I had a free morning so did some more exploring. I first visited the world famous Hagar Qim and Mnajdra Neolithic temple sites, two of the numerous temples on the island which date back to 5000 BC (Check out the Netflix series Ancient Apocalypse for some dodgy but entertaining pseudoscience that features these temples)
I got a bit distracted from the archaeology as the temple ruins hosted breeding colonies of 'Maltese Sparrows'. The jury is still out on 'Maltese Sparrows', Ebird classifies them as Spanish Sparrows as does various local ornithological texts, but Birds of the World (also Cornell/Ebird) suggests that Italian Sparrows are also present on Malta and one of the most recent reviews into the matter by Massa et al (here) concluded that there is a cline-like situation between Italian and Spanish Sparrows which form a large hybrid zone from Southern Italy to Malta- with birds becoming progressively Spanish Sparrow like as you go south. Italian Sparrow itself could be an ancient hybrid (between House and Spanish Sparrow) although Massa et al suggests there is some evidence that Italian Sparrow originated as a distinct species from North Africa and expanded North (and has since become extinct from North Africa).
So it's a bit messy and if I understand correctly we could have Italian and Spanish Sparrows here which certainly hybridise or otherwise the whole lot are just a big hybrid swarm with no pure Italian or Spanish sparrows remaining or pure birds were never here and colonising birds were from hybrid populations. Considering Malta forms the boundary between Spanish Sparrows in North Africa where Italian Sparrows are not present it seems to make sense that the hybrid wave moved through Malta first so indeed there could have been both pure Italian and Spanish Sparrows here at one point and there still might be.
Anyway here's a few of them that were at the Temples- presumably these sparrows have also been here for the 5000 years the temples have. This isn't the best time of year to look at these sparrows as most of the research done on them is during the breeding season in summer plumage but most of the males were already in summer plumage and were seemingly holding territory (singing and visiting nest sites). Only males distinguishable as the females of House, Spanish and Italian are largely inseparable.
Just heard from Nicholas Galea that 'pure' Spanish Sparrows do occur in Malta on migration in March and October which adds another fascinating layer to this situation.
Update 190123- see comment below for an even bigger twist to the plot. Pre-print on paper referred to in comment here. According to this work the Maltese Sparrows are indeed a population of Italian Sparrows and are cited as being an example of where hybridisation is a pervasive evolutionary force that generates new species. If I understand the paper correctly Italian Sparrows are indeed an ancient hybrid of House and Spanish Sparrow (formed when House Sparrows colonised the Mediterranean) and in Malta they just have a bit more Spanish Sparrow genes in them but are still a 'stable species unit' aligned with other populations of Italian Sparrows.
2 comments:
FWIW it has already been confirmed genetically that the sparrows in Malta are Italian sparrows with a high degree of Spanish introgression. See paper "Variation and constraints in hybrid genome formation" by Runemark et al. However some Maltese birders insist that the rural sparrows are different from the urban sparrows and not both of these were sampled in this study (not sure of the details on this). Regardless, on the basis of this paper italian sparrow is definitely present in Malta and should be on Malta's list.
Very interesting indeed. I can't find a full version of that paper (subscription or author request only) but I did find this pre-print pdf : https://www.biorxiv.org/content/10.1101/107508v1.full.pdf
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