By Orji Sunday YELWA, Nigeria — Nightfall at the Ngel Nyaki Forest Reserve field station is clad in the whispers, chirps and trills of insect song. Flames from the burning wood in the fire pit pierce the darkness as flashlights held by field assistants and patrollers reveal a river of fog wafting over the surrounding grassland and tree canopies. As night receded, the early hours of dawn vanquished the fog, revealing distant mountains, valleys and forest. Bees, butterflies and birds of all colors flit from flower to fruit, hive to nest. Gazetted on April 24, 1969, the reserve comprises some 40 …