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D. H. Ellis

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

At least 19 recordsLinked to original sources
USGS2010

Year-round movements of a Wahlberg's Eagle Aquila wahlbergi tracked by satellite

An adult female Wahlberg's Eagle from northern Namibia was tracked by satellite ovcr a total distance of 8816 km and located 104 times between 11 February and 4 November 1994. It migrated on an almost due north heading to northern Cameroon, north-eastern Nigeria and western Chad through the rain forest belt of the Congo and Zaire after the breeding season. The total trans-equatorial distance between the breeding and non-breeding ranges was 3520 km. During the non-breeding season the bird ranged over a large area (ca. 60 000 km2) for about six weeks (29 April - 14 June) in these three countries in a rather nomadic pattern covering a minimum distance of 1256 km. During two further months (14 June - 14 August) it restricted its movements to an area of about 50002 km near Maiduguri in the Sudan savannah of north-eastern Nigeria. The return migration took about two weeks longer than that to the north, which took about a month.

Ostrich↗
USGS2010

Satellite tracking of two lesser spotted eagles, Aquila pomarina, migrating from Namibia

One immature and one subadult Lesser Spotted Eagle, Aquila pomarina , were followed by satellite telemetry from their non-breeding areas in Namibia. Both birds were fitted with transmitters (PTTs) in February 1994 and tracked, the immature for six months and three weeks, the subadult for eight months and two weeks, over distances of 10 084 and 16 773 km, respectively. During their time in Namibia both birds' movements were in response to good local rainfall. The immature eagle left Namibia at the end of February, the subadult at the end of March. They flew to their respective summer quarters in Hungary and the Ukraine, arriving there 2.5 and 1.5 months later than the breeding adults. The immature eagle took over two months longer on the homeward journey than a breeding male followed by telemetry in a previous study. On returning, the immature eagle followed the narrow flightpath through Africa used by other Lesser Spotted Eagles on their outward migration. It reached this corridor, which run roughly between longitudes 31° and 36° East from Suez to Lake Tanganyika, veering from the shortest route in a direction east-northeast through Angola and Zambia to the southern end of Lake Tanganyika. The route taken by the subadult bird on its return migration differed markedly from that of all Lesser Spotted Eagles tracked to date, running further west through the Democratic Republic of Congo where, level with the equator, it flew over the eastern rainforest of that country. The outward migration, however, followed the same corridor and coincided in time with the migration of adults.

Lake Tanganyika↗
USGS2009

Unusual raptor nests around the world

From surveys in many countries, we report raptors using unusual nesting materials (e.g., paper money, rags, metal, antlers, and large bones) and unusual nesting situations. For example, we documented nests of Steppe Eagles Aquila nipalensis and Upland Buzzards Buteo hemilasius on the ground beside well-traveled roads, Saker Falcon Falco cherrug eyries in attics and a cistern, and Osprey Pandion haliaetus nests on the masts of boats and on a suspended automobile. Other records include a Golden Eagle A. chrysaetos nest 7.0 m in height, believed to be the tallest nest ever described, and, for the same species, we report nesting in rudimentary nests. Some nest sites are within a few meters of known predators or competitors. These unusual observations may be important in revealing the plasticity of a species' behavioral repertoire. ?? 2009 The Raptor Research Foundation, Inc.

Journal of Raptor Research↗
USGS2006

Gyrfalcon (Falco rusticolus) in Yakutia: Distribution, nesting areas, and features of nutrition

In Yakutia, gyrfalcon nests in tundra, forest-tundra, and taiga and may occur in the northeastern and, sometimes, in the northwestern parts, being almost absent or occasional over the large area separating these regions. The southern boundary of the nesting site is nowhere below 64 degrees N. In central Yakutia, gyrfalcon was suggested to be met as a visitant or migratory species. The long-term studies showed that this species occurred there in all the seasons, including winter periods. This fact became a reason to consider the bird as a migratory and wintering (not always) species, despite its repeated comings to inhabited localities that indicated difficulties in birds during winter periods. There are about 30 and 6 species of birds and mammals, respectively, in the gyrfalcon diet in Yakutia. The prevalence of birds is evident (65.4 to 91.3%). In the composition of food species, the share of willow and rock ptamigans is high everywhere, although in the Lower Kolyma tundra, they give way to ducks (19.2 and 30.7%, respectively). Ptamigans as an diet item seems to be of particular importance for the survival of the species. Gyrfalcons prey birds of medium size, such as ptamigans, ducks, and sandpipers. Large (geese. caterpillars) and small (small passerines) birds become gyrfalcon's prey less often. Species of open and semi-open habitats are mostly preferable among mammals. Drastic changes in the forage reserves of gyrfalcon are one of the most serious causes leading to the changes in its number and participation in the reproductive cycles.

