CHANGES IN ORNITOLOGIA NEOTROPICAL: MOVING WITH THE TIMES

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EDITORIAL DECISIONS AND RESPONSES BY AUTHORS: HOW TO PREPARE A REVISED VERSION OF YOUR MANUSCRIPT AND THE COVER LETTER

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WHAT IS THE SCOPE OF ORNITOLOGÍA NEOTROPICAL?

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Observations on breeding of two Furnariidae in Patagonia: White-throated Cacholote Pseudoseisura gutturalis and Patagonian Canastero Pseudasthenes patagonica

Describimos aspectos básicos de la biología reproductiva de dos especies de Furnariidae endémicas de la Argentina: el Cacholote Pardo Pseudoseisura gutturalis y el Canastero Patagónico Pseudasthenes patagonica. Además, documentamos el desarrollo de los pichones mediante fotografías y mediciones de peso. Hicimos el seguimiento de un nido de Cacholote Pardo y tres nidos de Canastero Patagónico, todos ubicados sobre arbustos espinosos a baja altura, en cercanía de Puerto Madryn, Chubut, Argentina. Ambas especies nidifican en nidos cerrados construidos con palitos espinosos. La puesta de Cacholote Pardo fue de cuatro huevos que fueron incubados durante 18 días. Los pichones permanecieron en el nido por 21 días antes de abandonar el nido de manera exitosa. Un nido de Canastero Patagónico fue seguido desde el inicio de su construcción que llevó un mínimo de 20 días. La puesta fue de tres (dos nidos) o cuatro huevos de color blanco depositados en la cámara de incubación forrada con material vegetal blando. Los huevos eclosionaron luego de 15–16 días de incubación. Un nido fue depredado durante incubación, otro 4–5 días luego de la eclosión de los huevos y el tercero probablemente haya sido exitoso, abandonando los pichones el nido alrededor de 15 días luego de la eclosión. La duración de los períodos de incubación y permanencia en el nido de los pichones son similares a los de otras especies de los géneros Pseudoseisura y Asthenes.Fil: Delhey, Kaspar. Max Planck Institute for Ornithology; Alemania. Monash University. School of Biological Sciences; AustraliaFil: Perez, Cristian Hernan Fulvio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

The carotenoid-continuum: carotenoid-based plumage ranges from conspicuous to cryptic and back again

<p>Abstract</p> <p>Background</p> <p>Carotenoids are frequently used by birds to colour their plumage with green, yellow, orange or red hues, and carotenoid-based colours are considered honest signals of quality, although they may have other functions, such as crypsis. It is usually assumed that red through yellow colours have a signalling function while green is cryptic. Here we challenge this notion using the yellow and green colouration of blue tits (<it>Cyanistes caeruleus</it>), great tits (<it>Parus major</it>) and greenfinches (<it>Carduelis chloris</it>) as a model.</p> <p>Results</p> <p>The relationship between colouration (chroma, computed using visual sensitivities of conspecifics) and detectability (contrast against natural backgrounds as perceived by conspecifics and avian predators) followed a similar curvilinear pattern for yellow and green plumage with minimum detectability at intermediate levels of carotenoid deposition. Thus, for yellow and green plumage, colours at or close to the point of minimum detectability may aid in crypsis. This may be the case for blue and great tit green and yellow plumage, and greenfinch green plumage, all of which had comparably low levels of detectability, while greenfinch yellow plumage was more chromatic and detectable. As yellow and green blue tit colouration are strongly affected by carotenoid availability during moult, variation in pigment availability between habitats may affect the degree of background-matching or the costliness of producing cryptic plumage.</p> <p>Conclusions</p> <p>Increasing carotenoid-deposition in the integument does not always lead to more conspicuous colours. In some cases, such as in blue or great tits, carotenoid deposition may be selected through enhanced background-matching, which in turn suggests that producing cryptic plumage may entail costs. We stress however, that our data do not rule out a signalling function of carotenoid-based plumage in tits. Rather, it shows that alternative functions are plausible and that assuming a signalling function based solely on the deposition of carotenoids in the integument may not be warranted.</p

