Research Interests: Reproduction, Biology, Ecology, Ibis, Parental investment, and 3 morePasserine Birds, Paternal Care, and Brood
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Acerca de la historia de vida, y particularmente de la nidificación y biología reproductiva de Cistothorus platensis.Fil: Zarco, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet -... more
Acerca de la historia de vida, y particularmente de la nidificación y biología reproductiva de Cistothorus platensis.Fil: Zarco, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Llambias, Paulo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin
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Studies of variation in breeding parameters are often based on temporal analyses of a singlepopulation. However, to differentiate between the effects of regional and local factors, neighboring populations withlimited interpopulational... more
Studies of variation in breeding parameters are often based on temporal analyses of a singlepopulation. However, to differentiate between the effects of regional and local factors, neighboring populations withlimited interpopulational dispersal need to be compared.We studied two nearby (< 5 km apart) populations of HouseWrens (Troglodytes aedon bonariae) at two ranches (Los Zorzales, 10 years; La Esperanza, 13 years) in south-temperateArgentina to assess the possible effects of regional and local factors on breeding phenology. For each breeding season,we recorded laying dates, clutch sizes, and length of the breeding season, and estimated the reproductive synchrony offirst and second breeding attempts. We examined how these breeding parameters were affected by weather, populationdensity, and rates of nest failure. With favorable temperatures during the pre-reproductive period (September-October), wrens in both populations initiated first breeding attempts earlier. However, ordina...
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ABSTRACT Nest predation is the primary cause of nest failure in passerines. In order to contribute to our understanding of how nest predators shape avian nesting ecology and life history traits, we report nest predator identity and nest... more
ABSTRACT Nest predation is the primary cause of nest failure in passerines. In order to contribute to our understanding of how nest predators shape avian nesting ecology and life history traits, we report nest predator identity and nest predation rates for 3 species of passerines in the Central Andes of south temperate Argentina. We used video cameras and opportunistic observations with photographic documentation to identify nest predators of Grass Wrens (Cistothorus platensis) breeding in a riparian grassland, as well as House Wrens (Troglodytes aedon) and House Sparrows (Passer domesticus) breeding in nest boxes in a tree plantation. From 13 nest predation events we were able to identify 3 nest predator species: mousehole snake (Philodryas trilineata), South American gray fox (Lycalopex griseus), and American Kestrel (Falco sparverius). Field observations also suggested fire ants (genera Solenopsis) as a possible nest predator. Mousehole snakes were identified at both grassland and forest plantation, representing 76.9% of the identified predation events. House Sparrows had the highest nest predation rate (43.1%), followed by Grass Wrens (30.8%) and House Wrens (29.3%). Egg predation was more frequent for House Wrens (64.2%) and House Sparrows (50.0%) than for Grass Wrens (22.1%). In contrast, nestling predation was considerably higher for Grass Wrens (77.9%) than for House Wrens and House Sparrows (34.7% and 50.0%, respectively). Knowledge of the nest predator community and information of nest predation rates of different species in temperate South America will contribute to understand nest predation effects on patterns and processes of nesting success, life history traits, and future management decisions in this region.
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The Nearctic and the Neotropic differ in several abiotic and biotic features that have profound implications in avian ecology. Several of these variables are predicted to affect social mating systems. The Sedge Wren (Cistothorus... more
The Nearctic and the Neotropic differ in several abiotic and biotic features that have profound implications in avian ecology. Several of these variables are predicted to affect social mating systems. The Sedge Wren (Cistothorus platensis) and the House Wren (Troglodytes aedon) are distributed from Canada to Cape Horn and are ideal species to evaluate the differences in social mating systems between hemispheres. We compared the social mating system, male contribution to feeding nestlings, clutch sizes, and number of nestlings fledged in north temperate and south temperate wrens using original data gathered in three study sites and published data from four additional sites. In the north, polygyny rates were higher and clutch sizes were larger than in the south. Furthermore, in the north polygyny was achieved when a male attracted an additional female to his territory while in the south, polygyny occurred when a monogamous male replaced a neighboring male and bred with the resident female. We did not find a clear association between parental care patterns and social mating system in the north. Although northern wrens had similar rates of social polygyny, northern Sedge Wren males contributed less to feeding nestlings than northern House Wrens males. Our results suggest social divergence between hemispheres and social convergence within hemispheres, probably caused by variation in underlying common factors. We suggest that differences in polygyny rates between hemispheres can be caused by a combination of migratory behavior and life-history strategies that affect the control and manipulation that males can exert over female reproduction.
