Search

Conservation area networks (CAN) must overlap spatial patterns of conservation priorities in order to ensure their persistence. Threatened species are among the least controversial biodiversity features taken into account to guide conservation policies. Due to growing human pressure and climate change worldwide, chances of planning an effective CAN may be reduced. Santa Fe province is located in the center-east of Argentina and encompasses four bioregions highly threatened of the subtropical temperate South America. Intensive agriculture, livestock and hunting have led to the loss and degradation of its natural habitats and the current CAN fails on the coverage of bioregions. Our aim was to find out areas that enhance the persistence of threatened bird species in the Santa Fe province. We defined spatial conservation priorities that overlap environmentally suitable areas of species over time and overcome the likely impacts of human activity. Conservation priorities (top 20%) belonged mainly to Dry Chaco and Atlantic bioregions and will remain the same in the province. The current CAN mismatches spatial patterns of environmental suitability of threatened species. Sporophila hypochroma, Asthenes hudsoni and Spartonoica maluroides may lose more than half of their current environmentally suitable area in the future. Human activity will lead to a CAN which will require a great number of patches and a large perimeter. Searching for the most environmentally suitable areas of species over time while minimizing conflicts with human activities is a useful conservation strategy regardless the biogeographical context considered.

The Reserva Biológica do Mato Grande encompasses 5,161 hectares of wetlands, restinga forests and grasslands in southern Brazil. Aiming to assemble a list of bird species occurring in the reserve, we carried out 21 monthly expeditions from July 2007 to March 2009 and an additional visit on October 2014, totaling 341 hours of sampling. We additionally searched for records in online databases and museums. In total, 211 species of birds were found, compared to 223.83 (SD = 3.88) and 214.68 (SD = 4.71) species respectively predicted through Jackknife 2 and Chao 2 estimations. Plegadis chihi was the most abundant bird roosting in the reserve. The area is important for the conservation of Circus cinereus, Spartonoica maluroides, Limnoctites rectirostris and Sporophila palustris, which are considered threatened or near-threatened in state, national and/or global levels. We emphasize the urgent need of implementing the Reserva Biológica do Mato Grande in order to conserve the regional avifauna.

Bay-capped Wren-Spinetail Spartonoica maluroides (Furnariidae) nests very close to the ground in dense clumps of grasses or sedges and builds both open and enclosed nest. We describe a proportion and characteristics of both types of nests and evaluate some causes that could force the construction of one nest architecture or another. In order to study the causes of this variation, we assessed the variability of nest types (architecture and size) and vegetation structure, and examined their consequences for breeding parameters in a population of Bay-capped Wren-Spinetail breeding in Spartina densiflora saltmarshes located at a coastal lagoon on Atlantic coast in east Argentina. We found that Bay-capped Wren-Spinetail builds nests enclosed and open with similar frequency within the same population and vegetation type. All nests were built with stems and grass leaves of S. densiflora. We found that open nests were built in sites with denser vegetation than enclosed nests. Nesting success and nest survival were not affected by nest architecture and size. The ability to adjust nest structure according to the vegetation density may be a strategy aimed at increasing nest concealment to reduce the temperature inside the nest or to avoid nest depredation. A flexible nest architecture strategy in Bay-capped Wren-spinetail is a possible adaptation to living in simple, yet structurally variable environments such as saltmarshes. Fil: Cardoni, Daniel Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Isacch, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Baladron Felix, Alejandro Victor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

