lnfluence of temperature on the wintering avifauna of a northern lberian peninsula coastal farm1and

The abundance of wintering passerines in a coastal farrnland was rneasured by rneans of line transects for eleven years. There were marked variations in the abundance of rnost species between Decernber and January. There was no apparent association of rneasured local temperatures with the abundance of any of the species. These data suggest that birds wintering in these coastal farmlands rnust be primarily affected by other environmental factors externa1 to the coastal farrnland. Variation in the abundance of sorne species seerns to be a consequence of the effect that severe winters have on resident and non-resident populations. However, the hypothesis that some of these species could be affected by land-use changes is not excluded. Key words: Weather, Wintering avifauna, Farmland, Northern Spain.The abundance of wintering passerines in a coastal farrnland was rneasured by rneans of line transects for eleven years. There were marked variations in the abundance of rnost species between Decernber and January. There was no apparent association of rneasured local temperatures with the abundance of any of the species. These data suggest that birds wintering in these coastal farmlands rnust be primarily affected by other environmental factors externa1 to the coastal farrnland. Variation in the abundance of sorne species seerns to be a consequence of the effect that severe winters have on resident and non-resident populations. However, the hypothesis that some of these species could be affected by land-use changes is not excluded. Key words: Weather, Wintering avifauna, Farmland, Northern Spain.The abundance of wintering passerines in a coastal farrnland was rneasured by rneans of line transects for eleven years. There were marked variations in the abundance of rnost species between Decernber and January. There was no apparent association of rneasured local temperatures with the abundance of any of the species. These data suggest that birds wintering in these coastal farmlands rnust be primarily affected by other environmental factors externa1 to the coastal farrnland. Variation in the abundance of sorne species seerns to be a consequence of the effect that severe winters have on resident and non-resident populations. However, the hypothesis that some of these species could be affected by land-use changes is not excluded. Key words: Weather, Wintering avifauna, Farmland, Northern Spain

Parada migratoria prenupcial de un águila pescadora (Pandion haliaetus) en el norte de España determinada por telemetría de satélite: implicaciones para la conservación

Actualmente, la mayor precisión de las localizaciones suministradas por la telemetría vía satélite permite llevar a cabo estudios más detallados sobre la migración, que pueden ser útiles para la conservación de las aves. En este trabajo describimos el comportamiento de una hembra adulta de águila pescadora seguida por telemetría vía satélite en la Reserva de la Biosfera de Urdaibai (N de España) para evaluar la adecuación de este área protegida a los requerimientos de la especie. Se utilizaron 145 localizaciones recibidas en 10 días de parada migratoria. Los dormideros utilizados estaban mayoritariamente rodeados de zonas con un nivel de protección alto o intermedio, separados más de 200 m de carreteras y edificios, y situados a menos de un km de la zona de alimentación. Durante las horas diurnas, la mayor parte de las localizaciones (76,5%) procedían de los bosques, con preferencia por los encinares, lo cual se sugiere que está relacionado con la tranquilidad que caracteriza a este tipo de bosques en el área de estudio. Asimismo, se sugiere que los estuarios del norte de España son un área importante para la alimentación de las águilas pescadoras en migración primaveral. Palabras clave: Comportamiento, Selección de hábitat, Rapaz migratoria, Espacio protegido, Idoneidad del área, Reserva de la Biosfera de Urdaibai.Improvements in the accuracy of satellite telemetry locations now allow detailed studies on territorial behaviour or use of habitat that can be used to enhance bird conservation. In this paper we describe the behaviour of a satellite–tracked adult female osprey (Pandion haliaetus) in the Urdaibai Biosphere Reserve (N Spain) to evaluate the suitability of this protected area for the species. The data set consisted of 10 complete days with a total of 145 exact fixes received. Night roosts were mainly surrounded by high or intermediate level protected land, separated from roads or buildings by more than 200 m and located less than one km away from the feeding area. During daylight hours, most fixes (76.5%) were located in wooded areas. We found that the bird selected holm oak woods and we suggest that this is related to low disturbance from human activity. We also suggest that northern Spanish estuaries are important as stopovers by migrating ospreys for feeding during migration. Key words: Behaviour, Habitat selection, Migratory raptor, Protected area, Site suitability, Urdaibai Biosphere ReserveActualmente, la mayor precisión de las localizaciones suministradas por la telemetría vía satélite permite llevar a cabo estudios más detallados sobre la migración, que pueden ser útiles para la conservación de las aves. En este trabajo describimos el comportamiento de una hembra adulta de águila pescadora seguida por telemetría vía satélite en la Reserva de la Biosfera de Urdaibai (N de España) para evaluar la adecuación de este área protegida a los requerimientos de la especie. Se utilizaron 145 localizaciones recibidas en 10 días de parada migratoria. Los dormideros utilizados estaban mayoritariamente rodeados de zonas con un nivel de protección alto o intermedio, separados más de 200 m de carreteras y edificios, y situados a menos de un km de la zona de alimentación. Durante las horas diurnas, la mayor parte de las localizaciones (76,5%) procedían de los bosques, con preferencia por los encinares, lo cual se sugiere que está relacionado con la tranquilidad que caracteriza a este tipo de bosques en el área de estudio. Asimismo, se sugiere que los estuarios del norte de España son un área importante para la alimentación de las águilas pescadoras en migración primaveral. Palabras clave: Comportamiento, Selección de hábitat, Rapaz migratoria, Espacio protegido, Idoneidad del área, Reserva de la Biosfera de Urdaibai