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ABSTRACT Levels of conspecific brood parasitism (CBP) and quasi-parasitism (QP) are important parameters for the general understanding of alternative female mating strategies. We deployed double-digest RAD sequencing to assess CBP and QP... more
ABSTRACT Levels of conspecific brood parasitism (CBP) and quasi-parasitism (QP) are important parameters for the general understanding of alternative female mating strategies. We deployed double-digest RAD sequencing to assess CBP and QP in a south temperate population of Grass Wrens (Cistothorus platensis). CBP rate was low and varied annually (0–10%). No cases of QP were identified in our population. Grass Wrens showed similar levels of CBP when compared to other Neotropical songbirds. Given that females could increase their reproductive output by laying eggs in both their nests and in other females' nests, it is striking that CBP is so rare. Future work should evaluate counter-adaptations (egg pecking and rejection, nest desertion, and retaliation) that reduce the success of CBP.
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Dispersal constitutes one of the main processes that shape population genetic structure and dynamics. Combining a capture-mark-resighting methodology and molecular genetics analyses, we studied the natal dispersal behaviour of House Wrens... more
Dispersal constitutes one of the main processes that shape population genetic structure and dynamics. Combining a capture-mark-resighting methodology and molecular genetics analyses, we studied the natal dispersal behaviour of House Wrens (Troglodytes aedon bonariae) inhabiting a naturally fragmented habitat in south temperate Argentina. Based on data collected over 12 breeding seasons (2005–2016), we tested if males and females differ in natal dispersal behaviour at different spatial scales. At local scale (within study sites), both resighting of banded individuals and genetic analysis showed that females dispersed greater distances than males. At a broader spatial scale (between study sites) resighting of banded individuals could not verify that females were the dispersing sex since long-distance dispersal was rare. However, genetic analyses revealed paradoxical evidence: while the females of populations separated by more than 5 km showed slight but significant genotypic differences among them, males showed genetic differences at a greater distance (> 16 km). Given that genetic analyses can provide evidence of both historical and present-day dispersal the observed genetic differentiation does not necessarily imply that the sex dispersal pattern is reversed at a regional scale. We propose that females have a higher probability of acquiring a partner/territory at closer distances due existing male-biased population sex ratio caused but higher female mortality. Also, although males are less likely to disperse, when they do, they must travel greater distances to find a suitable territory or mate. Such movements would prevent the occurrence of genetic differences among male populations.
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Theory proposes an adaptive relationship between male song complexity, including large song repertoires, and improved breeding success. Evidence supporting these relationships exists but is sometimes mixed or weak. Here we provide a first... more
Theory proposes an adaptive relationship between male song complexity, including large song repertoires, and improved breeding success. Evidence supporting these relationships exists but is sometimes mixed or weak. Here we provide a first comprehensive study of the relationship between male song diversity and breeding success in a non‐migratory, austral population of house wrens Troglodytes aedon chilensis breeding in Mendoza, Argentina. During a two‐year field study, we measured breeding success for a population of 62 males and recorded more than 34 000 songs from a subsample of 26 males. For the latter subsample, we tested for correlations between six measures of song diversity and four canonical measures of annual breeding success. Males that sang with greater overall syllable type diversity and that had larger song repertories paired with females that bred earlier and laid more eggs over the course of the breeding season. However, these males also showed lower levels of immediat...
