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The next morning, the kestrels were placed in the artificial neat box~ivhich had been attached to a telephone pole 9 meters in height and located about 50 meters from the original nest Bite. At this location the kestrel nest site was within 50 meters oP an active coal loadout and railroad maintenance building. The falcon advlte were observed flying in the railroad maintenance yard when I first arrived et a distance of approximately 100 meters. The neat box lid was placed in an open position to allow the young falcons to vocalize with parents. The female adult falcon responded to the young and flew into the nest box. The female remained in the box for five minutes and then left the box flying downwind. Approximately 15 minutes later, she returned to feed the young birds a cricket. After 2 hours of observation, the lid was closed and then the adult birds were observed flying through the hole which had been cut in the aide of the box Por nest access (see Photo #5). The nesting falcons were checked two weeks later using a bucket truck to raise and lower personnel to the nest box location. A VHS Video Tape recording was made of this event which shows the young birds about to fledge (see Photo #6). The three young were noted in Pree flight maneuvers with adult birds within the nest vicinity while they practiced hunting in the adjacent fields. The adult falcons returned in the Spring oP 1986 and were observed utilizing the nest box and protecting the territory from intruders. Although no young were hatched, the neat box contained three infertile eggs when checked the third week of June. MeaeuremenLs of the falcon eggs are listed in Table 1. No explanation could be found as to the sterile nature of the eggs. Bent found desert kestrel egg measurements to average 35.1 by 27.5 millimeters (Bent, 1938). Deserado Mine falcon eggs fell within this measurement. It should be noted that the State of Colorado initiated a pesticide spraying program during 1986 near the Dinosaur National Monument in order to control an infestation of crickets on rangeland. Colorado State University started a 5 year monitoring program using 40 kestrel neat boxes as a bioassay method to determine chemical spraying effects on the resident raptor population adjacent to the Dinosaur National Monument. Since this is the first attempt by the adults to use the neat box substrate on their own, I was pleased to see this event take place, since it ahowe they will occupy alternate Heating sites when presented with the option. During the Spring of 1987, the kestrel parents again returned to the neat box for another breeding season. On July 2, at 1030 hours the aerie was checked and 5 young were found inside only 2 - 3 days from fledging the nest box. Two female and three male juvenile birds were weighed and measured with data recorded on Table 2. Prey located in the box included leg and feather remains of a Meadow Lark (Sturnell neglects) and parts of an unidentified lizard. CONCLUSION The study revealed that artificial neat box can be used successfully when nesting habitat Por American kestrels has been altered or displaced by man's