Plumage refers both to the layer of feathers that cover a bird and the pattern and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can be different colour morphs; the placement of feathers on a bird is not haphazard, but rather emerge in organized, overlapping rows and groups, these feather tracts are known by standardized names. Most birds moult twice a year, resulting in a basic plumage. Many ducks and some other species such as the red junglefowl have males wearing a bright nuptial plumage while breeding and a drab eclipse plumage for some months afterward; the painted bunting's juveniles have two inserted moults in their first autumn, each yielding plumage like an adult female. The first starts a few days after fledging replacing the juvenile plumage with an auxiliary formative plumage. Abnormal plumages include a variety of conditions. Albinism, total loss of colour, is rare; some species are colour polymorphic, having two or more colour variants.
A few species have special types of polymorphism, as in the male ruff which has an assortment of different colours around the head and neck in the breeding season only. Hen feathering is an inherited plumage character in domestic fowl controlled by a single gene. Plumology is the name for the science, associated with the study of feathers. All species of birds moult at least annually after the breeding season, known as the pre-basic moult; this resulting covering of feathers, which will last either until the next breeding season or until the next annual moult, is known as the basic plumage. Many species undertake another moult prior to the breeding season known as the pre-alternate moult, the resulting breeding plumage being known as the alternate plumage or nuptial plumage; the alternate plumage is brighter than the basic plumage, for the purposes of sexual display, but may be cryptic to hide incubating birds that might be vulnerable on the nest. The Humphrey-Parkes terminology requires some attention to detail to name moults and plumages correctly.
Many ducks have colourful plumage, exhibiting strong sexual dimorphism. However, they moult into a dull plumage after breeding in mid-summer; this drab, female-like appearance is called eclipse plumage. When they shed feathers to go into eclipse, the ducks become flightless for a short period of time; some duck species remain in eclipse for one to three months in the late summer and early fall, while others retain the cryptic plumage until the next spring when they undergo another moult to return to their breeding plumage. Although found in the Anatidae, a few other species, including related red junglefowl, most fairywrens and some sunbirds have an eclipse plumage. In the superb and splendid fairywrens old males may moult from one nuptial plumage to another whereas in the red-backed and white-winged fairywrens, males do not acquire nuptial plumage until four years of age – well after they become sexually mature and indeed longer than the vast majority of individuals live. In contrast to the ducks, males of hummingbirds and most lek-mating passerines – like the Guianan cock-of-the-rock or birds of paradise – retain their exuberant plumage and sexual dimorphism at all times, moulting as ordinary birds do once annually.
There are hereditary as well as non-hereditary variations in plumage that are rare and termed as abnormal or aberrant plumages. Melanism refers to an excess of dark colours. Erythromelanism or erythrism is the result of excessive reddish brown erythromelanin deposition in feathers that lack melanin. Melanin of different forms combine with xanthophylls to produce colour mixtures and when this combination is imbalanced it produces colour shifts that are termed as schizochroisms. A reduction in eumelanin leads to non-eumelanin schizochroism with an overall fawn plumage while a lack of phaeomelanin results in grey coloured non-phaeomelanin schizochroism. Carotenism refers to abnormal distribution of carotenoid pigments; the term "dilution" is used for situations. Dilution occurs in normal plumage, but may in addition occur as an aberration. In some birds – many true owls, some nightjars and a few cuckoos being known examples – there is colour polymorphism; this means that two or more colour variants are numerous within their populations during all or at least most seasons and plumages.
Other cases of natural polymorphism are of various kinds. Albinism in birds is rare, occurring to any extent in one in 1800 individuals, it involves loss of colour in all par
Cospeciation is a form of coevolution in which the speciation of one species dictates speciation of another species and is most studied in host-parasite relationships. In the case of a host-parasite relationship, if two hosts of the same species get within close proximity of each other, parasites of the same species from each host are able to move between individuals and mate with the parasites on the other host. However, if a speciation event occurs in the host species, the parasites will no longer be able to "cross over" because the two new host species no longer mate and, if the speciation event is due to a geographic separation, it is unlikely the two hosts will interact at all with each other; the lack of proximity between the hosts prevents the populations of parasites from interacting and mating. This can lead to speciation within the parasite. According to Fahrenholz's rule, first proposed by Heinrich Fahrenholz in 1913, when host-parasite cospeciation has occurred, the phylogenies of the host and parasite come to mirror each other.
