Conservation organizations rely on social media platforms to raise awareness and fundraise. Social media is a double-edged sword: it can be a wide-reaching and effective tool for education and fundraising, but can also have counterproductive impacts on public views toward wildlife and understanding of wildlife conservation. For example, depicting humans interacting with wildlife may increase video popularity, but animals shown in anthropogenic contexts are also viewed as appealing pets. We are interested in understanding whether this is true for social media posts (YouTube videos) by orangutan rescue and rehabilitation organizations, which rely on social media for fundraising and awareness-raising. Our goal is to provide data and recommendations to best use social media. Using YouTube analytics and sentiment analysis of comments on 119 videos, we ask how viewer responses to videos vary with 1) the amount of human-orangutan interaction depicted, 2) the ages of the orangutans featured, and 3) the mention of threats to orangutans. Videos with longer human-orangutan interaction time were viewed more, and comments on them were significantly more likely to be negative about Indonesian/Malaysian people. Comments on orangutan rescue/rehabilitation videos were more likely to be categorized as negative for orangutan conservation compared to videos about orangutans generally, and within these, so were comments on videos featuring infant and juvenile orangutans. Based on our findings, we make specific recommendations for primate rescue and rehabilitation organizations to improve the pro-conservation impact of their media while minimizing negative impacts on orangutans and people.