Much-needed works to improve the Northern Line could prove an unwelcome interruption to the sex lives of some rare breeds of bat in Highgate Wood.

The ancient woodland hosts a variety of bats, and its 31 bat boxes' are known to be frequented by brown long-eared bats and two species of pipistrelles.

But it is the rare noctule bats, known to use an oak-tree roost near some disused land to mate, that are causing concern, as Tube Lines responsible for maintenance and upgrades of London Underground aims to start building a new Highgate Tube control centre there in May.

It would increase capacity on the so-called Misery Line' by 13 per cent, but Ray Poole, the wood's headkeeper, said it could play havoc with the bats' mating habits.

"A number of rare bat species have been found in Highgate Wood, but we will lose an important breeding roost if it's disturbed; wildlife does not like disturbance," he said.

"No matter what they do, it will affect Highgate Wood. I would prefer they go elsewhere, but the very least they should do is take account of the fact that this is an ancient woodland with a very important bat roost close by."

He has asked Tube Lines to halt its building work at 6pm every day between July and September the bats' breeding season and wants a host of other environment-friendly measures to be adopted to protect threatened species.

Residents, councillors and environmentalists also have other serious concerns about the impact the planned building near Archway Road and Lanchester Road could have, and want the control centre to be built elsewhere.

Haringey Council agreed last summer that the scheme came under the category of permitted railways development', which means it did not require planning consent or an Environmental Impact Assessment (EIA), a view it reaffirmed this week after reviewing the scheme's classification. The site backs on to the Lanchester Road home of John Prichard, who has concerns about potential extra traffic, noise and light disturbance from the round-the-clock centre.

He said: "As a user of the Northern Line, I welcome improvements, but there must be a better place. Does it have to be sited in a quiet residential area and a woodland?"

Tube Lines claims it is meeting its planning obligations and has carried out numerous environmental surveys itself, and agreed changes to the centre's design after meeting residents and councillors.

A Tube Lines spokeswoman said this week that a 3ft mound and sound-proof fencing would surround the building and a green-roof' was being considered.

The firm needs to build the centre in the next few years to meet London Underground targets. "The benefits of this for so many people would be huge," she said.

Bob Hare, Liberal Democrat councillor for Highgate, said: "It's crucial that Tube Lines takes real steps to minimise the impact on this sensitive site and a full EIA is highly desirable."