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D. H. Ellis

Publications and source records attributed to D. H. Ellis.

At least 37 records · Page 2Linked to original sources
USGS2001

Results of the first ultralight-led sandhill crane migration in eastern North America

In 1997, we led 8 sandhill cranes (Grus canadensis) south from Ontario, Canada by ultralight aircraft to a wintering area near Warrenton, Virginia, an area without a wild population. Six others were transported south in a trailer in hopes they would return north with those that flew. The migration was 863 km long, included 14 stops, and took 21 days to complete. All 13 surviving birds were wintered together. In March 1998, the surviving 7 'aircraft-led' birds departed the wintering site. The following day, 6 of the 7 were reported on the south shore of Lake Ontario. The flock then moved around the western tip of Lake Ontario. On 5 April 1998, we used 2 aircraft to lead the birds 104 km directly east to the rearing area. The flock soon moved off the fledging grounds, continued to associate with people, and was eventually removed from the flyway. Because no wild cranes are known to fly our chosen route, this study demonstrated not only the effectiveness of ultralight aircraft to lead cranes on migration, but it also proved that cranes so led can return from their wintering site to the general vicinity of their fledging area unassisted. The birds did not follow our indirect route south but rather flew north to the latitude of the fledging area, then wandered.

Book chapter↗
USGS2001

Promoting wildness in sandhill cranes conditioned to follow an ultralight aircraft

During the 1998 field season, we developed and tested a new protocol to teach sandhill cranes (Grus canadensis) to follow ultralight aircraft yet avoid humans. Although successful in teaching the cranes a migration route, our previous migration (1997) resulted in birds that were overly tame and sought association with humans. For this study, 16 sandhill cranes were costume-reared at USGS Patuxent Wildlife Research Center and transported to Ontario shortly before fledging. After the birds learned to follow the aircraft, 14 were transported to an isolated wintering site in South Carolina, 1300 km south of the training area. Twelve arrived safely. Eleven of 12 birds survived the winter. All of these 11 cranes moved north to Cape Hatteras in early May. Thereafter, 6 of the cranes were captured and translocated to northern New York state. The remaining 5 returned to South Carolina, autumn 1999. Prior to capture, although the cranes sometimes allowed humans to approach them, none of the cranes approached buildings or humans.

Book chapter↗
USGS2001

Results of the second (1996) experiment to lead cranes on migration behind a motorized ground vehicle

Fourteen greater sandhill cranes (Grus canadensis tabida) were trained to follow a specially-equipped truck and 12 were led along a ca 620-km route from Camp Navajo in northern Arizona to the Buenos Aires National Wildlife Refuge near the Arizona/Mexico border. Ten survived the trek, 380 km of which were flown, although only a few cranes flew every stage of the route. Major problems during the migration were powerline collisions (ca 15, 2 fatal) and overheating (when air temperatures exceeded ca 25 C). The tenacity of the cranes in following both in 1995 and 1996 under unfavorable conditions (e.g., poor light, extreme dust, or heat) demonstrated that cranes could be led over long distances by motorized vehicles on the ground.

Book chapter↗
USGS2001

Fate of the survivors of the 1995 and 1996 Arizona trucking migrations of costume-reared greater sandhill cranes

In 1995 and 1996, we trained 2 groups of costume-reared greater sandhill cranes (Grus canadensis tabida) (10 in 1995, 14 in 1996) to follow a truck. Thereafter we led 10 in 1995 and 12 in 1996 from Garland Prairie, northern Arizona, to the Buenos Aires National Wildlife Refuge, southern Arizona (ca. 620 km). These techniques were being developed to create additional, disjunct populations of the whooping crane (G. americana). The cranes taught the migration route in 1995 did not follow the desired migration route in 1996 but did travel north 140 km along the route in spring 1997. By the summer of 1997, we did not know the locations of any of these birds. Results were better for the 1996 tracking cranes. Between 1997 and 1999 there was a 92% (11 of 12) success rate for the 1996 trucking cranes with known locations flying unassisted from the summering to wintering grounds. Through 1999, 7 of the 12 cranes became lost on flights from the wintering to summering grounds. (Some of the trucking cranes apparently followed wild cranes to or toward breeding grounds.)

