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What is the mass of a pigeon tail feather?

What is the mass of a pigeon tail feather?


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There is question at Space.SE If I drop a feather from orbit, would it burn up or “hit” the ground? there is an attempt to answer the question, but the mass of pigeon tail feather and possibly the drag coefficient is required to complete the answer.

I have looked around on the web and if there is an answer it is not jumping out at me.

What is the mass & drag coefficient of a pigeon tail feather?


I just weighed a pigeon tail feather (~10 cm) long. The mass was 0.05 g. Although all tail feathers are not equal in length (and all pigeons are not equal in size), this is probably a good approximation.

Measuring the drag coefficient is going to be very challenging, because it will vary with the orientation of the oncoming airflow. A feather falling with its broad surface (in this feather ~1.2 cm in chord width) perpendicular to the flow will have a much high drag coefficient than a feather falling with the broad surface parallel to flow.


What is the mass of a pigeon tail feather? - Biology

FEATHER TERMS AND ILLUSTRATIONS

Basic terms that describe parts of a feather are illustrated below, and defined in the Glossary.

The major types of wing feathers are illustrated below, and defined in the Glossary


Axillaries: feathers in the axilla ("armpit") of the bird. In some birds, such as Bald Eagle, these are large enough to merit illustration in the Feather Atlas.

Barb: an individual strand of feather material (keratin), extending laterally from the rachis.

Barbule: a lateral branch of a feather barb.

Calamus: the hollow inner portion of the feather shaft that lacks barbs and attaches to the skin. Sometimes called the quill.

Contour Feathers: the feathers forming the bird's outer body covering, including the flight feathers and the overlapping body feathers that produce the bird's smooth aerodynamic shape.

Coverts: the contour feathers that cover the bases of the flight feathers. Those on the upper (dorsal) surface of the body are called upper wing and upper tail coverts those on the under (ventral) surface are called under wing and under tail coverts. In some birds, such as eagles, these are large enough to merit illustration in the Feather Atlas.

Dorsal: the upper surface of the body, or of any body part oriented in a normal horizontal position. Most scans in the Feather Atlas illustrate the feathers in dorsal view, showing the upper surface of the feathers.

Emargination: a distinct narrowing in the anterior vane of a primary flight feather.

Flight Feathers: the large wing and tail feathers that provide lift and maneuverability in flight (see "Remiges" and "Rectrices").

Immature: a young bird in its first year, before it has acquired adult plumage.

Notch: a distinct narrowing in the posterior vane of a primary flight feather.

Pennaceous Barbs: barbs with interlocking barbules that form a coherent vane.

Plumulaceous Barbs: barbs without interlocking barbules, forming a loose fluffy layer at the base of a contour feather or making up the entirety of a down feather.

Primary: one of the wing's outer flight feathers, which are attached to the fused bones of the bird's "hand." Most bird species have 9-10 primaries.

Rachis: the upper portion of the feather shaft, to which the barbs are attached.

Remiges: the flight feathers of the wing, including the primaries, secondaries, and tertials.

Rectrices: the flight feathers of the tail. Most bird species have 10-12 rectrices.

Secondary: one of the wing's inner flight feathers, which are attached to the ulna bone in the bird's "forearm." The number of secondaries varies from 9-25 depending on the species.

Subadult: a bird that is not fully adult, in species that require more than one year to achieve adult plumage (e.g. eagles). In such species, age is often estimated by plumage stage (e.g., Subadult I, II, and III for Bald Eagles).

Tegmen: a shiny or waxy-looking patch along the shaft on the underside of primaries of waterfowl and some gamebirds, gulls, and owl. If obvious, usually indicates that a feather is from waterfowl.

Tertial: the innermost flight flight feathers of the wing, attached to the humerus bone in the bird's upper arm. There are usually 3-4 tertials.

Vane: the smooth feather surface formed by the interlocked pennaceous barbs. On remiges, the anterior vane is on the forward side of the rachis (the leading edge). The posterior vane is the trailing edge of the feather.


Almost everyone has wished at one time or another to be able to fly like a bird. Just the thought of soaring above your city or town without any mechanical device gives us a reason to envy these feathered animals.

