The Spanish Ornithologist Association (SEO in Spanish), along with Birdlife International, have granted the barn owl (Tyto alba) the title of Bird of the Year 2018. This title is selected annually by a public poll in which they include a short list of species of interest. Not only does it allow you to know more about the biology of this chosen animal, but it also highlights the conservation issues of the species, and different bird species. Therefore, this is an interesting way to focus the conservation efforts towards threatened species of Spain, while raising awareness of the biodiversity of this country and the need for wildlife protection.
Facts about the barn owl and the population decline
The barn owl (Tyto alba) is catalogued within the strigiform order, in the family of Tytonidae. There is a notable range of colour variation amongst the 28 subspecies around the world, as well as between the male and female individuals. Barn owls are nocturnal predators specialized in hunting on the ground. Their diet is mostly based on voles and shrews, as well as other small mammals and athropods. This bird of prey is strongly associated with rural areas, forming monogamous pairs. They usually live in tree hollows or old church bell towers’ or other similar old/abandoned anthropogenic chambers. This means that barn owls take advantage of elements from human buildings. Over the last few decades the population size of this most iconic species in the rural environment has become compromised due to human activities.
In the year 2008, 64% of the 56 European bird of prey species have been given unfavourable conservation status’. Nowadays, the barn owl is a widespread bird of prey that inhabits all of Europe, but has experienced a population decline in most western European countries. In Spain, the decline was 13% in 2005, reaching a 50% decline rate in some areas of the Iberian Peninsula. This pronounced decline is highly significant in the southern Mediterranean region of Spain. Although catalogued as “Least Concern” by the IUCN, the situation in this country has led to the barn owl being included in the Special Protection Regime in the Spanish Royal-Decree Law 139/11.
The main threats that adversely affect the barn owls are the current agricultural model in Spain, together with the abandonment of rural areas to move into bigger cities. Barn owls are very sensitive to the land use changes leading to habitat loss in rural areas.
Monoculture plantations, as well as the use of pesticides, have been drastically reducing the numbers of barn owl prey. These pesticides can directly cause deaths by poisoning the species. Other factors related to human activities, like electrocutions on power lines and car collisions, are causing many mortalities of barn owls in Spain.
As in other wildlife conservation issues, it is essential to focus our efforts on the mitigation of the main causes of population decline, to provide a suitable environment for this species. In the case of the barn owl, the current monoculture model and the continued use of pesticides must end. Ecological agriculture through mixed farmlands creates a higher landscape diversity, enhancing the biodiversity of the area. Moreover, the toxic effect of rodenticides used in agriculture can be replaced with biological control, encouraging barn owl populations to increase again. They are natural predators of pest species; thus, they will maintain the rodent population by themselves. Taking this issue to the next level, at a European level, pressure needs to be applied to change the Common Agricultural Policy, allowing for more sustainable practices.
Due to the importance of the barn owl, especially this year in Spain, thanks to the Bird of the Year title, several volunteer organisations have acted to protect this species. Most of the actions by volunteers were focused on nest-box placements and the birds following trends programme Noctua developed by SEO/Birdlife. The objective of the Noctua programme is to monitor the population trends of different bird of prey species in Spain. These two voluntary activities allow people to directly help the conservation of the barn owl and the study of the population. On the other hand, research in ecology and population density in the barn owl’s main prey species is also needed to estimate the oscillation in barn owl populations.
In conclusion, the efforts of SEO/Birdlife in the conservation of bird species has shed light on their threats and the importance of protecting our biodiversity. This set of actions imply more appreciation for our biodiversity through environmental education, as well as transmitting biological knowledge of threatened species to as wide an audience as possible. All of this is essential to preserve species in endangered situations.
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De Bruijn, O. 1994. Population ecology and conservation of the Barn Owl Tyto alba in farmland habitats in Liemers and Achterhoek (The Netherlands). Ardea 82.
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Kross, S. M., Bourbour, R. P., Martinico, B. L. 2016. Agricultural land use, barn owl diet, and vertebrate pest control implications. Agriculture, Ecosystems and Environment 223: 167-174.