As is often the case, I agree with Alan.
There was a time when it was possible to argue in favour of JPEG over RAW, but then only from two perspectives; cost of storage (I remember paying a fortune for a 1GB MicroDrive) and the need for often clunky processing software. These days, neither is an issue.
Mr. Rockwell bemoans the fact that RAW formats are proprietary and may not be supported in the future. In that case, if you're worried convert everything to DNG on import, but in my experience the RAW files I shot on the Canon D30 in 2001 are still opened by every iteration of Adobe software (both Lightroom and Photoshop). That also raises an interesting point; if I want to go back to that precious photograph from 2001, I can apply 2010 processing to the RAW data, gaining from nine years' improvement in colour management and noise reduction. Impossible if I'd have shot JPEG.
An example is attached, and most will probably agree that it's the technical equal of many photographs shot on today's digital cameras, nine years on! (Prizes for IDing the elephants)
Rockwell even contradicts himself by saying that so-called "professional" and "prolific" shooters haven't got time to "piddle with anything in Photoshop", but goes on to explain "If you don't like the in-camera options, shoot unsharpened JPGs and sharpen elsewhere. Likewise, if you set the wrong white balance or underexposed you can always correct it later." He's therefore proposing the absolute worst work-flow; in-camera processing and in-camera compression, followed by compromised post-processing and yet another generation of lossy compression.
What does RAW get us? In short; loss-less compression (none of the data from that big sensor you just paid for is thrown away in-camera), at least two stops more dynamic range (most importantly the ability to recover blown highlights), much better noise reduction performance, the ability to correct colour balance precisely and without image degradation (as an exercise try correcting a JPEG shot outdoors with a "fluorescent" white balance setting for an eye-opening experience) and a much wider colour gamut.
In the real world, many of these things are particularly important to zoo photographers because of all the different environments and shooting compromises we face. For example, think of the challenges in setting an accurate white balance. If you're shooting JPEG, the options are either to continually select a manual setting from one enclosure or exhibit to the next, or rely on "Auto" which will get it wrong most of the time. In both cases you're going to end up having to spend ages fiddling with the control on the camera (and missing the shot) or the levels and curves controls in Photoshop as suggested by Mr. Rockwell, once again defeating his own argument. The same applies to exposure, and NR.
Regardless of the technical arguments, if you have a good quality digital SLR, then surely you'd want to get the best from the camera. Shooting JPEG on a high-end Canon or Nikon is like buying a Ferrari and only using it to tow a caravan.