73480
In the period before migration , many birds display higher activity or Zugunruhe ( ) , first described by Johann Friedrich Naumann in 1795 , as well as physiological changes such as increased fat deposition .
 Johann Friedrich Naumann
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Johann Friedrich Naumann