Showing posts with label capture-mark-recapture. Show all posts
Showing posts with label capture-mark-recapture. Show all posts

Friday, 13 December 2024

New Publication on Shearwaters!

Genovart, M., Ramos, R., Igual, J.M., Sanz-Aguilar, A., Tavecchia, G., Rotger, A., Militão, T., Vicente-Sastre, D., Garcia-Urdangarin, B., Pradel, R., González-Solís, J. and Oro, D. (2024), Individual Choices of Wintering Areas Drive Adult Survival Heterogeneity in a Long-Lived Seabird. Ecol Evol, 14: e70675. https://doi.org/10.1002/ece3.70675

In a shell:Wintering area preferences and environmental variability drive survival heterogeneity in long-distance migratory seabirds.

 Abstract:Seasonal migration has evolved as an adaptation for exploiting peaks of resource abundance and avoiding unfavourable climatic conditions. Differential migratory strategies and choices of wintering areas by long-distance migratory species may impose varying selective pressures and mortality risks with fitness consequences. Recently developed tracking technologies allow wintering movements of migratory species to be studied. However, these technologies typically involve a limited number of tracked individuals, which gives low statistical power for any robust estimate of survival probabilities. Additionally, when utilising geolocators, data become accessible only upon individual recapture, presenting a potential source of bias. We used multievent modelling to include information of 147 identified wintering tracks in the analysis of 1104 long-term individual capture histories (2000–2022) of migratory seabird Calonectris diomedea and then test if individual preferences for wintering areas may drive heterogeneity in adult survival. 

Photo: P. Arcos

We also examined individual fidelity to wintering areas and tested if climatic and oceanographic conditions, as represented by the wNAO and SOI climatic indices, influenced survival and fidelity. The probability of fidelity to a wintering area was ca. 0.79. Annual changes between areas were influenced by environmental variability driven by the wNAO. Survival probability was influenced by the SOI and differed between wintering areas; these differences coupled with high wintering site fidelity, generated individual heterogeneity in adult survival. Our study reveals that, over the last two decades, some individuals wintered in less suitable areas, with nonnegligible consequences on adult survival, the parameter to which the population growth rate is most sensitive in long-lived species. Winter oceanographic conditions such as stormy weather or the proximity to upwellings probably play a relevant role in driving survival heterogeneity. Further research is needed to enhance our understanding of how the interlinked effects of climate, local selective pressures and individual condition shape population dynamics in migratory species.

 

Thursday, 12 September 2024

Subscriptions to CMR workshop open!

Subscription to the upcoming workshop now open.
 
INTRODUCTORY COURSE: 25 - 29 Nov. 2024, Mallorca, Spain  
 (places: 20, price 390Є)
 
This introductory course aims to introduce students, researchers and environmental managers to the theory and practical aspects of the analysis of capture-mark-recapture and –recovery data to estimate survival, recruitment and dispersal probabilities. The course is based on theoretical classes as well as practical sessions with real and simulated data. The format of the course will be a combination of lectures and computer lab exercises with programs MARK, U-CARE and R (optional). No previous knowledge of these programs is needed.   
To register : http://fueib.org/curs/capture   (click on: "MATRICULA-t'hi")
Ask more information at: g.tavecchia-at-uib.es

Monday, 4 December 2023

The 2023 Workshop on CMR ended!

The 2023 Workshop on the Introduction to capture-mark-recapture analyses ended last Friday. It has been a busy and exciting week. We have learnt about bees, marmots, sharks, choughs, rays, vultures...and many other species and biological systems. Thanks to all for coming.

Tuesday, 4 July 2023

Ten years of Storm Petrel monitoring in Ibiza!

A. Sanz Aguilar and A. Rotger illustrated 10 years of monitoring of the Storm Petrel colony in Ibiza. A nice example of a successful collaboration between the GEDA, the Sant Josep city council and the Natural Park of  "Es Vedrá, es Vedranell i els Illots de Ponent".

Friday, 25 November 2022

CMR Workshop ended!

The 2022 Workshop on capture-mark-recapture and- recovery data applied to conservation of animal populations ended today! It has been an interesting and stimulating workshop. This year we had datasets on vultures, trouts, dolphins, sharks, gulls ... We always learn new systems, new challenges, new studies and more important new persons. 

Thanks to all for coming!


 

Wednesday, 28 September 2022

New Publication on Red kite and early life conditions!

Sergio, F., Tavecchia, G., Blas, J., Taferna, A., Hiraldo, F., Korpimaki, E., and Beissinger, S. R. 2022. Hardship at birth alters the impact of climate change on a long-lived predator. Nature Communication 13, 5517 https://doi.org/10.1038/s41467-022-33011-7

Summary:
Photo: es.wikipedia.org
Climate change is increasing the frequency of extreme events, such as droughts or hurricanes, with substantial impacts on human and wildlife communities. Extreme events can affect individuals through two pathways: by altering the fitness of adults encountering a current extreme, and by affecting the development of individuals born during a natal extreme, a largely overlooked process. Here, we show that the impact of natal drought on an avian predator overrode the effect of current drought for decades, so that individuals born during drought were disadvantaged throughout life. Incorporation of natal effects caused a 40% decline in forecasted population size and a 21% shortening of time to extinction. These results imply that climate change may erode populations more quickly and severely than currently appreciated, suggesting the urgency to incorporate “penalties” for natal legacies in the analytical toolkit of impact forecasts. Similar double impacts may apply to other drivers of global change.