In host-parasite phylogenies, all species phylogenies for that matter, perfect mirroring is rare. Host-parasite phylogenies can be altered by host switching, independent speciation, other ecological events, making cospeciation harder to detect. However, cospeciation is not limited to parasitism, but has been documented in symbiotic relationships like those of gut microbes in primates. In 1913, Heinrich Fahrenholz proposed that the phylogenies of both the host and parasite will become congruent, or mirror each other when cospeciation occurs. More more related parasite species will be found on related species of host. Thus, to determine if cospeciation has occurred within a host-parasite relationship, scientists have used comparative analyses on the host and parasite phylogenies. In 1968, Daniel Janzen proposed an opposing theory to Fahrenholz's rule. Studying cospeciation within plant-insect relationships, he proposed that species have a physiological range of conditions and environments. Over time, conserved traits within a parasitic species allows for survival in a range of conditions or environments.
"Ecological fitting", as it is known, means more related parasites will share similar traits that pertain to surviving on a particular host. This provides explanation for the congruence of the host-parasite phylogenies. Fahrenholz's rule appears to be observed in the parasitic cospeciation of pocket gophers and chewing lice, it is seen, between Poaceae grasses and Anguininae nematodes, between some plants and Phyllonorycter leaf-mining moths. Among animals, symbiotic cospeciation is seen between Uroleucon and Buchnera, between deep sea clams and chemoautotrophic bacteria, between Dendroctonus bark beetles and certain fungi. Symbiotic cospeciation is found between Crematogaster ants and Macaranga plants, between Ficus fig trees and chalcid wasps, between the Poaceae grasses and Epichloe fungi; the two main hurdles to determining cospeciation using Fahrenholz's rule are instances of false congruence and false incongruence. False congruence occurs when parasite and host phylogenies mirror each other but not due to cospeciation, for instance, if the parasites were to colonize the hosts after the host species had diverged and congruent phylogenies resulted by chance, but this is unlikely.
False incongruence, when cospeciation has occurred, but the phylogenies do not mirror each other, is more common, can be caused by a number of factors. Though parasites have been thought to be specialized to a certain host species, it is common for a parasite to colonize a different host, not previous colonized by the parasite species. If a "host switch" occurs after a cospeciation event, the presence of the parasite on other host species will disrupt any potential congruence in the two phylogenies. Coupled with extinction or independent speciation, phylogenetic comparisons can become complicated and mask the cospeciation event. Independent speciation does not alter the phylogenetic analysis used to measure cospeciation. However, in combination with extinction, independent speciation can become problematic when trying to sort out host and parasite phylogenies. Independent speciation occurs when a single population on a single host undergoes speciation resulting in two sister lineages of parasite on a particular host.
In other words, the parasite lineage speciates. This becomes complicated when the two lineages of parasites undergo cospeciation with the host. If one of the two parasite lineages goes extinct from the new host lineage, the phylogenies of the host and parasite will begin to break apart. Though the parasite and host cospeciated together, the phylogenies will not be congruent. After cospeciation, it is possible for a parasite to become extinct; this can happen if, for example, the host species adapts to a new habitat.. Prior to speciation of the hosts, if the distribution of the parasite population among the host population is sporadic, it is possible that when host speciation occurs, it will occur with hosts that do not have the parasite population; this phenomenon is known as "missing the boat". The parasites could cospeciate with their host down the line, the parasites could be absent from some host lineages. Like extinction and independent speciation, "missing the boat" alone will have a minimal effect on mapping phylogenies, however, in conjunction with independent speciation and host phylogenies can begin to bre
Bacillus licheniformis is a bacterium found in the soil. It is found on bird feathers chest and back plumage, most in ground-dwelling birds and aquatic species, it is a mesophilic bacterium. Its optimal growth temperature is around 50 °C; the optimal temperature for enzyme secretion is 37 °C. It can exist in a dormant spore form to resist harsh environments, or in a vegetative state when conditions are good. High capacity of secretion of the alkaline serine protease has made B. licheniformis one of the most important bacteria in industrial enzyme production. Subtilisin Carlsberg secreted by B. licheniformis is used as a detergent protease. It is sold under the name Alcalase by Novozymes. A small antisense RNA against Subtilisin Carlsberg named BLi_r0872 was discovered in an RNA-seq based study, it may serve as target for strain improvement. Scientists are exploring its ability to degrade feathers for agricultural purposes. Feathers contain high amounts of non-digestible proteins, but researchers hope that, through fermentation with B. licheniformis, they can use waste feathers to produce cheap and nutritious feather meal to feed livestock.
