San Joaquin antelope squirrel
The San Joaquin antelope squirrel or Nelson's antelope squirrel, is a species of antelope squirrel, in the San Joaquin Valley of the U. S. state of California. The San Joaquin antelope squirrel is found in the San Joaquin Valley, including slopes and ridge tops along the western edge of the valley, it is endemic to the region, is found in a much smaller range today than it inhabited. Since the San Joaquin Valley fell under heavy agricultural cultivation, habitat loss combined with rodenticide use has reduced the squirrels numbers enough that it is now listed as a threatened species. Most of today's remaining San Joaquin antelope squirrels can be found in the Carrizo Plain, where their original habitat remains undisturbed; the squirrels live in small underground familial colonies on sandy excavated grasslands in isolated locations in San Luis Obispo and Kern Counties. Common vegetation associated with the squirrel includes Atriplex and Ephedra, some junipers; the binomial of this species commemorates the American naturalist Edward William Nelson.
The San Joaquin antelope squirrel is dull yellowish-brown or buffy-clay in color on upper body and outer surfaces of the legs with a white belly and a white streak down each side of its body in the fashion of other antelope squirrels. The underside of the tail is a buffy white with black edges. Males are 9.8 inches and females are 9.4 inches in length. Studies by Hawbecker provide abundant information on breeding and the life cycle of Nelson's antelope squirrel, they have nearly all their young in March. Once pregnant, gestation lasts a little less than a month; the young do not emerge from their dens until the first week of April. Nelson's antelope squirrel has only one breeding season, timed appropriately so that the young are born during the time of year when green vegetation is the most abundant. Weaning is thought to start or be completed before the young emerge. Once above ground, young are seen foraging for food independently. During the weaning period, the mother feeds alone and ignores any attempt of the young trying to nuzzle or nurse from her.
A mother will sometimes spend the night in a different den if necessary. By early to mid-May the young squirrels have had their juvenile pelage for some time and begin to show the changes into adult pelage. By summer, the adult pelage is present. Once an individual has reached adulthood it is difficult to tell differences in age. Nelson's antelope squirrel is a short-lived species that does not survive to a year. However, several individuals have been observed to live more than four years in the wild. Colonies have about six or eight individuals, however these individuals are not distributed evenly across their range. There is about 1 per hectare. Nelson's antelope squirrel prefers deep, rich soil types since they are easy to dig through in both winter and summer temperatures. Although these squirrels may dig for food, they do not make their own burrows. Instead they claim abandoned Dipodomys burrows as their own. Both males and females have the same size home range of about 4.4 hectare. Of course, there are areas of concentration within this range where the squirrels spend the majority of their time.
It is omnivorous, feeding on seeds, green vegetation and dried animal matter. It caches food. Redstem fialree and brome grass are important food items for the squirrels. However, their diet may differ depending on the time of time of year. Green vegetation is the most common diet type from December to mid-April because it is the most abundant during this period. Insects make up more than 90% of the squirrel's diet from mid-April to December because they are more abundant. Although seeds are available for most of the year, it is not the preferable diet of the squirrels, they will choose insects or green vegetation when available over seeds if the seeds are more abundant and easier to access. Some speculate that this could be due to the higher amount of water in insects and green vegetation, which would be necessary for the species to survive in such a hot, dry climate. For the Nelson's antelope squirrel, there is not an abundant water source nearby. Under laboratory conditions, the squirrels accept water.
However, they can survive at least 7 months in the shade without water. At the end of 7 months they appeared healthy and not at all emaciated. Nelson's antelope squirrels are social animals; when individually taken out of their home range and released in an unknown area, they seem helpless and confused. They do not expend much energy throughout the day because of the extreme temperatures in their environment. In fact, when in the direct sunlight, a temperature of 31-32 °C can kill them. Therefore, there is little activity from the squirrels during the heat of the day. Although there is no evidence of hibernation, the squirrels are not bothered by the cold and can survive temperatures below freezing, in their burrows, they are not early risers and are not seen until after sunrise, however it does forage in the morning and evening, avoiding the midday heat. Around noon the squirrels disappear into their burrows and are not seen again until about 2 pm at the earliest. On moderate days, the squirrels will take their time foraging, in contrast to bringing as much food back to their burrows as as possible on hot or cold days.
