Determine the emotional tone of the following tweet: "@MendipHillsAONB do we think the swallows and swifts have gone? Photo'd 3 nights ago, not seen since. #sad #Autumn". Use the provided emotions: anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust. Respond with the emotions you identify or "neutral or no emotion".
pessimism, sadness