As a "Statistical Reporter" he travelled across the Deccan region, collecting data on populations apart from collecting natural history specimens. Some of statistical research contributions included the computations of the cost of maintenance per soldier. He calculated for instance that the French army had a much lower cost than that of the British army, which according to him allowed the French to maintain two soldiers for the cost of one "English" soldier. He also worked out that native Indian soldiers were healthier than their European counterparts and that it was possible to provide pension and insurance to Indian soldiers with a very low premium although this was never implemented. Sykes was a pioneer meteorologist in India, taking regular temperature and atmospheric pressure readings; he noticed regular patterns in diurnal pressure variations and noted that the range was greatest in winter, while the least difference occurred during the monsoons. Sykes' collections of animals resulted in the publications of catalogues of
birds and
mammals from the
Deccan region, many of which were published in the
Proceedings of the Zoological Society. His discoveries included fifty-six birds new to science, including the
Indian pond heron. Sykes also studied the
fish of the area, and wrote papers on the
quails and
hemipodes of India. His list of birds of the Deccan contained almost 236 species. He was an authority on the natural history of the Deccan region and he corresponded with many other naturalists. He used his influence during his position at the East India Company and
Charles Darwin wrote to him to influence decisions in favour of including
Edward Blyth on an expedition to China.
Sykes's lark (
Galerida deva) of peninsular India is named after him. In addition, a race of
blue-headed wagtail (
Motacilla flava beema) was given the common name Sykes's wagtail in
British Birds (1907). Sykes wrote extensively on Buddhism and its antiquity. In an 1842 paper published in the
Journal of the Asiatic Society, he contended that the
Brahmins were likely not native to India and that
Pali was older than
Sanskrit. He believed that, rather than
Brahmanism, it was Buddhism that had reigned supreme in India's ancient past. Referring to the recently translated travelogue of
Faxian, Sykes paid tribute to "the literature of that remarkable people—the Chinese" that thankfully existed to illuminate India's past. He hoped that, "by proper means, applied in a cautious, kindly and forbearing spirit, such farther changes may be effected as will raise the intellectual standard of the Hindus, improve their moral and social condition, and assist to promote their eternal welfare." In 1856, the citizens of Bombay presented Sykes with a medal for his advocacy in favour of a native system of education. He also held the British responsible for precipitating the
1857 rebellion by being insensitive to local customs, citing the earlier case of the
Vellore mutiny. In a commentary to the British media which had suggested that the mutineers were using greased cartridges, one of the immediate causes of the uprising, against the British he pointed out that they were all using 'Brown Bess' and conventional musket ammunition. He was one of the founding members of the
Asiatic Society of Bombay. ==Legacy==