Nesting of the Cinereous Warbling Finch (Poospiza cinerea) in Southeastern Brazil.
Abstract: We describe a nest and nesting activity of the Cinereous Warbling Finch (Poospiza cinerea) in Paredao da Serra do Curral City Park, State of Minas Gerais in southeastern Brazil. Little is known about the reproductive biology of this globally vulnerable species. The nest was built with fragments of grass spikes in an Australian pine (Casuarina equisetifolia). The clutch consisted of three eggs. We describe courtship feeding behavior of the Cinereous Warbling Finch and brood parasitism of the nest by the Shiny Cowbird (Molothrus bonariensis).
Article Type: Report
Subject: Nest building (Research)
Authors: Wischhoff, Uschi
Marques-Santos, Fernando
Rodrigues, Marcos
Pub Date: 03/01/2012
Publication: Name: The Wilson Journal of Ornithology Publisher: Wilson Ornithological Society Audience: Academic Format: Magazine/Journal Subject: Biological sciences Copyright: COPYRIGHT 2012 Wilson Ornithological Society ISSN: 1559-4491
Issue: Date: March, 2012 Source Volume: 124 Source Issue: 1
Topic: Event Code: 310 Science & research
Geographic: Geographic Scope: Brazil Geographic Code: 3BRAZ Brazil
Accession Number: 285207258
Full Text: The genus Poospiza (Emberizidae) is wide-spread across South America and the Andes Mountains (Ridgely and Tudor 1989); it includes two endangered Andean species and one vulnerable species in Brazil (BirdLife International 2010). The Cinereous Warbling Finch (Poospiza cinerea) is endemic to the large savannah-like biome known as Cerrado in central South America (Silva and Bates 2002). This species may have been extirpated in three of the five Brazilian states where it originally occurred (BirdLife International 2010) and its population is believed to be diminishing in the other two states (Minas Gerais and Goias). Habitat loss is considered the main cause of the 'vulnerable' designation (BirdLife International 2010).

We searched the literature for reproductive data on the clade in Poospiza which includes the Cinereous Warbling Finch (Lougheed et al. 2000). Data are available for Black-capped Warbling Finch (P. melanoleuca) (Di Giacomo 2005), suggested to be conspecific with the Cinereous Warbling Finch (Ridgely and Tudor 1989), and Ringed Warbling Finch (P. torquata) (Mezquida and Marone 2003). Reproductive data for the Plain-tailed Warbling Finch (P. alticola) and Rusty-browed Warbling Finch (P. erythrophrys) are scarce or unavailable. Little is known about reproduction of the Cinereous Warbling Finch. Lopes et al. (2010) reported two individuals carrying nest construction material near degraded pastures and orchards in Fortaleza de Minas (20 [degrees] 53' S, 46[degrees] 42' W; 900 m asl) in October 2006. We present the first detailed description of the nest of the Cinereous Warbling Finch in southeastern Brazil.

METHODS

Study Area.--We began studying the basic biology of a small population of Cinereous Warbling Finches in May 2010 in the Paredao da Serra do Curral City Park (19" 57' S, 43[degrees] 54' W) in Minas Gerais, southeastern Brazil. The park borders Belo Horizonte, a city of [greater than or equal to] 2 million residents. The climate is dry in winter and rainy in summer ([Cw.sub.a] in Koppen's system of classification; Peel et al. 2007), typical of tropical highlands of Minas Gerais. The vegetation in the area is classified as campo sujo with small portions of campo cerrado (Oliveira-Filho and Ratter 2002). It is heavily degraded by urbanization, exotic and ornamental species (e.g., Pinus spp. and Eucalyptus spp.), frequent illegal vegetation burning, and intensive mining.

The Cinereous Warbling Finch is frequently seen in small groups of two to four members foraging in typical plant species of Cerrado as well as in exotic species. We observed a small group with the aid of 8 X 40 binoculars and found a nest being constructed. The nest was monitored at a distance and its contents were verified when the female spontaneously left the nest.

