Topic
Chough
About: Chough is a research topic. Over the lifetime, 92 publications have been published within this topic receiving 1412 citations. The topic is also known as: Chough.
Papers published on a yearly basis
Papers
TL;DR: The predictions that environmental variability should select for investment in adult survival and for reduced reproductive effort in poor years are discussed.
Abstract: Summary
1
The consequences of environmental variability for life-history evolution are predicted to depend on the pattern of covariation amongst life-history traits Using data from a 20-year study of individually marked red-billed choughs, we investigate the short- and long-term life-history consequences of population-wide variation in reproductive conditions, and demonstrate clear among-cohort variation and covariation in life-history parameters
2
The mean number of offspring fledging per breeding event varied among years, and was correlated with environmental conditions (temperature and rainfall) during the months preceding breeding As the variance in breeding performance did not differ among years and choughs did not miss breeding seasons, variation in environmental conditions affected the whole breeding population Thus the quality of the chough's breeding environment varied amongst years
3
Juvenile survival, the probability of recruitment to the breeding population and breeding longevity varied amongst cohorts, and these were positively correlated with the quality of the cohort's natal environment Offspring fledging under good conditions were more likely to survive to breeding age and recruit, and had longer breeding lives than offspring fledging under poor conditions
4
Age at first breeding varied amongst cohorts, and increased with population size at maturity rather than natal conditions
5
The total number of offspring that recruits ultimately fledged varied primarily with breeding longevity rather than recruitment age Thus, the consistent positive covariation amongst life-history traits meant that the total number of offspring fledged by recruits during their breeding life varied amongst cohorts, and was correlated with the quality of a cohort's natal conditions Choughs fledging under good conditions themselves ultimately fledged more offspring
6
Such environmentally determined variation in offspring fitness is expected to influence optimal patterns of parental investment We discuss the predictions that environmental variability should select for investment in adult survival and for reduced reproductive effort in poor years
182 citations
TL;DR: It is suggested that genetic structure in white‐winged choughs reflects the interplay between social barriers to dispersal resulting in large family groups that can remain stable over long periods of times, and short dispersal distances which lead to above average relatedness among neighbouring groups.
Abstract: This study used eight polymorphic microsatellite loci to examine the relative effects of social organization and dispersal on fine-scale genetic structure in an obligately cooperative breeding bird, the white-winged chough (Corcorax melanorhamphos). Using both individual-level and population-level analyses, it was found that the majority of chough groups consisted of close relatives and there was significant differentiation among groups (F(ST) = 0.124). However, spatial autocorrelation analysis revealed strong spatial genetic structure among groups up to 2 km apart, indicating above average relatedness among neighbours. Multiple analyses showed a unique lack of sex-biased dispersal. As such, choughs may offer a model species for the study of the evolution of sex-biased dispersal in cooperatively breeding birds. These findings suggest that genetic structure in white-winged choughs reflects the interplay between social barriers to dispersal resulting in large family groups that can remain stable over long periods of times, and short dispersal distances which lead to above average relatedness among neighbouring groups.
85 citations
TL;DR: Foraging choughs showed a strong selection for the steep margins of the original scrubland and halophitic vegetation and utilized other habitats maintained by traditional crop rotation as mentioned in this paper, and a highly complex pattern of habitat selection was found which was not only related to seasonal changes in habitat availability, but also related between territorial pairs and the non-breeding population.
Abstract: Summary 0[ Agricultural land devoted to low!intensity practices supports many declining bird species in Europe[ The potential e}ects of intensi_cation or abandonment of tra! ditional farming practices are assessed from the point of view of the conservation of the chough Pyrrhocorax pyrrhocorax[ 1[ The study was conducted in Los Monegros "north!east Spain#\ in a pseudosteppe landscape of special relevance for this species[ In this area traditional farming survives in the form of low!intensity arable systems including fallowing and extensive sheep grazing[ 2[ Foraging choughs showed a strong selection for _eld margins\ avoided any remn! ant of the original scrubland and halophitic vegetation\ and utilized other habitats maintained by traditional crop rotation "e[ g[ fallow\ stubble# at di}erent times of the year[ 3[ A highly complex pattern of habitat selection was found which was not only related to seasonal changes in habitat availability\ but also di}ered between territorial pairs and the non!breeding population[ This emphasizes the importance of taking all the di}erent components of bird populations into account when analysing interactions between habitat selection and the annual farming cycle[ 4[ Chough habitat selection suggests that both agricultural intensi_cation and land abandonment would have detrimental consequences for this species in Los Monegros[ The maintenance of traditional farming is recommended\ especially by promoting the use of long fallow rotations grazed extensively by livestock\ encouraging the increase of grassland edges around landholdings and sand roads\ and maintaining a low input of biocides[ These management measurements could also favour most other endangered species of steppe birds\ and could be supported by the establishment of Zonal Programmes under the CAP Agri!Environment Regulation "1967:81#[ Key!words] Agri!Environment Regulation 1967:81\ birds\ Common Agricultural Policy\ habitat selection[
64 citations
TL;DR: In the Australian species, the helpers are often adults apparently capable of breeding and it seems possible that the behaviour could have been evolved in adults, and not from immature individuals assisting at the nest, as suggested by Skutch as mentioned in this paper.
Abstract: Records of birds additional to the pair helping at single nests in Australian passerine species are summarized. This behaviour is known to occur in the Ground Cuckoo-Shrike, the Yellow-tailed Thornbill, the blue wrens, the Sittella, four species of honeyeater, the White-winged Chough and Apostlebird, the woodswallows, and the Pied Butcher-bird; and there is a likelihood of its occurrence in the babblers. The proportion of birds showing the behaviour is high in comparison with other avifaunas and it is probably due to some common factor, the likeliest being climate. In species such as the blue wrens, which are rather sedentary, this behaviour can help to maintain the population at a high level in a poor habitat by ensuring nesting success. In other species small nomadic parties are more likely to discover suitable areas, and to contain a breeding pair, while additional birds help in nesting and the rearing of young and can also act as replacements for lost members of the dominant pair. In the Australian species the helpers are often adults apparently capable of breeding and it seems possible that the behaviour could have been evolved in adults, and not from immature individuals assisting at the nest, as suggested by Skutch for other regions. Selection for such behaviour could occur if it is assumed that the dominant pair pass on to their offspring the dual capacity to act as a member of a dominant pair or as a helper in different situations. The reduction or loss of male breeding plumage in subordinate males in the blue wrens might help to prevent the arousal of aggressive reactions associated with such plumages. There appears to be no information available concerning possible factors which inhibit breeding behaviour in subordinate birds or determine the selection of dominant individuals.
59 citations
TL;DR: In this paper, the authors mapped the distribution of six species of birds known to depend on extensive pastoral systems, as published in atlases of breeding birds, in Britain for two time periods: 1968-1972 and 1990-1992.
54 citations
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Performance Metrics
| Year | Papers |
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| 2020 | 3 |
| 2019 | 2 |
| 2018 | 2 |
| 2017 | 2 |
| 2016 | 2 |
| 2015 | 3 |