List of ecoregions in Nigeria in the context of "Niger State"

Lagos State (Yoruba: Ìpínlẹ̀ Èkó, Gun: Ayìmátẹ̀n Awọnlìn tọ̀n) is a state in southwestern Nigeria. Of the 36 states, Lagos is the most populous state but has the smallest landmass in Nigeria. Bounded to the south by the Bight of Benin and to the west by the international border with the Republic of Benin, Lagos State borders Ogun State to the north and east, making it the only Nigerian state to border only one other state. Named for the city of Lagos — the most populous city in Africa — the state was formed from the Western Region and the former Federal Capital Territory on 27 May 1967.

Geographically, Lagos State is dominated by bodies of water with nearly a quarter of the state's area being lagoons, creeks, and rivers. The largest of these bodies are the Lagos and Lekki lagoons in the state's interior with the Ogun and Osun rivers flowing into them. Many other rivers and creeks flow throughout the state and serve as vital means of transportation for people and goods. On land, non-urbanized areas are within the tropical Nigerian lowland forests ecoregion with natural areas containing threatened populations of mona monkey, tree pangolin, and hooded vulture along with a transitory population of African forest elephants. Offshore, the state is also biodiverse as there are large fish populations along with African manatees and crocodiles.

Kwara (Yoruba: Ìpínlẹ̀ Kwárà) is a state in Western Nigeria, bordered to the east by Kogi State, to the north by Niger State, and to the south by Ekiti, Osun, and Oyo states, while its western border makes up part of the international border with Benin. Its capital is the city of Ilorin and the state has 16 local government areas.

Of the 36 states of Nigeria, Kwara is the ninth largest in area but the sixth least populous with an estimated population of about 3.2 million as of 2016. Geographically, Kwara is split between the West Sudanian savanna in the east and the Guinean forest–savanna mosaic ecoregion in the rest of the state. Important geographic features include rivers with the Niger flowing along the northern border into Lake Jeba before continuing as the border while the Awun, Asa, Aluko, and Oyun rivers flow through the interior. In the far northwest of the state is the Borgu section of the Kainji National Park, a large national park that contains populations of grey heron, kob, hippopotamus, African bush elephant, olive baboon, and roan antelope, along with some of the last remaining West African lions on earth. In the far southwest, a small part of the Old Oyo National Park contains crowned eagle, martial eagle, African buffalo, oribi, and patas monkey populations.

Adamawa is a state in the North-East geopolitical zone of Nigeria, bordered by Borno to the northwest, Gombe to the west, and Taraba to the southwest while its eastern border forms part of the national border with Cameroon. It takes its name from the historic emirate of Adamawa, with the emirate's old capital of Yola serving as the capital city of Adamawa State. The state was formed in 1991 when the former Gongola State was broken up into Adamawa and Taraba states. The state is one of the most heterogeneous in Nigeria, having over 100 indigenous ethnic groups.

Of the 36 states, Adamawa is the eighth largest in the area, but the thirteenth least populous with an estimated population of about 4.25 million as of 2016. Geographically, the state is mainly composed of highlands and mountains (the Atlantika, Mandara, and the Shebshi ranges) and the Adamawa Plateau crossed by valleys and rivers, most notably the Benue and Gongola rivers. The lowlands of Adamawa are all part of the West Sudanian savanna in the north and the wetter Guinean forest-savanna mosaic in parts of the south, while elevated areas are parts of the Mandara Plateau mosaic and Cameroonian Highlands forests ecoregions. In the extreme south of the state is part of the Gashaka Gumti National Park, a large wildlife park that contains large populations of bushbuck, African buffalo, patas monkey, black-and-white colobus, giant pangolin, and hippopotamus along with some of Nigeria's last remaining Nigeria-Cameroon chimpanzee, African leopard, and African golden cat populations.

The North Central (often hyphenated to the North-Central) is one of the six geopolitical zones of Nigeria representing the majority of the country's Middle Belt. It comprises six states – Benue, Kogi, Kwara, Nasarawa, Niger, and Plateau — in addition to the Federal Capital Territory.

