Scientists are continuing to test dead birds near the Fife village in which one swan with the H5N1 avian flu virus was found last week.
AREA ON ALERT
Poultry owners within wild bird risk area must keep birds indoors or, if not possible, ensure they are kept away from wild birds
Bird transport within 6 mile (10km) surveillance zone will be curbed
Poultry within 1.8 mile (3km) protection zone must be kept indoors and will be tested
Since the dead swan in Cellardyke was confirmed as having the virus, there has been a marked increase in the number of dead birds being reported.
But every other bird analysed so far in Scotland has tested negative.
Scotland's eight laboratories that can test for bird flu have remained open this weekend and will open at Easter.
Out of nearly 2,500 calls from across the UK to a hotline on Friday, no suspected bird flu cases have been identified, according to the Department for the Environment Food and Rural Affairs.
A spokeswoman said so far no so-called "report" cases - which are suspected to be bird flu and are prioritised for testing - had been identified.
"Every case that has been tested has come back negative," she added.
Head of veterinary operations Derick McIntosh said everything possible was being done to stop the virus spreading.
Scottish Executive regional operations director Paul Neison said an extra 70 staff had been drafted in to the surveillance and protection zones around the coastal village of Cellardyke, where the swan was discovered.
A preliminary report into the death of the swan in Fife says provisional tests suggest the virus was very close to those found in wild birds in outbreaks in Europe.
BBC Radio 4's Today programme was told the virus found was an almost exact match to that found in an outbreak in the island of Ruegen, off north east Germany, in February.
The H5N1 virus cannot pass easily from one person to another and therefore currently does not pose a large-scale threat to humans.
But experts fear the virus could gain this ability if it mutates. They say it could trigger a flu pandemic in its new form, potentially putting millions of human lives at risk.
BIRD FLU FACTFILE
Bird flu viruses have 16 H subtypes and nine N subtypes.
Four types of the virus are known to infect humans - H5N1, H7N3, H7N7 and H9N2
Most lead to minor symptoms, apart from H5N1
H5N1 has caused more than 100 deaths in Cambodia, China, Indonesia, Thailand, Turkey and Vietnam
The World Health Organisation says not all H5 or H7 strains are severe, but their ability to mutate means their presence is "always a cause for concern"
A six-mile (10km) surveillance zone and 1.8 mile (3km) protection zone in place around the area will remain for at least 30 days from the day the swan was found.
The Scottish Executive has also declared a wild bird risk area of 965 square miles (2,500km) - stretching from Fife to Aberdeenshire - which includes 175 registered poultry premises, containing 3.1 million birds.
About 48 - housing 260,000 birds - are free-range premises.
In this area captive birds must be housed where possible, or at least isolated to minimise contact with wild birds. Gatherings of poultry or other captive birds is banned.
Mr McIntosh said scientists had already seen the number of samples being sent for testing increase "substantially" since the UK's first H5N1 case was confirmed.
Experts were out in the field this weekend collecting carcasses, photographing them for identification and sending samples for testing, said Mr McIntosh.
Some lab staff were working 12 to 14 hour shifts to keep up with the workload, he said.
A survey of domestic poultry premises within the affected area should be completed by Sunday, he added.
One of the scientists involved in the testing, Douglas Gray, said his laboratory was seeing "significantly more birds than previously".
He is regional veterinary adviser at the Scottish Agricultural College's veterinary services disease control centre, in Aberdeen.
If you find a dead swan, goose or duck; or three or more dead wild or garden birds in the same place, you should call the Defra helpline on 08459 335577.