Earth and Space News

Wednesday, February 9, 2011

William Herschel Saw Uranian Rings But Puzzling Views Created Doubt

Summary: Uranus discoverer William Herschel saw Uranian rings but puzzling views created doubt in the German-British astronomer about his annular discoveries.

Rare edge-on view of entire Uranian ring system, obtained Aug. 14, 2007, by NASA Hubble Space Telescope’s Wide Field Planetary Camera 2 (WFPC-2), shows edge-on rings spiking above and below Uranus; blocking out of the planet’s bright glare in the photo interferes with visibility of continuity of ring system across the planet’s face; fan-shaped image artifact represents residual glare, along with edge between inner and outer rings’ exposure: courtesy NASA / ESA (European Space Agency / M. (Mark Robert) Showalter (SETI Institute), via NASA Hubblesite / Space Telescope Science Institute (STScI)

Uranus discoverer William Herschel saw Uranian rings but puzzling views created doubt in the German-British observational astronomer about his annular discoveries.

After discovering Uranus on March 13, 1781, William Herschel (Nov. 15, 1738-Aug. 25, 1822) continued to study the seventh planet from the sun. In a report read at the Royal Society of London’s Dec. 14, 1797, Herschel summarized his 10-year search for definitive observational proof of a ring system on “the Georgian planet.”

He cited his journal entry for Feb. 4, 1787, as detecting “. . . no appearance of any ring . . .” (page 67). He specified that he had examined the planet with his 20-foot reflector telescope, power 300.

Three subsequent journal entries, for March 4 through March 7, noted annular views. The March 7 entry identified “the great ring R” and “Small ring r.”

But, without offering an explanation, Herschel quoted his March 8 entry as stating: “R and r are probably deceptions.”

He expressed doubt in his next journal entry: “Nov. 9. The suspicion of a ring returns often when I adjust the focus by one of the satellites, but yet I think it has no foundation.”

Four entries in 1789 offered positive notations concerning the existence of the Uranian ring system. In particular, Herschel discerned “. . . two annae . . . of a colour a little inclined to red” (page 68) on March 16.

In 1792, however, puzzling views created doubt in the keen-eyed astronomer. His entry for Feb. 26 extensively detailed his efforts to suss Uranus as ringed or ringless.

“6h 34’. My telescope is extremely distinct; and, when I adjust it upon a very minute double star, which is not far from the planet, I see a very faint ray, like a ring crossing the planet, over the centre. This appearance is of an equal length on both sides, so that I strongly suspect it to be a ring. There is, however, a possibility of its being an imperfection in the speculum, owing to some slight scratch: I shall take its position, and afterwards turn the speculum on its axis.

“8h 39’. Position of the supposed ring 55°, 6 from N.P. to S.F.

“9h 56’. I have turned the speculum one quadrant round; but the appearance of the very faint ray continues where it was before, so that the defect is not in the speculum, nor is it in the eye-glass. But still it is now also pretty evident that it arises from some external cause; for it is now in the same situation, with regard to the tube, in which it was 3 1/2 hours ago: whereas, the parallel is differently situated, and the ring, of course, ought to be so too” (pages 68-69).

In assessing his annular study, Herschel assigned great value to these findings. He stated: “. . . the observation of the 26th seems to be very decisive against the existence of a ring” (page 70).

Eight days later, on March 5, Herschel noted: “I viewed the Georgian planet with a newly polished speculum, of an excellent figure. It shewed the planet very well defined, and without any suspicion of a ring” (page 69).

Herschel evaluated the possibility of a ring system in the context of the hypothesis that established his observational guidelines. “When the surmises arose at first, I thought it proper to suppose, that a ring might be in such a situation as to render it almost invisible; and that, consequently, observations should not be given up, till a sufficient time had elapsed to obtain a better view of such a supposed ring, by a removal of the planet from its node. This has now sufficiently been obtained in the course of ten years; for, let the node of the ring have been in any situation whatsoever, provided it kept to the same, we must by this time have had a pretty good view of the ring itself,” he explained (page 70).

Herschel cited the last 1792 ring entry that he presented at the Royal Society’s Dec. 14, 1792, meeting as critical to the conclusion that he was drawing about the seventh planet’s ring system. “Placing therefore great confidence on the observation of March 5, 1792, supported by my late views of the planet, I venture to affirm, that it has no ring in the least resembling that, or rather those, of Saturn.”

Yet, despite his dismissal of a Saturn-styled ring system around his planetary discovery, Herschel included in his Dec. 14, 1792, report an entry for Dec. 4, 1793: “There is a suspicion of some apparatus about the planet” (page 69).

The takeaways for puzzling views creating doubt despite William Herschel’s sightings of the Uranian rings in 1787 and 1789 are that the German-British astronomer concluded his 10-year search for rings around the planet that he had discovered in 1781 by valuing ringless views obtained Feb. 26 and March 5, 1792, but that he included in his Dec. 14, 1797, report an entry for Dec. 4, 1793, that suspects “some apparatus around the planet.”

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

a ringed view of Uranus in a false color image assembled from exposures taken July 3, 1995, by Hubble Space Telescopes Wide Field Planetary Camera-2 (WFPC2); NASA ID: PIA01280; image addition date 1998-08-02; image credit NASA / JPL (Jet Propulsion Laboratory) / STScI (Space Telescope Science Institute): May be used for any purpose without prior permission, via NASA JPL Photojournal @ https://photojournal.jpl.nasa.gov/catalog/PIA01280;
Generally not subject to copyright in the United States; may use this material for educational or informational purposes, including photo collections, textbooks, public exhibits, computer graphical simulations and Internet Web pages; general permission extends to personal Web pages, via NASA Image and Video Library @ https://images.nasa.gov/details-PIA01280

For further information:

Dreyer, J.L.E. (John Louis Emil), comp. The Scientific Papers of Sir William Herschel Including Early Papers Hitherto Unpublished. Vol. I; Vol. II. London, England: The Royal Society and The Royal Astronomical Society, 1912.
Vol. I: Available via HathiTrust @ https://babel.hathitrust.org/cgi/pt?id=mdp.39015010954678
Vol. II: Available via HathiTrust @ https://babel.hathitrust.org/cgi/pt?id=mdp.39015010954744
Vol. I: Available via Internet Archive @ https://archive.org/details/scientificpapers032804mbp/
Vol. II: Available via Internet Archive @ https://archive.org/details/scientificpapers02hersuoft/

