ZION, BRYCE CANYON, CEDAR BREAKS Birds of Zion, Bryce and Cedar Breaks

THE BIRDS OF ZION, BRYCE, AND CEDAR BREAKS

BIRD PROBLEMS AND STUDIES

While there are numerous problems of more than usual interest, three stand out above all others in importance. First, there is the problem of the distribution and movement of local permanent residents. Second, there is the study of seasonal migration, both of local birds and species simply drifting through the region. Third, the effects of the creation of Lake Mead upon the local bird life is likely to become pronounced as time goes on, and careful studies are necessary to record these effects.

There are undoubtedly those who will differ as to the relative importance of the various problems and studies. The value of habitat studies will no doubt be mentioned, with stress placed upon food and nesting habits, enemies, etc. No doubt the relationships between birds and other animal forms, their economic value, and many other equally legitimate subjects will be advanced as being of primary importance. There is no denying that such studies are valuable, and all have a place. However, in regard to most bird forms, much data are already available on all of these subjects, and, while more material is needed, this need is not urgent. Thus, it is believed that the three primary objectives of study given above are of the greatest concern in planning future bird studies in this region.

The problem of the distribution and movement of local permanent residents has many important details that are as yet unsolved. In a general way, we know what species are resident in the region, but we are constantly finding that the status of some bird must be changed to conform to new data that are uncovered. Birds that have been classified as summer residents on the basis of early studies are now listed as permanent residents, as additional information was accumulated. Birds that were supposedly residents only of the higher reaches of the plateau have been found nesting in local habitats of a favorable nature in the low canyons. Large gaps occur in the year around record of many species, and a day by day, month by month study is necessary to clear away these uncertainties.

The more one studies the problems of migration, the more he is impressed with the meagerness of our information on the subject locally. It is now possible to obtain and read scores of excellent publications on the subject of bird migration, but these are all discussed from the standpoint of some other part of the continent, and the examples used are not from this region. In this part of the Southwest there is a virtual blank spot on the map of bird migration knowledge. This is slowly being corrected, but the process is one that takes time to complete. At Grand Canyon National Park and at the Museum of Northern Arizona (to name only two) studies have been carried on for years, and much valuable data have been obtained. In the main, these studies are devoted to field observation, collecting and bird banding. Here in Zion, Bryce Canyon and Cedar Breaks similar work has been in progress for several years, although more or less intermittent in nature. There are now many data available through the accumulation of field notes from several observers. These, however, are very inadequate, although they form a valuable basis for future field studies. Several species have been collected and preserved as study skins for future reference. This collection is slowly increasing to the point where it is possible to use our local material effectively in identifications requiring a rather minute examination and comparison. Much, however, remains to be done in this field. There are still several species known to nest in the region or drift through on migration whose complete sub-specific identities are uncertain. It will be necessary to collect these birds to clear up these uncertainties. Collections should not, however, be made in quantity of any species. Three or four study skins of each variety are sufficient for practically any need. The collection of these skins can be planned to include immature as well as adult plumage.

It is through bird banding that many valuable data are uncovered. Through such activities, we have found that birds migrate vertically as well as horizontally. Some bird species simply drift from the highlands to the lowlands during the winter months, and do not fly long distances to other regions. Through banding, it has been found that some species are permanent residents, but the individuals representing these species may or may not be. For example, a junco that nests in the park during the summer may travel many miles during the cold months, as a seasonal migrant, while others of his kind continue to reside in the park. Whether or not these winter resident birds are there throughout the year, or move into the area from other regions is as yet unknown. Only through banding can this be finally determined. Banding has demonstrated that many species have a rather rigid time schedule on migration. For example, seldom does the Gambel's Sparrow vary much in the time of year he first drifts into Zion Canyon. Usually there is not more than a week's difference from one year to the next. One can almost consult the calendar each fall and expect to see these birds when the date of their arrival falls due. Feeding habits have been found to be remarkably routine. Certain species, such as the Chipping Sparrow and the Nuthatches, will visit the feeding trays at very definite times during the day. Individual birds have been taken several times a day, and their capture time recorded. As this is repeated each day, it has been found that certain individuals can be expected at the traps throughout the day at very regular hours. These, and many other interesting details, have been uncovered in the process of banding.

One of the most fascinating of all our problems concerns itself with a nearby region—the Lake Mead area. The creation of this huge lake, approximately one hundred miles down the Virgin River from Zion, has made that region an important resting ground for thousands of ducks, geese and shore birds during spring and fall migrations. On the lake there are several areas that are extensively utilized by these birds, but the most important of all is that portion of Lake Mead where the Virgin River empties into the reservoir. Here birds of many species congregate in large numbers to feed in the shallow waters and around the mud flats. Species never before reported from Nevada have been observed in this area. With the Virgin River leading from this region to the northward, it is fairly safe to assume that many bird species drift up the river in the spring of the year on their northbound travels to the summer nesting grounds. Whether or not these birds leave the river course is as yet unknown, but studies carried on seem to indicate that many come right on up the Virgin to where it junctions with Parunuweap Canyon, near the boundary of Zion National Park. Here the birds apparently go on up the Parunuweap, instead of following the Virgin River into Zion Canyon. Occasionally there are evidently some exceptions to this case, as Gadwalls, American Mergansers and California Gulls have been seen in the main canyon. However, such birds as the Treganzai's Heron, Brewster's Egret, Western Sandpiper, Western Solitary Sandpiper, and other species have been seen in the Parunuweap, but not in Zion Canyon, which lends strength to the belief that the main migration route is via the Parunuweap. It seems very likely, then, that as the Virgin River arm of Lake Mead continues to grow in importance as a feeding ground, this region is going to be vitally affected. We should logically expect birds through here that have heretofore been unreported from southern Utah. Some hint of this is seen in the finding of such birds as the loon, egret, various grebes and several species of ducks on nearby reservoirs, ponds, and along the principal tributary streams. While these may have been accidental visitants, it seems much more likely that they were merely following a definite migration route thus far unreported. A study of the main flyers in this region discloses a very interesting fact. The Virgin River continues in an easterly direction for several miles after its junction with the north fork of the Virgin River, then turns northward. For some distance it follows along the route taken by U. S. National Highway 89, but finally disappears as its source is reached near the water divide at Long Valley Junction. However, only a short few hundred yards on the opposite side of this water divide a new stream develops and continues northward. This stream soon runs into the Sevier River, also northbound. The Sevier is definitely an important resting and feeding ground for migratory ducks and other species, and hundreds have been noted along it. Thus, it can be seen that a direct water route from Lake Mead to the Utah Lake-Salt Lake region is to be had via the Virgin and Sevier Rivers. It is interesting to note that it is along or near these streams that all of the above mentioned bird species have been observed.