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Research Interests: Geography, Biology, Argentina, Andes, Population, and 3 moreWetland, Check List, and Range Extension
Breeding dispersal is the movement of an individual between breeding attempts and is usually associated with the disruption of the social pair bond, although mates may disperse together as a social unit. In monogamous territorial species,... more
Breeding dispersal is the movement of an individual between breeding attempts and is usually associated with the disruption of the social pair bond, although mates may disperse together as a social unit. In monogamous territorial species, the decision to disperse may be affected by individual attributes such as sex, age and condition of the disperser. However, environmental and social contexts may also play a crucial role in the decision to disperse. We analysed capture-resighting data collected over 9 years to study breeding dispersal and divorce rates of a Southern House Wren Troglodytes aedon musculus population in South Temperate Argentina. Between-season dispersal was more frequent than within-season dispersal, with females dispersing more often than males, both between and within seasons. Both within-season and between-season breeding dispersal probability was affected by territory availability, but not by previous breeding success. When the adult sex ratio (ASR) was more skewed towards males, male between-season dispersal was also affected by mating status, with widowed and single males dispersing more often than paired males. Within-season divorce increased the reproductive success of females but not males, and was affected by the availability of social partners (with increasingly male-skewed ASR). Our results suggest that territorial vacancies and mating opportunities affect dispersal and divorce rates in resident Southern House Wrens, highlighting the importance of social and environmental contexts for dispersal behaviour and the stability of social pair bonds.
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ABSTRACT Alarm calls are usually used to signal the presence of a threat to members of the same species and have been studied broadly in social foraging species. We analysed the effects of conspecific alarm calls on the parental behaviour... more
ABSTRACT Alarm calls are usually used to signal the presence of a threat to members of the same species and have been studied broadly in social foraging species. We analysed the effects of conspecific alarm calls on the parental behaviour of a territorial species, the southern house wrens (Troglodytes aedon musculus), during nestling stage. We compared the parental response of adults feeding 9–11-day-old nestlings when faced with conspecific alarm calls and with a control non-sympatric species’ song broadcast from a neighbouring territory. We measured the time required by parents to return to the nest (latency) when exposed to the stimuli and estimated parent’s nest visitation rate and mean visit duration. Parents took longer to resume parental activities when we broadcast a conspecific alarm call, but they did not modify their nest visitation rate or the mean visit duration. Heterospecific songs did not seem to affect parental behaviour. Our results suggest that nesting southern house wrens can use alarm calls uttered from neighbouring territories to assess the presence of a threat and adjust their parental behaviour accordingly.
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The Vulnerable Pampas meadowlark Sturnella defilippii (Family Icteridae) is a Neotropical grassland bird that suffered a severe population reduction and range contraction during the 20th century. Formerly distributed across most of the... more
The Vulnerable Pampas meadowlark Sturnella defilippii (Family Icteridae) is a Neotropical grassland bird that suffered a severe population reduction and range contraction during the 20th century. Formerly distributed across most of the pampas grasslands, it is now confined to the southern tip of its original range. There are small groups of wintering birds in southern Brazil, a small reproductive population in eastern Uruguay, and the main reproductive population occurs on the southern pampas grasslands of Argentina. In this paper we report the results of an extensive field survey of these southern pampas grasslands, carried out to estimate the pampas meadowlark's population size and to identify the factors potentially responsible for its range contraction. During the 1999 breeding season we surveyed a total of 296 sample locations (transects, randomly selected points, and sites checked for nesting site reoccupation). We found 66 reproductive groups of pampas meadowlarks. The mi...