 

Thursday, 2 December 2021

Capture-recapture with state uncertainty!

The workshop on modelling encounter histories with uncertainity ended yesterday. Dr. R Pradel and Dr R Choquet had explained how to incorporate uncertainty when modelling capture-mark-recapture data. It has been an interesting workshop with particpants from Spain, UK, Italy, Romania, Greece, Japan, Portugal and France among others.  Amazing datasets and interesting questions.

Thanks to all!

Saturday, 27 November 2021

The introductory course on Capture-Mark-Recapture analyses ended!

 The introductory course on Capture-Mark-Recapture analyses ended this friday! It has been nice to recover a pre-COVID agenda and meet many colleagues. R. Pradel, A Sanz and A Rotger helped with the teaching and the practical exercises. We learned about mantas, little auks, newts, gulls, rodents, shearwater, nighjars and other animals. Thank you to all!

Friday, 24 September 2021

Workshop on Capture-Mark-Recapture analysis 2021!

We open the subscriptions to the workshop on Capture-Mark-Recapture analyses.

Photo: J Atero
Two CMR courses in a row:
1 - Introductory course (23-26 November, 15 places)
2 - Multievent course (29 November - 1 December, 15 places).
Pick up your level or join both !!! 

More information here

INTRODUCTORY COURSE: https://animaldemography.blogspot.com/p ... ourse.html
This introductory course aims to introduce students, researchers and environmental managers to the theory and practical aspects of the analysis of capture-mark-recapture and –recovery data to estimate survival, recruitment and dispersal probabilities. The course is based on theoretical classes as well as practical sessions with real and simulated data. The format of the course will be a combination of lectures and computer lab exercises with programs MARK, U-CARE and R (optional). No previous knowledge of these programs is needed.

MULTIEVENT : https://animaldemography.blogspot.com/p ... ourse.html
This course aims to provide participants with a solid background in the theory and practices of capture-recapture analysis with a specific emphasis on multievent data and models. Multievent models are a natural generalization of the multisite models. Contrary to multisite models, the uncertainty in sate assessment such as breeder, diseased, causes of death or capture heterogeneity can be incorporated into the analysis. They can be used to address fine questions on epidemiology, conservation and hidden biological processes. The format of the workshop will be a combination of lectures and computer lab exercises with the programs E-SURGE (or R2ESURGE) and U-CARE. No previous knowledge is needed although experience with CMR data and R-programming will be useful.



Saturday, 27 March 2021

New Publication: Don't mess with encounter probabilities!

Tavecchia, G., Gimenez, O., Choqut, R., Oro, D., Tenan, S. and Sanz-Aguilar, A. 2021.The trap of hidden processes: Why ‘quick & dirty’ methods to estimate mortality are not always good. A comment to De Pascalis et al. (2020) Biological Conservation, 109057, doi: 10.1016/j.biocon.2021.109057

CMRR models can be difficult to build and many conservation biologists are tempted to shortcut them for simpler, ‘quick & dirty’, methods, trading difficulty with the lack of precision. In some particular cases, it is a winning trade, however, in most cases, it is a very hazardous practice. The proportion of animal seen alive vs those seen dead depends, by definition, on the detection probability, p, that an animal alive is detected and on the probability, λ, that a dead animal is found or retrieved (c) and the tag reported (r), with λ = c*r. Not taking thi into acocunt would lead to biased estimates. Explore scenarios through an R shiny application provided at https://github.com/oliviergimenez/bias_recovery.


Thursday, 17 September 2020

Lizard campaign just started!

 The first island has been sampled. Likely we had good weather and animals were collaborating. Looking forward to calculate an estimate of population size from the CMR data collected.Only five to go!



Tuesday, 12 May 2020

New Publication on Lapped-faced vulture !

Santangeli A., Pakanen, V-M, Bridgeford, P., Boorman, M., Kolberg, H., and Sanz-Aguilar, A. 2020. The relative contribution of camera trap technology and citizen science for estimating survival of an endangered African vulture. Biological Conservation, vol, 246 https://doi.org/10.1016/j.biocon.2020.108593

Photo:wikipedia.org
Abstract: Technological advances such as camera traps, and citizen science, coupled with advanced quantitative approaches, can help fill existing knowledge gaps and aid effective conservation. We combine citizen and camera trap observations to estimate survival of the Endangered lappet-faced vulture, assess the relative contribution of data from camera traps and citizens, as well as impact of loss of individual marks (wing tags), on survival estimates.  We used data from 762 lappet-faced vultures wing tagged as nestlings during 2006-2017 in western Namibia. Observations of wing tagged individuals were provided by citizens or via camera traps.
We formulated a multievent capture-mark-recapture model to estimate survival while accounting for probabilities of resighting by citizens and/or camera traps, recovery of dead individuals, and loss of the wing tag.  Survival was relatively high for juveniles (0.79), and increased with age to 0.95. Citizen observations of live and dead birds were low in number. However, when combined with camera trap resightings of live individuals, citizen observations increased the precision of survival estimates of birds older than one year compared to using data from either sources separately. Wing tag loss was high after 5–6 years of tag age. If neglected, tag loss can result in severe underestimation of survival of the older age classes. Overall, we show that filling ecological knowledge gaps is possible through the efficient use of data provided by different sources, and by applying state-of the art approaches that minimise potential biases, such as those due to tag loss.

GEDA at the XXII CIO Conference!

S Bolumar and A Santangeli are participating to the XXII Italian Ornithology Conference in Lecce