máxima Entropía. También se estimó el cambio generado en la estructura trófi ca de la biota de mamíferos del Uruguay causado por los procesos de introducción y pérdida de especies. El cambio en los tamaños corporales se evaluó en relación a los datos de distribución de tamaños estimados para los principales grupos trófi cos de mamíferos. Este análisis se realizó a nivel de riqueza de especies y biomasa total por grupo trófi co, estimada a partir de alometrías conocidas. Los resultados sugieren que el cambio en biomasa es estimable sólo conociendo el exponente de las alometrías entre densidad y tamaño corporal, no requiriéndose conocer la constante de normalización. Las especies recientemente extintas son de mayores tamaños corporales y frecuentemente de dietas carnívoras en comparación a las actuales. Contrariamente, las especies introducidas son omnívoras (Mus musculus, Rattus norvegicus, Rattus rattus, Sus scrofa) y herbívoras (Lepus europaeus, Bubalus bubalis, Capra hircus, Axis axis, Dama dama). Estos cambios en la composición de especies se ven exacerbados cuando los consideramos desde el punto de vista de la biomasa. Asimismo evaluamos la idoneidad climática del territorio uruguayo para el establecimiento de dos especies potencialmente invasoras, la ardilla de vientre rojo (Callosciurus erythraeus) que estaría expandiendo su rango de distribución en Argentina y el visón americano (Neovison vison) que ha sido recientemente introducido con fi nes de cría comercial. No obstante la relativa homogeneidad geográfica y climática del paisaje de Uruguay, las estimaciones de idoneidad ambiental para el potencial de establecimiento de especies exóticas indican importantes variaciones a lo largo del territorio y entre especies. Nuestro estudio remarca la fortaleza de la teoría ecológica para adelantarse en el estado básico de las especies y su impacto, incluso cuando la información disponible sobre éstas y los sitios de invasión es limitada.Palabras clave: invasión, mamíferos, modelos de distribución de especies, redes trófi cas, tamaño corporal, Uruguay. ABSTRACTIt is an important input for conservation of biodiversity to survey the presence of exotic species and to know their environmental attributes. Through literature reviews and scientifi c collections, we were able to collect data on diet, body size, history and status of invasion of exotic mammals reported in Uruguay. Niche modeling was conducted for each species based on Maximum Entropy models. Also we estimated the changes generated in the trophic structure of the biota of the mammals in Uruguay caused by the processes of species introductions a...

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Section: Introductionunclassified

Mamíferos invasores en Uruguay, historia, perspectivas y consecuencias

Pereira-Garbero¹,

Barreneche²,

Laufer³

et al. 2013

Rev. chil. hist. nat.

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“…Most authors who have compared inventories of small mammals through pellets analysis and through conventional trapping have concluded that those methods were complementary (Bonvicino and Bezerra 2003, Scheibler and Christoff 2007, Magrini and Facure 2008, Rocha et al 2011. Thus, our results cannot be taken as an inventory of the non-volant small mammals living in the grassy savannas, marshes, and shrublands around Sinnamary.…”

Section: Weightmentioning

confidence: 87%

Barn owl pellets collected in coastal savannas yield two additional species of small mammals for French Guiana

