SAN FELIPE, Venezuela — Nicolás Maduro is certainly not the first political candidate to invoke the name and legacy of a dead leader to win votes. But he may be the first to say that his political mentor, President Hugo Chávez, visited him from beyond the grave in the form of a little bird.

In what stands out as the most surreal moment of Venezuela’s presidential campaign — a race whose central personality is the deceased president — Mr. Maduro told the nation that Mr. Chávez’s spirit came to him as a tiny bird that flew into a chapel where he was praying.

So now at campaign rallies he whistles like a bird.

An intense, compressed campaign for president is under way in Venezuela, a month after Mr. Chávez’s death from cancer. Voters will go to the polls on Sunday to choose between Mr. Maduro, Mr. Chávez’s handpicked political successor, and Henrique Capriles Radonski, a state governor who just six months ago mounted an energetic but losing campaign against Mr. Chávez.

With all the temporal troubles Venezuela faces, including out-of-control crime, high inflation and production problems in the country’s all-important oil industry, Mr. Maduro’s campaign has done its best to leverage the spiritual, emphasizing his close, continuing ties to the deceased leader.