The squirrels are known to stretch out and roll over in the dust on the ground. These dust baths appear to be enjoyable activities for the squirrels and may be used to prevent infestation of parasites. Nelson's antelope squirrels
Spiny lizards is the common name for the genus Sceloporus in the family Phrynosomatidae. This genus includes some of the most seen lizards in the United States; the 106 species in the genus Sceloporus are organized into 21 species groups. However, their relationships to each other are under review. Listed below are species of Sceloporus: Nota bene: A binomial authority in parentheses indicates that the species was described in a genus other than Sceloporus. Moloch horridus, an unrelated Australian lizard, sometimes referred to as "spiny lizard" Video of Sceloporus jarrovii in Arizona Data related to Sceloporus at Wikispecies Media related to Sceloporus at Wikimedia Commons Boulenger GA. Catalogue of the Lizards in the British Museum. Second Edition. Volume II. Iguanidæ... London: Trustees of the British Museum.. Xiii + 497 pp. + Plates I-XXIV.. Goin, Coleman J.. Introduction to Herpetology, Third Edition. San Francisco: W. H. Freeman. Xi + 378 pp. ISBN 0-7167-0020-4.. Powell R, Conant R, Collins JT. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition.
Boston and New York: Houghton Mifflin Harcourt. Xiv + 494 pp. 207 Figures. ISBN 978-0-544-12997-9.. Smith, Hobart M.. New York: Golden Press. 240 pp. ISBN 0-307-13666-3, ISBN 0-307-47009-1.. Wiegmann AF Jr. "Beyträge zur Amphibienkunde ". Isis von Oken 21: 364-383
Natural history is a domain of inquiry involving organisms including animals and plants in their environment. A person who studies natural history is called natural historian. Natural history is not limited to it, it involves the systematic study of any category of natural organisms. So while it dates from studies in the ancient Greco-Roman world and the mediaeval Arabic world, through to European Renaissance naturalists working in near isolation, today's natural history is a cross discipline umbrella of many specialty sciences; the meaning of the English term "natural history" has narrowed progressively with time. In antiquity, "natural history" covered anything connected with nature, or which used materials drawn from nature, such as Pliny the Elder's encyclopedia of this title, published circa 77 to 79 AD, which covers astronomy, geography and their technology and superstition, as well as animals and plants. Medieval European academics considered knowledge to have two main divisions: the humanities and divinity, with science studied through texts rather than observation or experiment.
The study of nature revived in the Renaissance, became a third branch of academic knowledge, itself divided into descriptive natural history and natural philosophy, the analytical study of nature. In modern terms, natural philosophy corresponded to modern physics and chemistry, while natural history included the biological and geological sciences; the two were associated. During the heyday of the gentleman scientists, many people contributed to both fields, early papers in both were read at professional science society meetings such as the Royal Society and the French Academy of Sciences – both founded during the seventeenth century. Natural history had been encouraged by practical motives, such as Linnaeus' aspiration to improve the economic condition of Sweden; the Industrial Revolution prompted the development of geology to help find useful mineral deposits. Modern definitions of natural history come from a variety of fields and sources, many of the modern definitions emphasize a particular aspect of the field, creating a plurality of definitions with a number of common themes among them.
