Unexpected diversity in socially synchronized rhythms of shorebirds

The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates, competitors, prey and predators. Individuals can temporally segregate their daily activities (for example, prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (for example, group foraging, communal defence, pairs reproducing or caring for offspring). The behavioural rhythms that emerge from such social synchronization and the underlying evolutionary and ecological drivers that shape them remain poorly understood. Here we investigate these rhythms in the context of biparental care, a particularly sensitive phase of social synchronization where pair members potentially compromise their individual rhythms. Using data from 729 nests of 91 populations of 32 biparentally incubating shorebird species, where parents synchronize to achieve continuous coverage of developing eggs, we report remarkable within-and between-species diversity in incubation rhythms. Between species, the median length of one parent's incubation bout varied from 1-19 h, whereas period length-the time in which a parent's probability to incubate cycles once between its highest and lowest value-varied from 6-43 h. The length of incubation bouts was unrelated to variables reflecting energetic demands, but species relying on crypsis (the ability to avoid detection by other animals) had longer incubation bouts than those that are readily visible or who actively protect their nest against predators. Rhythms entrainable to the 24-h light-dark cycle were less prevalent at high latitudes and absent in 18 species. Our results indicate that even under similar environmental conditions and despite 24-h environmental cues, social synchronization can generate far more diverse behavioural rhythms than expected from studies of individuals in captivity. The risk of predation, not the risk of starvation, may be a key factor underlying the diversity in these rhythms.</p

Long-distance migratory shorebirds travel faster towards their breeding grounds, but fly faster post-breeding

Long-distance migrants are assumed to be more time-limited during the pre-breeding season compared to the post-breeding season. Although breeding-related time constraints may be absent post-breeding, additional factors such as predation risk could lead to time constraints that were previously underestimated. By using an automated radio telemetry system, we compared pre- and post-breeding movements of long-distance migrant shorebirds on a continent-wide scale. From 2014 to 2016, we deployed radio transmitters on 1,937 individuals of 4 shorebird species at 13 sites distributed across North America. Following theoretical predictions, all species migrated faster during the pre-breeding season, compared to the post-breeding season. These differences in migration speed between seasons were attributable primarily to longer stopover durations in the post-breeding season. In contrast, and counter to our expectations, all species had higher airspeeds during the post-breeding season, even after accounting for seasonal differences in wind. Arriving at the breeding grounds in good body condition is beneficial for survival and reproductive success and this energetic constraint might explain why airspeeds are not maximised in the pre-breeding season. We show that the higher airspeeds in the post-breeding season precede a wave of avian predators, which could suggest that migrant shorebirds show predation-minimizing behaviour during the post-breeding season. Our results reaffirm the important role of time constraints during northward migration and suggest that both energy and predation-risk constrain migratory behaviour during the post-breeding season

Unexpected diversity in socially synchronized rhythms of shorebirds

The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment1, 2, 3, 4. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions1, 5, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates, competitors, prey and predators6, 7, 8, 9, 10. Individuals can temporally segregate their daily activities (for example, prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (for example, group foraging, communal defence, pairs reproducing or caring for offspring)6, 7, 8, 9, 11. The behavioural rhythms that emerge from such social synchronization and the underlying evolutionary and ecological drivers that shape them remain poorly understood5, 6, 7, 9. Here we investigate these rhythms in the context of biparental care, a particularly sensitive phase of social synchronization12 where pair members potentially compromise their individual rhythms. Using data from 729 nests of 91 populations of 32 biparentally incubating shorebird species, where parents synchronize to achieve continuous coverage of developing eggs, we report remarkable within- and between-species diversity in incubation rhythms. Between species, the median length of one parent’s incubation bout varied from 1–19 h, whereas period length—the time in which a parent’s probability to incubate cycles once between its highest and lowest value—varied from 6–43 h. The length of incubation bouts was unrelated to variables reflecting energetic demands, but species relying on crypsis (the ability to avoid detection by other animals) had longer incubation bouts than those that are readily visible or who actively protect their nest against predators. Rhythms entrainable to the 24-h light–dark cycle were less prevalent at high latitudes and absent in 18 species. Our results indicate that even under similar environmental conditions and despite 24-h environmental cues, social synchronization can generate far more diverse behavioural rhythms than expected from studies of individuals in captivity5, 6, 7, 9. The risk of predation, not the risk of starvation, may be a key factor underlying the diversity in these rhythms

