This book is published within the context of LIFE-Nature Project “Conservation of the aquatic warbler in the Nava-Campos SPA,” for which the European Com- mission provided 75% cofinancing, the Regional Executive of Castile-Leon was the beneficiary, and the Fundación Global Nature and town council of Fuentes de Nava were partners. Web proyect: www.carriceríncejudo.org Recommended bibliographic citation: Complete work: Jubete, F; M. Torres, E. Gómez, S. Cirujano and P. Zuazua. (eds.) 2006. The aquatic warbler: manual for managing helophytic vegetation and monitoring populations. Fundación Global Nature. 144 pp. Chapters: González-Villalba, C.; S. Cirujano and M. Sánchez-Rodríguez. 2006. ”La Nava wetland” in Jubete, F; M. Torres, E. Gómez, S. Cirujano and P. Zuazua (eds). The aquatic warbler: manual for managing helophytic vegetation and monitoring populations. Fundación Global Nature. 144 pp. Legal Deposit: P-248/2006 Graphic design and layout: Gráfico Gabinete de Comunicación Printed by: Graficolor Translated by: Barbara Thomas Total or partial reproduction of this work by any procedure, including photocopies and electromagnetic processing, as well as the distribution of rented copies, is prohibited strictly unless authorized by the Fundación Global Nature, and subject to the sanctions established by law. © Fundación Global Nature, 2006 The aquatic warbler Manual for managing helophytic vegetation and monitoring populations Introducción The aquatic warbler Manual for managing helophytic vegetation and monitoring populations F. Jubete, M. Torres, E. Gómez, S. Cirujano and P. Zuazua IntroducciónTABLE OF CONTENTS Preface 8 Introduction 10 LIFE-Nature Projects 12 LIFE-Nature Project “Conservation of the aquatic warbler in the Nava-Campos SPA” 13 First part La Laguna de la Nava 1.1. Location. Endorheic catchment area of La Nava wetlands 20 1.2. History 22 1.3. Recovery project 25 1.4. Description of the new wetland 30 1.4.1. Characterization of the water 36 1.4.2. Botanical characterization 38 1.4.3. Invertebrate fauna 44 1.4.4. Vertebrate fauna 46 Second part Experience with managing helophytic vegetation in La Nava wetland 2.1. Objectives of vegetation management 56 2.2. Description of methods 2.2.1. Mechanical removal 60 2.2.2. Grazing 62 2.2.3. Controlled burning 69 2.2.4. Mowing 71 Third part The aquatic warbler 3.1. The aquatic warbler 3.1.1. Description of the species 76 3.1.2. General biology 78 3.1.3. Migration and wintering-over areas 80 3.1.4. Conservation status 84 3.2. The aquatic warbler in Spain 86 3.3. The aquatic warbler in La Nava 88 66 The aquatic warbler Fourth part Results of the settling study of the aquatic warbler in La Nava 4.1. Results of transect analysis 92 4.2. Results of radio-tracking 96 4.3. Results of banding campaigns 100 Fifth part Conclusions 5.1. Comparative effectiveness of management methods used to control vegetation in La Nava wetland 116 5.2. Search and monitoring protocol of the aquatic warbler during migratory passage 5.2.1. Choice of habitat-based areas 126 5.2.2. Phenology of the species search 128 5.2.3. Sampling methods 130 Bibliography 136 El carricerín cejudo 7 Preface Carlos Fernández Carriedo Environmental Advisor of the Regional Executive of Castilla y León he conservation of natural spaces territory, and are part of the Natura 2000 and protected species is one of Network in Europe. Tthe mainstays of the policy of the One of the spaces defined by these legal Regional Office of the Environment of the figures of autonomic and Community Regional Executive of Castile-Leon. conservation is the “North La Nava- Campos SPA.” This natural space has In our region, the approval of Law 8/91 an area of 54,935.88 hectares, of which of 10 May on Natural Spaces marked somewhat more than 300 hectares the beginning of a new stage in the form La Nava wetland, a pond that was protection of natural areas. This stage recovered in 1990. La Nava is listed has been developed with the current among the Ramsar Convention wetlands declaration of 20 natural spaces with due to its international importance. The 539,197 hectares of extension and the lands that until recently were grazing proposed declaration of another 26 lands of the village of Fuentes de Nava natural spaces. have recovered their natural value and now offer refuge to thousands of Application of Directive 79/409/EEC water birds. One of the more than 220 on wild bird conservation established species of birds detected in La Nava that each member country of the is the aquatic warbler (Acrocephalus European Union and all the countries paludicola), a small bird whose that eventually join the EU would create conservation value has not passed a network of spaces in which wild birds unnoticed by the Regional Office of the would be widely represented. As a Environment. result, the European Union designated in Castile-Leon a total of 70 areas The aquatic warbler is a high-priority