#BOU18TC | SESSION 1
20 November 2018
1200 – 1530 UTC
Osteohistology and life history of the basal pygostylian, Confuciusornis sanctus
Anusuya Chinsamy (1), Jesús Marugán-Lobón (2,3), Francisco J. Serrano (3,4),
Luis Chiappe (3).
1 University of Cape Town, Department of Biological Sciences, Private Bag X3, Rhodes Gift, 7700, South Africa.
2 Universidad Autónoma de Madrid, Unidad de Paleontología, 28049 Cantoblanco (Madrid), Spain.
3 Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA.
4 Universidad de Málaga, Área de Paleontología, Málaga, 29071, Spain.
The biology and growth of early birds has largely been based on individual bones of particular species. This has been understandably so, since until recently fossils of Mesozoic bird species were rare and were generally not known from multiple individuals. However, this situation changed significantly with the discovery of the exceptional localities of the Jehol Group of Northeastern China. From these species-rich Early Cretaceous deposits thousands of Confuciusornis sanctus specimens preserving skeletal material and plumage were discovered. Remarkably, some of these individuals have distinctive ornamental rectrices, whilst others lack such ornamentation. Although the anatomy of Confuciusornis has been well studied, little is known about its life history. Since fossil bone microstructure is well recognized as enabling palaeobiological deductions, here we investigated the histology of 22 long bones sampled from 14 Confuciusornis specimens to deduce information about the life history of this basal pygostylian bird. Analysis of the bone histology of the various bones revealed differences in the histological structure of their bone walls. On the basis of the osteohistology, we separated the examined specimens into 5 histological age classes (HAC). We found that size and HAC were not strictly correlated, especially once the birds reached sexual maturity. These findings suggest that Confuciusornis had a high degree of developmental plasticity during ontogeny. Furthermore, the osteohistology shows that like several other basal birds (such as, Jeholornis, Sapeornis, and enantiornithines), Confuciusornis experienced rapid growth to sexual maturity, and thereafter took several years to reach skeletal maturity.
Professor Anusuya Chinsamy-Turan is a palaeobiologist based in the Department of Biological Sciences at the University of Cape Town in South Africa. She is a global expert on the microscopic structure of the bones of extinct and extant vertebrates. She has over 100 peer reviewed journal articles, and she has authored two academic books [Microstructure of Dinosaur Bone (Johns Hopkins University Press, USA, 2005) and Forerunners of Mammals (Indiana University Press, USA, 2012)], as well as, two popular level books, Famous Dinosaurs of Africa (RandomHouseStruik, SA, 2008) and Fossils for Africa (Cambridge University Press, 2014).
1230 UTC | Darren P. O’Connell @oconned5
UTC 1200 | Trinity College Dublin, Ireland
New white-eye species in the understudied Wallacea region: congeneric island colonisers with very different origins
White-eyes (Zosteropidae) are known for their remarkable diversification and speed of evolution, particularly, on isolated islands. Here we present evidence of two new white-eye species from the Wakatobi Islands in the Wallacea region. The Lemon-bellied White-eyes (Zosterops chloris) on the Wakatobis are distinct from mainland populations in genetics, morphology, plumage and song. Even more remarkably we have found a completely novel white-eye species, found on only on 155km2 Wangi-wangi Island, with its closest relatives over 3000km to the east in the Louisiade Archipelago (Zosterops griseotinctus and Zosterops murphyi). Our results demonstrate the uncharted biodiversity that remains in the Wallacea region.
1240 UTC | Susanne Jähnig @ SusanneJaehnig
UTC 1200 | University of Turin, Italy
Impacts of microclimate on the distribution of birds in an Alpine environment
Species distribution models of mountain birds have usually used large scale temperature estimates. However, the topographic complexity of mountain areas could create microclimatic refuges which may influence species distributions. We found that models based on microclimatic data outperformed those using large-scale temperature data for grassland birds, but for ecotone species there was no difference. Contrary to previous findings, grassland birds were positively associated with warmer microclimates. These results suggest that microclimate plays an important role in the settlement decisions of grassland species, and that previous predictions about impacts of rising temperatures on Alpine birds may have to be re-assessed.
1250 UTC | Sophie C. Edwards @scedwards19
UTC 1200 | University of St Andrews, UK
Blue Tits change when they build their nest in response to temperature
There is considerable variation in nests design, with and between species. Different populations, of the same species, use different amounts of material in their nest, and it is generally assumed that this is because individual birds respond to the local temperature during nest construction. To test this assumption, we investigated the response of Blue Tits (Cyanistes caeruleus) in St Andrews, UK, during the breeding seasons of 2016 and 2017 to ambient temperature. In the warmer year of 2017 birds built their nest and laid eggs earlier than they had in 2016. However, there was no difference in the materials used.