For example, while natural history is most defined as a type of observation and a subject of study, it can be defined as a body of knowledge, as a craft or a practice, in which the emphasis is placed more on the observer than on the observed. Definitions from biologists focus on the scientific study of individual organisms in their environment, as seen in this definition by Marston Bates: "Natural history is the study of animals and Plants – of organisms.... I like to think of natural history as the study of life at the level of the individual – of what plants and animals do, how they react to each other and their environment, how they are organized into larger groupings like populations and communities" and this more recent definition by D. S. Wilcove and T. Eisner: "The close observation of organisms—their origins, their evolution, their behavior, their relationships with other species"; this focus on organisms in their environment is echoed by H. W. Greene and J. B. Losos: "Natural history focuses on where organisms are and what they do in their environment, including interactions with other organisms.
It encompasses changes in internal states insofar as they pertain to what organisms do". Some definitions go further, focusing on direct observation of organisms in their environment, both past and present, such as this one by G. A. Bartholomew: "A student of natural history, or a naturalist, studies the world by observing plants and animals directly; because organisms are functionally inseparable from the environment in which they live and because their structure and function cannot be adequately interpreted without knowing some of their evolutionary history, the study of natural history embraces the study of fossils as well as physiographic and other aspects of the physical environment". A common thread in many definitions of natural history is the inclusion of a descriptive component, as seen in a recent definition by H. W. Greene: "Descriptive ecology and ethology". Several authors have argued for a more expansive view of natural history, including S. Herman, who defines the field as "the scientific study of plants and animals in their natural environments.
It is concerned with levels of organization from the individual organism to the ecosystem, stresses identification, life history, distribution and inter-relationships. It and appropriately includes an esthetic component", T. Fleischner, who defines the field more broadly, as "A practice of intentional, focused attentiveness and receptivity to the more-than-human world, guided by honesty and accuracy"; these definitions explicitly include the arts in the field of natural history, are aligned with the broad definition outlined by B. Lopez, who defines the field as the "Patient interrogation of a landscape" while referring to the natural history knowledge of the Eskimo. A different framework for natural history, covering a similar range of themes, is implied in the scope of work encompassed by many leading natural history museums, which include elements of anthropology, geology and astronomy along with botany and zoology, or include both cultural and natural components of the world; the pl
Clinton Hart Merriam
Clinton Hart Merriam was an American zoologist, ornithologist, entomologist and naturalist. Clinton Hart Merriam was born in New York City in 1855 to Clinton Levi Merriam, a U. S. congressman, Caroline Hart, a judge's daughter and a graduate of Rutgers Institute. The name Clinton, shared by both father and son, was in honor of New York governor DeWitt Clinton, whom the Merriam family had connections with. To avoid confusion, the younger Merriam went by his first initial combined with his middle name, his mother's maiden name, thus appears as C. Hart Merriam in both the literature of his time and thereafter. While born in New York City, where his parents were staying the winter, the family home and place where Merriam spent his boyhood days was "Locust Grove," a homestead in Lewis County, New York, it was located near the Adirondack Mountains, where Merriam's interests in the natural world flourished. Encouraged by his father, who gave the young Merriam a muzzle-loading rifle and an old storeroom to keep his trophies, Merriam began a collection of natural specimens at a young age, learning the basics of taxidermy from a retired army surgeon.
At the age of fifteen, Merriam's father took him to see naturalist Spencer F. Baird at the Smithsonian Institution, impressed with the boy's collection. Professor Baird would have a lasting impact on Merriam's career as a naturalist, he supported Merriam's entrance into the scientific community by setting up lessons with the taxidermist John Wallace, recommending Merriam to the Hayden Geological Survey, providing assistance in Merriam's first publication following the expedition. Though the recommendation of Professor Baird, the 16 year-old Merriam was appointed as naturalist of the Hayden Geological Survey of 1872. In June 1872 Congress had appropriated another $20,000 for completion of the notable Hayden Geological Survey of 1871, it had contributed to the founding of Yellowstone National Park. Both were part of the United States Geographical Survey of the Territories. Beginning in Ogden and the Wasatch Mountains of Utah, the expedition pushed between and the Teton Basinup through Idaho and Montana and into the newly established Yellowstone National Park.