Simulazioak fisikaren irakaskuntzan

Proiektu honetan, fisikako problema ugari aztertu, simulatu eta garatu dira helburu pedagogiko batekin. Hizkuntza: euskara

Tracking data highlight the importance of human-induced mortality for large migratory birds at a flyway scale

Human-induced direct mortality affects huge numbers of birds each year, threatening hundreds of species worldwide. Tracking technologies can be an important tool to investigate temporal and spatial patterns of bird mortality as well as their drivers. We compiled 1704 mortality records from tracking studies across the African-Eurasian flyway for 45 species, including raptors, storks, and cranes, covering the period from 2003 to 2021. Our results show a higher frequency of human-induced causes of mortality than natural causes across taxonomic groups, geographical areas, and age classes. Moreover, we found that the frequency of human-induced mortality remained stable over the study period. From the human-induced mortality events with a known cause (n = 637), three main causes were identified: electrocution (40.5 %), illegal killing (21.7 %), and poisoning (16.3 %). Additionally, combined energy infrastructure-related mortality (i.e., electrocution, power line collision, and wind-farm collision) represented 49 % of all human-induced mortality events. Using a random forest model, the main predictors of human-induced mortality were found to be taxonomic group, geographic location (latitude and longitude), and human footprint index value at the location of mortality. Despite conservation efforts, human drivers of bird mortality in the African-Eurasian flyway do not appear to have declined over the last 15 years for the studied group of species. Results suggest that stronger conservation actions to address these threats across the flyway can reduce their impacts on species. In particular, projected future development of energy infrastructure is a representative example where application of planning, operation, and mitigation measures can enhance bird conservation

Tarabilla norteña – Saxicola rubetra (Linnaeus, 1758)

Aves - Orden Passeriformes - Familia Muscicapidae en la Enciclopedia Virtual de Vertebrados Españoles, http://www.vertebradosibericos.org/A comprehensive review of the natural history of the whinchat Saxicola rubetra in Spain.Peer reviewe

Garceta común – Egretta garzetta (Linnaeus, 1766)

Aves - Orden Pelecaniformes - Familia Ardeidae en la Enciclopedia Virtual de Vertrebrados Españoles, http://www.vertebradosibericos.org/.A comprehensive review of the natural history of the Little Egret (Egretta garzetta) in Spain.Peer reviewe

Comportament pesquer de l'Àguila Pescadora Pandion haliaetus en un estuari del nord de la península Ibèrica durant la migració de tardor

Es descriu el comportament de pesca de l’Àguila Pescadora Pandion haliaetus en un estuari del nord de península Ibérica. El temps mitjà emprat en cada acció pesquera va ser de 6,3 min i l’èxit de captura del 68,8%. Quan únicament es van considerar les accions protagonitzades per adults, l’èxit va augmentar fins el 92%. Tots els peixos capturats i identificats en aquest estudi pertanyien a la família Mugilidae. L’activitat pesquera de l’espècie no va estar associada a l’altura o a la direcció de la marea. No obstant això, l’èxit de pesca va ser major durant l’ascens mareal. Se suggereix que la rapidesa i l’elevat èxit de pesca registrat reflecteixen una gran disponibilitat de preses com a conseqüència del comportament dels mugílids i la seva abundància a l’estuari