1,720,995 research outputs found
Conspecific and not performance-based attraction on immigrants drives colony growth in a waterbird
No full textLife span, growth, senescence and island syndrome: Accounting for imperfect detection and continuous growth
No full textSmall vertebrates on islands are expected to attain a larger body size, and a greater survival than their mainland counterparts. Comparative studies have questioned whether lizards exhibit this set of adaptations, referred to as the 'island syndrome'. We collected data on 730 individuals the endemic Lilford's lizard Podarcis lilfordi throughout a 10-year period on a small island of the Balearic archipelago (Spain). We coupled a growth function with a capture-mark-recapture model to simultaneously estimate size- and sex-dependent growth rate and survival. To put our results into a wider context, we conducted a systematic review of growth, life span and age at maturity in different Podarcis species comparing insular and mainland populations. We found a low average growth coefficient (0.56 and 0.41 year-1 for males and females to reach an asymptotic size of 72.3 and 65.6 mm respectively), a high annual survival probability of 0.81 and 0.79 in males and females, and a large variability between individuals in growth parameters. Survival probability decreased with body size in both sexes, indicating a senescence pattern typical of long-lived species or in populations with a low extrinsic mortality. Assuming a constant survival after sexual maturity, at about 2 years old, the average life span was 6.18 years in males and 8.99 in females. The oldest animal was a male last captured at an estimated age of ≥13 years and still alive at the end of the study. Our results agree with the predictions of the 'island syndrome' for survival, life span and growth parameters. A comparative analysis of these values across 29 populations of 16 different species of Podarcis indicated that insular lizards grow slower and live longer than their mainland counterparts. However, our data differed from other island populations of the same species, suggesting that island-specific characteristics play an additional role to isolation. Within this study we developed an analytical approach to study the body size-dependent survival of small reptiles. We discuss its applicability to contrast hypotheses on senescence in different sexes of this species, and provide the code used to integrate the growth and capture-mark-recapture models.The research was partially funded by the Government of the Balearic Islands (project number: PRD2018/25).Peer reviewe
Living in the edge: demographic responses driven by density-dependence and pulsed resources in a hibernating mammal
No full textPopulations at the edge of a species' distribution often encounter more challenging environmental conditions than those at the core, requiring unique adaptations and strategies. However, the demographic processes driving these populations remain poorly understood. This study aims to understand these processes and the population stability of the hibernating edible dormouse under challenging environmental conditions in two Iberian edge populations: Montseny and Montnegre. Despite their geographic proximity, Montnegre is demographically isolated and faces a harsher environment characterized by a drier climate and forests with lower deciduous tree diversity, whereas Montseny remains connected to other populations. Using long-term capture–recapture data, we analyzed the effects of density-dependence and seed availability on population growth, survival, and recruitment of dormice. Results indicated that both populations experienced large fluctuations in population growth rate, with a slight mean decline. Survival fluctuated less and was higher in Montseny than in Montnegre, likely reflecting the harsher conditions of the latter. We found a negative relationship between population size and both growth rate and survival in both populations especially in Montnegre, suggesting significant density-dependent effects that varied with stochastic annual seed abundance. This was likely influenced by the pulsed annual acorn production in Montnegre. Contrarily, high asynchrony between beechnut and acorn abundance in Montseny dampened the pulsed dynamics of seed availability. Interestingly, demographic contribution to population growth was dominated by survival in Montseny and by recruitment in Montnegre. When comparing survival rates with Central European core populations, we found that survival decreased with increasing climatic aridity, but was unrelated to proximity to the core, underscoring the role of spatial heterogeneity in habitat suitability, independent of range position. Our findings emphasize the complex interplay between ecological processes and evolutionary mechanisms at the edge of a species' range, highlighting the critical role of local adaptations and resource availability in shaping population dynamics.The study has been funded since its beginning by Diputació de Barcelona (grant no. 2023/0005732).Peer reviewe
Immigration as the main driver of population dynamics in a cryptic cetacean
Full text linkDescription of the data files:
'CH_Female_Multi_2004_6events_v3.txt': Capture-recapture multievent data for females;
'CH_Female_Multi_2004_z_init_Nimble.txt': Initial values for latent z states and state at first encounter for females;
'CH_headed_Male_Multi_2004.txt': Capture-recapture multievent data for males;
'CH_headed_Male_Multi_2004_z_init.txt': Initial values for latent z states and state at first encounter for males;
'count_data.RData': Population count data;
Model code: 'IPM_10.txt'
All files are called in the online supplementary code for running the integrated population model.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Data and code from: "Essential tools but overlooked bias: artificial intelligence and citizen science classification affect camera trap data"
No full textThis snapshot contains the exact code and scripted workflows used to produce all analyses in Santoro et al. 2025, Methods in Ecology and Evolution.R scripts in vignettes/; Raw and processed data summaries (no images); renv.lock file for package versionsPeer reviewe
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
