one study found that use of honeyguides by the boran people of east africa reduces their search time for honey by approximately two-thirds. because of this benefit, the boran use a specific loud whistle, known as the "fuulido", when a search for honey is about to begin. the "fuulido" doubles the encounter rate with honeyguides. another study of the yao honey-hunters in northern mozambique showed that the honeyguides responded to the traditional "brrrr-hmm" call of the honey-hunters. the chances of finding a bee-hive were greatly increased when the traditional call was used.