Herschel, Mr. (William). “XXXII. Account of a Comet. Communicated by Dr. Watſon. Read April 26, 1781.” Philosophical Transactions of the Royal Society of London. Vol. LXXI. For the Year 1781. Part II: 492-501. London, England: Lockyer Davis and Peter Elmsly, Printers to The Royal Society, MDCCLXXXII (1782).
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/51826184

Herschel, William. “I. A Letter From William Herschel, Eſq. F.R.S. to Sir Joseph Banks, Bart. P.R.S.” Philosophical Transactions of the Royal Society of London. Vol. LXXIII for the Year 1783. Part I: 1-3.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/51826827

Herschel, William. “Observations and Reports Tending to the Discovery of One or More Rings of the Georgian Planet, and the Flattening of Its Polar Regions.” Pages 67-71. “III. On the Discovery of Four Additional Satellites of the Georgium Sidus. The Retrograde Motion of its Old Satellites Announced; and the Cause of Their Disappearance at Certain Distances From the Planet Explained. Read December 14, 1797.” Philosophical Transactions of the Royal Society of London. For the Year MDCCXCVIII, [vol. LXXXVIII (88)], Part I: 47-79. London, England: Peter Elmsly, Printer to The Royal Society, MDCCXCVIII (1798).
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/49109940

Herschel, William. “III. On the Discovery of Four Additional Satellites of the Georgium Sidus. The Retrograde Motion of its Old Satellites Announced; and the Cause of Their Disappearance at Certain Distances From the Planet Explained. Read December 14, 1797.” Philosophical Transactions of the Royal Society of London. For the Year MDCCXCVIII, [vol. LXXXVIII (88)]], Part I: 47-79. London, England: Peter Elmsly, Printer to The Royal Society, MDCCXCVIII (1798).
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/49109920
Available via Royal Society of London Publishing @ https://royalsocietypublishing.org/doi/pdf/10.1098/rstl.1798.0005

Herschel, William. “Remarks Upon the Foregoing Observations.” Pages 69-71. “III. On the Discovery of Four Additional Satellites of the Georgium Sidus. The Retrograde Motion of its Old Satellites Announced; and the Cause of Their Disappearance at Certain Distances From the Planet Explained. Read December 14, 1797.” Philosophical Transactions of the Royal Society of London. For the Year MDCCXCVIII, [vol. LXXXVIII (88)], Part I: 47-79. London, England: Peter Elmsly, Printer to The Royal Society, MDCCXCVIII (1798).
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/49109942

Lavoie, Sue, site manager. “PIA01280: Hubble Captures Detailed Image of Uranus’ Atmosphere.” NASA Jet Propulsion Laboratory Photojournal. Image addition date 1998-08-02.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA18182

Lavoie, Sue, site manager. “PIA18182: Uranus as Seen by NASA’s Voyager 2.” NASA Jet Propulsion Laboratory Photojournal. Image addition date 1986-12-18.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA18182

Levy, David H. Skywatching. Revised and updated. San Francisco CA: Fog City Press, 1994.

Marriner, Derdriu. “William Herschel Discovered Mimas With Newly Built 40-Foot Telescope.” Earth and Space News. Wednesday, Sep. 21, 2019.
Available @ https://earth-and-space-news.blogspot.com/2011/09/william-herschel-discovered-mimas-with.html

Marriner, Derdriu. “William Herschel Discovered Saturnian Moon Mimas Sept. 17, 1789.” Earth and Space News. Wednesday, Sept. 14, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/09/william-herschel-discovered-saturnian.html

Marriner, Derdriu. “William Herschel First Glimpsed Uranian Ring System on March 4, 1787.” Earth and Space News. Wednesday, Feb. 2, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/02/william-herschel-first-glimpsed-uranian.html

Massey, Robert; and Anita Heward. “Did William Herschel Discover the Rings of Uranus in the 18th Century?” Royal Astronomical Society > Press. April 16, 2007.
Available via Internet Archive Wayback Machine @ https://web.archive.org/web/20120910092417/http://www.nam2007.uclan.ac.uk/press_releases.php?news=20070416b

Moore, Patrick, Sir. Philip’s Atlas of the Universe. Revised edition. London UK: Philip’s, 2005.

New Scientist Monitor Column. “Herschel Saw Rings Round Uranus in 1787.” New Scientist, vol. 74, no. 1052 (May 19, 1977): 396.
Available via Google Books @ https://books.google.com/books?id=Rt5VRWY4aR8C&pg=PA396

Rincon, Paul. “Uranus Rings ‘Were Seen in 1700s.’” BBC News > Science & Environment. April 18, 2007.
Available @ http://news.bbc.co.uk/2/hi/sci/tech/6569849.stm

Schmude, Richard, Jr. “1. The Uranus System: Rings.” Uranus, Neptune, Pluto and How to Observe Them: 27-34. Astronomers’ Observing Guides. New York NY: Springer Science + Business Media LLC, 2008.
Available via ePDF @ https://epdf.pub/uranus-neptune-and-pluto-and-how-to-observe-them-astronomers-observing-guides.html Available via Google Books @ https://books.google.com/books?id=47azIwooFqEC&pg=PA27

Villard, Ray; and Mark Showalter. “Going, Going, Gone: Hubble Captures Uranus’s Rings on Edge.” NASA Hubblesite > News > News Releases. Release ID 2007-32. Aug. 23, 2007. Available @ https://hubblesite.org/contents/news-releases/2007/news-2007-32.html

Young, Kelly. “Uranus Moons Seen Overtaking Each Other for First Time.” NewScientist > Space. May 18, 2007. Available @ https://www.newscientist.com/article/dn11891-uranus-moons-seen-overtaking-each-other-for-first-time/

Sunday, February 6, 2011

North American Red-Tailed Hawk Habitats: Brown Body, Nest Pile, White Egg

Summary: White eggs in nest piles give North American red-tail hawk habitats brown bodies seasonally in Canada and Mexico, year-round in the United States.

