In this idiom, "li" (唳) refers to the cry of a bird. "Cry of the wind and call of the crane" means mistaking the sound of the wind and the cry of cranes for the shouts of enemy troops, suspecting that pursuing forces have arrived. It describes a state of extreme panic and nervous tension.
This idiom originates from the "Biography of Xie Xuan" in the *Book of Jin*: "Jian's army fled in disarray; the remaining troops abandoned their armor and fled at night. Hearing only the wind howling and cranes crying, they believed the imperial army had arrived. Traveling through grass by day and sleeping in the open by night, suffering from cold and hunger, seventeen or eighteen out of every twenty died."
In the year 383 AD, Fu Jian, emperor of the Former Qin dynasty, assembled an army of 900,000 troops and marched south to attack the Eastern Jin dynasty. The Eastern Jin court appointed Xie Shi as commander-in-chief and Xie Xuan as vanguard, leading 80,000 elite soldiers to resist.
Fu Jian, confident in his overwhelming numerical superiority, believed he had a firm grasp of victory. He concentrated his forces along the Fei River east of Shouyang (present-day Shou County, Anhui), waiting for his main reinforcements to arrive before launching a full-scale attack on the Jin army.
To overcome the odds, Xie Xuan devised a strategy. He sent an emissary to the Qin camp, suggesting to the Qin vanguard: "Your forces are camped along the Fei River, clearly intending a war of attrition rather than a quick victory. Wouldn't it be better if your army slightly retreated, allowing our troops to cross the Fei River so we can fight a decisive battle?"
During internal discussions, Qin generals agreed that by holding the Fei River line, the Jin army could not cross. Once the main Qin forces arrived, they could completely crush the Jin army. Therefore, they concluded they should not accept the Jin proposal.
However, Fu Jian, eager for a swift victory, rejected his generals' advice, arguing: "If our army retreats slightly, once half of the Jin troops have crossed the river and half are still in the process, we can charge with our elite cavalry and surely achieve a great victory!"
Thus, the Qin army decided to withdraw. Fu Jian did not anticipate that his army was hastily assembled and poorly coordinated. When the retreat order was given, the troops mistakenly believed the front lines had been defeated and immediately panicked, fleeing in disorder. Seeing the enemy in disarray, Xie Xuan ordered his troops to quickly cross the river and attack. In their chaotic retreat, Qin soldiers abandoned weapons and armor, creating utter confusion; countless were trampled to death by their own comrades. Those few soldiers who侥幸 (fortunately) escaped Jin pursuit, upon hearing the howling wind and the cries of cranes along the way, imagined the Jin army was pursuing them again. Regardless of day or night, they fled desperately. In this way, the Jin army achieved a major victory in the Battle of Fei River.