One day, I asked a bird food seller, what bird seeds can gain birds’ weight. He introduced me sunflower seeds, hemp seeds, and canary seeds. I were curious, besides gaining weight, what other benefits of canary seeds for birds? I summarize the findings as below from various websites. Small and medium sized parrots love canary seeds, but it is not suitable for large parrots because the size of seeds is too small for them. Canary seeds is high in fat, don’t treat it as regular meal for your birds.