Taronga Zoo received 400 applications for its annual volunteer recruitment in March. About 150 were given interviews and just a few zoo-keepers selected. Last year, the Wayside Chapel at Kings Cross filled 200 Christmas volunteer roles in an hour.
But while some organisations are forced to turn away applicants, others struggle to supply their volunteer programs.
The Anglican Retirement Villages, which run 14 centres across Sydney, are consistently advertising for volunteers. The shortfall is not surprising as experts say community service areas, such as aged care and welfare have a regular turnover and often need volunteers.
More than 6 million Australians volunteered in 2010, according to the Bureau of Statistics, with many Sydney organisations confirming they have waiting lists for popular positions.
Volunteering NSW said among the reasons for the wait for a position is competition between organisations. "The power of the brand is very strong," research manager Tony Frew said.
Publicity surrounding certain issues, such as the environment, can also be a strong pull factor, he said.
"Fluffy, cuddly animals attract people more than some of the more serious social issues," he said.
Volunteering booms at Christmas and during natural disasters but at times people find they are turned away due to lack of training, Volunteering Australia's Peter Cocks said.
"You can't expect to walk in on Monday and volunteer on Tuesday," he said.
There are 2040 active positions listed in NSW on Volunteering Australia's online referral system GoVolunteer at present.
The organisations that receive the most expressions of interest on GoVolunteer are Mission Australia, Wesley Mission, Anglicare, Cancer Council and The Smith Family.
However, these organisations provide widespread services and are consistently looking for more hands.
"When there is a sense of financial uncertainty, a lot of welfare organisations are finding more demand for their services," Mr Cocks said.