So why can't humans fly and what makes birds so special that they are able to take to the air without needing a plane or a glider? The basic answer is they have feathers and also bones that are hollow, making them light and still strong. But there is more to the story of feathers than just flying. In fact bird feathers have a lot of different uses.


  1. Feather Types
  2. Feather Structure
  3. Pennaceous Structure
  4. Pennaceous Structure Animation
  5. Plumulaceous Structure
  6. Plumulaceous Structure Animation
  7. Feather Types on A Bird
  8. Feather Topography
  9. Wing Topography Animation
  10. Growth
  11. Growth Animation
  12. Evolution

Plumulaceous Structure

Wing Topography

Growth

The flight feathers are long, broad, stiff, and almost entirely pennaceous feathers without an afterfeather. A pennaceous feather has a shaft with a basal part, called a calamus, and is embedded in the skin. Flight feathers are adapted primarily to aerodynamic functions and have very little importance in insulation. The flight feathers of the wing are called remiges and are composed of primary remiges and secondary remiges: Combined, these feathers from the main horizontal surface of a wing. Rows of smaller feather called coverts overlap de basis of the remiges and cover the gaps between them.

Primary Flight Feathers

The long shafts of the primary flight feather or primary remiges attach to the bird’s hand bones. These feathers provide the forward thrust on the downstroke of the wing during flight.

Primary remiges have asymmetrical vane areas showing a narrow and stiffer outer vane on the leading edge and a wider and somewhat softer vane on the trailing side.

Most birds have ten primary remiges, but this number varies to nine in some passerine birds, eleven in grebes, storks, flamingos, and sixteen in ostriches.

Specialized barbules, called friction barbules, found in the inner primary feathers’ inner vanes, reduce slippages and separation of the feathers during flight.

Modification of Primary Remiges

Because flight efficiency is directly linked to the primary remiges’ structure, major structural modifications are uncommon. However, a few exceptions of primary flight feather modification include the sickle-winged guan, blue-throated piping guan, and male woodcock. These birds use the modified primary remiges to produce sound used during courtship display. An extreme case of a modification of the primary flight feathers is that of the standard winged nightjar. This crepuscular bird has long projections of a primary feather with vanes at the end the bird uses for courtship display.

Secondary Flight Feathers

The inner or secondary flight feathers attach to the ulna and form much of the inner wing surface. These feathers generate lift during flight. The secondary flight feathers range from six in hummingbirds to 19 in the great horned owl and 40 in albatrosses.


Mandarin Duck with modified head, neck, and secondary wing feathers.

Modification of Secondary Flight Feathers

In some species, such as the mandarin duck’s flag-like feather, the secondary flight feathers have been modified for courtship display purposes. The secondary flight feathers have been thickened in the club-winged manakin (Machaeropterus deliciosus), which produces a mechanic sound when the bird claps its secondary flight feathers.

Tail Feathers

The tail feathers or rectrices attach to the fused caudal vertebrae or pygostyle. There are usually 12 rectrices that function primarily in steering and braking during flight. As with other flight feathers, the rectrices have long rachis and, generally, vanes of equal length on both sides of the rachis.

Modification of Tail Feathers

The tail feathers have developed ornate lengths and shapes primarily for courtship display in some birds, though they can be a handicap during flight. Birds with elaborate tail feathers include pheasants, lyrebirds, birds of paradise, and perhaps the most conspicuous of them all the peacock. Male marvelous spatuletails (Lodigesia mirabilis) have only four rectrices, two of which are thin, flexible rachis about 15 cm long with a large flag or vaned tip.

Tail feathers are also modified for sound production in some snipes, hummingbirds, and bracing support, such as woodpeckers, woodcreepers, and swifts.

Contour Feathers

The contour or body feathers are generally composed of a fluffy basal portion, which remains hidden, and a cohesive longer portion above the fluffy part of the feather. The more extended portion of the feather constitutes the visible plumage of a bird. These feathers are arranged in an overlapping pattern like shingles on a roof. The basal fluffy part of the feather provides insulation, while the visible portion of the contour feather can be colorful, plain, or a plumage pattern that helps the birds blend in the environment. The contour feathers on the wing are called coverts.

Afterfeathers

The body feathers of a bird typically include a secondary feather called the afterfeather. The afterfeather emerges from the rachis’ underside, where the first basal barbs of the vane branch off. The afterfeather has the appearance of a typical feather. The primary function of the afterfeather is to enhance insulation.