Ecological research is being done looking at the interaction between plumage colors and B. licheniformis activity, the consequences thereof. Feather degrading bacteria may have played an important role in the evolution of molting, patterns in feather coloration. Bacillus licheniformis degrades feathers of parrots and other birds white feathers. Red feathers with high levels of psittacofulvin are more resistant. Bacillus licheniformis is cultured in order to obtain protease for use in biological laundry detergent; the bacterium is well adapted to grow in alkaline conditions, so the protease it produces can withstand high pH levels, making it ideal for this use - the other components of detergents create an alkaline pH. The protease has a pH optimum of between 9 and 10 and is added to laundry detergents in order to digest, hence remove, dirt made of proteins; this allows for much lower temperatures to be used, resulting in lower energy use and a reduced risk of shrinkage of garments or loss of colored dyes.
In 2012, scientists from Newcastle University studying Bacillus licheniformis as a possible agent to clean ships' hulls isolated an enzyme that has proven to be an unexpected tooth decay fighter as it has the ability to cut through plaque or a layer of bacteria. Bacillus licheniformis can be used in synthesis of gold nanocubes. Researchers have synthesized gold nanoparticles with sizes between 100 nanometres. Gold nanoparticles are synthesized at high temperatures, in organic solvents and using toxic reagents; the bacteria produce them in much milder conditions. B. licheniformis is competent for genetic transformation. Natural genetic transformation is a sexual process involving DNA transfer from one bacterium to another through the intervening medium, the integration of the donor sequence into the recipient genome by homologous recombination. Below is a list of differential techniques and results that can help to identify Bacillus licheniformis from other bacteria and Bacillus species. Anaerobic Growth: Positive Voges Proskauer test: Positive Acid produced from D-glucose: Positive L-arabinose: Positive D-mannitol: Positive Starch hydrolysis: Positive Nitrate reduction: Positive Degradation of tyrosine: Negative Growth at 10 °C: Negative 50 °C: Positive 55 °C: Positive Utilization of citrate: Positive Isolation and Characterization of a Feather Degrading Bacteria, Williams et al. 1990 Bacterial Degradation of Black and White Feathers, Goldstein et al. 2003 Complete genome of Bacillus licheniformis ATCC14580 - publication Microbial nanotechnologists, August 1, 2009 Bacillus licheniformis genome Type strain of Bacillus licheniformis at BacDive - the Bacterial Diversity Metadatabase
A region is arid when it is characterized by a severe lack of available water, to the extent of hindering or preventing the growth and development of plant and animal life. Environments subject to arid climates are called xeric or desertic. Most "arid" climates straddle the Equator; the distribution of aridity observed at any one point in time is the result of the general circulation of the atmosphere. The latter does change over time through climate change. For example, temperature increase across the Nile Basin over the next 30–40 years could change the region from semi-arid to arid, resulting in a significant reduction in agricultural land. In addition, changes in land use can result in greater demands on soil water and induce a higher degree of aridity. Aridity index Arid Forest Research Institute Desert climate Desiccation tolerance Drought Relative humidity Saturation vapor pressure Griffiths, J. F.'Climatology', Chapter 2 in Handbook of Applied Meteorology, Edited by David D. Houghton, John Wiley and Sons, ISBN 0-471-08404-2.
Durrenberger, R. W.'Arid Climates', article in The Encyclopedia of Climatology, p. 92-101, Edited by J. E. Oliver and R. W. Fairbridge, Van Nostrand Reinhold Company, New York, ISBN 0-87933-009-0. Stadler, S. J'Aridity Indexes', article in The Encyclopedia of Climatology, p. 102-107, Edited by J. E. Oliver and R. W. Fairbridge, Van Nostrand Reinhold Company, New York, ISBN 0-87933-009-0. Blue Peace for the Nile Report, 2009, Strategic Foresight Group
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of large animals evolving or having a reduced body size when their population's range is limited to a small environment islands. This natural process is distinct from the intentional creation of dwarf breeds, called dwarfing; this process has occurred many times throughout evolutionary history, with examples including dinosaurs, like Europasaurus, modern animals such as elephants and their relatives. This process, other "island genetics" artifacts, can occur not only on islands, but in other situations where an ecosystem is isolated from external resources and breeding; this can include desert oases, isolated valleys and isolated mountains. Insular dwarfism is one aspect of the more general "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, large species tend to evolve smaller bodies. There are several proposed explanations for the mechanism.