as Special Protection Areas (SPA), species for conservation in the European which occupy an area of 1,997,970.62 Union. La Nava has been shown to be hectares, 21.20% of the regional the most important point of passage for 8 this species in Spain, as a habitat that warbler in other Spanish wetlands, thus has the very specific characteristics contributing to the conservation of this required by the aquatic warbler. It was small, but not unimportant species, the precisely the combination of the priority aquatic warbler. to preserve an endangered species with the need to conserve and manage the habitat of a natural space that stimulated the Regional Office of the Environment to present a LIFE-Nature project to the European Union, a project that was approved in 2002 with a budget of 1,217,240 euros. This LIFE project has made it possible to implement numerous habitat improvement activities in La Nava, public use works, and interesting studies of the species that now have a practical application. Among the activities of this LIFE project was the publication of this manual, which shares the knowledge gained with different vegetation management methods developed in these four years, as well as study and population localization techniques. We of the Regional Office of the Environment trust that this information will be of interest to managers and students of the aquatic 9 IntroducciónIntroduction Fernando Jubete Area Director of the Fundación Global Nature in Palencia n recent years there have been conservation status, are considered visible and important advances in the “common” species, such as the house Iconservation of many endangered bird sparrow, skylark, starling or linnet. species. These projects have targeted mainly species that can be considered One of the avian species in this situation “star” species, such as the imperial eagle, is the aquatic warbler (Acrocephalus Bonelli’s eagle, griffon vulture, black paludicola), a bird weighing barely twelve vulture, black stork, great bustard and grams, with discrete plumage and habits, others. The results have been satisfactory which occupies a very specific habitat in most cases, with populations such as throughout its biological cycle: low-lying, the ospreys of Scotland that have grown flooded formations of marsh grass. Not from 2 pairs in 1967 to more than 190 long ago, this warbler was a reproducer pairs in 2005. found in almost every European country, but in less than a century its populations The case is very different with less have diminished considerably and spectacular species in terms of size or 90% of its population in the world now behavior or, simply, species that are is concentrated in a few wetlands in less attractive because it is difficult just three countries of Eastern Europe: to study them. Consequently, British Belarus, Ukraine and Poland. conservationists have been warning us for several years that we are running These are the circumstances that the risk of dedicating almost all our have caused the aquatic warbler to conservation efforts on “star” species be considered a “flag species,” a and overlooking other species that also species whose conservation implies are threatened but do not attract our the protection of entire ecosystems and protection efforts because of their small regions. These species have acquired size. It is paradoxical, but a large part of the significance of being living symbols the species of birds that are currently on of nature conservation, able to inspire the Red List prepared by the British Trust almost automatically feelings of solidarity for Ornithology, indicating an unfavorable among all people. The conservation of 1010 the aquatic warbler involves much more where it is not yet known to be present. than protecting specific zones such as This manual offers an organized nesting areas. The aquatic warbler stays description of how habitat management in nesting areas only three months out of and population monitoring were carried the year, so it is necessary to preserve its out within the context of the LIFE project. autumn and spring migration areas and The methods used and results are wintering-over areas to ensure effective described and evaluated from the vantage conservation. points of the cost and effectiveness of each measure and potential problems. This These are the principles that have practical manual is dedicated especially to inspired the LIFE-Nature project managers of natural spaces and to those “Conservation of the aquatic warbler in involved in the conservation and study of the Nava-Campos SPA.” The actions the aquatic warbler or its habitat. of this project are designed not only to conserve and recover part of the habitat that the species uses in La Nava during the scant time that its autumn migration lasts, but goes still farther to include habitat management measures that can be extrapolated to or applied in other wetlands similar to La Nava.