Shimba Hills National Reserve has plentiful flora and fauna and the hills host the highest density of African Elephants in Kenya. The Shimba Hills ecosystem along the south coast of Kenya is a key East African biodiversity hotspot. With their low undulating hills and plateaus, unlike the ordinary coastal lowland forests but like the Eastern Arc Mountains, the Shimba Hills present the first break or barrier to the moist rainfall winds from the Indian Ocean maintaining a stable montane forest environment. Shimba Hills is the only Reserve in Kenya with a healthy population of Sable Antelope hence the reason for incorporating the grassland areas into the National Reserve. The restricted Black-and-rufous Elephant Shrew also occurs here together with a distinctive race of the Bushy-tailed Mongoose. The forest also holds substantial numbers of small unique mammals.
Shimba Hills is one of the richest herpetological areas in Kenya; other rich herpetofauna areas include the Arabuko-Sokoke Forest, Kakamega Forest, and Taita Hills The Shimba Hills transcend as the most reptile and amphibian species-rich area in Kenya, uniquely due to the endemic and near-endemic species. A sum of 89 reptiles (47 snakes, 39 lizards, 1 terrapin, 1 tortoise, and 1 crocodile) and 38 amphibian species (36 frogs and 2 caecilians) occur in the Shimba Hills ecosystem. Two frog species, Forest Spiny Reed Frog and Shimba Hills Reed Frog are endemic to the Shimba Hills forests and are believed to be endangered. The little-known and range-restricted Sagalla Caecilian is also found in Shimba Hills. The proximity of the Shimba Hills to the Indian Ocean has resulted in a stable climate, leading to its diverse and unique herpetofauna.
The plants of Shimba Hills are exceptionally rich and important. A total of 1,100 plant taxa are recorded, around 280 of which are endemic to the Shimba Hills area, and nearly a fifth are considered rare globally or in Kenya. This qualifies Shimba Hills Reserve as a center of plant diversity
The butterfly fauna in Shimba Hills is very diverse, with some 295 species (35% of Kenya’s total), including the rare Aubyn Rogers Acraea and the endemic Shimba Mountain Charaxes
Shimba Hills forest is an important bird area and rich in forest bird fauna, including three threatened and two restricted-range bird species, and holds 18 of Kenya’s 30 East Coast biome species. The grasslands hold localized bird species such as Red-necked Spurfowl, Croaking Cisticola, and Zanzibar Red Bishop. The bird species of concern include Southern Banded Snake Eagle, Fishers Turaco, Spotted Ground Thrush, Sokoke Pipit, East-coast Akalat, Uluguru Violet-backed Sunbird, and Plain Backed Sunbird. Shimba Hills National Reserve is a favorite birding destination among bird watchers on Kenya’s coast. Bird species in Shimba Hills include several coastal endemics, restricted to the area, such as the Green-headed Oriole, Afrotropical migrants such as the African Pitta, Mangrove Kingfisher, Forbes-Watson’s Swift, and the Spotted Ground Thrush. From the months of October to April, the migratory birds arrive and add to the already interesting collection of species. Regarding the weather, be aware that November and April are peak months for rainfall
Southern-banded Snake Eagle, Red-necked Spurfowl, Fischer’s Turaco, Green-headed Oriole, Mangrove Kingfisher, Coastal Cisticola, Croaking Cisticola, Siffling Cisticola, Green Tinkerbird, White-eared Barbet, Green Barbet, Spotted Ground Thrush, East Coast Akalat, Plain-backed Sunbird, Sokoke Pipit, Uluguru Violet-backed Sunbird, Lesser Cuckoo, Madagascar Cuckoo, Tiny Greenbul, Eastern-Bearded Scrub-Robin, African Pitta.