Yahoo and Bing show different patterns in http://discovery.wmflabs.org/external/#traffic_by_engine but have the same engine and results, don't they? So the fluctuations there would be fluctuations in usage rather than in what the search engines themselves do?
Nemo
_______________________________________________
discovery mailing list
discovery@lists.wikimedia.org
https://lists.wikimedia.org/mailman/listinfo/discovery