Pigeon
Pigeons demonstrate legendary persistence in the face of human discouragement. Spikes on ledges? They nest between them. Fake owls? They befriend them. Ultrasonic deterrents? They appear to enjoy the ambience. Municipal culling programmes have achieved approximately nothing across centuries of implementation. The pigeon's capacity to remain where unwanted represents a masterclass in determination that motivational speakers might reference, were pigeons capable of purchasing seminar tickets.
Death
Death's persistence throughout history stands utterly undefeated. Alchemy, prayer, cryogenics, medical science, and increasingly desperate vitamin supplement regimens have collectively failed to produce a single verified permanent exception. The phenomenon demonstrates absolute constancy across all historical periods, social classes, and dietary preferences. Whilst timing varies, the outcome remains stubbornly consistent. Death has never taken a holiday, requested time off, or demonstrated any flexibility whatsoever.
VERDICT
Both demonstrate exceptional persistence, but death's perfect record stands unmatched. Pigeons can theoretically be relocated; death cannot be rescheduled.