One is a selective process where only smaller animals trapped on the island survive, as food periodically declines to a borderline level. The smaller animals need fewer resources and smaller territories, so are more to get past the break-point where population decline allows food sources to replenish enough for the survivors to flourish. Smaller size is advantageous from a reproductive standpoint, as it entails shorter gestation periods and generation times. In the tropics, small size should make thermoregulation easier. Among herbivores, large size confers advantages in coping with both competitors and predators, so a reduction or absence of either would facilitate dwarfing. Among carnivores, the main factor is thought to be the size and availability of prey resources, competition is believed to be less important. In tiger snakes, insular dwarfism occurs on islands where available prey is restricted to smaller sizes than are taken by mainland snakes. Since prey size preference in snakes is proportional to body size, small snakes may be better adapted to take small prey.
The inverse process, wherein small animals breeding on isolated islands lacking the predators of large land masses may become much larger than normal, is called island gigantism. An excellent example is the ancestors of which were normal-sized pigeons. There are several species of giant rats, one still extant, that coexisted with both Homo floresiensis and the dwarf stegodons on Flores; the process of insular dwarfing can occur rapidly by evolutionary standards. This is in contrast to increases in maximum body size; when normalized to generation length, the maximum rate of body mass decrease during insular dwarfing was found to be over 30 times greater than the maximum rate of body mass increase for a ten-fold change in mammals. The disparity is thought to reflect the fact that pedomorphism offers a easy route to evolve smaller adult body size. For both herbivores and carnivores, island size, the degree of island isolation and the size of the ancestral continental species appear not to be of major direct importance to the degree of dwarfing.
However, when considering only the body masses of recent top herbivores and carnivores, including data from both continental and island land masses, the body masses of the largest species in a land mass were found to scale to the size of the land mass, with slopes of about 0.5 log per log. There were separate regression lines for endothermic top predators, ectothermic top predators, endothermic top herbivores and ectothermic top herbivores, such that food intake was 7 to 24-fold higher for top herbivores than for top predators, about the same for endotherms and ectotherms of the same trophic level. Recognition that insular dwarfism could apply to dinosaurs arose through the work of Ferenc Nopcsa, a Hungarian-born aristocrat, adventurer and paleontologist. Nopcsa studied Transylvanian dinosaurs intensively, noticing that they were smaller than their cousins elsewhere in the world. For example, he unearthed six-meter-long sauropods, a group of dinosaurs which elsewhere grew to 30 meters or more.
Nopcsa deduced that the area where the remains were found was an island, Hațeg Island during the Mesozoic era. Nopcsa's proposal of dinosaur dwarfism on Hațeg Island is today accepted after further research confirmed that the remains found are not from juveniles. In addition, the genus Balaur was described as a Velociraptor-sized dromaeosaurid, but has been since reclassified as a secondarily flightless stem bird, closer to modern birds than Jeholornis. Island gigantism Foster's rule Dwarfing Franz Nopcsa Island tameness Pleistocene extinctions Strange world of island species October 31, 2004 The Observer
In ecology, crypsis is the ability of an animal to avoid observation or detection by other animals. It may be an antipredator adaptation. Methods include camouflage, subterranean lifestyle and mimicry. Crypsis can involve visual, olfactory, or auditory concealment; when it is visual, the term cryptic coloration a synonym for animal camouflage, is sometimes used, but many different methods of camouflage are employed by animals. There is a strong evolutionary pressure for animals to blend into their environment or conceal their shape, for prey animals to avoid predators and for predators to be able to avoid detection by prey. Exceptions include large herbivores without natural enemies, brilliantly colored birds that rely on flight to escape predators, venomous or otherwise powerfully armed animals with warning coloration. Cryptic animals include the tawny frogmouth, the tuatara, some jellyfish, the leafy sea dragon, the flounder. Methods of crypsis include camouflage and subterranean lifestyle. Camouflage can be achieved by a wide variety of methods, from disruptive coloration to transparency and some forms of mimicry in habitats like the open sea where there is no background.
