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Adan Abajo

Understanding the decline of the Cantabrian Capercaille (Tetrao urogallus cantabricus)

Adan is PhD Student of Moncho Obeso at the Ecology Unit at the University of Oviedo, Spain. He stayed several times in Leipzig to develop a spatially-explicit and individual-based population model for the Cantabrian Capercaille.

PhD project

Adán uses in his PhD project a multi-scale approach to (1) obtain a better understanding of habitat use and the extinction dynamics of the Cantabrian Capercaillie (Tetrao urogallus cantabricus), and (2) for assessing viability of the highly endangered metapopulation. The Cantabrian Mountains (in the NW of Spain) have a long history of human use and, consequently, the forests the capercaillie inhabits are largely fragmented. The Cantabrian Capercaillie was considered endangered in the Red Data Book in 1979, going since then through a pronounced decline of more than 50% of the birds and 42% in lek occupancy (Storch, 2000). In spite of this situation, basic questions like habitat use and requirements at the level of home range, and quality of the habitat at the population level remain unknown.

Adáns project includes models for habitat selection, based on data from periodic fieldwork, as well as predictive statistical models for construction of maps of habitat quality maps for the entire metapopulation. Finally, the habitat maps will be the input for a spatially-explicit and individual-based dispersal model and a population model. The  results of Adáns project will improve the understanding of the capercaillie population responses to changes in landscape structure and other aspects of their conservation biology. Further, the project will also enable us to develop objective methods for choosing between management options for capercaillie conservation.

Project in Leipzig

The objective in Leipzig is the development of a spatially explicit and individual-based simulation model for capercaillie. The model is arranged around the vital cycle processes from an individual perspective. The model takes into account both environmental and demographic stochasticity, as they usually play a main role in the decline and extinction of small and isolated populations. To determine factors and processes in which management actions must focus, Adán investigates the influence of the different demographic parameters on the extinction probability. In addition, he will analyze the viability under different scenarios of management derived from plausible improvements in habitat quality and in the demographic parameters.

A recurring problem in developing population models is estimating model parameters and assessing the adequacy of model structure. Often data for direct estimation of model parameters are few, especially for rare species, and this can lead to high parameter uncertainty. In a similar way as in statistical models higher level patterns are employed, we apply a pattern-oriented approach, making use of patterns like species distributions, to estimate model parameters in our simulation models (Wiegand et al. 2003, 2004). In this way, inherent uncertainty in a model can be reduced, allowing us a greater confidence in model predictions.

    Isa y Adan disfrutando codillo en Leipzig.