A study in South Texas showed that rattling may be more effective than even avid horn rattlers realize.

For years, no one could scientifically answer the question, "Does rattling really work?" Now someone can. Recently, Dr. Mickey Hellickson conducted a study on the response of deer to antler rattling at the Welder Wildlife Foundation Refuge in South Texas.

Cover on the 8,000-acre research refuge consists of low brush typical of the South Texas brush country. Numerous telephone-pole observation towers are scattered across the refuge. Deer numbers are high, the buck-to-doe ratio is fairly balanced, and plenty of mature bucks live on the area. Given light hunting pressure, deer on the refuge might be a little less wary than on heavily hunted areas, and they may respond better to rattling.

In Phase One of the study, Hellickson placed observers in observation towers to watch for bucks as other researchers rattled on the ground. In Phase Two, Hellickson placed activity collars on some older bucks, which allowed him to monitor the bucks' movements.

To determine the response rate of deer to various types of rattling, Hellickson set varied parameters: Loud rattling (banging the antlers together) versus soft rattling (tickling the antler points, grinding the bases). He rattled for a half-hour in each setup, in three 10-minute segments of either long rattling (seven minutes of rattling followed by three minutes of silence) or short rattling (one minute of rattling followed by nine minutes of silence). These sessions were further varied with combinations of long/loud, long/soft, short/loud, and short/soft rattling. Finally, the study covered varied times of year (pre-rut, peak-rut, and post-rut); all kinds of weather; and different times of the day.

Over a three-year period and 171 rattling sequences, Hellickson and his helpers observed 111 bucks responding.

Remember, those were bucks seen by the observers and persons rattling on the ground.

Here is the interesting fact: Persons rattling on the ground saw only 33 percent of the bucks seen by observers in towers. Sixty-six percent of the time, bucks did not come close enough for persons on the ground to see. Almost certainly some bucks circled downwind and vanished before being seen by anyone, because 67 of the 111 bucks that responded to rattling were first seen downwind. Clearly, an elevated position gives a person an advantage in spotting and observing approaching bucks.

Okay, rattling attracts bucks, but what approach works best? And when? During Hellickson's study (see Table 1), loud rattling brought in three times as many bucks as soft rattling. Early morning was by far the best time of day. The peak of the rut brought the peak of responses. In regard to weather, calm, cool days with 75 percent or more cloud cover proved optimum.

Relative to short or long rattling sequences, resear-chers found no difference in response rate. A higher percentage of bucks came during the first rattling sequence of each three-sequence set, but a good number showed up during the third sequence, too. The lesson? Always sit tight and rattle for at least 30 minutes.