Sexual selection and blue tit (Parus caeruleus) crown coloration

Conspicuous, sexually dimorphic plumage in birds is most likely a consequence of sexual selection favouring more ornamented males at obtaining a territory and/or a mate. Recent comparative analyses suggest that, among socially monogamous species, extra-pair paternity has also contributed to the elaboration of male ornaments. If females prefer more ornamented males as social or extra-pair mates this could translate into strong directional selection for ornament elaboration, since these males might sire more offspring in their own brood (within-pair success) or in broods of other males (extra-pair success). In this thesis I study the expression of the UV/blue crown coloration in the blue tit (Parus caeruleus) and investigate whether this trait could be selected through increased male within- or extra-pair success. Blue tits are socially monogamous passerines with relatively high levels of extra-pair paternity, and males in this species display more ultraviolet(UV)/blue reflectant crown feathers than females. Based on three years of data I found that crown coloration could be a cue used by females to assess male age since blue tits became more UV-ornamented as they aged. Crown coloration, however, did not correlate with survival to the next breeding season, suggesting that more UV-ornamented males are not necessarily of higher quality. While crown UV-ornamentation increased between years, it declined in the course of a year due to feather wear and dirt accumulation and this could affect female perception of male attractiveness. However, although the decline in UV ornamentation between winter and spring was large, it had no effect on male reproductive success, and winter and spring colour were still positively correlated. Using genetic paternity analysis I could show that more UV-ornamented males do not benefit through increased within-pair or extra-pair success. On the contrary, less UV-ornamented, adult males sired most of the extra-pair offspring. Hence the most successful males of the population were adult males that resembled juveniles in their crown colour. Accordingly, females seem to recognise less UV-ornamented males as highly successful, since they biased brood sex ratio towards male offspring if paired to these males. The causality of these patterns was tested in a colour manipulation experiment, where I treated males to become more (UV+) or less (UV-) ornamented within the natural range of variation. Against expectations UV(+) males sired significantly more extra-pair offspring than UV(-) males while the proportion of within-pair offspring was unaffected by the manipulation. Brood sex ratios did not differ between treatments but depended on male colour before manipulation. While these results do suggest that crown colour plays a role in paternity and brood sex allocation, they do not provide experimental support for the observed correlational patterns. I discuss the discrepancy between observational and experimental data, emphasising potential problems with the experimental manipulation of structural plumage colour. Finally, given that more UV-ornamented males did not sire more offspring, I explore the possibility that they would benefit by pairing with high quality females. High quality females in other species are often more ornamented, and birds of high quality pair assortatively based on ornament expression. This was not the case in this blue tit population, since female colour did not appear to indicate relevant female qualities (fecundity, seasonal reproductive success) and blue tits did not mate assortatively by crown colour in any of the three study years. To conclude, selection seems to favour older, less UV-ornamented males in this population. Whether this is due to female preference is unclear. Alternatively I hypothesise that being less ornamented may enable males searching for extra pair copulations to intrude into other territories without eliciting aggression by territory owners, perhaps by mimicking juveniles. Detailed behavioural observations in the wild coupled with choice chamber experiments in captivity are necessary to test this idea

Granivorous habit in olrog’s gull (<i>Larus atlanticus</i>): implications for its specialist status

En este trabajo se dan a conocer observaciones sobre hábitos de alimentación desconocidos para la Gaviota Cangrejera (<i>Larus atlanticus</i>) en el puerto Ingeniero White, Bahía Blanca, Buenos Aires, Argentina. Entre 2002 y 2005, 281 individuos fueron observados alimentándose de granos en las banquinas del acceso y playa de estacionamiento del puerto. Los grupos de alimentación variaron entre 2–51 individuos. En el 78% de los casos este comportamiento ocurrió durante la pleamar, cuando el acceso a sus presas del intermareal era restringido. El uso de recursos de origen humano apoya la hipótesis que Larus atlanticus posee cierta plasticidad trófica y que puede comportarse como generalista. Se presenta una síntesis del estado actual del conocimiento de la dieta de esta especie y se propone una explicación para las distintas observaciones obtenidas a lo largo de la costa argentina.We report on unknown feeding habits of the Olrog’s Gull (<i>Larus atlanticus</i>) in the area of Ingeniero White port, Bahía Blanca, Buenos Aires Province, Argentina. Between 2002 and 2005, 281 individuals were observed feeding on grains along the shoulder of the road and in a parking lot besides the port. Feeding groups were of 2–51 individuals. This behaviour was observed mostly (78%) during high tides, when access to intertidal prey is limited. The exploitation of human resources by Larus atlanticus supports the hypothesis that this species has some degree of trophic plasticity and could behave as a generalist. We briefly review the literature on its diet, proposing an explanation for the different observations obtained along the coast of Argentina

La distribución austral del Canastero Castaño (Pseudasthenes steinbachi)

