Are there seasonality for sars, swine flu, bird flu?

No, yes, yes: Influenza tends to start in the late fall, peak through the winter and taper off in the spring. Sars occurred over 1.5 years and had sporadic outbreaks based on contacts and animal carriers, and hasn't been seen since 2004.

Yes: Since 2004, no cases of sars reported anywhere in the world. In 2011, a specific h3n2 virus was detected with genes from avian, swine and human viruses and the 2009 h1n1 pandemic virus m gene. There were 12 human infections with this virus, termed h3n2v, most were associated with exposure to pigs. In 2012, h3n2v outbreaks in human associated with exposure to pigs began in july and never ended.