The Scops owl: the chu of a night singer
by Marco Mastrorilli
Between the end of March and the beginning of April a nocturnal predator returns to the Nure valley, to keep us company until the end of September: the Scops owl, Otus scops.
The Scops owl is a Strigiforme (a nocturnal bird of prey), small in size and easily recognised by its ear tufts, which many think are ears. Its colouring varies from greyish to reddish and these different colourings are called "morphisms".
In Italy some interesting research was carried out a few years ago precisely on this species and the predominant colours. The results showed that red or intermediate individuals were more common than the greyish. A difference was also noted in regional distribution. The "reddish" birds predominate in northern Italy while those with an intermediate plumage are most commonly found in Sardinia and Tuscany, and the "grey" birds in the south.
Apart from these questions linked to colour, the plumage of the Scops owl is very cryptic and forms a perfect camouflage. To understand how this works, we must look at the function of the camouflage stripes on the bird's breast. In fact, these are called "disruptive stripes", like those on the tiger's fur, which enable him to hide among the wild vegetation of the Indian forests. These stripes are found on the plumage of many birds and are useful as they break up the shape of the figure and help the Scops owl to camouflage itself against the bark of the trees.
Along the river Nure the Scops owl is widespread but actually it is common even in suburban areas and in some parks (e.g. the Park of the Castle of Grazzano Visconti, where at least two pairs have been counted).
The eyes are yellow, the beak dark grey, and in flight the wings are quite long compared to the tail, which is not very long.
The call of the Scops owl inspired Pascoli and Pasolini, who evoked the bird in two of their poems. It is a monosyllabic call with metallic notes, comparable to a repeated "chu" that can be prolonged for many hours in the middle of the night.
The Scops owl is a species found in warm areas. In particular it loves the Mediterranean environment but it does not scorn hills and even pre-alpine areas, where on slopes with a favourable exposure (south) it is found even at 800 metres. The record for altitude, in Corsica, is almost 2000 metres!
Its distribution ranges from Spain to central Asia, with a northern limit corresponding to the July isotherm of 16 °C.
As it is an almost entirely insectivorous species, it is found during spring and summer and the first cold weather induces it to migrate south, at times beyond the Mediterranean and the Sahara. Its preference when hunting is for small insects and invertebrates and its chosen prey are the orthoptera, grasshoppers and crickets, which are very common along the stony banks of the Nure during the summer. It may also feed on the ground, seeking different prey. A few years ago a community of Scops owls was monitored for a long time in the Oltrepò pavese and it was discovered that they fed prevalently on ants captured on the ground. So it is invertebrates that predominate in the diet of the Scops owl: principally grasshoppers and large coleoptera, moths, but also other invertebrates like spiders, scorpions, earthworms and slugs.
The reproductive habits of the Scops owl lead it to search for holes in trees to lay its eggs but if we provide it with artifical nests, it is very happy. The reproductive season lasts from the end of April to June and eggs are laid just once. 2-4 eggs are laid (with a maximum of 7) asynchronously (i.e. the eggs are laid with at least a day between one and the next); the female then sits on the eggs for 24-25 days. The nestlings leave the nest before they are completely autonomous, after 3 or 4 weeks.
Thanks to the trophic availability of entomofauna (i.e. insects), the mild climate and sunny areas, the Nure river is an ecosystem that is very attractive to the Scops owl and many other insectivorous species.
If we visit the Nure at night, we will easily realise with pleasure that these birds are around, but let us not forget that they have been noted in urban environments too, at Vigolzone, Podenzano, Ponte dell’Olio and San Giorgio Piacentino.
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