Book chapter↗
USGS2001

Results of the Utah-Arizona stage-by-stage migrations

In an effort to find a safer means of teaching cranes new migration routes, each year (in 1998 and 1999) we transported a group of greater sandhill cranes (Grus canadensis tabida) stage-by-stage, in a horse trailer, with stops for brief flights at about 30-km intervals, along a 1300-1400-km fall migration route from Fish Springs National Wildlife Refuge (Fish Springs) in west-central Utah to the vicinity of Gila Bend, Arizona. Thereafter, we released them into a wild flock of sandhill cranes. All stage-by-stage birds were hand-reared with both a plastic crane decoy (to encourage them to roost in water) and a costume-draped humanoid form (called a scare-eagle and used for its namesake purpose). When these 2 teaching aids were placed in water, our cranes readily roosted nearby. All but 4 of our cranes proved cooperative (i.e., catchable at each of the ca 25-36 stops) during the migration. All were efficiently released into a wild flock and experienced good survival. The stage-by-stage method proved to be a safe means of transporting cranes south and giving them experience along the route. Some cranes apparently learned their route from the limited experience afforded by releasing them at intervals, and the 1999 cranes have made repealed migrations to or near our chosen northern terminus. However, after 1 winter in our chosen area, the birds have moved elsewhere to winter.

Book chapter↗
USGS2001

Lessons from the motorized migrations

Ten experiments have been conducted to determine if cranes can be led on migration and if those so trained will repeat migrations on their own. Results have been mixed as we have experienced the mishaps common to pilot studies. Nevertheless, we have learned many valuable lessons. Chief among these are that cranes can be led long distances behind motorized craft (air and ground), and those led over most or the entire route will return north come spring and south in fall to and from the general area of training. However, they will follow their own route. Groups transported south and flown at intervals along the route will migrate but often miss target termini. If certain protocol restrictions are followed, it is possible to make the trained cranes wild, however, the most practical way of so doing is to introduce them into a flock of wild cranes. We project that it is possible to create or restore wild migratory flocks of cranes by first leading small groups from chosen northern to southern termini.

Book chapter↗
USGS2001

A comparison of behavior for two cohorts of captive-reared greater sandhill cranes released in northern Arizona

To determine how the behavior of greater sandhill cranes (Grus canadensis tabida) changes according to time of year, time of day, and number of days after release, we observed the activities of 2 groups of captive-reared greater sandhill cranes at Mormon Lake, northern Arizona. The behaviors we compared were alert, loafing, sleeping, foraging, preening, locomotion, and other. We found costume-reared subadult greater sandhill cranes that were established at the study site for a year spent more time foraging and being alert towards predators than parent-reared juvenile greater sandhill cranes that were recently released from captivity. We also found that with time juvenile sandhill cranes were increasingly alert and spent less time loafing. It appeared that captive-reared juvenile sandhill cranes learn behavior important for survival from previously released captive-reared cranes.

Book chapter↗
USGS2001

A reintroduction experiment involving mated pairs of parent-reared greater sandhill cranes in northern Arizona

In April 1997, 4 mated pairs of adult greater sandhill cranes (Grus canadensis tabida) were abrupt-released at Mormon Lake, Arizona. Five of 8 adult cranes died within 10 days of release. One crane flew from the release area within 10 days after release and was never relocated. One pair of cranes, with 1 pair member sustaining a broken wing 4 days after release, survived for 4 months and demonstrated the importance of maintaining pair bonds after release. The cause of death of at least 5 birds was predation. The high mediate mortality and complete long-term mortality experienced in this pilot project suggests that adult cranes are poor candidates for release. These poor results encourage that, in future release attempts with mated pairs or other adult cranes, it is important to provide the cranes with roosting habitat while still in captivity and to hold the cranes in an acclimation pen at the release site for several clays prior to release.

