Climate change was responsible for last year being the worst on record for seabird breeding in Northern Ireland, according to a report published yesterday.
Winter migrants to the province, such as ducks, geese, swans and wading birds, also dropped to their lowest level in a decade.
The conservation manager of the Royal Society for the Protection of Birds (RSPB) in Northern Ireland, Dr James Robinson, warned: "Climate change is without doubt the greatest long-term threat facing our wildlife today."
The charity expressed concern after the publication of the State of UK Birds report and said the problem cannot be ignored.
Ornithologists believe survey results such as those that show wading birds' populations moving eastwards are a response to climatic changes, such as milder winters.
Dr Robinson said: "Birds are very good indicators of the state of our environment. If imbalances take place, because they are so high up the food chain, birds reflect these changes very quickly. It's the 'canary in the coal mine' analogy - if birds are in danger, it could very well mean that we are in danger too."
The RSPB said the hen harrier was found to be doing well in Northern Ireland, despite a fall in numbers in England and southern Scotland.
But, despite making a comeback in the Western Isles, the corncrake has yet to return to the province.
The charity also reported that, so far in 2005, very few kittiwakes have managed to fledge on Rathlin Island, off the north Antrim coast. A lack of their staple food, sand eels, is thought to be responsible.
Dr Robinson said failure to address the problem could have grave consequences. "It is important that we heed the signs and do all we can to take steps to curtail the effect our lifestyle is having.
"While the report points to some areas of recovery for some birds, it will be largely meaningless if the wider picture changes. While some species will be able to adapt, others, like the golden plover, with nowhere to go may become extinct."
The report says there has actually been a 6 per cent rise in the combined populations of 111 widespread bird species since 1970.
But it is concerned that for every 10 pairs of birds living in UK farmed landscapes 35 years ago, less than six remain today.