The North Central stretches across the whole width of the country, from the border with Cameroon to that with Benin. In terms of the environment, the zone is dominated by the Guinean forest–savanna mosaic, with the western portion falling into the West Sudanian savanna ecoregion. Plateau State is also named for the Jos Plateau, which lies in the east-central portion of the zone.

Ogun StateListen (Yoruba: Ìpínlẹ̀ Ògùn [ìk͡pĩ́lɛ̀ ògũ̀]) is a state in southwestern Nigeria. It is bordered to the south by Lagos State and the Bight of Benin, to the east by Ondo State, and to the north by Oyo and Osun states while its western border forms part of the national border with the Republic of Benin. The capital and largest city is Abeokuta, and the state is divided into 20 local government areas.

Of the 36 states in the country, Ogun is the 24th largest in area but among the top fifteen most populous, with an estimated population of about 6.4 million as of 2020. Geographically, the state lies primarily in the tropical Nigerian lowland forests ecoregion, although parts of the state's north transition into the Guinean forest–savanna mosaic and some of the coastal south reach the Central African mangrove ecoregion. The Ogun and Yewa rivers are the state's major waterways while the Omo Forest Reserve in the southeastern part of the state is one of the most important conservation areas in the country—home to a variety of bird species along with some of Nigeria's last remaining Nigeria-Cameroon chimpanzee and African forest elephant populations.

BornoListen is a state in the North-East geopolitical zone of Nigeria. It is bordered by Yobe to the west, Gombe to the southwest, and Adamawa to the south while its eastern border forms part of the national border with Cameroon. Its northern border forms part of the national border with Niger and its northeastern border forms all of the national border with Chad. It is the only Nigerian state to border up to three countries. It takes its name from the historic emirate of Borno, with the emirate's old capital of Maiduguri serving as the capital city of Borno State. The state was formed in 1976 when the former North-Eastern State was broken up. It originally included the area that is now Yobe State, which became a distinct state in 1991.

Borno is the second largest in area of the 36 states, only behind Niger State. Despite its size, the state is the eleventh most populous with an estimated population of about 5.86 million as of 2016. Geographically, the state is divided between the semi-desert Sahelian savanna in the north and the West Sudanian savanna in the centre and south with a part of the montane Mandara Plateau in the southeast. In the far northeast of the state is the Nigerian portion of Lake Chad and the Lake Chad flooded savanna ecoregion; the lake is fed by the Yobe River which forms the state's border with Niger until it reaches the lakebed. In the centre of the state is part of the Chad Basin National Park, a large national park that contains populations of black crowned crane, spotted hyena, patas monkey, and roan antelope along with transient herds of some of Nigeria's last remaining African bush elephants. However, a section of the park, the Sambisa Forest, was taken over during the Boko Haram insurgency in the early 2010s forcing many fauna to flee; large animals were not seen until 2019 and 2020 when a massive herd of migratory elephants returned to Borno.

Kogi State is a state in the North Central region of Nigeria, bordered to the west by the states of Ekiti and Kwara, to the north by the Federal Capital Territory, to the northeast by Nasarawa State, to the northwest by Niger State, to the southwest by the states of Edo and Ondo, to the southeast by the states of Anambra and Enugu, and to the east by Benue State. It is the only state in Nigeria to border ten other states. Named for the Hausa word for river, the state was formed from parts of Benue State, Niger State, and Kwara State on 27 August 1991. The state is nicknamed the "Confluence State" as the confluence of the River Niger and the River Benue occurs next to its capital, Lokoja.

Of the 36 states of Nigeria, Kogi is the thirteenth largest in area and twentieth most populous with an estimated population of about 4.5 million as of 2016. Geographically, the state is within the tropical Guinean forest–savanna mosaic ecoregion. Important geographic features include the key rivers with the Niger flowing from the northwest and the Benue coming from the northeast before the two rivers meet in Kogi's center and bisect the state southward.