SHORT COMMUNICATIONS 475 ROADRUNNER PREDATION ON House Finch, Curpuducus me&anus), and several PASSERINE BIRDS times saw them stalking and attempting to catch passerines, it was not until 1969 that we witnessed another “kill.” On the afternoon of 6 June we watched DALE A. ZIMMERMAN an adult Roadrunner cross the lawn and nause be- Department of Biological Sciences neath a large, spreading alligator juniper (Juniperus Western New Mexico University deppeanu) tree. It seemed intent on some immature Silver City, New Mexico 88061 but full-sized House Sparrows (Passer domesticus) feeding on the ground nearby. After a few minutes it Roadrunners (Geococcyx colifo-rnianus) winter in jumped to a low branch and thence to a point mid- small numbers at least to elevations of 6066 ft in way up the 30-ft tree where it squatted with its southwestern New Mexico. Although the winters are tarsi essentially horizontal, its tail vertical, and its sunny, there are long cold periods which effectively neck unstretched. In this seemingly relaxed position eliminate insect and arachnid activity for many weeks it remained motionless except for frequent, short, at a time, and lizards only rarely are in evidence lateral movements of the head as it watched the between late November and March around Silver sparrows. About 15 min later several of these flew City where the following observations were made. into the thinly-foliaged juniper, some alighting within After watching Roadrunners there during the past 5 and 6 ft of the Roadrunner which they either over- 11 years I believe that they can survive by regularly looked or ignored. Suddenly the Roadrunner lunged feeding on small birds and perhaps at times on fruits. horizontally capturing one of them with its bill. It (A specimen killed on 21 January 1969 had been dropped to the ground with the motionless sparrow feeding extensively on fruits and seeds of a local firmly held by the neck, walked a few steps to a cactus, Opuntk engelmannii. ) gravelled path, dropped the bird, and began in- The literature contains a few references to this efficiently plucking it, making no attempt to secure species killing birds, and in places there exists a long- the carcass with its feet. It awkwardly removed a standing prejudice against Roadrunners because of few feathers at a time, including most of the remiges their quail-killing propensity. I believe the latter and perhaps half of the rectrices, often raising the to be exaggerated, for, despite numerous broods of sparrow and dropping it again. Sometimes it merely Gambels’ Quail (Lophortyx gambelii) about our struck the sparrow or, when pulling, failed to dislodge property each year, we have yet to see a Roadrunner any feathers. The Roadrunner worked thus for over attempt to capture the downy young. That they I5 min, then manuvered the still largely feathered occasionally do so, however, is suggested by the sparrow into its mouth head first, tried twice to prompt release of threat displays and even vigorous swallow it, and succeeded the third time. It stood pursuits by adult quail when a Roadrunner approaches gaping for a moment with the conspicuous bulge in their young. Scrub Jays (Aphelocoma coerulescens), its throat displacing the feather tracts so as to reveal Mockingbirds (Mimu.s polyglottos), Curve-billed the cervical apterium, then it bounded upward to near Thrashers ( Toxostoma curoirostre), and Brown Tow- its original perch in the tree and remained for several hees (Pip& fuscus) often voice alarm calls when minutes before leaving the area. On the preceding detecting a Roadrunner. They may so respond at any day we saw a Roadrunner make several unsuccessful time but react with increased intensity during the attempts to capture House Sparrows drinking at a breeding season. nearby pool. At the same place on 28 June 1969, There are several references to captive Roadrunners while investigating a birds’ distress call, we discovered eating birds, and to wild ones capturing wounded, a Roadrunner with a limp House Sparrow in its bill. trapped, or fledgling passerines (e.g., Sutton in Bent, The plucking operation was repeated in the same U.S. Nail. Mus., Bull. 176:45, 1940), but there appear manner and at the same site. After swallowing to be few observations of wild Roadrunners fre- the sparrow the Roadrunner drank from the pool, quently and successfully hunting full-grown, healthy, then moved into the shade where it vigorously wiped wild birds. its bill on a rock, dislodging some adhering sparrow On 11 February 1961, as my wife and I watched feathers. Following this it crouched on its tarsi, a group of juncos feeding on our lawn, a Roadrunner fluffed out its feathers and rested for several minutes raced into the flock from a place of concealment 10 ft before walking