Scottish Parliament bosses look set to carry on flying hawks at Holyrood to scare away pigeons despite saying the number has come down as much as it is ever likely to.

Birds of prey were brought in eight years ago as a deterrent after other measures such as bird wire, netting and anti-roosting spikes all failed.

A year ago, the parliament said the £16,000 a year contract was due to be reviewed and Holyrood bosses were considering ending it.

Monthly monitoring had shown there were between 11 and 18 pigeons regularly on the Holyrood campus and officials felt it may not be possible to reduce it any further.

But no review has yet taken place and now the parliament says the future of the contract with NBC Bird and Pest Solutions will only be looked at when the bigger high-level maintenance contract comes up for renewal in October 2017.

And despite the previous suggestion that the use of birds of prey would probably come to an end, parliament officials now say it is likely to continue.

But MSPs questioned why Holyrood should carry on paying out money if the hawks have now done their work.

The pigeon problem plagued the Holyrood building right from the start with its many nooks and crannies proving attractive perches.

Pigeon poo and feathers were blown through vents on to researchers' desks and some birds even got into MSPs' offices.

Monthly monitoring reports for the past year, released under freedom of information, no longer give average totals for the number of pigeons counted at the Holyrood campus but do highlight hotspots, particularly the MSP block.

Some of the politicians working there urged a review.

Lothian Tory MSP Jeremy Balfour said: "If the contract runs out this year, it is a good time to review the whole situation. Just to renew it automatically would be a mistake.

"It's quite a lot of money and if we have reached the optimum number [of pigeons] and the situation cannot be made any better, it is not the best use of public money.

"I will write to the chief executive and seek clarification of the position and ask if we have now got as much as we can out of it."

And Lothian Green MSP Alison Johnstone also urged a review.

She said: "It's important we know how effective this spending is. We should not continue with a contract that costs £16,000 a year unless we are clear it is proving effective.

"The evidence base must be available and I would welcome site of it to help parliament come to a decision as to whether or not this ongoing expenditure should be continued."

A parliament spokeswoman said there were no plans to end the NBC contract early.

She added: "Like many buildings in Edinburgh, a small number of pigeons visit regularly.

"We are aware the problem can never be fully eradicated and it is likely we will continue with the current approach."