The Ptarmigans exhibit a variation in the length of the afterfeather in their summer and winter plumages. They have longer afterfeathers in the winter plumage and shorter and less complex ones in the summer plumage when insulation is not vital to the bird.

Down Feathers

Unlike firm-vaned feathers, down feathers are soft and fluffy and provide excellent natural and lightweight thermal insulation. A down feather typically lacks a rachis, is somewhat flexible, and has barbs and barbules that extend directly and loosely from the basal calamus. Down feathers are also known as plumulaceous feathers. Downy barbules in down feathers tangle loosely with each other, trapping air in an insulating layer next to the skin.

Birds such as ducks, whose natal down covers their entire bodies, are said to be ptilopaedic. On the other hand, psilopaedic chicks, such as a hatchling sparrow, have only a few scattered feathers on specific tracts of the body. The down feathers of adult birds are called definitive down feathers and vary from thick continuous distribution underneath the contour feather coat to a restricted distribution on the feather tracts.

Semiplumes

Are intermediate in structure between down and contour feathers. They have long rachis with loose plumulaceous vanes. Some are close to down feathers in structure, whereas others more closely resemble contour feathers. Semiplumes always have a much longer rachis than any long barb. Semiplumes are found at the edges of contour feather tracts but are usually hidden from view. Semiplumes enhance thermal isolation and fill out the aerodynamic contours of the body plumage.

Filoplumes

Filoplumes are hair-like feathers distributed inconspicuously throughout the bird’s body. They are associated with contour and flight feathers. The filoplumes monitor the movement and position of vaned feathers. They are most numerous near mechanically active or moveable feathers such as the flight feathers. The calamus or quill of each flight feather may have eight to 12 filoplumes associated with it.

Filoplumes consist of a fine shaft that thickens distally, ending in a terminal tuft of one to six short barbs with barbules. The slightest disturbance of a filoplume’s enlarged tip is magnified and transmitted by the long thin rachis to the sensory corpuscle at its base. The disturbance is then sent to the muscles at the bottom of the vaned feather, causing them to adjust the feather position. Filoplumes aid fine adjustment of the remiges during flight. As might be expected, filoplumes are absent in ostriches and other flightless birds.

Bristles

Bristles are another specialized type of feather with both sensory and protective functions. Bristles are simplified feathers that consist only of a stiff, tapered rachis with a few basal barbs. Bristles have sensory functions, as they have sensory corpuscles at their base.

Semi bristles are similar but have more side branches. Except for a few differences, bristles are found only on the bird’s head. The facial feathers of raptors have simplified bristles and semi bristles, which are easier to keep clean than fully vaned feathers.

Bristles are present on the head of carrion-eating birds, which have bare heads with scattered bristles.
The eyelashes of such birds as hornbills, rheas, and cuckoos consist of protective bristles, as do the nostril covering of woodpeckers, jays, and crows. Most aerial insect-eating birds have bristles and semi bristles around their mouths. The semi bristles around the mouth of nightjars are well-developed, acting not only as an insect net but possibly also as sensors of tactile information, like a cat’s whiskers.


Bird preening its body and wing feathers


Biology & Ecology

The diversity of Australia's birdlife is amazing. They vary greatly in size and shape, ranging from the enormous Emu (nearly 2 metres tall and weigh in at 50 kg) to tiny birds such as the dainty Southern Emu-wren (some weigh just 5 grams). Some, like the Red-necked Stint, are able to fly many thousands of kilometres from their breeding grounds in the wilds of Siberia to the shores of southern Australia and back again every year, while others cannot fly at all, but instead, run over the ground, like the Southern Cassowary, or swim to great depths in the ocean, like the Little Penguin. Yet, when we see a bird, most of us can instantly identify it as a bird. What is it, then, that distinguishes birds from all the other animals?

The feature which sets birds apart from all other animals is that they have feathers.

Feathers

What are feathers made of?

Feathers set birds apart from all other animals. They are made of keratin, which is the same material that your toenails, a horse's hoofs and an antelope's horns are made of. Some birds may have up to 25,000 feathers, comprising up to 20% of its body-weight, and two or three times heavier than its skeleton.

