Composición y calidad de la dieta del ciervo (Cervus elaphus L.) en el norte de la península ibérica

Plant composition and quality of the red deer (Cervus elaphus L.) diet in the northern Iberian peninsula The feeding pattern of red deer varies greatly among the different European populations. The aim of our study was to elucidate the plant composition and the quality of the red deer diet in the Pyrenees (Northern Iberian peninsula). Over a one-year period, the red deer fed mainly on browse, pines being the main food. However, unlike other populations on the Iberian peninsula, consumption of herbaceous plants was higher than browse in the spring-summer period. Nevertheless, the diet of Pyrenean red deer shared some features with the Mediterranean populations such as browsing on woody legumes. Fecal nitrogen content, as an index of diet quality, showed low annual values with a marked decrease in winter. The overall feeding pattern was similar to that of other Central European populations. The large size of the surveyed population probably affected its high level of browse consumption and poor quality diet

Composición vegetal y calidad de la dieta del ciervo (Cervus elaphus L. ) en el norte de la península Ibérica

The feeding pattern of red deer varies greatly among the different European populations. The aim of our study was to elucidate the plant composition and the quality of the red deer diet in the Pyrenees (Northern Iberian peninsula). Over a one–year period, the red deer fed mainly on browse, pines being the main food. However, unlike other populations on the Iberian peninsula, consumption of herbaceous plants was higher than browse in the spring–summer period. Nevertheless, the diet of Pyrenean red deer shared some features with the Mediterranean populations such as browsing on woody legumes. Fecal nitrogen content, as an index of diet quality, showed low annual values with a marked decrease in winter. The overall feeding pattern was similar to that of other Central European populations. The large size of the surveyed population probably affected its high level of browse consumption and poor quality diet.El patrón de alimentación del ciervo es muy variable entre las diferentes poblaciones europeas. El objetivo de nuestro estudio fue determinar la composición vegetal y la calidad de la dieta del ciervo en los Pirineos (norte de la península Ibérica). Durante un periodo de un año, el ciervo se alimentó principalmente de plantas leñosas, siendo los pinos su principal alimento. Sin embargo a diferencia de otras poblaciones de la península Ibérica, el consumo de plantas herbáceas fue superior al de leñosas en primavera y verano. No obstante, la dieta del ciervo del Pirineo comparte algunas características con la de las poblaciones mediterráneas, como el consumo de plantas leguminosas leñosas. El contenido en nitrógeno fecal, como índice de calidad de la dieta, presenta valores anuales bajos con una marcada disminución en invierno. El patrón de alimentación global fue similar al de otras poblaciones centroeuropeas. El gran tamaño de la población estudiada influye probablemente en el alto nivel de consumo de leñosas y la baja calidad de su dieta

State-space modelling of the drivers of movement behaviour in sympatric species

Understanding animal movement behaviour is key to furthering our knowledge on intra- and inter-specific competition, group cohesion, energy expenditure, habitat use, the spread of zoonotic diseases or species management. We used a radial basis function surface approximation subject to minimum description length constraint to uncover the state-space dynamical systems from time series data. This approximation allowed us to infer structure from a mathematical model of the movement behaviour of sheep and red deer, and the effect of density, thermal stress and vegetation type. Animal movement was recorded using GPS collars deployed in sheep and deer grazing a large experimental plot in winter and summer. Information on the thermal stress to which animals were exposed was estimated using the power consumption of mechanical heated models and meteorological records of a network of stations in the plot. Thermal stress was higher in deer than in sheep, with less differences between species in summer. Deer travelled more distance than sheep, and both species travelled more in summer than in winter; deer travel distance showed less seasonal differences than sheep. Animal movement was better predicted in deer than in sheep and in winter than in summer; both species showed a swarming behaviour in group cohesion, stronger in deer. At shorter separation distances swarming repulsion was stronger between species than within species. At longer separation distances inter-specific attraction was weaker than intra-specific; there was a positive density-dependent effect on swarming, and stronger in deer than in sheep. There was not clear evidence which species attracted or repelled the other; attraction between deer at long separation distances was stronger when the model accounted for thermal stress, but in general the dynamic movement behaviour was hardly affected by the thermal stress. Vegetation type affected intra-species interactions but had little effect on inter-species interactions. Our modelling approach is useful in interpreting animal interactions, in order to unravel complex cooperative or competitive behaviours, and to the best of our knowledge is the first modelling attempt to make predictions of multi-species animal movement under different habitat mosaics and abiotic environmental conditions

