Yves Bonnardel, an egalitarian grassroots activist, is one of the main founders of both World Days, where he has served on the association's board since 2015, contributing to their strategic direction. His commitment to animal equality dates back to the origins of the contemporary movement in France, as a long-time contributor to Les Cahiers antispécistes, a major theoretical and activist journal that launched the movement in 1990. He has supported the development of numerous initiatives, including the Veggie Pride march, Les Estivales de la question animale, and the Swiss association Pour l'Égalité Animale. He founded the Réseau contre le spécisme and World Day for the Abolition of Meat, which later became the Marche pour la fermeture des abattoirs. He also co-founded éditions tahin party and the antispeciesist journal L’Amorce. He is the author of numerous theoretical and strategic articles and two books on the animal question (La Révolution antispéciste, Presses universitaires de France, 2018, and Solidarité animale. Défaire la société spéciste, La Découverte, 2020).