They do not grow randomly all over a bird's body, but sprout in specific areas known as feather tracts. Each tract generates feathers of particular shapes and sizes for specific functions. Different feathers have specific functions, including assisting flight, insulation, camouflage and attracting a mate, but they are not specialized in flightless birds such as emus or penguins, on which the feathers are the same shape all over the body. There are three basic types of feathers: contour feathers, down feathers, and filoplumes.

Colours

Since they first appeared on the earliest birds, feathers have developed a wide variety of colours. The combination of different coloured feathers forms different patterns, and on some birds these patterns form a camouflage which helps to make the bird blend into its surroundings, and this helps to makes it less obvious to predators. Tawny Frogmouths, for example, look so much like a broken-off branch that they are often completely overlooked by people walking right underneath them and the markings on a Spotted Nightjar look so much like the leaf litter that it roosts in that they are almost impossible to find. It is no mistake that young birds, less experienced in evading predators, are generally duller than adults, and birds which incubate the eggs or brood the chicks (often the female) are usually dull and plain, so they do not draw attention to the nest. In some species, the colours of feathers or the patterns they form are used by males to attract a mate, often performing a display which serves to accentuate the effect of the feathers, some of which may be highly ornamental.

As feathers become worn, they become less efficient in assisting in flight or whatever other function they serve, and they need to be replaced. The process of replacing worn feathers is known as moulting, and occurs about once a year. Feathers are moulted gradually over a few weeks. When moulting, some birds find it difficult to fly. The feathers of moulting penguins do not offer sufficient insulation against the cold of the ocean depths, and penguins may sit on a beach for a week or two while their new feathers develop. Replacement feathers sprout from small pores in the skin (which are known as follicles) where the old feathers grew.

Types of Feathers

Contour feathers

The contour feather is the most familiar type of feather. These are the feathers which cover the body of the bird. They consist of a central shaft, known as the 'rachis', and a stiff vane projecting from either side. These vanes are made up of a series of 'barbs', which to the naked eye look like a series of hairs or stiff fibres, but when viewed more closely each barb has many smaller barbs, or 'barbules', branching off it. Each barbule has a tiny hook (barbicel) at its end which is used to attach itself to other barbicels. It is this ability to hook the barbs together which makes each vane a smooth surface. Birds are often seen preening their feathers by running individual feathers through the beak. This refastens any barbules which may have come undone by zipping them up, just like a zipper.

Contour feathers have evolved into all sorts of shapes and sizes. The flight feathers of the wings (remiges) are modified contour feathers which are uneven, with the vane on the leading side narrower than the vane on the trailing side, which, due to its aerodynamic qualities, make the bird capable of flight. The tail feathers (rectrices) are also modified contour feathers. On some species these have evolved into all sorts of varied shapes and sizes. For example, the rectrices of the tiny Southern Emu-wren are so elongated that they are more than twice as long as the rest of the bird, and the rectrices of the Superb Lyrebird have become modified into fantastic shapes which resemble a lyre, and these are shimmered and waved during spectacular mating displays. At the other end of the body, the crest on the head of the Sulphur-crested Cockatoo is also formed by modified contour feathers.

Down feathers

Down feathers have the same basic stricture of contour feathers, except they lack barbules, so that the barbs do not interlock, and do not form flat vanes. The air spaces between the barbs of down feathers trap tiny pockets of air, and are used to insulate the bird. Chicks are often covered only in down feathers before their contour feathers develop.

Filoplumes

Filoplumes are simple, hairlike feathers which grow around the base of contour feathers, and comprise a thin rachis topped with a few barbs at the distal end. They are shorter than the contour feathers, and their function is not fully understood, but may be related to maintaining the contour feathers in the correct position.

Flight

The ability to fly is a major feature of most species of birds, though some birds such as emus and penguins are incapable of flight. Although some other animals, such as bats, are able to fly, birds have many highly evolved characteristics which allow them to fly more efficiently. The first of these is that birds are generally light-weight, and birds have many features of their skeletons which minimize their weight. Birds' bones are usually not solid, but are hollow or contain air sacs, which allow air to circulate to make the bird lighter. These bones are supported by internal struts which brace the bone to give it extra strength. Other weight-reducing features of a bird's skeleton are that it has few joints within its skeleton they lack teeth and feathers are also light weight. Birds also have exceptionally well-developed breast muscles which allow them to flap their wings.

