There is no Jain scripture that makes feeding pigeons an essential practice. In Jainism, the essential duties for both householders and monks are the five great vows (ahimsa, satya, asteya, brahmacharya, aparigraha) and other related observances. Feeding birds or performing charity to animals is praiseworthy, but it is not listed as an essential vow or canonical requirement.

In short:

• The core, essential practices are the five Mahavratas and related vows.
• Bird-feeding is a noble charitable act (and aligns with ahimsa), but not an essential duty.

You can read more about the five great vows here