Avaluació de la situació de la població d'òlibes (Tyto alba) al Parc Natural del Aiguamolls de l'Empordà: estat de l'hàbitat, ocupació de caixes niu i reproducció

Abstract

Following the trend of many studies that move motivated by wanting to better understand the causes of the globally decline suffered by the common barn owl (Tyto alba), this study aims to know the situation of the population of barn owl in the Parc Natural dels Aiguamolls Empordà (PNAE). This study takes place within the Projecte Òliba, which began in the PNAE in order to evaluate and improve the situation of the barn owl population in the area. After two years since the start of the project, the aim of this study is to review the actions that have been done and determine which is the current status of the population of barn owls in PNAE. I analyzed 75 human constructions, 23 nest boxes has been tracking and I have quantified the breeding couples and its characteristics. I have also been able to compare data from previous years with the data obtained with the current actions. I observed a decrease of barn owls in buildings where there are clear traces of their presence in the past (24% of the points analyzed) and I checked that sometimes this is due to actions of the owners. In addition, this revision has also determined that there is a minimum of 4 couples breeding in the park which are not free of risks and dangers, fact that puts the population in a fragile situation. Despite this, it has been checked that nest boxes may be an alternative to the loss of roost and nest sites, considering its collocation in places without unwanted species such as the pigeon (Columba livia domesticus). However, it is necessary to take into account that some data were insufficient to make a good assessment of the ecological status of the population. For example, the average of eggs per pair and success of the young barn owls could be far from reality because of sample size (N = 4). Therefore, this study offers a base and some actions from which next studies should continue working