Ask Mr. Smarty Plants

If all the leaves are gone, I would suspect deer.  I don't know what part of Austin you are in but some parts of Austin have high populations of deer and I can speak from experience that deer do like to eat Aquilegia canadensis (Eastern red columbine) and Aquilegia chrysantha var. hinckleyana (Hinckley's golden columbine).  Both are listed as moderately deer resistant but in this time of drought the deer are very likely to eat whatever is available.  You can try some of the deer repellents (chemical or mechanical) that are available at nurseries or you can fence the area to keep the deer out of your garden.  Some people put black plastic netting over or use it to make a barrier around the plants to keep the deer from eating them.  It would depend on how tall your columbines are or how big your flower bed is as to whether this method would be a feasible method for your situation.  The Rhode Island Department of Environmental Management has an excellent article, "Reducing Deer Damage to Your Yard and Garden", with descriptions of several methods of control, including homemade repellents.