The Humane League

THL had been involved in over 100 campaigns to convince global companies to pledge using only non-battery cage eggs after a certain date,[6] including Sodexo,[7] Mariott International,[8] Costco, Grupo Bimbo, Starbucks, Compass Group, and Dunkin' Donuts. The Open Philanthropy Project wrote in 2015 that "Other leading organizations in corporate campaigns have consistently reported to us that THL plays a key role in these campaigns."[9]

Following negotiations with THL, United Egg Producers—which represents companies that produce 95% of all eggs produced in the United States—announced that it will eliminate the culling of male chicks by 2020. Chick culling refers to the routine killing of male chicks (which are useless for meat or egg-laying), usually by gassing or grinding them alive.[10] United Egg Producers continued chick culling despite this commitment, stating in 2021 that it was still searching for "an ethical, economically feasible alternative to the practice of male chick culling at hatcheries".[11][12]

THL also promotes the adoption by companies of the European Chicken Commitment, which seeks to improve the welfare of broiler chicken in intensive animal farms.[1]

In 2021, THL released a report which found that "99% of U.S. store-brand chickens" were afflicted by white striping,[13] a poultry disease that causes "elevated serum creatine kinase levels, increased fat content in pectoral muscle, gross white striations in the direction of muscle fiber, and hypertrophy of pectoral muscle which are similar to observations in hereditary muscular dystrophy".[14]

THL seeks to strengthen the animal advocacy movement. It provides grants, increases collaboration between organisations, hosts online volunteer initiatives, organizes events, and helps with recruiting and training.[15]

THL created in 2016 the Open Wing Alliance, a global coalition of more than 100 animal welfare organizations aiming to end the use of cages in egg production.[16][17] In the following years, THL received millions of dollars of donation from the Open Philanthropy Project to continue to grow and sustain the Open Wing Alliance.[18]

Since 2008, THL has been educating the public about intensive animal farming and advocating for a vegan lifestyle. THL uses social networks, online ads, media, leaflets, cookbooks and newsrack.[15]

THL founded in 2013 a research unit called "The Humane League Labs" that evaluates on the effectiveness of different animal advocacy tactics.[19] As of June 2016, The Humane League Labs is planning to conduct research on the degree to which farm animal advocacy motivates the purchase of vegan products[20] and on the effectiveness of online vegan outreach.[21] Vegan Publishers has criticized the methodology and reporting of previous Humane League Lab studies.[22]

The Open Philanthropy Project made several grants for "general support": $1 million in 2016,[27] $10 million in 2018,[5] $7 million in 2021[4] and $8.3 million in 2022.[3] It also made grants for THL to support and expand the Open Wing Alliance.[28] It also made grants for specific projects such as cage-free campaigns[9] or for helping THL to support the Open Wing Alliance.[18]