_____________________________________________________________________________________________________ ++ Ph.D. Research Scholar; # Professor; *Corresponding author: Email: sam_chondekar@yahoo.com; Cite as: Chavan, Akash S., and Ramesh P. Chondekar. 2025. “Comparative Analysis of Calcium Carbonate Content in the Eggshells of Domestic Hen and Selected Wild Bird Species from the Marathwada Region of Maharashtra, India”. UTTAR PRADESH JOURNAL OF ZOOLOGY 46 (15):177-84. https://doi.org/10.56557/upjoz/2025/v46i155159. Uttar Pradesh Journal of Zoology Volume 46, Issue 15, Page 177-184, 2025; Article no.UPJOZ.5240 ISSN: 0256-971X (P) Comparative Analysis of Calcium Carbonate Content in the Eggshells of Domestic Hen and Selected Wild Bird Species from the Marathwada Region of Maharashtra, India Akash S. Chavan a++ and Ramesh P. Chondekar a#* a Department of Zoology, Dr. Babasaheb Ambedkar Marathwada University, Chhatrapati Sambhajinagar (Maharashtra), 431 004, India. Authors’ contributions This work was carried out in collaboration between both authors. Both authors read and approved the final manuscript. Article Information DOI: https://doi.org/10.56557/upjoz/2025/v46i155159 Open Peer Review History: This journal follows the Advanced Open Peer Review policy. Identity of the Reviewers, Editor(s) and additional Reviewers, peer review comments, different versions of the manuscript, comments of the editors, etc are available here: https://prh.mbimph.com/review-history/5240 Received: 16/06/2025 Published: 08/08/2025 ABSTRACT Eggshells in birds are primarily composed of calcium carbonate (CaCO3), which provide mechanical strength and protection to the developing embryo. In this study, CaCO3 content in the eggshells of the domestic hen (Gallus gallus domesticus) as a control species, compared with three wild bird species — Baya weaver (Ploceus philippinus), Spotted munia (Lonchura punctulata), and Red- wattled lapwing (Vanellus indicus) — collected from different districts of the Marathwada region of Maharashtra, India. Eggshells were collected from poultry farms and natural nesting sites, then Original Research Article