(NAFB)--The yearly survey of beekeepers was released Thursday. The results show fewer colony losses occurred in the U.S. during the 2013-2014 winter than in recent years - yet beekeepers say losses remain higher than the level they consider to be sustainable. Overall - losses of managed honey bee colonies from all causes were 23.2-percent across the nation - which is above the 18.9-percent level beekeepers say is acceptable for economic sustainability - but also a better percentage over the 30.5-percent loss reported the previous winter. USDA Agricultural Research Service Bee Research Laboratory Research Leader Jeff Pettis says yearly fluctuations in the rate of losses like these only demonstrate how complicated the whole issue of honey bee health has become. Agriculture Secretary Tom Vilsack says pollinators are essential partners for farmers and ranchers and help produce much of the food supply. Vilsack says healthy pollinator populations are critical to the continued economic well-being of agricultural producers.