Whether he enjoys a better life than he would at home is hard to say, but his job as a night telephonist in one of the city's big hotels has given him a taste of the urban dream and he means to pursue it.
As Mr Dikio's shift moves into the small hours and calls become fewer, he finds himself talking politics with his colleague, Benjamin, a member of another minority - the Ogoni. In recent weeks, the subject of Ken Saro- Wiwa's execution has been uppermost in their conversation. Saro-Wiwa, who was hanged with eight other civil rights activists by Nigeria's military government, had long campaigned for the economic and environmental rights of the Ogoni.
"Ken's death on behalf of the Ogoni people has brought their plight to the attention of the outside world," Benjamin said. "Perhaps it will raise awareness of the problems facing other minorities in this country."
Dennis would like to agree. As far as he is concerned, the Calibaris, like the Ogonis, are being cheated of their birthright - the oil wealth which lies beneath their land - by the multinational oil companies and by a government dominated by the majority tribes. "We need someone like Ken Saro-Wiwa," he said.
"He was a great man and I admired him. But he was fighting for the Ogonis, not for anyone else. We have no Calabari rights movement. Our region isn't as badly off as Ogoniland - for a start, we have electricity. But there is environmental damage caused by oil and we don't get much compensation. People express their dissatisfaction in private. But we're too afraid to hold public meetings."
The main ethnic groups in Nigeria are the Hausa-Fulanis in the north, about 22 million; the Yorubas in the south-west, about 17 million, and the Ibos in the south-east, about 15 million. In all, there are more than 45 separate ethnic groups and as many as 250 distinct language groups.
The Ogonis have been the most vocal and politically active minority in recent years. But there are a number of other groups in the south which are also pressing for some degree of political autonomy. Among the more prominent of these minorities are the Ijaws, the Urhobos, the Edos, the Ibibios, the Effiks and the Annangs.
Such minorities found their traditional ways of life threatened after the discovery of oil in the Niger Delta region in the late-1950s. With the beginning of large-scale production of crude oil in 1973, the farming of cash crops such as palm oil declined and thousands of miles of oil pipelines invaded the landscape.
Nor have the minorities benefited greatly from the discovery of oil. The profits go straight to the government, in which ownership of all federal lands containing minerals is vested, or to oil companies such as Shell, Elf and Chevron, which operate in joint-venture partnerships with the state petroleum company. Few good oil jobs are held by the inhabitants of the oil-producing areas.
"We're not fighting for separate countries," Alfred Ilenre of the Ethnic Minority Rights Organisation of Africa said. "We're campaigning for control of our economic resources and also for control of such things as health and education.
"What we want is a return to the genuine sort of federalism which existed in Nigeria before the military first seized power and turned the country into a unitary state in 1966."
Mr Ilenre would like to see Nigeria reverting to the system of revenue- sharing introduced by the British colonial government in 1946. This system, which existed until the end of the Biafran civil war in 1970, ensured that 50 per cent of profits earned from mineral resources went to the region where they were mined.
With more than 80 per cent of Nigeria's foreign currency earnings coming from oil production, however, there is little chance that a military government driven by the self-interest of a few powerful men is likely to accede to the demands of minorities bent on regional and economic self-determination.
It was out of fear of the Ogoni campaign for more autonomy spreading to other minorities that the President, General Sani Abacha, dealt so ruthlessly with Saro-Wiwa and his fellow activists. Whether their executions have the intended deterrent effect remains to be seen.
Some of the minorities have militant movements campaigning for their rights, but none is so powerful as Saro-Wiwa's Movement for the Survival of the Ogoni People - and that has been effectively driven underground.
Many of its leading members have been detained or otherwise persuaded to keep their silence. A number of Ogoni chiefs have been bought out by the government with a combination of threats and bribes.
Nigeria's minorities know they are unlikely to win many concessions from the military regime, which in October pledged to stay in power for another three years.
But even if the death of Saro-Wiwa has not given them new hope, there are many minority-rights supporters who realise that it has brought their grievances to the top of the political agenda.