How do fruit pigeons digest fruit differently from seed-eating pigeons?

The digestive systems of fruit pigeons and seed-eating pigeons are adapted to their respective diets through distinct anatomical differences:

• Intestinal Structure: Fruit pigeons possess a broad, short intestine, which allows them to void the stones of the fruits they consume intact. In contrast, seed-eating pigeons have long, narrow intestines.1
• Gizzard Strength: Seedeaters require and possess stronger gizzards to process their diet, whereas fruit pigeons do not rely on the same level of mechanical grinding for their softer food sources.1
• Bill Morphology: The physical processing of food begins with the bill; fruit eaters often have deeply hooked bills—particularly those that consume large, hard fruits like figs—to help tear and nibble food. Seed eaters typically have smaller, more slender bills suited for their diet.1

Regardless of diet, all pigeons utilize a crop, a bilobed pouch of the esophagus that serves as a storage organ. This allows them to consume large quantities of food rapidly and digest it later, which is particularly important for birds subsisting on low-nutrient items like seeds and fruit.2