We studied variation in bird assemblages with plant associations for three different coastal marshes from Southeastern South America (SESA) and assessed how marsh bird assemblages related to nearby upland bird assemblages. We surveyed bird species and plant structure along the tidal gradient of each locality from the low tide level to the upper habitats bordering coastal marshes. Twenty species frequently used coastal marshes, including relatively few migratory species. We found that birds occurring in SESA coastal marshes do not have distributions constrained to coastal marshes. Nonetheless, four bird assemblages were recognized in association with vegetation types and/or sites. Among the recorded coastal marsh species, the bay-capped wren-spinetail (Spartonoica maluroides) is both the most frequent and the most habitat constrained. Bird richness increases steadily along the tidal gradient associated with the increase in vegetation structure, suggesting that bird richness is directly explained by vegetation and indirectly by the physical conditions influencing vegetation structure. Results highlight the importance of SESA middle marshes as habitat for conservation of some threatened SESA grassland birds. Fil: Isacch, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Cardoni, Daniel Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Iribarne, Oscar Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Fil: Cardoni, Daniel Augusto. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Spartonoica maluroides (Furnariidae) es el ave más especializada y amenazada que habita marismas costeras de esparto de Spartina densiflora del sudeste de América del Sur. Estos ambientes están siendo modificados a un ritmo acelerado principalmente por el pastoreo del ganado y la quema de espartillares, determinando la vulnerabilidad que presenta este furnárido. Para evaluar cómo el uso del suelo afecta las poblaciones de S. maluroides, se estudió la abundancia, el hábitat de nidificación y el éxito reproductivo en marismas bajo diferentes intensidades de pastoreo por ganado y quema. Además, se llevaron a cabo experimentas de depredación de nidos para determinar cómo la altura del nido afecta las tasas de depredación y el tipo de depredadores. S. maluroides presentó similar abundancia, éxito reproductivo y sitio de nidificación en marismas con bajo o nulo pastoreo. Por otro lado, la especie no fue registrada en marismas con alta presión de pastoreo y quemas. La altura del nido fue la variable que mejor explicó la tasa de supervivencia diaria. La tasa de depredación y el tipo de depredadores difirieron en relación a la altura del nido sobre el suelo. Nuestros resultados indican que el pastoreo con baja presión sería compatible con la presencia y reproducción de S. maluroides. De esta manera, el manejo ganadero con baja intensidad de uso es una alternativa viable para el uso sustentable de las marismas del sudeste de América del Sur. The Bay-capped Wren-Spinetail (Furnariidae, Spartonoica maluroides) is the most specialized and threatened bird inhabiting Spartina saltmarshes in southeastern South America. These marshes are being modified at an increased rate, primarily by cattle grazing and burning, which make this furnarid highly vulnerable. To assess how land use affects Bay-capped Wren-Spinetail populations, we estimated their density under different intensities of burnings and cattle grazing, studied nesting habitat selection and nesting success, and conducted nest predation experiments to determine predation rates and predator type. We found similar population densities, nesting microhabitats, and nest predation rates in marshes with low grazing intensity and marshes with no grazing. In contrast, the species was absent from marshes with high intensity of grazing and burning. Nest height was the best predictor of daily survival rates. Nest predation experiments demonstrated that nest high influences predation intensity and predator type. Our results suggest that low grazing intensities are compatible with the presence and reproduction of the Bay-capped Wren-Spinetail. Thus, low-impact cattle raching is a viable alternative for the sustainable development of saltmarshes in southeastern South America. Fil: Cardoni, Daniel Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Isacch, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Iribarne, Oscar Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

We evaluated how grazing affects bird assemblages in short and tall coastal salty grasslands at Samborombón Bay, Argentina. We studied ranches with three patterns of grazing (spatial rotation, continuous, and winter grazing) and a control site, at each censusing birds and surveying vegetation monthly. Results allowed us to compare the various treatments and their effects on endangered birds of short and tall grassland. Three species of special conservation concern showed significant responses to grazing. In short grasslands, the Buffbreasted Sandpiper (Tryngites subruficollis) is supported by continuous grazing. In tall grasslands, the Bay-capped Wren-Spinetail (Spartonoica maluroides) uses only grasslands with extensive cover of tall grass, whereas Hudson’s Canastero (Asthenes hudsoni) uses those with high levels of cattle grazing. The diverse responses of grassland birds to grazing of different types of grassland leads us to propose a system of heterogeneous grazing that optimizes both production and conservation of grassland birds. Se evaluó de qué manera el pastoreo afecta los ensambles de aves que habitan pastizales halófitos cortos y altos de la bahía Samborombón, Argentina. El estudio se realizó en establecimientos rurales donde se desarrollaban tres tipos de sistemas pastoriles (rotación espacial, pastoreo continuo e invernal) y en un sitio de control. En cada sitio y ambiente, mensualmente se realizaron censos de aves y muestreos de la fisonomía de la vegetación. Los resultados permitieron determinar un contraste entre los tipos de manejo ganadero y sus efectos sobre diferentes aves amenazadas de pastizales altos y cortos. Tres especies de particular importancia para la conservación mostraron respuestas significativas a los tratamientos de pastoreo. Tryngites subruficollis utiliza principalmente pastizales cortos con pastoreo continuo, Spartonoica maluroides utiliza pastizales altos con bajos niveles de pastoreo, y Asthenes hudsoni utiliza pastizales altos con pastoreo continuo y rotativo. Las diversas respuestas de las aves de pastizal al pastoreo en los diferentes tipos de pastizales nos llevan a proponer un sistema de pastoreo heterogéneo que optimice al mismo tiempo la producción y la conservación de las aves de pastizal. Fil: Isacch, Juan Pablo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina Fil: Cardoni, Daniel Augusto. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina

O unico registro de reproducao de Spartonoica maluroides (d'Orbigny & Lafresnaye, 1837) no Brasil e baseado na observacao de um filhote recem-saido do ninho no sul do Rio Grande do Sul em janeiro de 1976. Em 7 de dezembro de 2005, descobrimos um ninho contendo tres filhotes na extremidade sudoeste da Lagoa Pequena, municipio de Pelotas, Rio Grande do Sul. O ninho estava oculto na base de uma cavidade dentro de uma touceira de Spartina densiflora (Poaceae) situada na margem de uma marisma. O ninho era constituido de pedacos delgados de folhas mortas de Scirpus olneyi (Cyperaceae) e S. densiflora firmemente entrelacados as folhas da touceira. Folhas vivas de S. densiflora que orlavam a cavidade compreendiam uma parte substancial da arquitetura do ninho, constituindo a maior parte da porcao superior das paredes laterais e o teto. A secao inferior era mais elaborada, similar a uma taca profunda e formando uma câmara incubatoria distinta. Os adultos acessavam o ninho atraves de uma abertura apical de formato irregular por entre as folhas. O ninho media 244 mm de altura e 140 mm de largura. A câmara incubatoria apresentava um diâmetro externo de 138,5 mm, um diâmetro interno de 79,4 mm e uma profundidade de 86 mm, sendo forrada de folhas delgadas e fibras vegetais brancas. Os ninhegos tinham de cinco a seis dias de idade. Um ninhego exibiu um total de 107 neossoptilas restritas aos tratos capital, espinal e alar. A distribuicao das neossoptilas na regiao ocular de S. maluroides forma um padrao distinto que pode ser tipico de Furnariidae e familias afins. Dois adultos atendiam o ninho, trazendo pequenos insetos para os ninhegos e removendo sacos fecais. Registramos pelo menos 74 visitas ao ninho em um periodo de ca. 6 h durante uma tarde. O numero medio de visitas por hora foi de 12,8 ± 1,3. Os adultos permaneceram em media 0,7 ± 0,56 minutos dentro do ninho atendendo os filhotes. O ninho permaneceu sem atendimento em media por 3,61 ± 3,13 minutos. O horario do dia nao influenciou o tempo de permanencia dos adultos no ninho ou longe deste. Retornamos ao local em 15 de dezembro de 2005 e encontramos o ninho abandonado. Observacoes confirmam que S. maluroides e um residente reprodutor no sul do Brasil e que as marismas do estuario da Lagoa dos Patos constituem um importante habitat para a especie durante todo o ano. Um ninhego e o ninho foram coletados para documentar o registro.

We studied breeding biology, parental roles, and social mating system of the Bay-capped Wren-Spinetail (Spartonoica maluroides), a habitat specialist furnariid, in the Argentinean pampas. We found 42 nests during 2004–2007, two during egg laying, 28 during incubation, and 12 with nestlings. Mean clutch size was 3.17 eggs (n = 29), the incubation period was 13 days, and nestlings remained in the nest for 12 days before fledgling. Bay-capped Wren-Spinetails are socially monogamous; both males and females develop a brood patch and contribute to incubation, brooding, and provisioning of nestlings. Wren-Spinetails are unique among furnariids as they build an open cup nest with a few presenting a loose domed roof. Breeding success of Bay-capped Wren-Spinetails was higher (total probability of nesting success = 0.508) than other species of sympatric passerines because of low nest predation and high nest survival rates during incubation and nestling rearing stages.

The burrowing crab,Chasmagnathus granulatus, is the dominant benthic macroinvertebrate of southwest Atlantic salt marshes and tidal flats, having strong ecosystem engineering effects by direct and indirect effects on soil, vegetation, invertebrates, fishes, and birds. Vegetation structure is a main component for bird habitat selection, since greater habitat complexity generates higher niche diversity. This environmental complexity can be modified by species interactions or disturbance events (i.e., by crabs), in turn modifying the associated community. The bird species of salt marshes of the southwest Atlantic are highly dependent on these ecosystems. We assessed the effects of the burrowing crab on the structure of the cordgrass,Spartina densiflora, marshes, and how these changes affected the composition and diversity of birds. This study was conducted at the Mar Chiquita Coastal Lagoon, Argentina (37°40′S, 57°23′W).S. densiflora marshes were classified within three categories: marshes without burrowing crabs, marshes with low burrow densities, and marshes with high burrow densities. We made vegetation and bird surveys during spring beforeS. densiflora produce seeds and in summer when seeds are abundant. We also manipulated inflorescence (i.e., spike) density (a variable affected by crabs) to assess the effect on bird habitat use. The highest inflorescence density ofS. densiflora and highest bird diversity were recorded at low burrow densities. Cover and height ofS. densiflora were negatively correlated with burrow density. The number of bird species and the number of red-capped wren-spinetail,Spartonoica maluroides, were negatively related with cover and height ofS. densiflora. Experiments confirmed that granivorous species used areas with higher spike densities, a variable related to crab burrow density. Burrowing crabs directly and indirectly affect the cover, height, spike density, and morphologic characteristic of seeds ofS. densiflora marshes. These effects indirectly affect the bird community that uses these marshes, being negatively related toS. maluroides and total bird abundance, and positively related to bird diversity.