Book chapter↗
USGS2001

Water conditioning and whooping crane survival after release in Florida

About 50% of the whooping cranes (Grus americana) released in Florida die within the first year of release. Most of these deaths and those in subsequent years result from bobcat (Lynx rufus) predation. Choosing release sites in open marshes away from bobcat habitat has improved survival. We hypothesized that exposure to ponds (water conditioning) at the rearing site would encourage birds to roost in deeper water marshes after release and such exposure would thereby reduce bobcat predation. In this study, we moved young birds (ca 50 days of age) to netted pens with large (15-m diameter), deep 30-60 cm) naturally vegetated ponds. We randomly assigned the costume-reared whooping cranes into 2 equal-sized groups at fledging. Some groups were placed in pens with a pond (experimental or ponded groups) and the others we reared without additional water exposure (control groups). All birds in the pens with ponds used the water. At night, they roosted at a depth of 36-46 cm. During the day, the birds used the ponds as well as other areas of the pen. We released 3 pairs of water-conditioned and control cohorts, 1 set in 1995 and 2 in 1996. No obvious behavioral differences were noted between the cohorts released in those years. Controls survived as expected (about 60% first year survival). The water-conditioned birds had much higher survival the first year (85%) and continued to survive better for the next 3 years.

Book chapter↗
USGS2001

Natural fertility in whooping cranes and Mississippi sandhill cranes at Patuxent Wildlife Research Center

The first fertile whooping crane (Grus americana; WC) egg produced through natural breeding at Patuxent Wildlife Research Center (Patuxent) was laid in 1991. Prior to that time, all fertile whooping crane eggs were the result of artificial insemination. Since 1991, eight different whooping crane pairs at Patuxent have produced fertile eggs through natural breeding. Mean fertility averages over years for each pair range from 40% to 93%. Fertility rates for each pair also vary greatly between years, from 0% to 100% but the causes of the variance are unknown. Experiences with natural fertility in Mississippi sandhill cranes (G. canadensis pulla; MSC) have been similar. Annual natural fertility rates averaged from 21% to 89% and fertility averages for each of 7 pairs also varied greatly between years. Rearing methods have not determined success in natural breeding for either species. Both hand-reared and parent-reared pairs have been fertile. Wing condition, however, has been an important factor affecting natural fertility. Becausce artificial insemination (AI) generally results in higher fertility rates than natural breeding, Al should continue for some pairs.

Book chapter↗
USGS2001

Recommendations for the attachment of satellite transmitters to cranes

Recent advances in miniaturization of satellite transmitters have resulted in thumb-sized packages weighing less than 30 g. These are smaller than VHF radios routinely mounted on crane leg bands. With this development and with favorable signal reception results, there is no need for, and much to recommend against the continued use of back-pack mounts. We provide details for leg-mount attachments.

Book chapter↗
USGS2001

The one-by-one method for releasing cranes

Although the trend for the past 2 decades has been toward releasing naive groups of juveniles after a lengthy acclimation period, in 5 separate releases (1996-2000) we tested the idea that naive juvenile greater sandhill cranes (Grus canadensis tabida) would survive better if released singly into a wild flock of predator-wary birds than if left as a group, inexperienced at foraging and ill prepared to avoiding predators. We released 3 groups of hand-reared juveniles (n = 12 [1996]; n = 8 [1998], n = 12 [1999]) into a wild flock of sandhill cranes (ca 300 birds) on wintering grounds near Gila Bend, Arizona. Another 8 parent-reared colts were released into a small group (4) of subadult greater sandhill cranes (survivors of the 1996 trucking experiment [Ellis, et al. 1997; Ellis et al. 2001, Mummert et al. 2001]) in northcentral Arizona. Another 8 juveniles, costume-reared from hatching, were released into wild sandhill crane flocks in central Wisconsin at autumn staging areas. In all of these tests, cranes were released 1 or 2 at a time, either at the periphery of a wild flock or at a known roost site. Most birds were released in daylight at a foraging area, but because this was a pilot project, we tried a variety of methods. We released a few individuals at odd times (e.g., midnight) and in odd ways (e.g., by flushing a release crane as a wild flock passed overhead). A few birds were initially left stranded after we placed them at ephemeral roosts that had been used recently, but not subsequent to our visit. However, once we made the necessary adjustments, and regardless of release time or situation, all of our cranes very quickly joined their adoptive flocks. We experienced excellent survival, including 100% survival for all 8 of our parent-reared fledgling colts released on the summering ground and followed until they disappeared at the time of migration. Further, all (32) hand-reared birds released on the wintering grounds survived the winter. Also all 8 of the juveniles reared and released in Wisconsin successfully migrated south and returned north to Central Wisconsin the following spring. These results recommend the one-by-one method as a promising strategy for releasing juvenile cranes with minimal training, handling, and maintenance. The method provides a likely strategy for building wild flocks of endangered cranes once a core group is established by some other method.