Research Interests: Zoology, Geography, Ecology, DISTRIBUTION, Population, and 15 moreHabitat, Field Survey, Population Size, Transect, Grassland, Ecologia De Poblaciones, Distribution, Long Term Monitoring, Conservacion De La Biodiversidad, Southern Brazil, Aves Amenazadas, Pastizales, ENVIRONMENTAL SCIENCE AND MANAGEMENT, Breeding season, and Grassland bird
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... PAULO E. LLAMBÍAS 1 , 2 , VALENTINA FERRETTI 1 , PABLO S. RODRÍGUEZ 1. ... Although the Great Kiskadee (Tyrannidae: Pitangus sulphuratus), has been described as an extreme generalist and even piratic forager (Fitzpatrick 1980), there... more
... PAULO E. LLAMBÍAS 1 , 2 , VALENTINA FERRETTI 1 , PABLO S. RODRÍGUEZ 1. ... Although the Great Kiskadee (Tyrannidae: Pitangus sulphuratus), has been described as an extreme generalist and even piratic forager (Fitzpatrick 1980), there is only one report of intraspecific ...
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... Sick, H. 1985. Ornitologia brasileira, uma introdução. Editora Univ. de Brasilia, Brasilia. Siegel, S. and NJ Castellan. 1988. ... Stutchbury, B. J M. and ES Morton. 2001. Behavioral ecology of tropical birds. Academic Press, San... more
... Sick, H. 1985. Ornitologia brasileira, uma introdução. Editora Univ. de Brasilia, Brasilia. Siegel, S. and NJ Castellan. 1988. ... Stutchbury, B. J M. and ES Morton. 2001. Behavioral ecology of tropical birds. Academic Press, San Diego, California. Verner, J. and MF Willson. 1969. ...
Research Interests: Zoology and Parental care
... PAULO E. LLAMBÍAS 1 , 2 , VALENTINA FERRETTI 1 , PABLO S. RODRÍGUEZ 1. ... Although the Great Kiskadee (Tyrannidae: Pitangus sulphuratus), has been described as an extreme generalist and even piratic forager (Fitzpatrick 1980), there... more
... PAULO E. LLAMBÍAS 1 , 2 , VALENTINA FERRETTI 1 , PABLO S. RODRÍGUEZ 1. ... Although the Great Kiskadee (Tyrannidae: Pitangus sulphuratus), has been described as an extreme generalist and even piratic forager (Fitzpatrick 1980), there is only one report of intraspecific ...
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ABSTRACT We studied the relationship among re-mating, site fidelity and breeding performance in the tree swallow Tachycineta bicolor using 16 y of data on reproductive biology in a population breeding in nest boxes near Ithaca, New York.... more
ABSTRACT We studied the relationship among re-mating, site fidelity and breeding performance in the tree swallow Tachycineta bicolor using 16 y of data on reproductive biology in a population breeding in nest boxes near Ithaca, New York. Of 217 pairs for which both members survived the non-breeding season, 76% mated with a new partner and 24% reunited with their previous mate. Pairs did not increase their breeding success by breeding together for more than one breeding season. Males produced fewer fledglings after breeding with a new partner, but females neither increased nor decreased their success when breeding with a new mate. Females who bred with a new partner were younger than females that reunited with their previous mates, and they were more likely to move to a different nest box. Males that bred with a new mate were of similar age to males that reunited, and they did not move more often. The probability of breeding with a new partner was better predicted by female age than by previous breeding success, suggesting that re-mating was not strongly affected by past breeding performance. Because younger females change breeding sites more frequently than do older females and females that mated with a new partner were younger than females that reunited with their previous mates, we suggest that the tendency of tree swallows to change partners between years is a by-product of lower site fidelity of younger females rather than a strategy for increasing breeding success.