Merriam returned from the expedition with 67 nests with eggs. His report from the trip appears in the Sixth Annual Report of the U. S. Geological Survey of the Territories and marks his first major contribution to the zoological literature. Following the expedition, Lt. George Wheeler, a rival of Hayden's in surveying the American West, tried to poach Merriam for his own survey, putting Merriam in the midst of an old feud between the two explorers. A third expedition, without Merriam, explored Colorado in 1873. Again Professor Baird stepped in on behalf of Merriam, resolving the issue by recommending that Merriam return to school to prepare for college. Merriam followed Professor Baird's advice and prepared for college in 1872 and 1873 by attending Pingry Military School in Elizabeth, New Jersey − and Williston Seminary in Easthampton, Massachusetts. In 1874, Merriam attended the Sheffield Scientific School of Yale University, where he studied natural history and anatomy. Among the faculty there, Merriam received instruction from such prominent figures as Alpheus Hyatt Verrill, Sidney Irving Smith, Daniel Cady Eaton.
During this time, Merriam published a short paper entitled "Ornithological Notes from the South," following a trip to Florida with his father. Around this time, Merriam published "A Review of the Birds of Connecticut," significant in that it recognized that the distribution of birds' ranges is governed by temperature during the breeding season. From assisting a Dr. Bacon in New Haven with surgeries, Merriam developed an interest in anatomy, Merriam and his roommates would practice dissections of human cadavers obtained through a New York morgue; this interest in medicine and surgery led Merriam to move from Yale to the College of Physicians and Surgeons of Columbia University in 1877. In 1878, while at medical school, Merriam helped organize the Linnaean Society of New York and served as its first president. Merriam was an early member of the Nuttall Ornithological Club and an early contributor to its bulletin. Merriam graduated with his M. D. returned to Locust Grove to practice medicine. From 1879-1885, after earning his M.
D. Merriam returned to Locust Grove to practice medicine as a country doctor, becoming quite successful in the endeavor. During this time, Merriam invented scientific and surgical instruments as well as wrote a medical treatise, though the manuscript was lost on the way to the printer. While practicing medicine, Merriam corresponded with his naturalist colleagues, continued to build his collection of animal specimens, with a growing interest in mammals. In 1881, he published a "Preliminary List of the Birds of the Adirondacks," followed by an exhaustive "Mammals of the Adirondacks" in 1884, which set a new standard for local wildlife studies in mammalogy, not a well-established a field. At this time, Merriam became interested in the underlying questions of species distribution, hired a clerk to search meteorological records and compute monthly mean temperature in preparation. Merriam met with prominent figures in the sciences, including famed geologist and paleontologist James Hall and Charles Doolittle Walcott of the US Geological Survey, in an attempt to enlist their aid in securing state funding from the New York legislature for a statewide biological survey, but this effort was unsuccessful.
Merriam continued to e
Terrestrial animals are animals that live predominantly or on land, as compared with aquatic animals, which live predominantly or in the water, or amphibians, which rely on a combination of aquatic and terrestrial habitats. Terrestrial invertebrates include ants, crickets and spiders; the term terrestrial is applied for species that live on the ground, in contrast to arboreal species, which live in trees. There are other less common terms that apply to specific groups of terrestrial animals: Saxicolous creatures are rock dwelling. Saxicolous is derived from the Latin word "saxum," meaning a rock. Arenicolous creatures live in the sand. Troglofauna predominantly live in caves. Terrestrial invasion is one of the most important events in the history of life. Terrestrial lineages evolved in several animal phyla, among which vertebrates and mollusks are representatives of more successful groups of terrestrial animals. Terrestrial animals do not form a unified clade; the transition from an aquatic to terrestrial life has evolved independently and many times by various groups of animals.