Book chapter↗
USGS2001

Preface

Explore the source record for details and available documents.

Book chapter↗
USGS2001

Recent history of Saker Falcon studies in Mongolia

This report clarifies recent studies on the saker falcon in Mongolia. In the last five years, three museum studies appeared on the Altay falcon (is it a gyrfalcon, saker or separate species). These showed that all of the most distinct Central Asian summer specimens were from only two mountain ranges. However, there is a continuum between sakers and Altay falcons and the two should be considered synonymous. Of field studies focused on the saker in Mongolia, the first was conducted by Baumgart in the 1970s. The next (my own) began in 1994 with a Mongolia-wide study of the nesting ecology of the species. From that study, we now have over 150 breeding territories with over 200 eyries described. Resulting publications dealt with reproductive performance of the falcons and unusual breeding situations. Not only were many nests in odd situations, many were also composed mainly of manmade materials. We found that birds sometimes became entangled in twine and cloth in such nests and either died or would have died without our intervention. Our work also led to observations of novel social behavior including the first documentation of siblicide for any falcon and the description of a new falcon display, splayed-toes-flight. Aware that saker populations in Kazakhstan and elsewhere were plummeting due to over harvest for falconry and seeing a growing harvest in Mongolia, in 1997, we began efforts to build artificial eyries for the falcons. To date, over 150 artificial eyries have been created. In 1998, there was a great expansion of saker field work after the National Avian Research Center (NARC) of the United Arab Emirates became directly involved in hiring Mongol students and scientists. Those efforts resulted in an immediate estimate of the breeding population. Continuing work promises to provide good information on home range, food habits, productivity and other topics.

Falco↗
USGS2001

Annual movements of a steppe eagle (Aquila nipalensis) summering in Mongolia and wintering in Tibet

An adult female steppe eagle (Aquila nipalensis Hodgson) was captured and fitted with a satellite transmitter in June 1995 in southeastern Mongolia. In fall, it traveled southwest towards India as expected, but stopped in southeastern Tibet and wintered in a restricted zone within the breeding range of the steppe eagle. In spring, the bird returned to the same area of Mongolia where it was captured. These observations, though derived from the movements of a single bird, suggest three things that are contrary to what is generally believed about steppe eagle biology. First, not all steppe eagles move to warmer climes in winter. Second, not all steppe eagles are nomadic in winter. Finally, because our bird wintered at the periphery of the steppe eagle breeding range in Tibet, perhaps birds that breed in this same area also winter there. If so, not all steppe eagles are migratory.

Journal of the Bombay Natural History Society↗
USGS1999

Golden Eagle predation on experimental Sandhill and Whooping Cranes

There are very few published records of Golden Eagles preying upon cranes, especially in North America. During our experiments to lead cranes on migration behind motorized craft in the western United States, we experienced 15 attacks (four fatal) and believe many more attacks would have occurred (and more would have been fatal) without human intervention. We recognize eagle predation as an important risk to cranes especially during migration.

Condor↗
USGS1999

Siblicide, splayed-toes-flight display, and grappling in the Saker Falcon

We observed two incidents of novel social behavior in the saker falcon (Falco cherrug) in Mongolia. First, we provide an account of a two-week-old saker falcon chick killing its nest mate, the first direct observation of siblicide in the genus Falco. We also report aerial combat between three adult saker falcons including observations of talon grappling, whirling, and Splayed-toes-flight, a previously undescribed social display.

Journal of Raptor Research↗