North American red-tailed hawk (Buteo jamaicensis) at John Heinz National Wildlife Refuge, Philadelphia, southeastern Pennsylvania; January 2011: Mark Bohn/U.S. Fish and Wildlife Service, Public Domain, via USFWS National Digital Library

North American red-tailed hawk habitats allay cultivator anxieties with Accipitridae raptor family member appetites for field animals and hunters and naturalists with distribution ranges from Canada southward through Mexico and the Caribbean.

Red-shouldered hawks bear their common name and the scientific name Buteo jamaicensis (Jamaican buzzard) for colorfully mature tails and the location of the first European-described specimens. Predatory humans and secondary poisoning from consuming lead- or warfarin-containing animals challenge red-tailed hawks, described in 1788 by Johann Friedrich Gmelin (Aug. 8, 1748-Nov. 1, 1804). Bio-geography and physique divide them into continental alascensis, borealis, calurus, costaricensis, fuertesi, hadropus, harlani, kemsiesi, kriderii and umbrinus and insular fumosus, nominate, socorroensis and solitudinus subspecies.

Twenty-one-year lifespans expect nest-friendly, perch-worthy buildings, cacti, cliffs, outcrops, poles, snags or trees in bottomlands, clearings, estuaries, fields, grasslands, marshes, meadows, parklands, prairies, rangelands or savannas.

February through September facilitate brooding one two- to five-egg clutch in nest piles in buildings, shrubs, snags, towers or trees or on cacti, cliffs and outcrops.

Monogamous parents-to-be gather twigs into bark-, stem-lined, 4- to 6-inch- (10.16- to 15.24-centimeter-) deep, permanent nest piles 35 to 90 feet (10.67 to 27.43 meters) up. Nests with inner 14- to 15-inch (35.56- to 38.1-centimeter), outer 28- to 38-inch (71.12- to 96.52-centimeter) diameters house buff-washed, elliptical to subelliptical, non-glossy, smooth white eggs. Parents-to-be incubate brown-, buff-, red-brown-, purple-blotched, speckled, 2.16- to 2.67-inch (55- to 68-millimeter) by 1.69- to 1.97-inch (43- to 50-millimeter) eggs for 28 to 35 days.

Bald eagles, bobcats, coyotes, crows, golden eagles, great horned owls, prairie dogs and skunks and drivers, feather-collectors, hunters and researchers jeopardize North American red-tailed hawk habitats.

Semi-helpless nestlings, active as two-day-old hatchlings, know a first, buff- or gray-white, long, silky down, a second, short, white, woolly down and, as 16-day-olds, first feathers. They learn food-pecking within one week, self-feeding and then finding separate nests within four to five weeks, flying within six weeks and foraging within seven weeks.

Red-tailed hawks, sexually mature as three-year-olds, mark as prey blackbirds, crows, grouse, gulls, nutcrackers, orioles, owls, pheasants, pigeons, thrashers, vireos and warblers and crabs and spiders. They also need chipmunks, cottontails, geckos, jackrabbits, lemmings, lizards, mice, moles, pikas, pocket gophers, prairie dogs, raccoons, rats, shrews, skunks, snakes, squirrels, toads, voles and woodchucks.

North American red-tailed hawks up to 10,498.69 feet (3,200 meters) above sea level offer winter's coldest temperatures at minus 10 degrees Fahrenheit (minus 23.33 degrees Celsius).

Alder, ash, aspen, beech, birch, cottonwood, cypress, elm, fir, gum, hemlock, hickory, juniper, larch, maple, oak, pine, red-cedar, redwood, spruce and sycamore protect red-tail life cycles.

Brown upperparts, brown-spotted and streaked white underparts, semi-banded gray-brown tails and yellow eyes qualify as juvenile hallmarks before the two-year-olds' richly browning plumage and reddening tails. Brown eyes and upperparts, dark-banded pale underparts, dark-barred wing undersides, rusty tails and yellow ceres, feet and legs reveal broad-, round-winged large-sized females and small-sized males. Circular soaring, slow-flapped flight on 44.88 to 52.36-inch (114- to 133-centimeter) wingspans suggests 17.71- to 25.59-inch (45- to 65-centimeter), 24.34- to 51.49-ounce (690- to 1,460-gram) adults.

North American red-tailed hawk habitats transmit hoarse, screaming kee-eee-arr calls by soaring adults, low, soft peeps by hungry youngsters and shrill chwirk vocalizations by courting adults.

illustration of eggs of red-tailed hawk subspecies of Buteo borealis; Illustrations of the Nests and Eggs of Birds of Ohio, Plate XLIV, figure 4, opposite page 170: Public Domain, via Biodiversity Heritage Library

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Audubon, John James. 1830. "Red-tailed Hawk. Falco borealis, Gmel." The Birds of America, From Original Drawings, vol. I (1827 to 30): plate LI (51). New York NY: J.J. Audubon; Philadelphia PA: J.B. Chevalier.
Available via Cincinnati Digital Library - The Public Library of Cincinnati and Hamilton County @ http://digital.cincinnatilibrary.org/digital/collection/p16998coll33/id/52/rec/53

Audubon, John James. 1840. "Harlan's Buzzard Buteo harlani, Aud." The Birds of America, From Drawings Made in the United States and Their Territories, vol. I: 38-40. New York NY: J.J. Audubon; Philadelphia PA: J.B. Chevalier.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/40382988

Baicich, Paul J.; and Colin J.O. Harrison. 2005. Nests, Eggs, and Nestlings of North American Birds. Second edition. Princeton Field Guides Book 35. Princeton NJ: Princeton University Press.

Bangs, Outram. 31 July 1901. "On an Apparently Unnamed Race of Buteo borealis: Buteo borealis umbrinus subsp. nov." Proceedings of the New England Zoölogical Club, vol. II (1900-1901): 68-69.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/12603593

Cassin, John. February 1855. "14. Buteo calurus, nobis." Proceedings of the Academy of Natural Sciences of Philadelphia, vol. VII (1854, 1855): 281. Philadelphia PA: Merrihew & Thompson.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/1694395
Available via HathiTrust @ https://hdl.handle.net/2027/hvd.32044093291839?urlappend=%3Bseq=307

Dickerman, R.W. (Robert W.). 1993. "Buteo jamaicensis suttoni." C.R. (Charles) Preston and R.D. Beane, "Red-Tailed Hawk." In A. (Alan) Poole, P. (Peter) Stettenheim and F. (Frank) Gills, eds., The Birds of North America, no. 52: 3. Philadelphia PA: American Ornithologists' Union.

