By the time you are reading this many volunteers will have completed the first of the three annual visits for a national study of nocturnal birds, called Noctua. It is organised by SEO/Birdlife (Spanish Ornithological Society) and is an example of citizen science. The annual surveys have been carried out for the last 20 years by up to seven hundred volunteers all across the country. The results highlight population trends and we now know that those species which favour agricultural habitats have been suffering declines, whilst those which live in our forests have increased.
The population decline in agricultural areas is thought to be due to increased intensification and use of pesticides, both of which have reduced biodiversity in these habitats. A result of the European Common Agricultural Policy!?
Nocturnal species aren’t very numerous and the surveys target 9 different nocturnal species: Stone Curlew, two species of Nightjar, and the six species of Owl that occur regularly in Spain.
What do I see on my survey?
The answer is normally nothing, but I will explain a bit more. I visit the same five listening places on each visit. These listening points are in the mountains, or the general countryside of the 10km x 10km square where I live. I go to each site after dusk and listen quietly in the dark for bird calls and note down each individual that I hear.
It can be very beautiful being in the mountains at night with clear skies, eavesdropping on the creatures of the night. It can also be cold and a bit boring on some occasions! I sometimes wonder what I would say if the Guardia Civil turned up and asked me what I was doing! Would they believe that I was listening to birds, or think I was up to no good! Well, so far, so good; I haven’t been challenged.
Nocturnal birds aren’t generally that well known by most people, so I will talk about those that I have recorded on my patch, which are: Stone Curlews (Alcaraván), Little Owls (Mochuelo), Scops Owls (Autillo), Tawny Owls (Cárabo) and Eagle Owls (Búho real).
Stone Curlews are curious looking birds, but can be incredibly difficult to see as they are beautifully camouflaged and generally remain fairly still during the day. They have a staring yellow eye, long yellow legs and are large, up to 45cms tall with a wing span a little short of a metre. They hunt at night looking for large insects. They are relatively common in the region and are found in dry, level, open country, vineyards and almond groves. On my December visit I am unlikely to record them as their loud, wailing, mournful notes are normally heard during the spring/summer breeding season. In winter time they tend to form largish flocks, so if you spot one in winter, look around to check if there are others nearby.
For the first visit in December, Owls are the focus of my attention. I am lucky to live an area with a good population of Little Owls and I often hear them in the almond fields around the house as they excitedly call to reinforce their territorial boundaries. They have a number of different calls, but the sharp screeching and quickly repeated notes are quite striking in the silence of the night. Although a night-time bird that hunts mainly at dusk or dawn, they can be seen quite frequently in daylight hours. They are small owls, as the name suggests; about 24cms tall, just a bit bigger than a Starling. They can look very cute as they sit, often quite noticeably on favourite perches, searching for their prey of mainly large insects and small rodents. They nest in holes and cavities in trees or buildings, holes in cliffs and amongst boulders, but rely on finding an appropriate place rather than constructing something themselves. Around my area they often use an old nest hole of a green woodpecker in olive trees. They are an indigenous species here, but they were introduced into the UK towards the end of the 19th century.
Tawny Owls are another resident species, but in Murcia they are at the South Eastern limit of their Spanish range. These owls have the typical ‘Twit twoo’ call that is so beloved of Hollywood horror movie producers. They live in the woodlands of some of our Sierras and prefer the shady side of the mountains. Besides the NOCTUA survey, I have been out helping a Spanish birding pal who is undertaking a study project on this species. At the moment he is plotting all the Tawny Owl territories in our two local Sierras. As they are territorial birds, we go into the mountains late at night, listening for them in different locations. I do find it a therapeutic experience listening to the ‘twit twoo’ of Tawny Owls and identifying the different calls of the males and females, “There’s nowt as queer as folk!” My friend is also erecting nest boxes for them in suitable sites. They like to nest in tree cavities, but as there are very few in the local pine trees, it could be an obstacle to breeding success. Hopefully, our local Tawny Owls will come to like the nest boxes he is erecting. I’ll let you know in the spring if we get a tenant! In the UK Tawny Owls mainly prey on rodents, but here they are more adept at hunting other birds and blackbirds particularly need to be very careful around them!
The other small owl of the region, the Scops Owl, is a little bit smaller than the Little Owl at 19-21cms; the same size as a Starling. It is a summer visitor and migrates to Africa to spend the winter just south of the Sahara. It hunts at night and is difficult to see, but its distinctive call is easily recognised once it is pointed out to you. It is a constantly repeated, short, whistling, single note “tyuh” every 3-4 seconds.
It reminds me somewhat of the pinging sound of radar in old war films when they are searching for a hidden submarine. It certainly doesn’t sound like a bird! As it is migratory, I only hear them from March/April onwards and they are relatively common in the region.
The last owl that I hear locally (and sometimes see), is the big daddy of them all, the Eagle Owl. This is a large powerful bird, standing up to 73cms tall and with a wingspan of up to 1.75 metres (6 feet). They are stunning birds to see in the wild, but you may be familiar with them as they often feature in falconry displays and collections. They hunt at night and also at twilight and their main prey are rabbits, but they will also opportunistically hunt other large mammals and birds, rats, young foxes, crows, gulls etc. Cats are also on the menu at times and if you think about it objectively, cats are very similar in size and shape to a rabbit. Their breeding success can be adversely affected by problems to local rabbit populations if diseases such as myxomatosis take hold. However, we are lucky in Murcia that we have healthy and thriving populations of Eagle Owls across the region.
I had the great fortune, a year or so ago, to go out finding Eagle Owl nests with a Spanish ornithologist who has been doing scientific research on this species. His skill in quickly locating a nest with youngsters was testament to his knowledge and understanding of these birds. Within a short time he had climbed to the nest, put them in a rucksack, brought them to our position, ringed the 2 youngsters and had taken feather and blood samples for both DNA testing and chemical analysis (eg. a test for presence of pesticides). My contribution was extremely limited and amounted to carefully holding one of the chicks whilst he carried out the tests. These birds, even as fledglings, have large, razor sharp claws that could do a lot of damage if you are not careful. Afterwards, he quickly returned them to the nest with no harm done and little disturbance. It was an unforgettable experience for me and I will be forever grateful for the opportunity. It’s not something that happens every day.
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