How do birds fly?

It seems obvious, but birds fly by flapping their wings. It takes lots of strength to flap a pair of wings, so birds have developed large muscles for the task, and the size and shape of the sternum (breastbone) of a bird is enlarged to attach the muscles to the skeleton. It is, however, the shape of their wings which provides the lift birds need to become airborne. The upper surface of each wing is convex in shape and slightly longer than the underwing, which is concave. As the bird flaps its wings, air is forced both over and beneath each wing, and the difference in air pressure caused by the shape of each surface forces the bird upwards. All birds that can fly have convex and concave surfaces on their wings, but the overall shape of the wings varies greatly, and determines the type of flight that the bird does. Birds with long, pointed wings, such as Peregrine Falcons or Fork-tailed Swifts, are capable of high-speed flight those with shorter, more rounded wings, such as Superb Fairy-wrens or Brown Goshawks, generally do not fly very quickly but are able to manoeuvre deftly between obstacles such as trees or shrubs in the forest and birds with long, narrow wings, such as Shy Albatrosses or Australasian Gannets, can glide for long periods without flapping their wings at all.

Ecology

Ecology refers to the relationships between animals and plants, as well as the physical environment that surrounds them. The complex interactions between organisms reflect every aspect of their lives. The balance between birds and other animals and plants is a delicate one, and the consequences of changes to any aspect of this balance are never restricted to a single species, but affect many, either in terms of food (eating or being eaten), shelter or breeding opportunities. The ecology of birds tells us how they fit into the environment in which they live, and how they coexist with other organisms. There are two main aspects of ecology of birds: feeding ecology and breeding ecology.

Feeding ecology

Whether it's a flower, a berry, a seed, some nectar, a fish, a worm, a crab, a mouse or even another bird, there is a bird that eats it. There are few forms of life that birds do not eat. The best way of finding out what a bird eats is to look at the shape of its beak. With so many different types of food, many birds have beaks that are adapted to specific types of food, or specific methods of foraging. By having differently shaped bills and feeding on different food sources, birds are able to exist in the same habitats and not compete with one another for food.

Nectar

Different species use different methods to obtain nectar from flowers. The long, slender, slightly curved bill of the Eastern Spinebill is used to probe deep into the base of long, tubular flowers to get to the sweet, energy-rich nectar of plants such as correas. Some other species have become adapted to feeding on nectar of different plants, but have a different strategy. The Swift Parrot, for example, often forages on nectar in open flowers, especially those of flowering eucalypts. Its bill is shaped differently to those of honeyeaters: it has a typically parrot-shaped beak, but instead its tongue is shaped like a brush. The Parrot wipes its tongue around the eucalypt flower to gather nectar and pollen. Because its bill is the wrong shape it cannot feed in long tubular flowers like those used by Spinebills, and has become specialised in feeding in eucalypts.

Seeds

To feed on seeds birds require a beak that is capable of exerting sufficient pressure to break open the hard seed husk to expose the nutritious endosperm within. Finches, such as the Zebra Finch, forage on seeds, usually of various types of grasses, and have bills which are stout and conical, perfect for the task. For seeds that are contained within tougher seed-pods, such as those of banksias, a tougher bill is required. Though cockatoos and other parrots often feed on grass seeds, they are also capable of extracting seeds from hard, woody seed-pods. It is the shape of their bills which allows them to do it. The stout, curved bill of the Yellow-tailed Black-Cockatoo, for example, allows the bird to exert enormous pressure on seed-pods to split them open or tear them apart to expose the seeds. The strong curved bill also allows Cockatoos to tear branches open to expose insect larvae that may be tunnelling into the wood.

The hooked bills of hawks, eagles and owls are perfectly adapted for tearing flesh from prey they have caught. The sharp point of the bill allows the bird to pierce the flesh, and its curved profile allows the bird to exert great pressure to tear it away from the prey item. The size of the bill gives an indication of the types of prey that each species takes. For example, the Nankeen Kestrel and Southern Boobook both have small hooked bills which only allow them to feed on small items, such as grasshoppers, moths and mice. Larger species, such as the Powerful Owl, have much larger beaks which enable then to peck at and tear the flesh from larger animals, such as possums and gliders, and the Wedge-tailed Eagle has a powerfully hooked beak which it uses to tear the flesh from kangaroos after first piercing the tough skin.