Dickerman, Robert W. December 1994. "Undescribed Subspecies of Red-Tailed Hawk From Baja California." The Southwestern Naturalist, vol. 39 (4): 375-377.

Gmelin, Johann Friedrich. 1788. "74. Falco jamaicensis." Caroli a Linné Systema Naturae, tom. I, pars I: 266. Editio Decima Tertia, Aucta, Reformata. Lipsaie [Leipzig]: Impensis Georg Emanuel Beer.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/2896866

Gmelin, Johann Friedrich. 1788. "75. Falco borealis." Caroli a Linné Systema Naturae, tom. I, pars I: 266. Editio Decima Tertia, Aucta, Reformata. Lipsaie [Leipzig]: Impensis Georg Emanuel Beer.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/2896866

Grinnell, Joseph. 18 February 1909. "Birds and Mammals of the 1907 Alexander Expedition to Southeastern Alaska: The Birds: Buteo borealis alascensis, new subspecies." University of California Publications in Zoology, vol. 5, no. 2: 211-212.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/29393501

Grzimek's Animal Life Encyclopedia, 2nd edition. Volumes 8-11, Birds I-IV, edited by Michael Hutchins, Jerome A. Jackson, Walter J. Bock and Donna Olendorf. Farmington Hills MI: Gale Group, 2002.

Jones, Howard. 1886. Illustrations of the Nests and Eggs of Birds of Ohio. Illustrations by Mrs. N.E. Jones. Vol. II. Circleville OH: s.n. (sine nomine).
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/34908243

Nelson, E.W. (Edward William). 27 January 1898. "Descriptions of New Birds From the Tres Marias Islands, Western Mexico." Buteo borealis fumosus subsp. nov." Proceedings of the Biological Society of Washington, vol. XII: 7-8.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/3849871

Oberholser, Harry C. (Church). 4 November 1959. "A New Red-Tailed Hawk From Honduras: Buteo jamaicensis kemsiesi, new subspecies." Proceedings of the Biological Society of Washington, vol. 72: 159.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/34641938

Peterson, Alan P., M.D. "Buteo jamaicensis (Gmelin) 1788." Zoonomen: Zoological Nomenclature Resource > Birds of the World -- Current Valid Scientific Avian Names > Accipitriformes > Accipitridae > Buteo.
Available @ http://www.zoonomen.net/avtax/acci.html

Ridgway, Robert. 1874. "Buteo borealis, var. costaricensis Ridgway." In Baird, S.F. (Spencer Fullerton); T.M. (Thomas Mayo) Brewer; R. Ridgway. A History of North American Birds, vol. III: Land Birds: 285 note 1. Boston MA: Little, Brown, and Company.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/13183479

Storer, Robert Winthrop. 30 January 1962. "Variation in the Red-Tailed Hawks of Southern Mexico and Central America: Buteo jamaicensis hadropus new subspecies." Condor A Magazine of Western Ornithology, vol. 64, no. 1 (January-February): 78.
Available via SORA (Searchable Ornithological Research Archive) @ https://sora.unm.edu/sites/default/files/journals/condor/v064n01/p0077-p0078.pdf

Sutton, George Miksch; Josselyn Van Tyne. 23 September 1935. "A New Red-Tailed Hawk From Texas: Buteo jamaicensis fuertesi." Occasional Papers of the Museum of Zoology, University of Michigan, no. 321:1-6. Ann Arbor MI: University of Michigan.
Available via University of Michigan Deep Blue Data Repository @ https://deepblue.lib.umich.edu/bitstream/handle/2027.42/56760/OP321.pdf?sequence=1&isAllowed=y

Saturday, February 5, 2011

Mallard Duck Habitats: Drab Female, Gaudy Male, Green Egg, Ground Nest

Summary: North American mallard duck habitats in Canada summers, Mexico winters get drab females, gaudy males from the United States' green eggs in ground nests.

female (right) and male (left) mallard ducks (Anas platyrhynchos); Flourtown, Montgomery County, southeastern Pennsylvania; April 19, 2008: Manjith Kainickara, CC BY SA 2.0 Generic, via Flickr

North American mallard duck habitats aid cultivators through the Anatidae family member's appetite for crustaceans, earthworms, insects and mollusks and hunters and naturalists through year-round distribution ranges from Canada southward into Mexico.

The mallard bears its common name and the scientific name Anas platyrhynchos as the French loan words for wild drake and the Latin for flat-nosed duck. Agro-industry, pesticides, pollution, predation, recreation, tourism and urbanization challenge round-, short-tailed mallard ducks, described in 1758 by Swedish zoologist Carl Linnaeus (May 23, 1707-Jan. 10, 1787). Arctic, subtropical or temperate, brackish, fresh- or salt-water, built or natural wetlands and sometimes open prairies draw mallards into flocks with same and territorially overlapping species.

Twenty-nine-year lifespans expect buildings, grasslands, ground-cover, tree crotches or holes and wetlands for food, nests and roosts even though mallards endure prairie potholes and roadside ditches.

February through September furnish opportunities for brooding six- to 16-egg clutches, followed by a second by feral pairs farther from North America's wild and urban interfaces.

Mothers-to-be give 4-inch- (10.16-centimeter-) deep, grass-, leaf-, reed-, sedge-lined nests inner 6- to 7-inch (15.24- to 17.78-centimeter) and outer 11- to 12-inch (27.94- to 30.48-centimeter) diameters. Nests with brown, white-centered, white-tipped down from maternal breast feathers house blue, blue-green, buff-green, gray-buff, green-tinged creamy, pale green or white, elliptical to subelliptical, waxy eggs. The last 1.97- to 2.56-inch (50- to 65-millimeter) by 1.26- to 1.77-inch (32 to 45-millimeter), smooth, unmarked egg initiates 22- to 29-day incubations for completed clutches.