away, distant and caotured with its bill an adult lunco The following afternoon, I saw a Roadrunner oreganus mear&. The junco had been banded by ascend into the juniper tree and settle down as before. us and was a regular visitor to the feeding station; House Sparrows were feeding close by and eventually it seemed to be in perfect physical condition. The some alighted near enough in the tree to tempt the Roadrunner seized it across the carpal area of one Roadrunner to lunge twice unsuccessfully. On the wing as it attempted flight. A quick vertical snap third attempt, following a 6-ft leap, it caught a by the captor abruptly ended its life, and it was sparrow across the upper body. The victim uttered carried beyond our view. We were impressed both one brief cry and fluttered its wings feebly as the by the speed of the Roadrunner and by the apparent Roadrunner sharply jerked it up and down and inability of the junco to take flight in time to avoid dropped with it to the ground. I could not witness capture, although it faced the direction of the attack the plucking operation. On two subsequent occasions across 10 ft of bare lawn. The other juncos also were I found remains of sparrow “kills” which I attributed surprised and flew only as the Roadrunner was in to a Roadrunner. their midst. The incident occurred when the air The incidents described above took place in and temperature was 70”F, and when insects were in near the same tree where we watched a full-sized evidence throughout the neighborhood. The entire immature Roadrunner fail in attempts to catch spar- performance reflected efficiency and suggested rows on 8 September 1968. All observations were practice in the art of bird hunting. made when air temperatures were 80-93”F, and in- Although we later saw Roadrunners carrying what dicate that Roadrunner predation on birds is not con- appeared to be freshly killed birds (one of them a fined to times of year when reptiles and invertebrates 476 SHORT COMMUNICATIONS are scarce. Lizards of the genera Urosuurus, Scelop- seem that House Sparrows and other small passerines orus, Cnemidophmous, and Phqrwsomu were plentiful are at times easier to capture than are the nimble throughout the area where the sparrow hunting took lizards we customarily think of as Roadrunner food. place. We have seen lizards moving about both before and after the Roadrunners’ captures. It would Accepted for publication 29 December 1969. AMERICAN KESTREL, FALCO a well ordered nest. At this point I removed all the SPARVERZUS, EXHIBITS RELIC NEST chips lining the cup and placed them with a few others in a pile six inches away from the eggs. By BUILDING BEHAVIOR the following day all the chips had been placed back into the cup by the hawk, and nearly all were again GERALD L. RICHARDS aligned with their long axis to the horizontal. Biology Department Later when two other female kestrels were laying Wisconsin State University eggs, wood chips about 1 x 4/s inch were placed Wbitewater, Wisconsin 53190 in their nest boxes to see if they followed the same pattern. During egg laying no manipulation of the It is generally accepted that members of the genus chips occurred, but, as soon as incubation started, F&o do not build nests as such, but may occupy the birds arranged the chips to form a well ordered the old nests of other species, or merely make a cup. shallow scrape in the debris of a ledge or on the The fact that kestrels lay pigmented eggs, while ground. This is generally true for American Kestrels most cavity nesters lay white eggs, has led to the (F&o spuromius) with the exception that kestrels notion that kestrels may have only recently evolved frequently lay their eggs in hollows excavated by to the habit of nesting in hollows, and that during woodpeckers. Bent (U.S. Natl. Mus., Bull. 167, 1937) the past they used open nests of some type. The states that kestrels habitually use their chosen cavity evidence that kestrels have considerable skill in as they find it. They add little if any nesting manipulating nesting material, as indicated by this material, and lay their eggs either on the bare floor study, tends to support the idea that kestrels may have or on whatever the previous occupant has left behind. at one time built their own nests, or at least remodeled In the course of breeding experiments with the the stick nests of other species. It should also be noted American Kestrel under confinement, several female that kestrels have sometimes utilized the old nests kestrels exhibited what appeared to be nest building of magpies, and that the European Kestrel, F&o behavior. During the last week of March 1969 a tinnuncdus, a close relative of the American Kestrel, captive female kestrel laid four eggs in a modified often lays in the open nests of rooks.