The Darter specializes in eating fish. It captures them by swimming through the water, and when a fish is detected, the Darter coils its long neck like a spring, then darts forward with its long, sharp beak to spear the fish. Another fish-eating bird is the Australasian Gannet, which catches fish in the sea by diving spectacularly from a great height, head-first into a shoal of fish which are caught in its sharp bill.

Insects in bark

The beak of the Varied Sitella looks like a pair of tweezers, and the bird uses its bill exactly like tweezers when it probes into cracks in the bark of tree-trunks or branches to winkle out small invertebrates hiding there. Small flocks of these birds can be seen spiralling head-first down the trunks of trees, conscientiously investigating every fissure, crack and knothole. Striated Thornbills and Silvereyes also have tweezer-like bills which they use to pick tiny insects from the surface of the foliage or bark of trees. Robins, such as the Hooded Robin, pounce onto insect prey among the leaf-litter on the ground, and grab it in their bill before returning to a perch to eat it.

Insects in the Air

Some birds catch insects in the air. Swallows, swifts, frogmouths and nightjars all have rather wide bills (and mouths) which allow then to catch insects while flying. Species such as the Welcome Swallow and the White-throated Needletail, catch insects during the day, and their quick, acrobatic flight allows them to actively chase insects through the air, but nocturnal species, such as Tawny Frogmouths and White-throated Nightjars, are much less manoeuvrable when hunting flying insects in the dark.

Invertebrates in the Mud

Birds which forage for invertebrates in the mud have the most varied bill morphology of all. Because mud may support a wide range of potential invertebrate prey, varying from crabs to worms and tiny gastropods, different types of birds may all forage together on mudflats without competing with one another. Eastern Curlews have long, downcurved bills which allow them to probe deep into the mud to extract crabs or worms from their long burrows Royal Spoonbills have remarkable spoon-shaped bills which they use to extract invertebrates by sifting through liquified mud stilts have long slender bills which they use to peck tiny invertebrates from the surface of the water oystercatchers use their strong bills to lever open the shells of bivalves and hammer limpets from rocks plovers and stints have shorter, finer beaks which they use to peck at tiny gastropods and other invertebrates from the surface of moist mud. By foraging using different methods, many species are able to be seen foraging together on mudflats without competing directly with one another.

Generalist Diet

The Pied Currawong is omnivorous, and plucks berries from shrubs, snatches insects from the leaves of plants, probes into soil for insects and their larvae, pulls bark from branches to expose invertebrates from underneath, sometimes snatches eggs or nestlings from nests, and even eats carrion (the meat of dead animals). To cater for this, its bill is more generalized than many other species. It is robust, strong and pointed, with a small hook at the end. These attributes allow the species to forage on a wide variety of food items, but not specialize in any particular type of food.

Breeding ecology

When breeding, birds have many different interactions with the animals and plants around them, as well as with other aspects of the environment. To breed successfully, birds require a place to build a nest and materials to build it with, they need enough food for their young, and they need to protect their young from potential predators or other sources of danger.

Breeding season

Birds usually breed at the time when there is optimum chance for their chicks to survive. This usually coincides with the period when food for the young birds is most abundant. Clearly this varies from region to region, and from species to species, and is inextricably linked both to the feeding ecology of the bird, and the prevailing climatic conditions. Some species undertake extensive movements between regions (and some even move between continents) to experience suitable breeding conditions, while other species remain in the same area and wait for favourable conditions.

Some shorebirds (also known as waders) only breed when there is an abundant supply of insects for their young to eat. To do this they undertake regular migration between Australia and Siberia. After spending the Australian summer feeding on the coastal mudflats, they form great flocks and fly through eastern Asia to breeding grounds in the Siberian tundra, only stopping off at a few key sites to 'refuel' on invertebrates along the way. They time these movements so that they arrive just as the frozen wastes are thawing out, and there are clouds of insects swarming everywhere. They lay their eggs among the stunted vegetation, and the chicks that hatch are able to gorge on the insects.

