Image caption Gashaka Gumti, known as a biodiversity hotspot, is the largest of Nigeria's seven national parks

A Chester Zoo team is set to visit a remote, mountainous region in Nigeria to assess what species live in an area where few surveys have been conducted.

They will carry out the first biodiversity assessment in the Gashaka Gumti National Park.

The area is said to be home to the last viable population of the endangered Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti).

A 12-strong team from the zoo includes security and maintenance staff.

"Obviously it would be great to find a big, sexy bug or frog but it is hard to tell you how likely that will be because we do not know what is there," explained Chester Zoo director general Mark Pilgrim.

"But there is a good chance that there are a lot of things there that we currently do not know about.

"Whether it is a brightly coloured big thing or not, we will have to wait and see."

The team was hoping to leave immediately but has had to delay its departure because of the murders of foreign nationals by a Nigerian Islamist militant group at the weekend.

Biodiversity hotspot

The park, located in eastern Nigerian on the border with Cameroon, is the country's largest national park and is considered to be one of the continent's most important biodiversity hotspots.

Nigeria-Cameroon chimpanzee Scientific name: Pan troglodytes ellioti

Global population: 6,500 (estimated)

One of four subspecies of chimpanzee

Found predominantly in moist and dry forests

Omnivores - fruit comprises about half of their diet, but leaves, bark, and stems are also important

Mammals comprise a small but significant component of the diet of many populations

Chimpanzees form social communities of 5 to 150 animals (Source: IUCN Red List of Threatened Species)

Dr Pilgrim said that the zoo had been funding the core support facilities a research field camp in the park for more than a decade, but was now becoming directly involved.

"The field camp was mainly set up to look at and protect the Nigerian chimpanzee, which is a sub-population of chimpanzee," Dr Pilgrim added.

The Nigeria-Cameroon chimpanzee is under threat.

Conservationists say that high levels of exploitation, loss of habitat and habitat degradation has led to the species experiencing a "significant population reduction" over the past 20-30 years.

The total population is estimated to be in the region of 6,500, with up to 1,500 found in the Gashaka Gumti National Park.

It is one of four subspecies of the primate, although some recent research suggest that the differences between the subspecies are too small to warrant such classifications.

The camp allows about 20 students each year to work on projects researching the area's population of primates, led by Prof Volker Sommer from University College London.

Dr Pilgrim told BBC News that the presence of the research projects was "what helps protect the forests".

"By having these strange foreigners wandering around, looking for primates is what keeps the forest safe," he observed.

As the zoo would become more involved in the field project, Dr Pilgrim said that it was also an opportunity to widen the focus of the research carried out from the camp.

"Of course, the flagship research remains the Nigerian chimpanzee, which is what makes the area so special and important.

"But because the zoo has wider expertise than that, we are taking out a range of experts to also look at the frogs, birds, small mammals etc because those areas have had very little in the way of surveys in the past."

"This is really the first biodiversity assessment of this forest."

Dr Pilgrim said that he hoped the data gathered during the the field trips will allow partnerships to be forged with scientists working in Nigerian universities.

"For example, it may be that we turn up a number of strange beetles that we do not have the expertise to identify," he suggested.

"This will be an intense, short trip but there will be more follow-up trips to get some really strong scientific papers out of the project."

On Tuesday afternoon, Chester Zoo announced that a decision had been taken to postpone the trip following news at the weekend that a Nigerian Islamist militant group had killed seven foreign hostages.

A spokeswoman for the zoo said: "It is fair to say the safety of the group was paramount in that decision and it wasn't made easily."

She added that a new date for the trip had yet to be decided.