Tree sparrows (Passer montanus) are rather special birds in the Family ‘little brown jobs’ (!), having declined drastically in numbers in the United Kingdom since the 1970s, most probably as a result of changing farming practices. There was even an Operation Tree Sparrow, which was launched by the RSPB and Natural England to try to halt the declining populations in the north-west of England (1). Volunteers put up over 1,400 nest boxes for the sparrows and maintained hundreds of feeding stations on at least 85 farms (2). The results were encouraging with a substantial increase in the numbers of tree sparrows on these farms; good news for tree sparrows and for lovers of tree sparrows!
Fortunately, things are not so bad when looked at on a global scale: the species has a huge distribution which stretches all the way from western Europe, across Asia and down into S E Asia and Indonesia. In the course of this so-called cline, there are a succession of different sub-species, at least 10 according to the HBW (3). So, for example, our own subspecies P. m. montanus is found right across Europe, but changes to P. m. transcaucasicus in the Caucasus region, and so on, until P. m. saturatus is encountered in Japan, Taiwan, the Philippines, N Borneo and N Indonesian islands (3). The subspecies exhibit subtle differences in colour tones and shades, as well as in sizes. For example, P. m. malaccensis (shown here), is a relatively dark race – with darker streaks on its upper parts – but is noticeably smaller than our own UK tree sparrow (P. m. montanus). P. m. tibetanus on the other hand, which lives on the Tibetan Plateau and in central China, is the biggest of all of the subspecies, probably as an adaptation to the cold.
So despite the spectacular ‘local’ declines of this species in places such as the UK (and Ireland), worldwide, the species does not appear to be suffering unduly, and its conservation status is ranked as being of ‘Least Concern’ N (4). Remarkably, there may be somewhere between 159 to 576 million individual tree sparrows worldwide, with about 78,000,000-144,000,000 individuals (perhaps a quarter to a half of the total?) occurring in Europe, according to BirdLife International (4). So seen as a whole, this species has a very large and stable population, despite fluctuating number and severe declines in some locations. Let’s hope it stays that way.
The subspecies which occurs in Thailand (P. m. malaccensis) – where I took these photographs – is a very common bird seen in parks and gardens across the country. These photos were taken in a hotel garden where the sparrows feed on grass seed, but supplement their diet with a variety of other pickings from the open air breakfast area! It is probably an ideal habitat, being enclosed and largely protected from predators and with an all year round supply of supplemental food.
I am a retired entomologist with a background in quarantine pests and invasive invertebrates. I studied zoology at Imperial College (University of London) and did a PhD on the population dynamics of a cereal aphid (Metopolophium dirhodum) in the UK. I spent 5 years with the British Antarctic Survey studing cold hardiness of Antarctic invertebates and 17 years with the Food and Environment Research Agency. My main interests now are natural history, photography, painting and bird watching.