The breeding season of some species of waterbirds, such as the Blue-billed Duck, is determined by the season, and they breed each spring, regardless of the conditions. During droughts, however, the size of their broods is usually much smaller than during wetter years, and the levels of survival are low. Some other species, such as the Freckled Duck and the Black-tailed Native-hen, are far more discerning (or more opportunistic), and usually breed after the wetlands have been flooded. This is a response to an increase in abundance of food, such as aquatic vegetation, invertebrates and fish, which is directly triggered by the inundation, and it ensures that there is plenty of food for the ducklings to eat.

Honeyeaters usually breed in spring, which coincides with the flowering of many native plants. Honeyeater chicks, however, do not eat nectar, so why do they hatch when the plants are flowering? The answer is twofold. As the weather warms up in spring, many insect larvae hatch and turn into flies, moths, wasps and the like, and it is these insects that are fed to the honeyeater chicks. Insects are often attracted to the flowers to feed, and many of them depend on taking nectar or pollen to maintain their population. Honeyeaters (and other insectivorous species) are able to catch unsuspecting insects attracted to the flowers as they feed. Another advantage to this timing is that nectar provides high levels of energy for the adult honeyeaters, and this allows them to chase flying insects extremely energetically, and increases their chances of a successful pursuit.

Nests

There are almost as many types of nests as there are types of birds. Some species barely build a nest at all. The nests of some resident shorebirds, such as the Pied Oystercatcher, simply consist of eggs laid in a shallow scrape in the sand, though some have a shell or two, or a strand of seaweed as decoration. Most parrots, cockatoos, owls and many ducks nest at the bottom of tree hollows, where the eggs are laid among a few pieces of rotten wood. Some other species of birds, such as the Australian Hobby, refuse to build a nest at all, and use old nests built by crows or other raptors. Most birds, however, build a nest to lay their eggs in.

Many birds, from gulls to eagles to honeyeaters, use a variation on a simple cup-shaped nest, made from intertwined sticks, grass or bark. A few species have taken these designs a little further. Most species of robins build a neat woven nest of grass, but tastefully decorate the exterior with moss or lichen. The Northern Fantail builds a simple cup-shaped nest, but with an amazingly long tail hanging beneath it. The Zebra Finch has added a roof to its cup-shaped nest to turn it into a sphere of grass with a roof to protect the eggs and young. The Spotted Pardalote also builds a spherical nest, and places it at the end of a long tunnel which is excavated into a cliff or bank of soil. The Yellow-rumped Thornbill builds a spherical nest, but with a fake nest on top to fool any passing cuckoos that may want to lay their eggs. The Yellow-bellied Sunbird builds an oval-shaped nest which hangs by a long cord made from bark, grass and fibres, all intertwined together, and there is often also a similar tail which hangs below the nest. The Mistletoebird also builds a nest which is made from spider webs and plant down, and looks like a small bag or purse hanging from a branch.

Probably the most unusual nests belong to the megapodes, such as the Orange-footed Scrubfowl. After building a nest which consists of a huge mound of soil and organic material such as leaf litter scraped from the floor of the forest, they lay their eggs in the huge pile of debris. As the organic material rots down, like a compost heap, it heats up, and it is this process which incubates the eggs. The adult birds usually stay close by so that they can scrape some material away if the nest becomes too hot, or scrape extra onto it if it cools down, and in this way the temperature of the eggs is regulated and maintained.

How Birds Protect Eggs

All species of birds lay eggs. Because each egg contains the embryo of a developing chick it is full of protein, and eggs are highly sought after by all sorts of predators which find them a nutritious food-source.

Most eggs that are laid in open cup-shaped nests have shells that are patterned with spots, blotches or streaks which act as camouflage to protect them from potential predators. Some are so well disguised that even when you are looking for them they are almost impossible to find.

The eggs of birds which nest in hollows or tunnels, or in nests with a roof, are well hidden from view, so they have no need for camouflage, and are often white. Other birds hide their nests by building them in dense shrubs where they are difficult to notice, or in prickly bushes which make it difficult for predators to move through the spines to get to the eggs, and other species build their nests in the outermost foliage of trees where most predators cannot reach.