1300 UTC | Samantha Franks @_SamanthaFranks
UTC 1200 | British Trust for Ornithology, UK
Consequences of changes in seasonal timing for productivity and population trends in songbirds
Differential responses of birds and their prey to changing spring timing are thought to be contributing to avian population declines. We use spatially extensive survey data of plants, invertebrates and birds to investigate whether asynchronous changes in egg-laying dates relative to spring onset are associated with reduced avian productivity and population change. Species which have advanced egg-laying the least are declining fastest. In warmer springs, birds breed late relative to spring onset and productivity is reduced. Although species whose productivity is reduced the most are declining fastest, the mechanism cannot be directly attributed to the effects of asynchrony on productivity.
1310 UTC | Belgic Porras @BelgicaPorras
UTC 1200 | Centro Tlaxcala de Biología de la Conducta,
UTC 1200 | Mexico
Sexual differences in parental care in western bluebirds (Sialia mexicana)
There are sex differences in the amount and type of parental care. In addition, there is variation in parental care, which could be explained by changes in brood demands, and sexes may respond differently to these demands. The distribution of parental care might also affect offspring fitness. Western bluebirds present a high proportion of extrapair offspring and a biased social environment, so sexual differences were expected. However, no differences had been found. We evaluated if there are sexual differences in parental care associated with brood demand, and if the distribution between the sexes is related to nestlings’ body condition.
1320 UTC | Brandon P.M. Edwards @bedwards144
UTC 1200 | Canadian Wildlife Service, Canada
bbsBayes: An R Package for Hierarchical Bayesian Analysis of North American Breeding Bird Survey Data
SThe North American Breeding Bird Survey (BBS) is a key program in assessing population status and trends for more than 400 North American bird species. The R package bbsBayes was developed as a wrapper for hierarchical Bayesian analysis of the BBS data. The goal of bbsBayes is to provide an easy-to-use package for anyone in the conservation community to generate estimates of population trajectories and trends for a customized selection of species and/or regions, and to provide a framework for researchers to customize the underlying status and trend model (e.g., adding covariates).
1330 UTC | BREAK
1400 UTC | Rich Howells @howellsrj
UTC 1200 | Centre for Ecology & Hydrology, UK
Around the island: long-term trends in breeding distribution and consistency at a European Shag colony over two decades
Colonial breeding is a widespread phenomenon, particularly in seabirds. Such colonies generally comprise multiple sub-colony aggregations, which vary geographically in key metrics, with linked reproductive consequences. However, there remains a very limited understanding of sub-colony temporal dynamics, and associated changes in colony structure. Utilising a dataset comprising 13,532 individual breeding events, from 2617 nest sites, we quantified long-term temporal variation in European shag Phalacrocorax aristotelis sub-colony structure over two decades. In the first analysis of its kind, we identify remarkable consistency in core breeding areas over the study, along with a dramatic shift in nest distribution around the island perimeter.
1410 UTC | Lucy Garrett @garrettlucy1
UTC 1200 | University of Birmingham, UK
Friends for benefits: the importance of sociality for seabird chick survival
Many seabird species exhibit high degrees of sociality, especially when breeding. Chick social group formation is thought to provide benefits such as predator avoidance and thermoregulation. Few studies have explored social group size or the number of ‘friends’ in relation to survivorship. We studied a large population of Sooty Terns on Ascension Island in the South Atlantic. We recorded social group size at different developmental stages together with the loyalty of these groups over time. Social group size had a positive effect on chick survival and friendships remained stable up to a critical age point.
1420 UTC | Anouk Spelt @AnoukSpelt
UTC 1200 | University of Bristol, UK
Habitat use of an urban-nesting seabird
Urbanisation negatively affects animal populations, however can also be advantageous for some species. The number of large gulls has been increasing in the UK as they use the urban environment for breeding. Currently, there is a lack of information on how these gulls utilise their surroundings. By combining high resolution GPS units with behavioural and habitat data we found that these gulls avoid the marine environment spending on average 70% of their time away from the nest in urban areas. This suggests that the urban environment provides the majority of the resources required over the breeding season.