Zoologicheskii Zhurnal↗
USGS2006

Short-term oscillations in avian molt intensity: evidence from the golden eagle Aquila chrysaetos

From a year-long study of molt in the golden eagle Aquila chrysaetos, we recorded 2069 contour feathers replaced in 137 d (6 May-19 September). Very few contour feathers were lost outside this period. From precise daily counts of feathers lost, and using time series analysis, we identified short-term fluctuations (i.e., 19-d subcycles) around a midsummer peak (i.e., a left-skewed normal distribution). Because these subcycles have never before been reported and because the physiological basis for many aspects of avian molt is poorly known, we offer only hypothetical explanations for the controls responsible for the subcycles.

Journal of Avian Biology↗
USGS2006

Thinking about feathers: Adaptations of Golden Eagle rectrices

The striking black and white plumage of the juvenile Golden Eagle (Aquila chrysaetos) provides an excellent opportunity to examine the possible selective forces influencing the strategic placement of dark pigment in birds. The conflict between opposing selective pressures (first, toward large white patches, which may allay aggression in adults, and second, toward dark plumage to promote camouflage and limit solar and abrasive wear) provides the stage whereon are revealed a score of pigmentation traits of potential adaptive value. The general pigmentation trend is for zones that are more exposed to the sun to be darker than elsewhere. More specifically: (1) for rectrices and remiges, outer webs are darker than inner; (2) for those few feathers (e.g., central rectrices, some scapulars, and some tertials), where both inner and outer webs are heavily and nearly equally solar exposed, pigmentation is supplied similarly on both webs; (3) outermost primaries and rectrices are darkest of all and are structurally similar; (4) for central rectrices, subject to high levels of abrasion with substrate, the tip is paler (resultant flexibility may limit breakage); and (5) pigment is heavier along or on the rachis than on the webs. Many of the traits listed above for the Golden Eagle are also found in other families of birds. Traits of the tail common to many species were a terminal pale tip, a subterminal dark band, rachis darker than vane, and outer webs darker than inner for both remiges and rectrices. The most widespread traits likely have adaptive value. ?? 2006 The Raptor Research Foundation, Inc.

Journal of Raptor Research↗
USGS2005

Quantitative assessment of pair formation behavior in captive whooping cranes (Grus americana)

Instantaneous scan sampling for mean distance and synchronous action patterns and all-occurrence sampling for unison call, dance, strut, and hoover-up behaviors were conducted for five potential whooping crane pairs at Patuxent Environmental Science Center, Laurel, Maryland. Dance, strut, and hoover-up differed among pairs, as did total frequency of social behaviors. It was unclear whether or not total frequency of social behaviors during pair formation can be used as an index for potential breeding success. The relative importance of different action patterns should be used as indices of pair compatibility in captive whooping cranes.

Zoo Biology↗
USGS2005

Initial training of cranes for an airship migration

We describe the first year of our efforts to train cranes to accept the unnatural stimuli associated with being transported south in cages suspended beneath an airship. All 4 experimental cranes readily acclimated to entering a suspended cage and were trained to accept being jostled while in the cage, even when the cage was transported in the back of a pickup truck. With minor changes, the training protocol is ready for use in an actual airship migration.

Book chapter↗
USGS2004

Summer diet of the Peregrine Falcon in faunistically rich and poor zones of Arizona analyzed with capture-recapture modeling

We collected prey remains from 25 Peregrine Falcon ( Falco peregrinus ) territories across Arizona from 1977 to 1988 yielding 58 eyrie-years of data. Along with 793 individual birds (107 species and six additional genera), we found seven mammals and nine insects. In addition, two nestling peregrines were consumed. We found a larger dependence upon White-throated Swifts ( Aeronautes saxatalis ) and birds on migration in northern Arizona, while in southeastern and central Arizona average prey mass was greater and columbiforms formed the largest dietary component. In northern, central, and southeastern Arizona, 74, 66, and 56 avian prey taxa, respectively, were recorded. We used capture-recapture modeling to estimate totals of 111 ± 9.5, 113 ± 10.5, and 86 ± 7.9 (SE) avian taxa taken in these same three areas. These values are counterintuitive inasmuch as the southeast has the richest avifauna. For the entire study area, 156 ± 9.3 avian taxa were estimated to be taken by peregrines.

Arizona↗
USGS2003

Subadult and pale steppe eagles breeding in Mongolia

One pale morph and two rufous-tawny morph Steppe Eagles (Aquila rapax) were observed among about 20 breeding pairs found in Mongolia. All three were attending live young. Plumage features of the rufous-tawny birds suggest that they were not adults. Subadult breeding is thereby documented for the Steppe Eagle. Breeding is also documented for a pale morph bird, but the age of this bird is uncertain; either it was the first pale morph adult known for the species or, more likely, it represents breeding of a two-, three-, or four-year old bird.