As a strategy, crypsis is used by prey against predators. Crypsis applies to eggs and pheromone production. Crypsis can in principle involve olfactory, or auditory camouflage. Many animals have evolved so that they visually resemble their surroundings by using any of the many methods of natural camouflage that may match the color and texture of the surroundings and/or break up the visual outline of the animal itself; such animals may resemble rocks, twigs and bird droppings. Other methods including transparency and silvering are used by marine animals; some animals change color in changing environments seasonally, as in ermine and snowshoe hare, or far more with chromatophores in their integuments, as in chameleon and cephalopods such as squid. Countershading, the use of different colors on upper and lower surfaces in graduating tones from a light belly to a darker back, is common in the sea and on land, it is sometimes called Thayer's law, after the American artist Abbott Handerson Thayer, who published a paper on the form in 1896 that explained that countershading paints out shadows to make solid objects appear flat, reversing the way that artists use paint to make flat paintings contain solid objects.
Where the background is brighter than is possible with white pigment, counter-illumination in marine animals, such as squid, can use light to match the background. Some animals camouflage themselves with local materials; the decorator crabs attach plants, small stones, or shell fragments to their carapaces to provide camouflage that matches the local environment. Some species preferentially select stinging animals such as sea anemones or noxious plants, benefiting from aposematism as well as or instead of crypsis; some animals, in both terrestrial and aquatic environments, appear to camouflage their odor, which might otherwise attract predators. Numerous arthropods, both insects and spiders, mimic ants, whether to avoid predation, to hunt ants, or to trick the ants into feeding them. Pirate perch may exhibit chemical crypsis, making them undetectable to frogs and insects colonizing ponds; some insects, notably some Noctuid moths, some tiger moths, were theorized to defend themselves against predation by echolocating bats, both by passively absorbing sound with soft, fur-like body coverings and by creating sounds to mimic echoes from other locations or objects.
The active strategy was described as a "phantom echo" that might therefore represent "auditory crypsis", with alternative theories about interfering with the bats' echolocation. Subsequent research has provided evidence for only two functions of moth sounds, neither of which involve "auditory crypsis". Tiger moth species appear to cluster into two distinct groups. One type produces sounds as acoustic aposematism, warning the bats that the moths are unpalatable, or at least performing as acoustic mimics of unpalatable moths; the other type uses sonar jamming. In the latter type of moth, detailed analyses failed to support a "phantom echo" mechanism underlying sonar jamming, but instead pointed towards echo interference. There is a self-perpetuating co-evolution, or evolutionary arms race, between the perceptive abilities of animals attempting to detect the cryptic animal and the cryptic characteristics of the hiding species. Different aspects of crypsis and sensory abilities may be more or less pronounced in given predator-prey species pairs.
Zoologists need special methods to study cryptic animals, including biotelemetry techniques such as radio tracking and recapture, enclosures or exclosures. Cryptic animals tend to be overlooked in studies of biodiversity and ecological risk assessment. Dive Gallery: decorator crabs. Caterpillar that resembles bird droppings on leaves
Harvard University Press
Harvard University Press is a publishing house established on January 13, 1913, as a division of Harvard University, focused on academic publishing. It is a member of the Association of American University Presses. After the retirement of William P. Sisler in 2017, the university appointed as Director George Andreou; the press maintains offices in Cambridge, Massachusetts near Harvard Square, in London, England. The press co-founded the distributor TriLiteral LLC with Yale University Press. TriLiteral was sold to LSC Communications in 2018. Notable authors published by HUP include Eudora Welty, Walter Benjamin, E. O. Wilson, John Rawls, Emily Dickinson, Stephen Jay Gould, Helen Vendler, Carol Gilligan, Amartya Sen, David Blight, Martha Nussbaum, Thomas Piketty; the Display Room in Harvard Square, dedicated to selling HUP publications, closed on June 17, 2009. HUP owns the Belknap Press imprint, which it inaugurated in May 1954 with the publication of the Harvard Guide to American History; the John Harvard Library book series is published under the Belknap imprint.
Harvard University Press distributes the Loeb Classical Library and is the publisher of the I Tatti Renaissance Library, the Dumbarton Oaks Medieval Library, the Murty Classical Library of India. It is distinct from Harvard Business Press, part of Harvard Business Publishing, the independent Harvard Common Press, its 2011 publication Listed: Dispatches from America's Endangered Species Act by Joe Roman received the 2012 Rachel Carson Environment Book Award from the Society of Environmental Journalists. Hall, Max. Harvard University Press: A History. Cambridge, MA: Harvard University Press. ISBN 978-0-674-38080-6. Official website Blog of Harvard University Press