America’s wealthy are in a less generous mood so far this year.

The number of donations of $1-million or more has dropped 8 percent since the beginning of 2012 compared with the same period last year, according to a Chronicle tally.

Since the start of 2012, The Chronicle has confirmed, 318 gifts of $1-million or more have been made, totaling $2.5-billion. In the first half of 2011 there were fewer such gifts, 292, but the overall total was larger, $2.7-billion.

Gifts of $100-million or more have decreased significantly. In the first half of last year The Chronicle reported six such gifts, totaling $835-million, while only two donations of that size have been announced this year, totaling $450-million.

The two largest gifts awarded so far this year are a $300-million pledge to the Allen Institute for Brain Science, from its founder, Paul Allen, a co-founder of Microsoft; and a $150-million bequest to the Oregon Community Foundation from Fred Fields, an Oregon businessman who died last year.