Sélection du régime alimentaire chez la Marmotte des Alpes (Marmota m. marmota L.) dans les Pyrénées

We studied the diet composition and selection of plants in the Alpine marmot Marmota m. marmota of two family groups in the Western Pyrenees from May to September. The food consumed was determined by faecal analysis, and the plant selection was determined comparing the plant composition in faeces and plant availability in the area surrounding the marmot burrows, which was measured by the point-intercept method. Most of the available plants belonged to a few families whose abundance did not change remarkably through the studied months, although the plants’ phenological stage changed considerably. The Alpine marmots primarily ate plants, consisting of a wide variety of leaves, flowers, and fruits of grasses and forbs, although the leaves of dicotyledonous herbs clearly dominated in the overall diet. Leguminosae, Compositae, Liliaceae, Plantaginaceae, and Umbelliferae were positively selected, and Labiatae and Rubiaceae were avoided. Flowers were actively chosen on the basis of relative abundance and phenology. The ingestion of animal prey (Arthropoda) was confirmed at the beginning of the active seasonNous avons étudié de mai à septembre dans les Pyrénées occidentales la composition du régime alimentaire et la sélection des plantes dans deux groupes familiaux de Marmotte des Alpes Marmota m. marmota. La nourriture consommée a été déterminée par analyse des fèces et la sélection des plantes en comparant la composition des fèces au cortège de plantes disponibles dans la zone entourant les terriers des marmottes. La plupart des plantes disponibles n'appartenaient qu'à quelques familles dont l'abondance ne changea pas de manière remarquable durant les mois d'étude contrairement aux stades phénologiques des plantes. Les marmottes ont surtout consommé des végétaux consistant en une grande variété de feuilles, de fleurs et de graines de graminées et autres herbes, les feuilles de dicotylédones dominant nettement dans le régime. Les Légumineuses, Composées, Liliacées, Plantaginacées et Ombellifères étaient positivement sélectionnées ; les Labiées et les Rubiacées étaient évitées. Les fleurs étaient activement choisies sur la base de leur abondance relative et de leur phénologie. L'ingestion de proies animales (Arthropodes) a été confirmée au début de la saison d'activité

Different effects of alpine woody plant expansion on domestic and wild ungulates

Changes in land-use and climate affect the distribution and diversity of plant and animal species at different spatiotemporal scales. The extent to which species-specific phenotypic plasticity and biotic interactions mediate organismal adaptation to changing environments, however, remains poorly understood. Woody plant expansion is threatening the extent of alpine grasslands worldwide, and evaluating and predicting its effects on herbivores is of crucial importance. Here, we explore the impact of shrubification on the feeding efficiency of Pyrenean chamois (Rupicapra p. pyrenaica), as well as on the three most abundant coexisting domestic ungulate species: cattle, sheep and horses. We use observational diet composition from May to October and model different scenarios of vegetation availability where shrubland and woodland proliferate at the expense of grassland. We then predicted if the four ungulate species could efficiently utilize their food landscapes with their current dietary specificities measuring their niche breath in each scenario. We observed that the wild counterpart, due to a higher trophic plasticity, is less disturbed by shrubification compared to livestock, which rely primarily on herbaceous plants and will be affected 3.6 times more. Our results suggest that mixed feeders, such as chamois, could benefit from fallow landscapes, and that mountain farmers are at a growing economic risk worldwide due to changing land-use practices and climate conditions

Influence of Snowmelt Timing on the Diet Quality of Pyrenean Rock Ptarmigan (Lagopus muta pyrenaica): Implications for Reproductive Success

