I notice that several budget-priced camcorders offer 30x optical magnification. Does this level give a good performance for bird photography? What about the quality of budget models such as Panasonic's NV-GS27EB-S and VDR-D100EB?
Or would digiscoping be better? What typical magnification is achieved by digiscopes?
You could use these camcorders to record video of birds, although you should use a tripod to keep them steady when you're working at maximum zoom. They are far from ideal for taking photographs, though.
In general, camcorders don't make good still cameras, because they are optimised for video -- which is more complicated than still photography in some ways, but a lot more forgiving in others, because the movement conceals all sorts of image problems.
The resolution of video images is quite low, so they don't record fine detail. A frame of standard-definition video only contains around 0.4 megapixels, and even hi-def video only contains 0.9 or 1.8 megapixels per frame. Digital camera resolutions currently range from around 5 megapixels to 10 megapixels or more. If you want to capture the details of a bird's plumage, rather than an overall impression of its size and markings, you'll appreciate the greater resolution of a proper camera. It will also give you more control over the focus and exposure of your photographs.
The camcorders you mention would be particularly poor choices for photography. Because the NV-GS27EB-S and the VDR-D100EB are budget models, Panasonic has concentrated on the core features required for video. They can capture still images, but only at low resolutions, and only onto tape or DVD respectively. Neither camcorder enables you to record photographs onto a memory card. This feature is commonly offered by more expensive models and makes it much easier to transfer the photos onto your computer.
I think you'll get better results by digiscoping (using a digital camera to take photos through a spotting scope). Depending on your scope and camera, you can achieve effective focal lengths of anything from around 1000mm (30x magnification) to over 4000mm. Richard Ford has a nice set of photographs showing the magnifications you can achieve on his Digital Wildlife Web site and Dylan Mackay has an animated explanation of a typical setup on DigiDylan.