Estudio preliminar sobre la abundancia y distribución de la perdiz roja (Alectoris rufa Linnaeus, 1758) en el Parque Natural Sierra de Mariola (Alicante-Valencia)

El presente estudio tiene como objeto analizar la abundancia y distribución de la perdiz roja en función de las diferentes matrices de usos del suelo. Parte del trabajo se ha centrado en la Finca Buixcarró, finca forestal de 652 has. de superficie, cuya propiedad y gestión pertenecen a la Fundación de la Comunidad Valenciana C.V. Victoria Laporta Carbonell. La zona de estudio se encuentra en la Sierra de Mariola es un Parque Natural de 17.500 ha situado entre las provincias de Alicante y Valencia que cuenta con una vegetación climática de carrascal de termotipo mesomediterráneo y ombrotipo subhúmedo. Entre marzo y junio del 2011 se han realizado un total de 12 itinerarios de censo de 500 m de longitud, distribuidos en las diferentes matrices de usos del suelo (matorral, bosque, cultivo y zona de regeneración). El análisis de los resultados, muestra una mayor abundancia de los individuos de la población en zonas de matorral denso y bajo (IKA=1,33), siendo visibles a primeras horas de la mañana en sendas y/o bordes de caminos; y así mismo, un mayor contacto visual en días parcialmente despejados y sin viento. También se han hecho escuchas puntuales en la zona de regeneración arbolado post-incendio.

Influence of habitat on nest location and reproductive output of Montagu’s Harriers breeding in natural vegetation

We examined distribution and breeding success of semi-colonial Montagu’s Harriers (Circus pygargus) in relation to habitat in Castellón province (eastern Spain). Breeding areas used by harriers at a 1-km2 scale were characterised by having intermediate percentages of scrub cover, their nesting habitat, and also had intermediate coverage of herbaceous crops and non-irrigated orchards. Out of all habitat variables considered, only the percentage of herbaceous crops within 500 m from individual nests had a positive and significant effect on breeding output of the species, suggesting that this habitat may be efficiently used by harriers to forage. Breeding output was also related to laying date and number of breeding neighbours within 500 m around nests, with pairs laying later and having a higher number of breeding neighbours showing lower fledged brood sizes. Number of neighbours (but not laying date) was positively related to scrub cover within 500 m and to cover of herbaceous crops within 2,000 m. Conservation actions for Montagu’s Harrier in the study area should be aimed at preserving areas of scrub with nearby presence of herbaceous crops or natural grasslands. However, habitat improvement for semi-colonial species such as Montagu’s Harrier may not result in a change of species distribution area, and good habitat areas may remain unoccupied, as social factors like presence of conspecifics play an important role in breeding area selection for these species.

Short-Term Effects of a Wildfire on the Endangered Dupont's Lark Chersophilus duponti in an Arid Shrub-Steppe of Central Spain

In Europe, Dupont’s Lark Chersophilus duponti is a threatened open-habitat bird. Prescribed burning has sometimes been proposed for its conservation, but without evidence of its effectiveness. To evaluate the short-term effects of a summer wildfire on this species, we performed several transect counts in the burnt and unburnt parts of a shrubsteppe in central Spain. The same transects were counted within a three-year interval prior to the fire and were repeated during the first two springs after the fire. We also measured the vegetation during the first two springs after the fire. In the burnt area, we observed a decrease of about 85–100% in Dupont’s Lark abundance, and about 7–15% in the control area. The disappearance of the scrub cover after fire and its slow regeneration, as well as the large increase in grass cover during the second year, may explain the decrease in this habitat-specialist bird species. Fire should be avoided in areas occupied by the Dupont’s Lark, as its negative effects in the short-term may cause local extinctions. However, prescribed burning may be used in neighboring areas to create new open habitats that may be subsequently colonized by this species.