In light of the recent tiger incident, the news claims more people visit US zoos than attend sprting events! That’s hard to believe! Even if we’re just talking pro sports, that’s still hard to believe! How can one get the Straight Dope on this?
What news? 
Who claims this?
Cite?
Maybe they said that more people see Tigers at zoos than they do at sporting events. Are you listening, Detroit?!
I’d like to see a cite for that too. According to the website for the St. Louis Zoo, the total attendance was about 2.9 million in 2002 (the last year for which figures were posted). The Cardinals by themselves drew 3.0 million the same year. That doesn’t count the other pro sports, college, high school, etc. In Cincinnati in 2006, the Zoo pulled in 1.0 million, while the Reds drew 2.1 million. That’s a very small data set, of course, and maybe there are lots of small zoos in small cities without pro sports teams. I’m not buying it, though.
If you are talking about unique individuals, then the 1 million that visited the zoo probably represents more individuals than the 2 million that went to the ball game (many people go multiple times to a ball game). Just a WAG.
The Association of Zoos and Aquariums, which covers about 240 accredited members in the US, gives a total attendance of 143 million in 2005.
There are no doubt other zoos and menageries which are not members of AZA.
The World Association of Zoos and Aquariums says that 600 million visitors pass through the gates of member organizations every year.
Lots of people go to the zoo multiple times, too. I know I go to the St. Louis zoo more often than I go to Cardinals games, but the zoo is free.
Unfortunately, you can’t get drunk at the zoo. (Unless they close it off for a day and allow only the employees of Anhauser-Busch and their families, handing out unlimited free beer for all invitees. Man, that was a great day. Apes are twice as fun to look at when drunk. 
)
A little more info:
According to a US Census estimate (PDF here), about 26.5 million people went to zoos in 1998. If I understand correctly, that would be unique individuals. The same document estimates baseball attendance at 26.3 million unique visitors (again, assuming I’ve read the information correctly.) The document doesn’t differentiate between pro and amateur baseball, but it does differentiate between pro and college football and basketball. Pro football looks like about 16.1 M and basketball about 10.6 M. That’s 26.7 M, plus some part of baseball’s 26.3 M. Altogether, it’s higher than the 26.5 M for zoos.
Well, I’ve been to quite a few zoos in my life, but I’ve never attended a single sporting event.
Anecdotes, data, plural, etc…
I have been to sporting events but I go way more to zoos and so do my kids.
299,999,998 more to go.
I would note that that’s way out of line with the AZA figure above. (It’s unlikely attendance increased by sixfold in seven years.) And the difference clearly isn’t due to multiple visits by the same individuals; the census figures indicate relatively few multiple visits.
Unless you’re counting amateur sports, high school games, little leagues and the like, I believe the assertion. There are, what, 32 MLB teams (who each play 81 home games/year) and 32 NFL games (8 home games/year), plus NBA, NHL, NASCAR, etc. Add them all up, it’s still a relatively limited number of opportunities to attend a professional sports event.
By contrast, there are hundreds and hundreds of zoos in the country – probably one in just about every medium-sized city, and many large cities have several. And most of these are open nearly every day, the entire year.
I’d actually be surprised if the total zoo attendance wasn’t higher.
Hmm. I gathered the figures for MLB, NFL, NBA, and NHL found on ESPN (here, for example), for the last full year of each sport. It looks like the total attendance was:
NFL: 17.6 M
MLB: 76.0 M
NHL: 20.9 M
NBA: 7.1 M
TOTAL: 121.6 M
That’s getting close to the 143 M, without taking into account auto racing, boxing, minor sports, etc. I’m not sure how reliable these guys are, but they claim 15 M for NASCAR. That brings the total to about 136 M.
In terms of total attendance, it’s a lot closer than I would have thought. In terms of unique attendance, if the Census is correct, sports are pretty far ahead. Although, as Colibri points out, the Census numbers are way off from the AZA.
If we count NCAA, I don’t think it’s close anymore. According to www.ncaa.org, the total 2006 attendance for football was 47.9 M and for men’s basketball 30.9 M.
Don’t forget college sports. The NCAA says the attendance at college football games in 2006 was almost 48 million people (pdf available here). Attendance for men’s basketball in 2007 was almost 33 million (pdf here ). Attendance for women’s basketball in 2006/2007 was almost 11 million (pdf here ).
Something’s off here. Both the NHL and the NBA have 30 teams who play 41 home games in approximately the same size arenas…
(Incidentally I heard the same claim as the OP on TV news.)
That’s because I’m a doofus who picked the wrong year from the website. The 2006-2007 NBA total was about 21.8 M. Thanks!
Is it?
Think about it. It makes sense.
Every major city has a zoo. It’s open all day, every day, and can take thousands of people coming in and going out constantly for all that time. A sporting event is generally open for about 3 hours, and not every city has sporting events worth going to.