Journal of Raptor Research↗
USGS2002

Teaching migration routes to canada geese and trumpeter swans using ultralight aircraft, 1990-2001

This paper summarizes eleven years (1990-2001) of experiments to teach Canada Geese (Branta canadensis) and Trumpeter Swans (Cygnus buccinator) pre-selected migration routes using ultralight aircraft. When Canada Geese were trained to follow an ultralight aircraft for southward autumn migrations of 680 or 1,320 km, 81% (83/103) returned on their own in the next spring to near their place of training. In contrast, none returned of 21 similarly raised geese that were transported south in a closed truck over a route of 680 km. Trumpeter Swans have proven more difficult to train. However, in two experiments in which Trumpeter Swans followed an ultralight for the entire pre-selected route, one of three and two of four returned close to their training area. A stage-by-stage method, in which swans were transported in trucks between stops, flown in the vicinity and penned with a view of the night sky, has shown some promise. So far an established migration route (north and south twice) has been confirmed in only two geese

Book chapter↗
USGS2002

Schizochromism in a Peregrine Falcon from Arizona

Herein, we report the first record of schizochromism in the Peregrine Falcon (Falco peregrinus). Our example is a nestling from southern Arizona. The lack of dark brown pigment in this bird made it closely resemble the blue-gray plumage of an adult. Near fledging time, the bird was eaten by its nestmates, so this article also documents cannibalism.

Journal of Raptor Research↗
USGS2002

Prey of the Peregrine Falcon (Falco peregrinus cassini) in Southern Argentina and Chile

The Peregrine Falcon (Falco peregrinus cassini) in Patagonia attracted wide interest two decades ago when there was a focus on determining the taxonomic position of the Pallid Falcon (also called Kleinschmidt's falcon and Tierra del Fuego falcon; formerly named Falco kreyenborgi). In 1981, however, the pallid falcon was confirmed to be a pale color morph of the peregrine, and since that time, little work has been conducted on this color morph. Continent-wide research has continued and has yielded a fair understanding of the breeding distribution of the Peregrine Falcon in South America. Also, two preliminary food habits studies on the peregrine have been completed in Patagonia. Together those papers provided a list of 23 species observed as prey, and McNutt listed another eight species seen pursued (but not captured) by peregrines. The purpose of this paper is to assemble all that has been published on peregrine food habits for Patagonia and Tierra del Fuego and to add to that list from our 1980 and 1981 expeditions.

Journal of Raptor Research↗
USGS2001

Whooping crane egg management: options and consequences

Eggs to build captive whooping crane (Grus americana) flocks and most eggs for reintroduction experiments have come from second viable eggs in 2-egg clutches in Canada. Four years ago, egg removal ceased. Based on reproductive rates for years when second eggs were removed and for years when eggs were not removed, we project numbers of young fledging in the wild and in captivity for the 2 most likely egg-management strategies. From existing data sets, we find that reproductive performance was, on average, better during the era of routine removal of the second viable eggs than when no manipulation occurred. Further, the number of young produced in captivity from the removed eggs, on average, resulted in a doubling of the number of young birds (wild and captive) alive each autumn.

Book chapter↗
USGS2001

Tracking sandhill crane migration from Saskatchewan to the Gulf Coast

Four adult sandhill cranes (Grus canadensis rowani) were captured in east-central Saskatchewan, equipped with transmitters, and tracked by satellite to determine if their migration routes and wintering areas would allow their use as guide birds to establish a new migratory flock of whooping cranes (G. americana). Two birds captured near Yorkton died or their transmitters were lost before migration. Two adults from the Overflowing River moved to staging areas in southern Saskatchewan in September. By 29 September, Crane A left Saskatchewan and moved to North Dakota where it remained until late October. By 21 December, it arrived a few km inland from the Gulf Coast near McFaddin, Texas, 3,378 km from its capture location. It remained there until at least 9 March 1995. On 15 March, it was relocated near Grand Island, Nebraska and by 20 April, it had returned to the Overflowing River area. Crane B spent most of September and October near the Quill Lakes, Saskatchewan, then migrated with brief stops in South Dakota and Kansas, arriving 29 November at its winter area near the northwestern comer of the Laguna Madre in Tamaulipas, Mexico, 3,998 km from its summering area. It remained there until at least 25 December, whereafter no further transmissions were received. Because both cranes wintered or migrated near the current whooping crane winter area at Aransas National Wildlife Refuge (Aransas), Texas, this population was judged unsuitable to provide guide birds for a new flock of whooping cranes.

Book chapter↗
USGS2001

Minimum survival rates for Mississippi sandhill cranes: a comparison of hand-rearing and parent-rearing

Hand-reared (56) and parent-reared (76) juvenile Mississippi sandhill cranes (Grus canadensis pulla) were produced at the Patuxent Wildlife Research Center (Patuxent), Laurel, Maryland over a 4-year period (1989-92) and released at the Mississippi Sandhill Crane National Wildlife Refuge (Refuge), Gautier, Mississippi in a controlled experiment. Hand-reared survival rates proved higher than for parent-reared survival for each time category: 6 months, 86% versus 75%; 1 year, 77% versus 68%; 2 years 66% versus 53%; 3 years, 55% versus 43%: partial data for fourth and filth years were 57% versus 31% and 48% versus 37%.

Maryland, Mississippi↗