Most terrestrial lineages originated under a mild or tropical climate during the Paleozoic and Mesozoic, whereas few animals became terrestrial during the Cenozoic. When excluding internal parasites, free living species in terrestrial environments are represented by the following ten phyla: flatworms, nematodes, tardigrades, arthropods, mollusks and chordates. Roundworms and rotifers are microscopic animals that require a film of water to live in, are not considered terrestrial. Flatworms, ribbon worms, velvet worms and annelids all depend on more or less moist habitats, as do the arthropods centipedes and millipedes; the three remaining phyla, arthropods and chordates, all contain species that have adapted to dry terrestrial environments, contain species that have no aquatic phase in their life cycles. Labeling an animal species "terrestrial" or "aquatic" is obscure and becomes a matter of judgment. Many animals considered terrestrial have a life-cycle, dependent on being in water. Penguins and walruses sleep on land and feed in the ocean, yet they are all considered terrestrial.
Many insects, e.g. mosquitos, all terrestrial crabs, as well as other clades, have an aquatic life cycle stage: their eggs need to be laid in and to hatch in water. There are crab species that are aquatic, crab species that are amphibious, crab species that are terrestrial. Fiddler crabs are called "semi-terrestrial" since they make burrows in the muddy substrate, to which they retreat during high tides; when the tide is out, fiddler crabs search the beach for food. The same is true in the mollusca. Many hundreds of gastropod genera and species live in intermediate situations, such as for example, Truncatella; some gastropods with gills live on land, others with a lung live in the water. As well as the purely terrestrial and the purely aquatic animals, there are many borderline species. There are no universally accepted criteria for deciding how to label these species, thus some assignments are disputed. Fossil evidence has shown that sea creatures related to arthropods, first began to make forays on to land around 530 million years ago.
There is little reason to believe, that animals first began living reliably on land around this same time period. A more hypothesis is that these early arthropods' motivation for venturing on to dry land was to mate or lay eggs out of the reach of predators; as time went on, evidence suggests that by 375 million years ago the bony fish best adapted to life in shallow coastal/swampy waters, were much more viable as amphibians than were their arthropod predecessors. Thanks to strong, muscular limbs, lungs which existed in conjunction with gills and animals like it were able to establish a strong foothold on land by the end of the Devonian period; as such, they are the most recent common ancestor of all modern tetrapods. Gastropod mollusks are one of the most successful animals that have diversified in the terrestrial habitat, they have evolved terrestrial taxa in more than nine lineages. They are referred to as land snails and slugs. Terrestrial invasion of gastropod mollusks has occurred in Neritopsina, Littorinoidea, Ellobioidea, Veronicelloidea and Stylommatophora, in particular, each of Neritopsina and Ellobioidea has achieved land invasion more than once.
Most terrestrialization events have occurred during the Mesozoic. Gastropods are unique due to several terrestrial and epifaunal lineages that evolved during the Cenozoic; some members of rissooidean families Truncatellidae and Pomatiopsidae are considered to have colonized to land during the Cenozoic. Most truncatellid and assimineid snails amphibiously live in intertidal and supratidal zones from brackish water to pelagic areas. Terrestrial lineages evolved from such ancestors; the rissooidean gastropod family Pomatiopsidae is one of the few groups that have evolved terrestrial
USS Jeannette (1878)
USS Jeannette was a naval exploration vessel which, commanded by George W. De Long, undertook the Jeannette expedition of 1879–1881 to the Arctic. After being trapped in the ice and drifting for two years, the ship and its crew of 33 were released from the ice trapped again and sunk some 300 nautical miles north of the Siberian coast; the entire crew survived the sinking. The others reached nine subsequently perished in the Lena Delta, including De Long; the vessel had begun its active career in 1861 as a Royal Navy gunboat. After more than a decade's service off the West African coast and in the Mediterranean, Pandora was retired from duty and sold as a private yacht to a British explorer, Allen Young. Young took her on two voyages to the Arctic, in 1875 and 1876, before selling her to James Gordon Bennett, Jr. proprietor of The New York Herald, who changed her name to Jeannette. Although she sailed to the Arctic under the U. S. flag as USS Jeannette, subject to naval laws and discipline, Bennett remained responsible for the costs of the expedition.
