Showing papers by "Francisco S. Tortosa published in 2008"
TL;DR: In this paper, a radio-tracking study of free living partridge (Alectoris rufa) was carried out in Spain during 2000-2002, 275 individuals were captured in four areas with different environmental and management characteristics.
51 citations
TL;DR: Results show that, during the 2 years following habitat management, rabbit numbers increased in the experimental plot in contrast to the not managed one, suggesting its effectiveness to reinforce low-density rabbit populations.
Abstract: Wild rabbit scarcity in Spain is a serious problem due to its economic and ecological value; thus, management techniques to reinforce their populations are being implemented. Translocations are traditionally applied but high short-term mortality by predation makes them unsuccessful and increases their biological cost. An alternative to translocation would be to strengthen local reduced populations through habitat management (building artificial warrens and increasing food availability). Here, we test this method to determine its efficiency as an exportable protocol to recover wild rabbit populations. We compare two areas with and without artificial warrens and increased food availability and assess relative rabbit abundance by means of pellet counts. Results show that, during the 2 years following habitat management, rabbit numbers increased in the experimental plot in contrast to the not managed one, suggesting its effectiveness to reinforce low-density rabbit populations.
45 citations
TL;DR: The results of this study suggest that extra food during the incubation period could help the parent birds resolve the conflict between incubation behaviour and minimizing the time off the nest, i.e. increasing nest attentiveness in nests with extra food and enhancing hatching success.
Abstract: . Clutch size is an important life history trait, and factors such as nest predation and food availability can both be of crucial importance for its variation in nature. The aim of the present study was to evaluate the effects of extra food on clutch size, laying date and hatching success in the White Stork. Three different colonies of White Storks were studied in northern Algeria over a three-year period (2002–2004) that was characterised by considerable variation in both food availability and precipitation. This study demonstrated that an extra food supply during the pre-laying period had a positive effect on clutch size — nests with extra food had larger clutches. There was also an advance in laying date and a greater hatching success in nests with access to extra food. In addition to food supply, clutch size was independently affected by the year, which could have been due to differences in rainfall. Furthermore, the results of this study suggest that extra food during the incubation period co...
35 citations
TL;DR: It is concluded that parents may control intra-brood food distribution which enables them to invest more in larger sibs but not (under favourable conditions) at the expense of junior chicks.
Abstract: Intra-brood food distribution in altricial birds can strongly affect nestling competitive hierarchies and subsequent brood reduction. Food allocation patterns result from scramble competitions among the nestlings, various forms of parental favoritism, and/or agonistic interactions among nestlings. Food allocation is related to agonistic interactions among nestlings or to parental favouritism in non-aggressive species. Since white stork chicks are not aggressive and they do not receive direct feeding, parental infanticide has been proposed as an alternative mechanism to control brood reduction. The capacity of white stork parents to control food allocation was examined. We hypothesized that parents favour the senior chick by adjusting prey size to suit its ingestion capacity. We experimentally manipulated (Spain 1996 and Algeria 2004) nestling size by exchanging the senior chick for a larger one. After the exchange parents delivered longer and heavier prey items and they increased the total food amount del...
15 citations