The gender of the individuals at the nest site was assigned based on morphological, behavioral, and vocalization characteristics (FMS and UW, unpubl, data). Measurements were taken with a spring scale with 0.l-g precision, a caliper with 0.1-mm precision, and a measuring tape.

[FIGURE 1 OMITTED]

RESULTS

We observed nest construction activity by Cinereous Warbling Finches on 17 October 2010. The nest (Fig. 1) was under construction and both male and female were seen building the nest, although another female member of the flock stayed with the pair passively until the first egg was laid.

The nest was 1 m from a paved street adjacent to the Park at 1,179 m asl (19[degrees] 57' S, 43[degrees] 55' W). The nest was not a completely symmetric cup (Fig. 1B). It was supported by three branches in a fork of an Australian pine (Casuarina equisetifolia) which had a total height of 4-5 m, was forked 35 cm from the ground, and had a shrub-like appearance.

The dimensions of the nest were: external diameter at the largest axis = 78.9 mm, external diameter at the smallest axis = 70.4 mm, internal diameter at the largest axis = 61.0 mm, internal diameter at the smallest axis = 59.6 mm, external height = 47.4 mm, and depth = 41.2 mm. The distance from the ground was 2.97 m. The nest consisted of fragments of dried rachis and peduncles from grass spikes (Poaceae) with small roots and twigs (max diam = 0.9 mm). Several Poaceae peduncles (6-16 cm) protruded from the nest.

The nest appeared to be complete on 19 October 2010. The first egg was laid on 22 October 2010 and on the following day three eggs were present (including 1 Shiny Cowbird [Molothrus bonariensis] egg); four eggs were present on the next day (Fig. 1C).

We photographed all three eggs of Cinereous Warbling Finch in situ. The eggs were light-cream in color and had irregular reddish-brown spots concentrated in the rhomb pole resembling a crown. The only egg of Cinereous Warbling Finch measured (Fig. 1A) weighed 2.2 g and was 19.7 mm in length and 14.9 mm in width. The volume, calculated with the equation of Hoyt (1979), was 2,230 [mm.sup.3].

The egg of the Shiny Cowbird (Fig. 1A) weighed 3.4 g and was 21.9 mm in length and 17.3 mm in width. The estimated volume was 3,342 [mm.sup.3]. The Shiny Cowbird egg was white and had irregular dark-brown spots concentrated in the rhomb pole without forming a crown.

Only the female Cinereous Warbling Finch incubated the eggs. We observed the male bringing food to its partner during the building of the nest (n = 1) and during incubation (n = 2). The male would bring intact food in its beak and offer it to the female, which did not adopt a 'begging' behavior.

We saw the female eject one of her own eggs from the nest on 24 October 2010. She held the egg with the beak in a manner that left no doubt the egg was already broken and then flew from the nest dropping the egg on the ground under the nest. We found only two eggs in its chamber (1 Shiny Cowbird and 1 Cinereous Warbling Finch, Fig. lB) on 25 October 2010. We searched for evidence in the surrounding area and found another Cinereous Warbling Finch egg on the ground, 1.95 m from the nest's vertical projection to the ground. The pair of Cinereous Warbling Finches was not seen attending the nest on 27 and 29 October 2010 and the two eggs, whose temperatures were equal to that of the environment, remained in the nest, indicating the nest had been abandoned. The nest was empty but intact on 3 November 2010 suggesting the eggs had been predated. We did not verify any further attempt of reproduction by the pair.

DISCUSSION

The placement of the nest by the Cinereous Warbling Finches was in an Australian pine which is exotic and invasive in Brazil (Santana and Encinas 2008). The tree with the nest was short with numerous forks and absence of its natural monopodial growth pattern, differing from other Australian pines adjacent to it. The nest was active from October to November, overlapping the reproductive period of the Black-capped Warbling Finch (Oct to Jan) (Di Giacomo 2005) and Ringed Warbling Finch (Oct to Feb) (Mezquida and Marone 2003).