Crows, eagles, falcons, fish, foxes, gulls, harriers, hawks, humans, magpies, martens, opossums, owls, raccoons, ravens, skunks, snakes, turtles and weasels jeopardize North American mallard duck habitats.

Downy nestlings hatched simultaneously from day-apart laid eggs know dark brown upper-parts, dark bill-eye-nape streaks, dark-marked ear-covert rears and yellow neck fronts and sides of heads.

Fast-functioning dark olive-brown bills, gray-brown feet and legs and open eyes quickly launch nestlings with yellow-patched back and rump sides and yellow-tipped wings into the water. Seven- to eight-week-old ducklings manage fledgling stages and yearlings with blue wing-patches, broad-based wings and white outer tail feathers, sexual maturity 47 to 48 weeks later. Adults need beetles, caddisflies, dragonflies, earthworms, fish eggs, flies, freshwater shrimp, grains, river-bottom and swamp grassy, herbaceous and tree nuts, roots, seeds and tubers, and snails.

North American mallard duck habitats up to 1,000-foot (304.8-meter) altitudes above sea level offer winter's coldest temperatures at minus 60 degrees Fahrenheit (minus 51.11 degrees Celsius).

Mallards prefer alfalfa, bushes, cattails, grasses, reeds and thickets alongside lakes, ponds, reservoirs and sloughs spring through fall and open grasslands, prairies and wetlands in winter.

Ashes, aspens, asters, baldcypresses, birches, bulrushes, cattails, cedars, cottonwoods, elms, grasses, hickories, junipers, oaks, sedges, sowthistles, sugarberries, sweetgums, sycamores, tupelos and willows qualify as camouflage vegetation. Females reveal mottled brown underparts and yellow-brown upper-parts and white neck-collared males black curly-feathered rumps, gray bodies rusty in summer and metallic heads grayer in summer. Fast, regular, shallow flight on 32.28- to 37.4-inch (82- to 95-centimeter) wingspans suggest 1.88- to 3-pound (0.85- to 1.36-kilogram), 19.5- to 2.6-inch (49.53- to 6.6-centimeter) adults.

North American mallard duck habitats transmit high-pitched courtship whistles and raspy raab calls from yellow-billed males and quack calls from dark-capped, dark-eyelined females' black-patched orange bills.

mallard duck (Anas platyrhynchos) nest with eggs; near Detroit Lake, Linn and Marion counties, northwestern Oregon; ; Sunday, May 15, 2005, 04:42:45: Oregon Department of Fish & Wildlife, Public Domain, via Flickr

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

female (right) and male (left) mallard ducks (Anas platyrhynchos); Flourtown, Montgomery County, southeastern Pennsylvania; Saturday, April 19, 2008: Manjith Kainickara, CC BY SA 2.0 Generic, via Flickr @ https://www.flickr.com/photos/manjithkaini/2426445603/

mallard duck (Anas platyrhynchos) nest with eggs; near Detroit Lake, Linn and Marion counties, northwestern Oregon; Sunday, May 15, 2005, 04:42:45: Oregon Department of Fish & Wildlife, Public Domain, via Flickr @ https://www.flickr.com/photos/odfw/4404568507/

For further information:

Baicich, Paul J.; and Harrison, Colin J.O. Nests, Eggs, and Nestlings of North American Birds. Second edition. Princeton NJ: Princeton University Press, Princeton Field Guides. 2005.

Brehm, Christian Ludwig. 1831. "4. Die grondlandische Stockente. Anas conboschas, Br. (Anas boschas, Linn.)." Handbuch der Naturgeschichte Aller Vögel Deutschlands, pages 865-866. Ilmenau, Germany: Bernh. Friedr. Voigt.
Available via MDZ (Münchener DigitalisierungsZentrum Digitale Bibliothek) Digitale Sammlungen @ http://reader.digitale-sammlungen.de/de/fs1/object/display/bsb11121761_00895.html

Grzimek's Animal Life encyclopedia, 2nd edition. Volumes 8-11, Birds I-IV, edited by Michael Hutchins, Jerome A. Jackson, Walter J. Bock and Donna Olendorf. Farmington Hills MI: Gale Group, 2002.

Linneaus, Carl. 1758. "17. Anas playrhynchos." Systema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis, Tomus I, Editio Decima, Reformata: 125. Holmiae [Stockholm, Sweden]: Laurentii Salvii [Laurentius Salvius].
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/727030

Peterson, Alan P., M.D. "Anas platyrhynchos (Linnaeus) 1758." Zoonomen: Zoological Nomenclature Resource > Birds of the World -- Current Valid Scientific Avian Names > Anseriformes > Anatidae.
Available @ http://www.zoonomen.net/avtax/anse.html

Wednesday, February 2, 2011

William Herschel First Glimpsed Uranian Ring System on March 4, 1787

Summary: German-British astronomer William Herschel first glimpsed the Uranian ring system on March 4, 1787, less than six years after discovering Uranus.

William Herschel’s sketches of Uranian ring system on March 4 and March 5, 1787 (figure 7) and on March 16, 1787 (figures 8-10); engraving by James Basire I (Oct. 6, 1730-Sept. 6, 1802) and/or James Basire II (Nov. 12, 1769-May 13, 1822); W. Herschel, “On the Discovery of Four Additional Satellites” (1797), Tab. III, between pages 78 and 79: Public Domain, via Biodiversity Heritage Library

German-British astronomer William Herschel first glimpsed the Uranian ring system on March 4, 1787, less than six years after his discovery of the ring system’s parent body, ice giant planet Uranus.

William Herschel (Nov. 15, 1738-Aug. 25, 1822) discovered the seventh planet from the sun on March 13, 1781. He referred to his planetary discovery as Georgium Sidus and as “Georgian planet” in honor of his royal patron, King George III (June 4, 1738-Jan. 29, 1820).

The conscientious observational astronomer continued to scrutinize the Uranian system. He evaluated the planet’s shape and considered the possibility of a ring or rings as shaping the planet’s outline. He detailed his ring search in an article read at the Royal Society’s Dec. 14, 1797, meeting.