The ship that became USS Jeannette began her life as a Royal Navy gunboat, built at the Pembroke Naval Dockyards in 1860. She was of wooden construction, 146 feet in length and 25 feet at the beam, with a draught of 25 feet, her tonnage, calculated by Builder's Measure, was 428 tons, with a displacement of 570 tons. She was rigged as a barque, her armament was five guns. After her launch on 7 February 1861, Pandora was taken from Pembroke to Portsmouth Dockyard, where she was fitted with her engines and boilers, underwent trials before commissioning. On October 22 she concluded her trials achieving a speed of 9.25 knots over a measured mile. In November 1861, during the American Civil War, the diplomatic incident known as the Trent affair caused the Admiralty to bring additional ships into active service. On 27 December 1861, Pandora was formally commissioned, as tender to HMS Majestic, the following day sailed for Liverpool where Majestic was berthed; the crisis was resolved. In April 1863 Pandora left Portsmouth for service off the coast of West Africa.
She returned after four years, was transferred to the reserve. In April 1868 she was recomissioned, returned to West Africa. Two years she was transferred to the Mediterranean squadron, based at Valletta, Malta; this was her last commission in British naval service. In July 1872, after two years in the Mediterranean she returned to Spithead, where she was taken out of active commission and berthed in Portsmouth as part of the steam reserve. In 1875 Pandora was acquired from the navy by the yachtsman Allen Young, for use in one of the last expeditions sent to the Canadian Arctic to investigate the disappearance, thirty years of the Franklin Expedition. Young sailed in June 1875, seeking not only for signs of Franklin but discover and complete the Northwest Passage unconquered, he was unsuccessful on both counts. One of the financiers for this venture was James Gordon Bennett, Jr. the owner of The New York Herald. In 1876 Young took Pandora north again, for a second attempt on the Northwest Passage.
He was diverted by a request from the Admiralty to look for the British Arctic Expedition under George Nares, engaged in an attempt to reach the North Pole from Smith Sound. The expedition did not require Pandora's assistance, Young returned home. In 1877 Young sold Pandora to Bennett, planning his own Arctic expedition. Bennett's plan was to sail a vessel through the Bering Strait, on the theory that the warm Pacific Ocean current known as the Kuro Siwo would provide a "thermometric gateway" whereby a suitable ship might reach the North Pole; this was the primary objective, but the ship was equipped for scientific observation. By agreement with the U. S. Department of the Navy, Bennett would finance the expedition, but would sail under naval laws and discipline, would be commanded by a naval officer, George W. De Long. Pandora was renamed Jeannette, after Bennett's sister, in January 1879 arrived at the Mare Island Naval Shipyard, to be fitted for Arctic service. Jeannette departed San Francisco on July 8, 1879.
She sent her last communication to Washington from St. Lawrence Bay, Siberia, on August 27. Shortly afterwards she encountered ice, of increasing severity as she pushed her way forward to Herald Island. On September 7 she was caught fast in the ice at 71°35′N 175°6′E. For the next 21 months, Jeannette drifted in an erratic fashion to the northwest but doubling back on herself. In May 1881, two islands were discovered, which De Long named Jeannette Island. On the night of June 12, when they had reached 77°15′N 154°59′E the pressure of the ice began to crush Jeannette. De Long and his men unloaded provisions and equipment onto the ice, the ship sank the following morning; the expedition began the long trek to the Siberian coast, hauling their sledges with boats and supplies. On their way they discovered a further island which they named Bennett Island in honor of the expedition's sponsor. After reaching the New Siberian Islands and gaining some food and rest, the party took to their three boats on September 12 for the last stage of their journey to the Lena Delta, their planned landfall.
As a violent storm blew up, one of the boats sank. The other two craft, commanded by De Lo