The nest of the Cinereous Warbling Finch was a low cup/fork, following the classification of Simon and Pacheco (2005), as it was built with a shallow semi-sphere shape and was attached to a branch fork. The nest of the Ringed Warbling Finch is also a low cup (Mezquida and Marone 2003), in contrast to the nest of the Black-capped Warbling Finch which is a deep semi-sphere (high cup) (Di Giacomo 2005). The Black-capped Warbling Finch, like the Cinereous Warbling Finch, builds its nest with radicles, straw, and vegetal fibers but also with lichen and brown wool (Di Giacomo 2005). The Ringed Warbling Finch also uses grass; other materials include spider oothecas and silk (Mezquida and Marone 2003).

The crown pattern of eggs of the Cinereous Warbling Finch is common in Emberizidae (Sick 1997, Rodrigues et al. 2009), but not for the Black-capped Warbling Finch (Di Giacomo 2005, De La Pena 2006). The frequency of egg laying by the Cinereous Warbling Finch of one egg/day is similar to that of the Black-capped Warbling Finch and Ringed Warbling Finch (Mezquida and Marone 2003, Di Giacomo 2005).

The food offering by the male to the female Cinereous Warbling Finch was interpreted as courtship feeding. This behavior has been reported for the Ringed Warbling Finch (Mezquida and Marone 2003).

The conspicuous occurrence of Shiny Cowbirds, the only brood parasite in the area (Vasconcelos 2007), allowed us to conclude the different egg in the nest belonged to that species. There are records of brood parasitism of the Cinereous Warbling Finch by the Shiny Cowbird (Friedmann and Kiff 1985); however, these records are in Argentina, an area not included in the species' range (Silva and Bates 2002). There are also records of brood parasitism by Shiny Cowbirds for the Black-capped Warbling Finch (Salvador and Salvador 1984, Di Giacomo 2005).

We infer the cause of the ejection of the egg and abandonment of the nest. We speculate a Shiny Cowbird, when placing its egg in the nest, punctured two eggs of the Cinereous Warbling Finch. This behavior has been described by Hoy and Ottow (1964) and Post and Wiley (1977). Nest abandonment suggests this is a strategy used to evade parasitism by the Shiny Cowbird; a strategy also reported for the Black-capped Warbling Finch (Hoy and Ottow 1964).

ACKNOWLEDGMENTS

This work was supported by the Brazilian Research Council (CNPq) and 'Fundacao O Boticairio de Protecao a. Natureza'. MR received fellowships from CNPq and FAPEMIG (PPM). FMS received an undergraduate scholarship from CNPq. We thank the administration of Mangabeiras City Park and the Belo Horizonte Parks Foundation for permission to work in Paredao da Serra do Curral City Park. We also appreciate the reviews by Dietrich W. Wischhoff and Fabio V. Vione, and the valuable comments of C. E. Braun and two anonymous referees.

Received 3 January 2011. Accepted 28 August 2011.

LITERATURE CITED

BIRDLIFE INTERNATIONAL. 2010. Species factsheet: Poospiza cinerea. BirdLife International, Cambridge, United Kingdom. www.birdlife.org

DE LA PENA, M. R. 2006. Guia de fotos de nidos, huevos y pichones de ayes argentinas. L.O.L.A.--Literature of Latin America, Buenos Aires, Republica Argentina.

DI GIACOMO, A. G. 2005. Ayes de la Reserva E1 Bagual. Pages 201-465 in Historia natural y paisaje de la Reserva El Bagual, Provincia de Formosa, Argentina. Inventario de la fauna de vertebrados y de la flora vascular de un area protegida del Chaco Humedo (A. G. Di Giacomo and S. F. Krapovickas, Editors). Temas de Naturaleza y conservacion 4. Ayes Argentinas/Asociacion Ornitologica del Plata, Buenos Aires, Argentina.