1430 UTC | Nina O’Hanlon @Nina_OHanlon
UTC 1200 | Environmental Research Institute – UHI, UK
Spatial variation in Herring Gull colony size
To investigate potential habitat drivers, associated with local food availability, of variation in Herring Gull colony sizes we compared the colony size of 68 Herring Gull colonies across southwest Scotland and Northern Ireland to relate to the availability of potential foraging habitats surrounding each colony. We found spatially clustered variation in changes of the size of Herring Gull colonies indicating that neighbouring colonies experienced similar environmental conditions. We also highlight the importance of intertidal and farmland habitats in buffering against declines. (Co-author: Ruedi Nager)
1440 UTC | Becky Ingham @ hookpod
UTC 1200 | Hookpod, UK
Trialling the Hookpod: a ‘one-stop’ mitigation solution for seabird bycatch in pelagic longline fisheries
Seabird bycatch in longline fisheries is one of the most pervasive sources of mortality. Uptake of mitigation has not been widespread. We present the results of 18 trials between 2011—2015 onboard pelagic longliners targeting tuna and swordfish using the Hookpod, encasing the point and barb of the hook, preventing seabirds becoming hooked during line-setting. We observed 59130 experimental branchlines over 129 sets and recorded a single mortality on the Hookpod branchlines compared to 24 on the control, a rate of 0.04 birds/1000 hooks and 0.8 birds/1000 hooks, respectively. No difference in catch rate of target species was detected. This demonstrates that Hookpods could help halt the decline of many seabird populations.
1450 UTC | Airam Rodríguez @Airam_Rguez
UTC 1200 | Estación Biológica de Doñana, EBD-CSIC, Spain
Seabird plastic ingestion differs among collection methods: Examples from the Short-tailed Shearwater
Few seabird plastic ingestion studies have assessed how plastic loads vary with sampling methods. Most studies use necropsies of naturally dead seabirds, but seabirds killed accidentally may be more representative. We used the Short-tailed Shearwater to test different sampling methods: naturally beached fledglings and accidentally road-killed fledglings after being grounded by artificial lights. Beached birds showed higher plastic loads, poorer body condition and reduced isotopic variability, suggesting that they are not a representative subsample of the fledgling population. Our results might have implications for long-term monitoring programs of seabird plastic ingestion.
1500 UTC | Kyle Elliott @ArcticEcology
UTC 1200 | McGill University, US
Top-down and bottom-up responses of Arctic seabirds to climate change
Whereas ectothermic animals, such as fish, can respond rapidly to climate change, endothermic animals, such as birds, typically respond much more slowly because their responses are controlled via hormonal and other cascades. Thus, the classic effect of climate change on seabirds is via mismatch between timing of peak energy availability and predator energy demand. Using data from two sub-Arctic seabird colonies (Coats Island, Canada, and Middleton Island, Alaska) I will argue that although such bottom up mechanisms are important in seabird populations, top-down effects from predation and parasitism are likely more important, at least in the short-term. Both bottom-up and top-down effects from climate change must be considered when modeling seabird population responses to climate change.
1510 UTC | Julia Gulka @julia_gulka
UTC 1200 | University of Manitoba, Canada
Individual-level variation in the foraging ecology of a marine predator, the Common Murre
Individual variation provides insight into resource utilization in space and time. We used GPS tracking and stable isotope analysis to examine behavioral and dietary specialization in a breeding Common Murres (Uria aalge), over two years with varying prey availability. We found high within-individual variation in behavior, coupled with low spatial overlap, indicative of generalist behavior, while dietary niche breadth was narrower on the scale of weeks relative to days, suggesting a degree of dietary specialization. Our research suggests interplay between diet, behavior, and prey availability and provides insight into how individuals respond to environmental variation, a critical aspect of conservation.
1520 UTC | Edward Jenkins @pterodromas
UTC 1200 | University of Manitoba, Canada
The effect of superabundant prey on the dietary niche dynamics of three auks in Newfoundland
Similar predators may respond differently to shifts in the availability of prey. An annual pulse of capelin (Mallotus villosus) on the Newfoundland coast allows for investigation into the influence of prey availability on the dietary niche of Atlantic puffins (Fratercula arctica), razorbills (Alca torda), and common guillemots (Uria aalge) using stable isotope analysis. While niche breadth contracted and trophic position increased for all species after capelin arrived, dietary proportions varied by species. Findings reiterate the importance of capelin for breeding seabirds and highlight potential changing species interactions and conservation concerns if capelin declines in the future.
UTC 1530 | BREAK
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