Baglan¹,

Catzeflis

2016

Mammalia

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A sample of 251 pellets regurgitated by the barn owl in an old building located in Sinnamary (French Guiana) provided a rare opportunity to get a preliminary inventory of small rodents and opossums living in grassy savannas along the coastal non-forested landscapes of this Guianan region. From a total of 329 specimens of vertebrate remains, we focused on 259 small rodents and opossums that could be positively identified. Two species previously unknown in French Guiana were evidenced: a very small opossum of the genus Cryptonanus and the medium-sized terrestrial rodent Sigmodon alstoni. Although Cryptonanus was an unexpected finding so far away from its Amazonian distribution area, the presence of Sigmodon in French Guiana fills a gap between Suriname and Brazilian Amapa where this species is typical of grassy savannas. The species of small mammals most commonly preyed upon by the barn owls of Sinnamary was a large semi-aquatic rodent, Holochilus sciureus, followed in decreasing order by two sigmodontines typical of non-forested ecosystems: Oligoryzomys fulvescens and Zygodontomys brevicauda. The analysis of owl pellets contents is a useful tool for providing an inventory of small mammal communities especially in open habitats such as agricultural landscapes or in cerrado-like biotopes (caatinga, savannas, llanos, grassy marshes, etc.) in the Neotropics Christoff 2007, Rocha et al. 2011). The barn owl [Tyto alba (Scopoli, 1769)] is a specialized predator and most of its preys are small non-volant mammals weighting from 15 to 250 g. Several recent investigations of barn owl pellets in Brazil and elsewhere in South America have evidenced the presence of some species of small rodents and opossums, which otherwise were very rarely caught by standard trapping methods using live-or snap-traps. KeywordsFor example, Souza et al. (2010) found two rare dwarf opossums [Gracilinanus agilis Burmeister, 1854, and Cryptonanus agricolai (Moojen, 1943)] among 162 pellets collected in the Northeastern Atlantic Forest realm, and those records were new for the coastal region of Pernambuco state. Similarily, Bonvicino and Bezerra (2003) found three rare species (two small opossums and one cerrado mouse) in barn owl pellets that could not be collected with traps, suggesting that trapping "was either inefficient or was not performed near their specific microhabitats". This study reports on barn owl pellets that were collected in an old water tower in downtown Sinnamary, French Guiana (05°23′N; 52°57′W) in March 2011 (120 pellets) and in September 2013 (131 pellets). Sinnamary is a small city (3100 inhabitants in 2013) at ca. 100 km northwest from Cayenne; it is located within the coastal northern strip of the country, where non-forested areas, such as agricultural lands, grass and bush savannas, small thickets of trees, grassy swamps, and marshes, predominate. The nearest large area of well-drained tropical rainforest starts at 3-4 km southwest from the village and extends for dozens of kilometers toward the south [the for...

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“…Salles et al 1999, 2006, Bonvicino and Bezerra 2003, Scheibler and Christoff 2007, Rocha et al 2011. With a good taxonomic identification it is possible to go beyond listing the species that occur at an area.…”

Section: Discussionmentioning

confidence: 99%

Taxonomic identification using geometric morphometric approach and limited data: an example using the upper molars of two sympatric species of Calomys (Cricetidae: Rodentia)

Boroni¹,

Lobo²,

Romano³

et al. 2017

Zoologia

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ABSTRACT. The taxonomic identification of micromammals might be complicated when the study material is fragmented, as it is the case with pellets and fossil material. On the other hand, tooth morphology generally provides accurate information for species identification. Teeth preserve notably well, retaining their original morphology, unlike skulls and mandibles, which can get crushed or have missing parts. Here, we explored a geometric morphometrics approach (GM) to identify fragmented specimens of two sympatric Calomys Waterhouse, 1837 species -Calomys tener (Winge, 1888) and Calomys expulsus (Lund, 1841) -using the morphology of intact molars as the basis for identification. Furthermore, we included some specimens of uncertain taxonomic identification to test their affinities and the utility of the shape of the molar to identify incomplete specimens. We evaluated the variations in the shape of the first upper molar (M1) among 46 owl pellets specimens of Calomys, including C. expulsus (n = 15), C. tener (n = 15), and unidentified specimens treated as Calomys sp. (n = 16) through GM analysis using 17 landmarks. The data was explored using PCA, PERMANOVA, and Discriminant analyses over the Procrustes residuals matrix were applied to evaluate inter-and intraspecific shape differences. Also, we evaluated whether allometric shape differences could impact the data, but found no evidence of a correlation between size and shape. Our results support that shape differences in the M1 are effective for discriminating between C. tener and C. expulsus. Moreover, the unidentified specimens do not represent a third shape but could be identified with confidence either as C. tener or C. expulsus. Our results show that even with fragmentary materials, GM is a feasible and useful tool for exploring inter-specific shape differences and assisting in taxonomic identification as a complement to traditional qualitative description of diagnostic features in poorly preserved specimens.

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Small mammals in the diet of barn owls, Tyto alba (Aves: Strigiformes) along the mid-Araguaia river in central Brazil

Cited by 36 publications

References 21 publications

Mamíferos invasores en Uruguay, historia, perspectivas y consecuencias

Mamíferos invasores en Uruguay, historia, perspectivas y consecuencias

Barn owl pellets collected in coastal savannas yield two additional species of small mammals for French Guiana

Taxonomic identification using geometric morphometric approach and limited data: an example using the upper molars of two sympatric species of Calomys (Cricetidae: Rodentia)

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