Seven of the entries from Herschel's observational journals for 1787 and 1789 noted his detection of a ring system for the planet. He included four sketches of his sightings in his report to the Royal Society.

On Feb. 4, 1787, Herschel viewed Uranus with his 20-foot reflector telescope, power 300. In his observational journal entry, he noted: “Well defined; no appearance of any ring; much daylight” (page 67).

Yet, one month later, on March 4, he pondered: “I begin to entertain a suspicion that the planet is not round. When I see it most distinctly, it appears to have double, opposite points. See figure 7. Perhaps a double ring; that is, two rings, at rectangles to each other.”

He reported for the following day, March 5: “The Georgian Sidus not being round, the telescope was turned to Jupiter. I viewed that planet with 157, 300, and 480, which shewed it perfectly well defined. Returning to the Georgian planet, it was again seen affected with projecting points. Two opposite ones, that were large and blunt, from preceding to following; and two others, that were small and less blunt, from north to south. See figure 7.”

He reported that two days later, on March 7: “Position of the great ring R, from 70° S.P. to 70° N.F. Small ring r, from 20° N.P. to 20° N.F. 600 shewed R and r. 800 R and r. 1200 R and r.”

The next annular sighting reported by Herschel occurred a little over one year 11 and one-half months later, on Feb. 22, 1789. He summarized his findings as: “A ring was suspected.”

His entry for March 16, 1789, extensively described his ring findings: “7h 37’. I have turned my speculum 90° round. A certain appearance, owing to a defect which it has contracted by exposure to the air since it was made, is gone with it; (see fig. 9 and 10;) but the suspected ring remains in the place where I saw it last.

“7h 50’. Power 471 shews the same appearance rather stronger. Power 589 still shews the same.

“Memorandum. The ring is short, not like that of Saturn. It seems to be as in figure 8; and this may account for the great difficulty of verifying it. It is remarkable that the two ansæ seem of a colour a little inclined to red. The blur occasioned by the fault of the speculum is, to-night, as represented in figure 9. The other evening it was as in figure 10; and the ring is likewise as it was the same evening” (page 68).

Four evenings later, on March 20, Herschel observed: “7h 53’. When the satellites are best in focus, the suspicion of a ring is the strongest.”

Herschel’s entry for Dec. 15, almost nine months later, announced: “The planet is not round, and I have not much doubt but that it has a ring.”

The takeaways for William Herschel’s first glimpse of the Uranian ring system on March 4, 1787, are that he reported his annular search at the Dec. 14, 1787, meeting of The Royal Society of London; that only one of the entries (for Feb. 4, 1787) in his observational journals for 1787 and 1789 noted the absence of a ring system; and that the German-British astronomer included four sketches of his ringed sightings in his report.

The National Aeronautics and Space Administration’s (NASA) Hubble Space Telescope captured ever more oblique (shallower) tilts of Uranus, as viewed from Earth; the Uranian ring system culminated in fully edge-on view (right), obtained Aug. 14, 2007, by Hubble’s Wide Field Planetary Camera 2 (WFPC-2): courtesy NASA / ESA (European Space Agency / M. (Mark Robert) Showalter (SETI Institute), via NASA Hubblesite / Space Telescope Science Institute (STScI)

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Goddard, Richard. “Drawing on Copper”: The Basire Family of Copper-Plate Engravers and Their Works. Maastricht, Netherlands: Datawyse / Universitaire Pers Maastricht, n.d.
Available @ https://cf217bb1-2e31-40ae-9fee-eafd4327025c.filesusr.com/ugd/a5bf58_f6385540cf8b44f282fd2db5df612590.pdf

Herschel, William. “XVIII. Description of a Forty-Feet Reflecting Telescope. Read June 11, 1795.” Philosophical Transactions of the Royal Society of London for the Year MDCCXCV, vol. LXXXV, Part II: 347-409. London UK: Peter Elmsly, Printer to The Royal Society, 1795.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/51831451

Levy, David H. Skywatching. Revised and updated. San Francisco CA: Fog City Press, 1994.

Marriner, Derdriu. “Mimantean Crater Herschel Honors Mimas Discoverer William Herschel.” Earth and Space News. Wednesday, Sept. 7, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/09/mimantean-crater-herschel-honors-mimas.html

Moore, Patrick, Sir. Philip’s Atlas of the Universe. Revised edition. London UK: Philip’s, 2005.

Rincon, Paul. “Uranus Rings ‘Were Seen in 1700s.’” BBC News > Science & Environment. April 18, 2007.
Available @ http://news.bbc.co.uk/2/hi/sci/tech/6569849.stm

Sunday, January 30, 2011

North American Wood Duck Habitats: Cavity Nests, Drab Females, Gaudy Males, White Eggs

Summary: North American wood duck habitats link cavity nests, drab females, gaudy males and white eggs seasonally in Canada and Mexico, year-round in the United States.

North American wood duck habitats advance cultivation through appetites for crustaceans, insects and spiders, hunting through appearances from Canada to Mexico and naturalism through year-long distribution ranges in the eastern United States.

Wood ducks bear the common names acorn, Carolina and summer ducks and the scientific name Aix sponsa (diving-bird [in] bridal [dress]) as nut-eating, southern-, warmth-, wood-lovers. Collection, development, drainage, hunting, pollution, predation, recreation and tourism challenge the wood duck, described in 1758 by Swedish zoologist Carl Linnaeus (May 23, 1707-Jan. 10, 1787). Flocks draw together half-siblings and their mothers into cavity nests and nest boxes since mothers-to-be sometimes develop built and natural domiciles into communal, maternity ward-like domains.

Eighteen-year lifespans expect open water and vegetative cover from beaver ponds, bottomland forests, freshwater marshes and swamps and wooded shores of creeks, lakes, rivers and streams.

January through August furnish seasonally monogamous opportunities for brooding two six- to 16-egg clutches in farm buildings, natural holes, nest boxes, tree cavities and woodpecker nest-holes.