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ABSTRACT We studied egg-pecking behaviour in males and females of three cowbird species: the shiny cowbird (Molothrus bonariensis), a host generalist brood parasite, the screaming cowbird (M. rufoaxillaris), a host specialist brood... more
ABSTRACT We studied egg-pecking behaviour in males and females of three cowbird species: the shiny cowbird (Molothrus bonariensis), a host generalist brood parasite, the screaming cowbird (M. rufoaxillaris), a host specialist brood parasite, and the bay-winged cowbird (Agelaioides badius), a non-parasitic species. We conducted three experiments in which we offered each bird an artificial nest with two plaster eggs and recorded whether egg pecking occurred and the number of pecks on each egg. In expt 1, we tested if there were species and sex differences in egg-pecking behaviour by offering the birds two spotted eggs of similar pattern. Shiny and screaming cowbirds responded in 40.3% and 44% of the trials, respectively, with females and males presenting similar levels of response. In contrast, bay-winged cowbirds did not show any response. In expt 2, we tested if shiny cowbirds responded differentially when they faced a choice between one host and one shiny cowbird egg, while in expt 3, we tested if screaming cowbirds responded differentially when they faced a choice between one shiny and one screaming cowbird egg. Shiny cowbirds pecked preferentially host eggs while screaming cowbirds pecked more frequently shiny cowbird eggs. Our results show that egg-pecking behaviour is present in both sexes of parasitic cowbirds, but not in non-parasitic birds, and that parasitic cowbirds can discriminate between eggs of their own species and the eggs of their hosts or other brood parasites.
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ABSTRACT In the House Wren (Troglodytes aedon), polygyny is characterized by males&#39; partial desertion, males providing little or no help in feeding the nestlings of one of their mates. We evaluated whether contributions to feeding... more
ABSTRACT In the House Wren (Troglodytes aedon), polygyny is characterized by males&#39; partial desertion, males providing little or no help in feeding the nestlings of one of their mates. We evaluated whether contributions to feeding nestlings and patterns of provisioning by partially deserted females can explain geographic variation in the species&#39; rate of polygyny. From 2003 to 2007, we studied two populations differing in polygyny rate (U.S., 40%; Argentina, 2%). We induced polygyny in the monogamous population by removing males from their territories before the onset of egg laying. We predicted that if patterns of parental care are related to variation in the social mating system, monogamous males should contribute more in the monogamous population than in the polygynous population, in the monogamous population partially deserted females should not compensate for the lack of help by feeding at rates higher than do aided females, and partial desertion should be more costly in the monogamous population. Monogamous males of the two populations did not differ significantly in their contribution to provisioning. Females&#39; pattern of provisioning was also similar; partially deserted females fed nestlings at a rate higher than did aided females but did not fully compensate for the lack of help. Furthermore, the cost of male desertion seems greater in the polygynous population, as the breeding and fledging success of poorly aided females were lower. We suggest that the male&#39;s contributions to parental care and the patterns of unaided females&#39; feeding cannot explain the geographic variation in the House Wren&#39;s mating systems.
Research Interests: Zoology and Parental care
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ABSTRACT Risk-taking behaviour of short lived nesting birds is often explained in relation to the reproductive value of offspring (the reproductive value hypothesis) and the harm that the absence of parental care can cause to nestlings... more
ABSTRACT Risk-taking behaviour of short lived nesting birds is often explained in relation to the reproductive value of offspring (the reproductive value hypothesis) and the harm that the absence of parental care can cause to nestlings (risk of harm-to-offspring hypothesis). The reproductive value hypothesis predicts that the risk assumed by adults should increases with nestling age, whereas the risk of harm-to-offspring hypothesis predicts the opposite pattern. We assessed the risk-taking behaviour of nesting males and females Northern House Wrens, Troglodytes aedon, faced with a predation threat (plastic owl model) when rearing 3–4 and 10–12 days old nestlings. We used the time elapsed until parents first entered the nest-box as a measure of risk-taking behaviour and alarm calling rate as a proxy of nest defence. Females resumed sooner parental activities when exposed to the model when nestlings were young, supporting the risk of harm-to-offspring hypothesis. In contrast, the time lasted to resume parental duties by males did not differ between nestling ages. Alarm calling rate increased with the nestling stage, as predicted by the reproductive value hypothesis. We suggest that nesting House Wrens responded to both nestling requirements and to the reproductive value of the brood, assuming greater risks when nestlings are more vulnerable and a more intense nest defence when nestlings are older