There isn’t a precise historical date or duration for “how long pigeons have been fed by Jains.” Feeding birds and animals is a long-standing expression of ahimsa (non-violence) in Jainism, practiced by many Jain communities for centuries as part of acts of charity and compassion. The exact frequency or tradition (for example, pigeon feeding specifically) varies by community, region, and temple, and there isn’t a single canonical timeline that applies to all Jains.

In short: it’s a long-standing, centuries-spanning practice tied to Jain values of non-harm, but no fixed historical duration can be stated. If you’d like, I can share more about how ahimsa and dana (charity) are described in Jain sources.