Females gather downy nest-lining from white breast-feathers after going cavity-hunting with their mates early in the morning up to 1.2 miles (1.93 kilometers) from water bodies. Two- to 15-foot- (0.61- to 4.58-meter-) deep nests with 4-plus-inch (10.16-plus-centimeter-) wide openings 2 to 60 feet (0.61 to 18.29 meters) high house glossy, smooth clutches. Mothers-to-be incubate cream-white to tan, 1.8- to 2.4-inch (4.57- to 6.09-centimeter) by 1.4- to 1.7-inch (3.56- to 4.32-centimeter), subelliptical to oval eggs 28 to 37 days.

Alligators, black rat snakes, bullfrogs, collectors, gray and red foxes, great horned owls, hunters, mink, raccoons, snapping turtles and woodpeckers jeopardize North American wood duck habitats.

Brown-eyed, downy, long-tailed, precocious hatchlings know black-brown crowns and upper-parts, dark eye-to-nape lines, gray-white to yellow faces and underparts, white rear-edged wings and white-spotted lower backs.

Fast-functioning blue-gray bills with red-brown nails, gray-yellow feet and legs and open eyes launch sharp-clawed nestlings from nest entrances to the ground one day after hatching. Chicks manage five alarm, contact and threatening calls within two to three days, flight 54 to 67 days later and sexual maturity one year after hatching. Adults need arachnid-, crustacean-, insect-, mollusk-rich diets of ants, bees, beetles, caddisflies, caterpillars, crabs, damselflies, dragonflies, flies, moths, pillbugs, shrimp, slugs, snails, sowbugs, spiders and wasps.

North American wood duck habitats also offer omnivorous adults acorns, blackberries, duckweed, hickory nuts, maple seeds, millet, panic-grass, smartweed, soybeans, water primrose, waterlily and wild cherries.

Daytime forages, defensive chasing, hitting, jabbing, jerking and pecking, speed in diving, flying, swimming and walking and 12 adult calls protect flock-based wood duck life cycles.

Alder, arrowhead, buttonbush, smartweed and willow qualify as camouflage, during winter-coldest temperatures of minus 40 degrees Celsius and Fahrenheit, through 900-foot (274.32-meter) altitudes above sea level. Burgundy flanks, maroon breasts, pale bellies and under-tails, red eyes and white breast, chin, face, head and neck stripes reveal black bill-tipped, helmet-headed, rectangular-tailed, stout-bodied males. Deep-winged, heads-up, rapid flights on 26- to 29-inch (66.04- to 73.66-centimeter) wingspans suggest 16- to 30-ounce (453.59- to 850.49-gram), 18.5- to 21.5-inch (46.99- to 54.61-centimeter) adults.

The rising oh-eek-oh-eek call and the up-slurred, wheezy, whistled zweeet vocalization respectively tell of brown-and-white females and of gaudy males in North American wood duck habitats.

An unhatched wood duck (Aix sponsa) egg, held in gloved hand of wildlife technician Kelly Tingle, was retrieved during annual nest box maintenance check conducted by Biological Sciences, Environmental Management Division, at Marine Corps Base Camp Lejeune, Jacksonville, Onslow County, southeastern North Carolina; Tuesday, Jan. 24, 2012, 09:45: U.S. Marine Corps, Public Domain, via Wikimedia Commons

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

A pair of female (front) and male (back) North American wood ducks (Aix sponsa) take a walk; Saturday, March 6, 2010, 09:25: Andrea Westmoreland from DeLand, United States, CC BY SA 2.0 Generic, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Mr._and_Mrs._Wood_Duck_Taking_a_Stroll_-_Flickr_-_Andrea_Westmoreland.jpg

Baicich, Paul J.; and Harrison, Colin J.O. Nests, Eggs, and Nestlings of North American Birds. Second edition. Princeton NJ: Princeton University Press, Princeton Field Guides, 2005.

Grzimek's Animal Life Encyclopedia, 2nd edition. Volumes 8-11, Birds I-IV, edited by Michael Hutchins, Jerome A. Jackson, Walter J. Bock and Donna Olendorf. Farmington Hills MI: Gale Group, 2002.

Linnaeus, Carl. 1758. "35. Aix sponsa." Systema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis, Tomus I, Editio Decima, Reformata: 128. Holmiae [Stockholm, Sweden]: Laurentii Salvii [Laurentius Salvius].
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/727033

Peterson, Alan P., M.D. "Aix sponsa (Linnaeus) 1758." Zoonomen: Zoological Nomenclature Resource > Birds of the World -- Current Valid Scientific Avian Names > Anseriformes > Anatidae > Aix.
Available @ http://www.zoonomen.net/avtax/anse.html

"The 2012 USDA Plant Hardiness Zone Map." The National Gardening Association > Gardening Tools > Learning Library USDA Hardiness Zone > USDA Plant Hardiness Zone Map.
Available @ https://garden.org/nga/zipzone/2012/

Saturday, January 29, 2011

American Red-Shouldered Hawk Habitats: Platform Nest, Pale Egg, Brown Body

Summary: Pale eggs in platform nests get North American red-shouldered hawk habitats brown bodies seasonally in Canada and Mexico, year-round in the United States.

red-shouldered hawk (Buteo lineatus); Kanapaha Botanical Gardens, Gainesville, Alachua County, north central Florida; Wednesday, April 9, 2008, 10:39: Sfullenwider, CC BY SA 4.0 International, via Wikimedia Commons

North American red-shouldered hawk habitats address cultivator anxieties through Accipitridae raptor family member appetites for rampaging reptiles but aggravate hunters and naturalists through distribution ranges along coasts and into the eastern interior.

Red-shouldered hawks bear their common name and the scientific name Buteo lineatus (striped buzzard) from red leading edges on wings and from black-and-white-striped tails and wings. Agro-industry, construction, pollution, predation, recreation, tourism and urbanization challenge the red-shouldered hawk, described in 1788 by German naturalist Johann Friedrich Gmelin (Aug. 8, 1748-Nov. 1, 1804). A thousand-mile (1,609.34-kilometer) distance divides four subspecies of eastern Mexico and the United States from the only subspecies in western coastal Mexico and the United States.

Eighteen-year lifespans expect moist coniferous, deciduous or mixed forests and woodlands, especially of eucalyptus and oak in the west and of mangrove and palmetto in Florida.

