Photo taken on April 5, 2020 shows a redstart on the Margalla hills in Islamabad, capital of Pakistan. (Photo by Pharahnaz Naveed/Xinhua)

Photo taken on April 5, 2020 shows a blue-throated barbet eating food on the Margalla hills in Islamabad, capital of Pakistan. (Photo by Pharahnaz Naveed/Xinhua)

Photo taken on April 4, 2020 shows an Indian paradise flycatcher on the Margalla hills in Islamabad, capital of Pakistan. (Photo by Pharahnaz Naveed/Xinhua)

Photo taken on March 3, 2020 shows a scaly-bellied woodpecker on the Margalla hills in Islamabad, capital of Pakistan. (Photo by Pharahnaz Naveed/Xinhua)

Photo taken on March 15, 2020 shows a grey-headed warbler on the Margalla hills in Islamabad, capital of Pakistan. (Photo by Pharahnaz Naveed/Xinhua)