FRIEDMANN, H. AND L. F. KIFF. 1985. The parasitic Cowbirds and their hosts. Proceedings of the Western Foundation of Vertebrate Zoology 2:226-302.

HoY, G. AND J. OTTOW. 1964. Biological and oological studies of the molothrine cowbirds (Icteridae) of Argentina. Auk 81:186-203.

HOYT, D. F. 1979. Practical methods of estimating volume and fresh weight of bird eggs. Auk 96:73-77.

LOPES, L. E., G. B. MALACCO, E. F. ALTEFF, M. F. VASCONCELOS, D. HOFFMANN, AND L. F. SILVEIRA. 2010. Range extensions and conservation of some threatened or little known Brazilian grassland birds. Bird Conservation International 20:84-94.

LOUGHEED, S. C., J. R. FREELAND, P. HANDFORD, AND P. T. BOAG. 2000. A molecular phylogeny of Warbling-Finches (Poospiza): paraphyly in a neotropical emberizid genus. Molecular Phylogenetics and Evolution 17:367-378.

MEZQUIDA, E. T. AND L. MARONE. 2003. Comparison of the reproductive biology of two Poospiza warbling-finches of Argentina in wet and dry years. Ardea 91:251-262.

OLIVEIRA-FILHO, A. T. AND J. A. RATTER. 2002. Vegetation physiognomies and woody flora of the Cerrado Biome. Pages 91-120 in The cerrados of Brazil: ecology and natural history of a neotropical savanna (P. S. Oliveira and R. J. Marquis, Editors). Columbia University Press, New York, USA.

PEEL, M. C., B. L. FINLAYSON, AND T. A. MCMAHON. 2007. Updated world map of the Koppen-Geiger climate classification. Hydrology and Earth System Sciences 11:1633-1644.

POST, W. AND J. W. WILEY. 1977. Reproductive interactions of the Shiny Cowbird and the Yellow-shouldered Blackbird. Condor 79:176-184.

RIDGELY, R. S. AND G. TUDOR. 1989. The birds of South America: the oscine passerines. University of Texas Press, Austin, USA.

RODRIGUES, M., L. M. COSTA, G. H. S. FREITAS, M. CAVALCANTI, AND D. F. DIAS. 2009. Ninhos e ovos de Emberizoides herbicola, Emberizoides ypiranganus e Embernagra longicauda (Passeriformes: Emberizidae) no Parque Nacional da Serra do Cipo, Minas Gerais, Brasil. Revista Brasileira de Ornitologia 17:155-160.

SALVADOR, S. A. AND L. A. SALVADOR. 1984. Notas sobre hospedantes del Renegrido (Molothrus bonariensis) (Aves, Icteridae). Historia Natural 4:121-130.

SANTANA, O. A. AND J. I. ENCINAS. 2008. Levantamento das especies exoticas arboreas e seu impacto nas especies nativas em areas adjacentes a depositos de residuos domiciliares. Biotemas 21:29-38.

SICK, H. 1997. Ornitologia Brasileira. Editora Nova Fronteira, Rio de Janeiro, Brazil.

SILVA, J. M. C. AND J. M. BATES. 2002. Biogeographic patterns and conservation in the South American Cerrado: a tropical savanna hotspot. BioScience 52:225-234.

SIMON, J. E. AND S. PACHECO. 2005. On the standardization of nest descriptions of neotropical birds. Revista Brasileira de Ornitologia 13:143-154.

VASCONCELOS, M. F. 2007. Aves observadas no Parque Paredao da Serra do Curral, Belo Horizonte, Minas Gerais, Brasil. Atualidades Ornitologicas 136:6-11.

Uschi Wischhoff, (1,2) Fernando Marques-Santos, (1) and Marcos Rodrigues (1)

(1) Laboratorio de Ornitologia, Departamento de Zoologia, Universidade Federal de Minas Gerais, Caixa Postal 486, 31.270-901, Belo Horizonte, Brazil.

(2) Corresponding author; e-mail: uschiw@gmail.com
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