January through July furnish opportunities for brooding one two- to five-egg clutch, followed by more if the first smooth, somewhat glossy, subelliptical to elliptical eggs fail.

Parents-to-be gather twigs into bark-, leaf-, lichen-, stem-lined, bulky, flat-topped, 2- to 3-inch- (5.08- to 7.62-centimeter-) deep, 8- to 12-inch- (20.32- to 30.48-centimeter-) high platform nests. Nests with 8-inch (20.32-centimeter) inner and 18- to 24-inch outer (45.2- to 60.96-centimeter) diameters house eggs 20 to 60 feet (6.09 to 18.29 meters) up trees. Parents-to-be initiate 23- to 40-day incubations with the first-laid buff or white, 2.06- to 2.22-inch (52.4- to 56.5-millimeter) by 1.65- to 1.73-inch (42- to 44-millimeter) egg.

Great-horned owls and raccoons jeopardize brown,-, lilac-, red-brown-blotched, specked or spotted eggs, hatchlings and nestlings and their co-incubating, co-tending parents in North American red-shouldered hawk habitats.

Downy, semi-helpless hatchlings know long- and soft-coated buff-white upperparts, purple-buff-tinted backs and wings and white underparts and subsequently thick- and woolly-coated gray-white upperparts and white underparts.

Black-billed, different-aged, different-sized, yellow-cered nestlings with dark eye surrounds live off parent-foraged food and, two to four or five weeks after hatching, look active and feathered. Six-week-olds move nearby, for meals with parents for another eight to 10 weeks, until independence at 17 to 19 weeks and sexual maturity at one year. Adults need beetles, caterpillars, chipmunks, crayfish, doves, earthworms, fish, frogs, gophers, grasshoppers, lizards, mice, moles, pigeons, rabbits, shrews, snakes, sparrows, spiders, squirrels, starlings, toads and voles.

North American red-shouldered hawk habitats up to 8,202.1 feet (2,500 meters) above sea level offer winter-coldest temperatures at minus 25 degrees Fahrenheit (minus 31.66 degrees Celsius).

Bio-geography and physiques put orange-breasted, rufous-headed red-shouldered hawks into California's elegans and Texas' texanus subspecies and pale-breasted, pale-headed red-shouldered hawks into Florida's alleni and extimus subspecies.

Brown upperparts, brown- and white-banded tails, adult-like in fanning for soaring, brown-mottled, spotted, streaked cream-white underparts and translucent patches near dark wing tips quicken juvenile identifications. Black- and white-barred tails, dark-streaked gray heads, red shoulder patches, red- and white-barred breasts, white undertail feathers and white-spotted dark brown plumage reveal yellow-footed, yellow-legged adults. Circular soaring, fast-flapped flight on 3- to 3.5-foot (0.91- to 1.07-meter) wingspans suggests 17- to 27-ounce (481.94- to 765.44-gram), 17- to 24-inch (43.18- to 60.96-centimeter) adults.

North American red-shouldered hawk habitats transmit Allen's, elegant, furthermost, striped and Texas subspecies' alarmed or territorial female and male kee-ahh whistles and nesting female kee calls.

illustration of red-shouldered hawk eggs; Illustrations of the Nests and Eggs of Birds of Ohio, figure 3, opposite page 170: Public Domain, via Biodiversity Heritage Library

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

red-shouldered hawk (Buteo lineatus); Kanapaha Botanical Gardens, Gainesville, Alachua County, north central Florida; Wednesday, April 9, 2008, 10:39, 10:39: Sfullenwider, CC BY SA 4.0 International, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Kanapaha-2008_04_09-IMG_0128.JPG

illustration of red-shouldered hawk eggs; Illustrations of the Nests and Eggs of Birds of Ohio, Plate XLIV, figure 3, opposite page 170: Public Domain, via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/34908293

For further information:

Baicich, Paul J.; and Harrison, Colin J.O. Nests, Eggs, and Nestlings of North American Birds. Second edition. Princeton NJ: Princeton University Press, Princeton Field Guides, 2005.

Bangs, Outram. 16 January 1920. "A New Red-Shouldered Hawk From the Florida Keys: Buteo lineatus extimus subsp. nov." Proceedings of the New England Zoölogical Club, vol. VII (1919-1921): 35.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/12606572

Bishop, Lois B. (Bennett). April 1912. "An Apparently Unrecognized Race of the Red-Shouldered Hawk: Buteo lineatus texanus subsp. nov. Texas Red-Shouldered Hawk." The Auk, vol. XXIX (old series vol. XXXVII), no. II: 232-233. Cambridge MA: The American Ornithologists' Union.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/16020142

Cassin, John. 27 February 1855. "Notes on North American Falconidae, With Descriptions of New Species: 15. Buteo elegans, nobis." Proceedings of the Academy of Natural Sciences of Philadelphia, vol. VII (1854, 1855): 281-282. Philadelphia PA: Merrihew & Thompson.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/1694395
Available via HathiTrust @ https://hdl.handle.net/2027/hvd.32044093291839?urlappend=%3Bseq=307

Gmelin, Johann Friedrich. 1788. "82. Falco lineatus." Caroli a Linné Systema Naturae, tom. I, pars I: 268. Lipsaie [Leipzig]: Impensis Georg Emanuel Beer.
Available via Biodiversity Heritage Library @ http://biodiversity library.org/page/2896868

Grzimek's Animal Life Encyclopedia, 2nd edition. Volumes 8-11, Birds I-IV, edited by Michael Hutchins, Jerome A. Jackson, Walter J. Bock and Donna Olendorf. Farmington Hills MI: Gale Group, 2002.

Peterson, Alan P., M.D. "Buteo linneatus (Gmelin) 1788." Zoonomen: Zoological Nomenclature Resource > Birds of the World -- Current Valid Scientific Avian Names > Accipitriformes > Buteo.
Available @ http://www.zoonomen.net/avtax/acci.html

Ridgway, Robert. 26 January 1885. "Description of a New Race of the Red-Shouldered Hawk From Florida: Buteo lineatus alleni, subsp. nov." Proceedings of the United States National Museum, vol. VII (1884), no. 33: 514-515.
Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/7306308