El Canastero Castaño (Pseudasthenes steinbachi) es un furnárido restringido al Desierto del Monte, y por lo tanto endémico de Argentina (Hartert y Venturi 1909, Wetmore 1926, Areta et al. 2012). Aunque fue erróneamente incluido en la zona de endemismo de los Andes Australes junto a especies de Puna y bosques húmedos de altura (Cracraft 1985), pertenece a la zona de endemismo del Desierto del Monte (Areta et al. 2012). Su distribución conocida se extiende a lo largo de la pendiente este de los Andes desde el oeste de la provincia de Salta hasta el norte de la provincia de Neuquén (Olrog 1979, Veiga et al. 2005) incluyendo el oeste de la provincia de San Luis (Contreras 1979, Nellar 1993). Los reportes para la provincia de Córdoba (Castellanos 1932 según Contreras 1979, 1980) son erróneos (Navas y Bo 1987). Aunque hasta recientemente se ubicaba al Canastero Castaño en el género Asthenes, estudios filogenéticos muestran que no está estrechamente emparentado a sus miembros y debe colocarse en el género Pseudasthenes (Derryberry et al. 2010).Fil: Areta, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Hernández, Ignacio.Fil: Prieto, Jaime.Fil: Delhey, Kaspar. Monash University; AustraliaFil: Povedano, Hernán. Provincia de Rio Negro. Secretaria de Medio Ambiente. Dirección de Areas protegidas; Argentin

Granivorous habit in Olrog’s Gull (Larus atlanticus): implications for its specialist status

En este trabajo se dan a conocer observaciones sobre hábitos de alimentación desconocidos para la Gaviota Cangrejera (Larus atlanticus) en el puerto Ingeniero White, Bahía Blanca, Buenos Aires, Argentina. Entre 2002 y 2005, 281 individuos fueron observados alimentándose de granos en las banquinas del acceso y playa de estacionamiento del puerto. Los grupos de alimentación variaron entre 2–51 individuos. En el 78% de los casos este comportamiento ocurrió durante la pleamar, cuando el acceso a sus presas del intermareal era restringido. El uso de recursos de origen humano apoya la hipótesis que Larus atlanticus posee cierta plasticidad trófica y que puede comportarse como generalista. Se presenta una síntesis del estado actual del conocimiento de la dieta de esta especie y se propone una explicación para las distintas observaciones obtenidas a lo largo de la costa argentina.We report on unknown feeding habits of the Olrog’s Gull (Larus atlanticus) in the area of Ingeniero White port, Bahía Blanca, Buenos Aires Province, Argentina. Between 2002 and 2005, 281 individuals were observed feeding on grains along the shoulder of the road and in a parking lot besides the port. Feeding groups were of 2–51 individuals. This behaviour was observed mostly (78%) during high tides, when access to intertidal prey is limited. The exploitation of human resources by Larus atlanticus supports the hypothesis that this species has some degree of trophic plasticity and could behave as a generalist. We briefly review the literature on its diet, proposing an explanation for the different observations obtained along the coast of Argentina.Facultad de Ciencias Naturales y Muse

When does early-life telomere length predict survival?:A case study and meta-analysis

Suboptimal conditions during development can shorten telomeres, the protective DNA caps on the end of chromosomes. Shorter early-life telomere length (TL) can indicate reduced somatic maintenance, leading to lower survival and shorter lifespan. However, despite some clear evidence, not all studies show a relationship between early-life TL and survival or lifespan, which may be due to differences in biology or study design (e.g., survival period measured). In superb fairy-wrens (Malurus cyaneus), we assessed whether early-life TL predicts mortality across different life-history stages (fledgling, juvenile, adult). However, in contrast to a similar study on a congener, early-life TL did not predict mortality across any life stage in this species. We then performed a meta-analysis including 32 effect sizes from 23 studies (15 birds and 3 mammals) to quantify the effect of early-life TL on mortality whilst taking into consideration potential sources of biological and methodological variation. Overall, the effect of early-life TL on mortality was significant, corresponding to a 15% reduction in mortality risk with each standard deviation increase in TL. However, the effect became weaker when correcting for publication bias. Contrary to our predictions, there was no evidence that effects of early-life TL on mortality varied with species lifespan or the period over which survival was measured. However, negative effects of early-life TL on mortality risk were pervasive throughout life. These results imply that effects of early-life TL on mortality are more likely context-dependent rather than age-dependent, although substantial power and publication bias issues highlight the need for more research.Funding provided by: Australian Research CouncilCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000923Award Number