Jane and Professor Porter aren't surprised to hear the animals talking, even though the animals never spoke to them in the first movie.
Robert Canler refers to serving the Queen, which is presumably Queen Victoria. However, the first powered flight wasn't until 1903, two years after Victoria's death. Additionally, the references to Victoria, Charles Darwin and Rudyard Kipling in the first film pinpoint the time period as late 19th century and this film is supposed to take place a year after it, not during World War I as it appears.