Advances in treating metastatic bone cancer: Summary statement for the First Cambridge Conference

The First Cambridge Conference on Advances in Treating Metastatic Bone Cancer, a symposium held in Cambridge, Massachusetts, October 28 to 29, 2005, was convened to discuss recent advances and research related to the natural history of bone metastases and skeletal complications, bone cancer biology, treatment of myeloma and other solid tumors, and treatment-induced bone loss. The conference format combined brief presentations with extended periods of discussion. The conclusions reached during the 2-day meeting are summarized in this article and presented in more detail in the individual articles and accompanying discussion sessions that comprise the conference proceedings.SCOPUS: cp.jinfo:eu-repo/semantics/publishe

Composition, Similarity, and the Measurement of Economic Homogeneity

The concept of economic homogeneity in regional science is based on two very different notions: composition and similarity. In the case of the states of the US, measures of homogeneity based on these different notions are "negatively" correlated with each other, suggesting that the results of studies that use measures of economic homogeneity are likely to be sensitive to the conceptual basis of the specific measure. In order to overcome this problem, a portfolio-theoretic measure of economic homogeneity with some attractive properties is presented. It is naturally decomposable into two components reflecting each of these notions and easy to construct using widely available data. Using this measure, patterns of homogeneity for the states of the US are illustrated and discussed, and hypotheses about the relationship between homogeneity and economic instability are tested. Copyright Blackwell Publishers, 2005

Unexpected diversity in socially synchronized rhythms of shorebirds

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Supporting Information for 'Unexpected diversity in socially synchronized rhythms of shorebirds'

Comparative stud

Supplementary Data 3 - Study sites: location, population wing length, monitoring method, tide

------------------------------------------------------------------------------------------------------ Description of the dataset "Supplementary Data 3 - Study sites.csv" -------------------------------------------------------------------------------------------------------- The dataset - is used in the paper "Unexpected diversity in socially synchronized rhythms of shorebirds" Nature 2016 by M. Bulla et al - contains estimates of mean female and male wing length for each population of biparental shorebirds from a specific study site, plus the locations of the study site, whether the locations had tide, and whether the tide was used by the population for foraging, and how the incubation was monitored. -------------------------------------------------------------------------------------------------------- Questions can be directed to: Martin Bulla ([email protected]) -------------------------------------------------------------------------------------------------------- Values are separated by comma. -------------------------------------------------------------------------------------------------------- 1. scinam : scientific name of the species 2. sp : four letter abbreviation of the species's English name 3. study_site : name of the study site 4. site_abbreviation : four letter abbreviation of the study site 5. type : was the study site at the breeding ground (breeding) or not (wintering) 6. lat : latitude of the study site (decimal) 7. lon : longitude of the study site (decimal) 8. tidal_habitat : is the study site at primarily tidal habitat (y=yes, n=no) 9. tidal_used : if the study site is at primarily tidal habitat, do the birds use it for foraging (y=yes, n=no) 10. incubation_monitoring : method used to monitor incubation (for details see the paper's Extended Data Table 4) 11. sexing_method : identifies the method used to sex individuals to estimate the mean female and male wing length 12. pop_wing_f : mean female wing length for the population 13. f_wing_N : sample size used for the female mean estimate 14. pop_wing_m : mean male wing length for the population 15. m_wing_N : sample size used for the male mean estimate 16. data_source : is the mean wing estimate based on the primary data ("our primary data") or literature (citation)) -------------------------------------------------------------------------------------------------------- WHEN USING THIS DATA, PLEASE CITE: Bulla et al (2016). Supplementary Data 3 - Study sites: location, population wing length, monitoring method, tide. figshare. https://doi.org/10.6084/m9.figshare.1536260. Retrieved ADD DATETIME. -------------------------------------------------------------------------------------------------------