This is what Philimon told us at the beginning of the month. Hatari means danger or dangerous in Swahili, and Philimon was explaining how the hyenas can be naughty this time of year.
The migration has moved on, and the rains are (theoretically) over; so there is a lot less prey in the area. This means that the hyenas are having to look harder for food. We can see their GPS points clustering around the trash pit in Serena or town in Talek; human scraps can be easy pickings.
The hyenas also come into camp more and can get into trouble... hence, this is what happened to Philimon's chair the other night.