Jul. 2013 - African Plains + African Lion Exhibits

Zoos have to consider allowing the plantings to get established well enough to stand up to the animals.
And then they generally want to time a new exhibit opening to create a long bump in attendance. So in the North, exhibits are often opened around Memorial Day and attendance bump can last until October.
To open such an exhibit in, say, August or September is a wasted opportunity.

Zooplantman said:

Zoos have to consider allowing the plantings to get established well enough to stand up to the animals.
And then they generally want to time a new exhibit opening to create a long bump in attendance. So in the North, exhibits are often opened around Memorial Day and attendance bump can last until October.
To open such an exhibit in, say, August or September is a wasted opportunity.

Click to expand...

This is an intelligent, accurate response, and for the most part the month of May (or close to that time) sees the debut of many shiny new exhibits in northern American zoos. I agree wholeheartedly. However...

Interestingly enough there have been a few exceptions to the rule over the years as for instance Oregon Zoo in Portland opened Predators of the Serengeti in September of 2009 and Red Ape Reserve in September of 2010. I found out that the general thinking at that facility was that the zoo has for years been jam-packed all summer long and annual attendance has broken numerous records over the years. The 1.6 million annual visitors are there in the summer (and also during the zoo's successful Christmas light spectacular) but the zoo wished to prolong the summer lineups by opening new exhibits in September and therefore sustaining the high numbers throughout the fall.