|Spanish Sparrow – complicated female|
|On 20 March 2009, Michiel
van den Bergh and I created a guerilla garden in our favourite dunes
between IJmuiden’s marina and North Sea coast. At regular
intervals we provided bird food, much to the delight of the local House
Sparrows. In no time our garden list grew to over 50 species, including
Common Cuckoo, Common Firecrest, Shorelark, Bluethroat,
Richard’s Pipit and Common Rosefinch.
In the morning of Thursday 6 May 2010, while walking to the garden, my attention was drawn by an unusual squeaky chwee call coming from a small flock of sparrows. As it vaguely reminded me of Rock Sparrow Petronia petronia I stopped to have a look. The call came from a female sparrow, which looked a bit odd but definitely not like a Rock Sparrow. I now started wondering whether it could be a female Spanish Sparrow. But since I remembered having read in various books and articles that female Spanish cannot be safely identified from female House Sparrow, trying to find answers to this question would be merely pastime. I informed only Michiel, who came to see the bird together with Jacob Garvelink later that day. Nonetheless, studying sparrows became an obsession for me and, as it turned out, our photographs and recordings of the IJmuiden bird showed a full set of features of Spanish Sparrow (Slaterus 2012).
Individual variation and overlap seriously impede the identification of female sparrows. Yet, a combination of features makes many Spanish stand out. The most striking individuals show a heavy bill, pale ‘tramlines’ on mantle sides, dark streaks on breast and flank, an open face with pale lores, hardly any rufous tones to the plumage, pale sandy-grey fringes to greater coverts, tertails, primaries and secondaries and poorly marked scapulars. Furthermore, a pale general impression, a rather peaked crown, dark shaft streaks on crown, rump and uppertail-coverts, a conspicuous white wing-bar and strongly patterned undertail-coverts are often associated with Spanish.
At the end of the spectrum, there are large-billed individuals with strongly patterned sandy-coloured plumages. They show small but striking spots and streaks on breast and flank, which alone is a strong indication of Spanish. I have never seen a House Sparrow with such intense markings on the underparts as the most distinct Spanish. However, I came to the conclusion that probably none of the other plumage features is truly diagnostic. Although the majority of House Sparrows show none of the aforementioned features, some approach Spanish Sparrow’s appearance quite convincingly in one or more aspects.
With such a huge – almost worldwide – distribution, House Sparrow will no doubt show more variation than I am aware of. In fact, in certain populations many females lack the rufous plumage tones, that I am so familiar with. Relatively close to home, Italian Sparrow Passer italiae further complicates matters. Although to me the females are practically identical to House, I would not be surprised to find individuals with a more or less intermediate look. Variation in Spanish is also considerable; those showing rich brown plumage tones and lacking markings on breast and flank create a real identification challenge.
The vocalizations of female Spanish are much like those of House Sparrow. However, the chwee call noted from the IJmuiden bird stood out not without reason. In Spanish this call has a typical, squeaky or nasal timbre. This is caused by a slight mismatch between the contributions coming from the left syrinx and the right syrinx; the shape of each vocal organ’s sound is slightly different and their peaks do not lie exactly above one another. Typical examples also last slightly longer than the equivalent call of House Sparrow. Although I am constantly on the look-out for them, I have never found identical calls in House Sparrow. Its corresponding call – a rather nondescript chwip – lacks the typical squeaky sound, since the contributions from the vocal organs run neatly parallel to each other. Other call types, such as the well-articulated flight call – chu-vit rather than chuwiv as in House – could also show differences between the two species, but further study is needed to clarify this. Altogether, close observations and recordings will allow safe identification of typical female Spanish Sparrows, even of vagrants. So keep your eyes and ears open!
|The sighting was accepted as the sixth record of Spanish Sparrow for the Netherlands. For an overview of all seven records up to 2014 see Ebels et al (2015).|
|Published 31 July 2018|