Informe de actividades y resultados obtenidos en 2021., Este trabajo ha sido posible gracias a la financiación obtenida por varios proyectos: - Ayudas Ramón y Cajal a Ana Sanz Aguilar y Raül Ramos, financiadas por el Ministerio de Innovación y Universidades, la Agencia Estatal de Investigación y el Fondo Social Europeo (RYC-2017- 22796/ RYC-2017- 22055). Fundación Balearia nos facilitó los desplazamientos entre Baleares y la península., Peer reviewed

Survival is a key parameter in species' management and conservation. Most methods for estimating survival require time series data, large sample sizes and, overall, costly monitoring efforts. Inverse modeling approaches can be less data hungry, however they are underused in conservation sciences. Here we present an inverse modeling approach for estimating relative survival rates of long-lived species that is mathematically straightforward and evaluate its performance under constraints common in conservation studies related to small sample sizes. Specifically, we (i) estimated the relative survival rates in a Testudo graeca population based on one-year monitoring, (ii) assessed the impact of sample size on the accuracy, and (iii) tested alternative hypotheses on the impact of fire on the survival rates. We then compared the results of our approach with capture-recapture (CRC) estimates based on long-term monitoring. Our approach (153 individuals within a single year) yielded estimates of survival rates overlapping those of CRC estimates (11 years of data and 1009 individuals) for adults and subadults, but not for juveniles. Simulation experiments showed that our method provides robust estimates if sample size is above 100 individuals. The best models describing the impact of fire on survival identified by our approach predicts a decrease in survival especially in hatchlings and juvenile individuals, similar to CRC estimates. Our work proves that inverse modeling can decrease the cost for estimating demographic rates, especially for long-lived species and as such, its use should be encouraged in conservation and management sciences.

El estudio del movimiento de los individuos informa directamente sobre los tamaños de las áreas de campeo, las rutas migratorias o la selección de hábitat. Pero, además, la integración de datos de movimiento en modelos ecológicos permite además abordar mayores escalas. En este trabajo mostramos los resultados de nuestra línea de investigación utilizando STEPLAND, un modelo basado en el individuo de desarrollo propio. El modelo se parametrizó con datos de movimiento, demográficos y genéticos de tortugas terrestres (Testudo graeca) del SE de España. Llevamos a cabo diferentes experimentos de simulación con el fin de contestar a cuestiones sobre los efectos del cambio global en la conservación de la especie. A nivel de especie, identificamos aquellos rasgos evolutivos de las tortugas, como el almacenamiento de esperma por parte de las hembras, que evitan las extinciones en hábitats antropizados. A escala de paisaje, evaluamos el impacto del abandono agrícola y la intensificación en la dinámica poblacional de esta especie de vida larga. La intensificación afectó negativamente las tasas reproductivas, la densidad de población y la probabilidad de extinción de T. graeca, con respuestas de retardo de 20, 30 y 130 años respectivamente. Finalmente, en un contexto regional, pretendemos simular las primeras etapas de una expansión. Los primeros resultados sugieren patrones característicos de surfing genético, un proceso que afecta la expansión de especies de baja dispersión afectadas por deriva genética. Creemos que nuestra línea de investigación ejemplifica bien que el valor científico de los datos de movimiento excede el nivel de individuo.

Waterbirds are particularly affected by the high hunting pressure they face in many regions, which in some cases is compromising conservation actions for threatened species. The marbled teal Marmaronetta angustirostris is one of the most endangered waterbirds in Europe. In order to restore its population, several conservation actions have recently been undertaken, including a population reinforcement programme in Spain using captive-bred birds. With the aim of assessing the success of the reinforcement programme to establish a long-term self-sustaining population, we identified mortality causes of marbled teal, evaluated the survival of individual birds of the reinforcement programme and estimated the viability of the population under different management scenarios. We used data from wild and captive-bred individuals tracked by GPS since 2018 (n = 42) and from a mark–recapture programme initiated in 2015 (n = 297). We recovered 15 dead birds or transmitters: 20% died of natural causes, 60% of non-natural causes (including all anthropic causes) and 20% of unknown causes. Furthermore, the GPS tags of 24 birds unexpectedly stopped transmitting without any indication of malfunction, and for 66.7% of these disappeared birds, the cessation was suspected to be caused by illegal shooting. Survival during the hunting season was higher for males (31.3%) than for females (12.5%), and for the wild (50%) than for the captive-bred birds (9.4%), probably due to differences in migration patterns to North Africa. Population viability models revealed that maintaining the breeding population at the current mortality rates is only possible with a permanent release programme of captive-bred individuals, and that in order to establish a self-sustaining population, non-natural mortality would have to be reduced by at least 40%. We recommend management measures to reduce marbled teal mortality, such as limiting legal hunting to hours with clear visibility, prosecuting illegal shootings, controlling exotic predators and improving water management to reduce disease outbreaks. Some improvements can be implemented in captive-breeding programmes, such as earlier release times and incorporating anti-predator training.