New Publication on Plover survival in Mallorca

Garcia, P. J. and Tavecchia, G., 2018 Apparent survival and long-term population growth rate of the Kentish Plover Charadrius alexandrinus in Mallorca, Balearic Archipelago, Spain. Ardeola 65. 2-2. doi: http://dx.doi.org/10.13157/arla.65.1.2018.sc2

This was a collaboration between the GEDA and the GOB aiming to estimate the survival probability of Kentish Plovers in Mallroca using data from 1977. The main question was whether there was a trend in survival probability in the last twenty years.

https://commons.wikimedia.org/wiki/File:Charadrius_alexandrinus_0711.jpg

Abstract: During the last few decades, many breeding waders have been declining worldwide, probably due to the reduction of suitable coastal habitats. Diagnosis of population parameters has become increasingly important for the conservation of waders.
 We used capture-recapture information of 214 adult Kentish Plovers Charadrius alexandrinus, marked between 1977 and 2015 at two breeding areas in Mallorca, Spain, to assess any possible temporal trend in the survival probability. Mean adult survival probability was 0.756 ± 0.05 with no differences between the two areas. The sparseness of the data did not permit robust estimates of yearly survival. However, models with a temporal trend in survival probability were not retained. An age-structured population model including demographic stochasticity suggested a stable population (l = 1.024 ± 0.09). Perturbation analyses indicated that a 10% increase in mean breeding success (from 0.44 to 0.63), by reducing habitat loss or nest predation, would be sufficient to obtain positive population trajectories. 

New Publication on immune response in seabirds

Garnier, R., Ramos, R. Sanz-Aguilar, A., Poisbleau, M., Weimerskirch, H., Burthe, A., Tornos, J. and Boulinier, T., 2017. Interpreting ELISA analyses from wild animal samples: Somerecurrent issues and solutions Funcitonal Ecology, 31, 2255–2262 .DOI: 10.1111/1365-2435.12942

Abstract
1.Many studies in disease and ecological immunology rely on the use of assays that quantify the amount of specific antibodies (immunoglobulin) in samples. Enzymelinked immunosorbent assays (ELISAs) are increasingly used in ecology due to their availability for a broad array of antigens and the limited amount of sampling material they require. Two recurrent methodological issues are nevertheless faced by researchers: (1) the limited availability of immunological assays and reagents developed for non-model species, and (2) the statistical determination of the cut-off threshold used to distinguish individual samples that are likely to have or not to have antibodies against a specific antigen.

Photo: Victor París

2. Here, we outline two solutions to deal with these issues. First, we show that implementing two assays with differing detection methods can help validate the use of reagents, such as antibodies, in species different from their intended target. We illustrate this by comparing the quantification of  specific vaccinal antibodies against Newcastle disease virus (NDV) using two ELISA approaches in four seabird species (Cory’s shearwater, European shag, European storm petrel and Southern rockhopper penguin).
3. Second, we provide a simple way to determine from the distribution of ELISA values whether the assayed samples are likely to be made of a single group of individuals (likely negative) or of two groups of individuals (negative and positive). We illustrate the use of this approach with two independent datasets: NDV antibody levels following vaccination and anti-Borrelia antibody levels following natural exposure.
4. The practical implementation of these methodological approaches could provide a way to efficiently apply ELISAs and other immune-based assays to address questions in the growing fields of ecological immunology and disease ecology.