The Pyrenean rock ptarmigan (Lagopus muta pyrenaica) is the southernmost subspecies of the species in Europe and is considered threatened as a consequence of changes in landscape, human pressure, climate change, and low genetic diversity. Previous studies have shown a relationship between the date of snowmelt and reproductive success in the Pyrenean ptarmigan. It is well established that birds laying early in the breeding season have higher reproductive success, but the specific mechanism for this relationship is debated. We present an explicative model of the relationship between snowmelt date and breeding success mediated by food quality for grouse in alpine environments. From microhistological analyses of 121 faecal samples collected during three years in the Canigou Massif (Eastern Pyrenees), and the assessment of the chemical composition of the main dietary components, we estimated the potential quality of individual diets. Potential dietary quality was correlated with free-urate faecal N, a proxy of the digestible protein content ingested by ptarmigan, and both were correlated with phenological stage of consumed plants, which in turn depends on snowmelt date. Our findings suggest that the average snowmelt date is subject to a strong interannual variability influencing laying date. In years of early snowmelt, hens benefit from a longer period of high quality food resources potentially leading to a higher breeding success. On the contrary, in years of late snowmelt, hens begin their breeding period in poorer nutrient condition because the peaks of protein content of their main food items are delayed with respect to laying date, hence reducing breeding performance. We discuss the possible mismatch between breeding and snowmelt timing

Pastos herbáceos y brezales de la montaña atlántica: estructura y valor nutritivo

Atlantic mountain pastures are composed by mosaics of semi-natural grasslands and heathlands. A knowledge of their structure and feeding value is useful to understand their livestock use and improve management of these communities. This study was carried out in the Gorbeia Natural Park in northern Spain. Pasture composition, sward height and nutritive value were measured over four grazing seasons (spring, summer, late summer and autumn) in three plant communities: grassland (GR), open heathland (OH) and dense heathland (DH). The grassland community had lower sward height and better nutritive value. In less favoured grazing periods, when sward height in GR becomes limiting livestock move to OH with higher pasture height and lower sward cover and nutritive value. Even both heathlands have similar height and quality, the selection of OH, and avoiding of the dense one, could be due to its higher sward cover, which could make it easier to look for feed. Moreover, considering the woody component the estimated nutritive value of DH does not cover the minimum required for livestock production.Los pastos de las zonas de montaña atlántica están compuestos por comunidades herbáceas en combinación con brezales. El conocimiento de su estructura y valor nutritivo resultan útiles para entender su utilización por el ganado y mejorar el manejo de estas comunidades. El estudio se llevó a cabo en el Parque Natural de Gorbeia (Norte de España). La composición del pasto, la altura de la hierba y el valor nutritivo se midieron en cuatro estaciones de pastoreo (primavera, verano, finales de verano y otoño) en tres comunidades vegetales: pasto herbáceo (GR), brezal ralo (OH) y brezal denso (DH). Los pastos herbáceos presentaron menor altura y mejor valor nutritivo. En los periodos menos favorables, cuando la altura de la hierba se vuelve limitante, el ganado se mueve al OH, donde la altura es mayor, aunque la cobertura herbácea y su calidad sean menores. Aunque ambos brezales tengan una altura y calidad similar, la selección del OH puede ser debida a la mayor cobertura de hierba, lo que hace que la búsqueda de alimento sea más fácil. Además, cuando en la estimación de la calidad se considera el componente arbustivo, el DH no cubre los mínimos para mantener al ganad

Ugaztun ertain eta larrien jarraipenerako metodoen konparazioa Bertizeko Jaurerria Parke Naturalean

En el presente trabajo se ofrecen los resultados del seguimiento efectuado sobre mamíferos de mediano y gran tamaño en el Parque Natural del Señorío de Bertiz (PNSB) entre Agosto de 1996 y Julio de 1997; asimismo, se ha comparado la cantidad de individuos - y especies - observados mediante 6 técnicas de seguimiento diferentes.Lan honetan Bertizeko Jaurerria Parke Naturalean (BJPN) 1996ko Abuztua eta 1997ko Uztaila bitartean hilabetero eginiko ugaztun ertain eta larrien jarraipenaren emaitzak eskaini dira, eta halaber, 6 jarraipen - tekniken bidez behatutako banako - eta espezie-kopurua konparatu ditugu.On présente, dans ce travail, les résultats du suivi effectué sur des mammifères de moyenne et grande taille dans le Parc Naturel du Señorio de Bertiz (PNSB) entre août 1966 et juillet 1997; on a également comparé la quantité d'individus - et d'espèces - observés au moyen de 6 techniques de suivi différentes.In this study we show the results of a monthly survey of medium - and large -sized mammals carried out between August 1996 and July 1997 in the Bertiz State Nature Park (BSNP), and we compare also the number of individuals and species observed through 6 survey techniques