Another way that birds protect their eggs or chicks from predation is by their behaviour. Some species, such as the Australian Magpie and the Masked Lapwing, aggressively swoop at intruders near the nest, which is a very effective deterrent. Other species, such as the Spotted Nightjar, are so well camouflaged that when an incubating bird is approached it remains on its nest, keeping its eggs hidden, and most predators will walk past, unaware that the nest or bird was there.

Some species nest in large colonies, where the presence of many birds means that there is an increased likelihood that any predator will be detected quickly. An offshoot of this is that some species of birds nest cooperatively, with a number of birds looking after a single nest.


Anatomy

In general, feathers have a fairly simple anatomy they consist of a shaft, barbs and barbules. The shaft is the long circular midrib of the feather and can be split into the rachis, which has no barbs and is the end nearest the body of the bird, and the calamus, the hollow end of the shaft.

Barbs are thin hair-like structures that protrude parallel to each other from the shaft, usually in a flattened plane. The barbs can be all interconnected by barbules, tiny branchlet growths from the side of barbs which hook onto the barbules of neighboring barbs. The entire section of barbs and barbules is known as the vane.


The wings :-

The forelimbs as modified wings are located in the anterior region of the trunk. The limbs are of the pentadactyl type. The wing has three typical divisions as - the upper arm, forearm and hand. The hand has three imper-fectly marked digits. While the pigeon is at rest the three divisions of the wing are bent upon one another in the form of the letter 'Z'. During flight the wings are straightened and extended. A fold of skin the alar membrane orprepatagium , stretches between the upper and forearm along the anterior border of the limb. A smaller fold known as postpatagium is present between the trunk and upperarm.

While the pigeon is not flying the whole weight of the body has to be supported by the hind limbs, In order to balance the heavy trunk the hindlimbs are attached for forwards. Each hindlimb or leg has three typical divisions, the thigh, shank and foot. The thigh without being free is enclosed within the boundaries of the trunk. Each hindlimb has four digits. The first toe is directed backward. The feet are naked and covered with horny epidermal scales. Each digit is provided with a horny claw. The tail is small and concealed by the feathers of the trunk. It bears the tail feathers or rectrices.


Top 8 Racing Pigeon Breeds

The Racing Pigeon Breeds List has more than 22 Pigeon breeds that can fly so fast but not fast as some other birds, and we have here 8 racing homer pigeons breeds that we will talk about in this article.

8/Belgian postal Pigeon

Belgian postal Belgium is the forerunner of modern pigeon racing. The first competitions were held in 1840 with a distance of 320 km. Legend has it that Belgian poultry breeders crossed a pigeon with a seagull for excellent flight qualities. The Belgian researchers themselves believe that their pigeons were obtained as a result of the crossing of individuals brought from the Crusades.

Belgian postal Pigeon

The racing pigeon of the Belgian postal considered breed is of medium size, similar to the usual grey-grey, with wings of a lighter shade than the body. Featherless legs. It is these birds that hold modern records of flight speed and the cost of the flyers themselves.

7/English Quarry Pigeon

The ancestors of the English quarry are considered the Baghdad bearded and the Asian quarry descended from ancient Persian blood. A distinctive feature of these birds is a long, straight beak with a warty waxworm. They are rather large, with a long, thin, almost vertical body, and come in a variety of colours. Only three basic colours are approved by the breed standard: white black brownish-grey.

English quarry Pigeon

6/Moscow Monk Pigeon

The origin of this racing pigeon breed’s name supposedly goes back to the way of flight – these birds fly and feed alone, or from the colour of the head, similar to a hat. It is a white dove with a tail and a cap on its head. The tail and cap can be black coffee yellow.

The head of this racing homer pigeons is also decorated with a small crest. The physique is harmonious, the landing is medium-high, the body is slightly sloping, the plumage is dense and dense. In the post-war period, the selection of Moscow monks led to improved external data and a deterioration in flight qualities.

Moscow Monk Pigeon

5/Tape Turman Pigeon

The first mention of this racing homer pigeons breed dates back to 1687. The homeland of the Ribbon Turman is the city of Rzhev it has been used as a racing pigeon. Colouring can be any, but a distinctive feature of the breed is a wide ribbon in the tail. The birds are large, with a faceted head and a harmonious body. Within the breed, there are varieties with and without a tuft. Turmans have proven themselves well not only in daytime but also in night flights.

Tape Turman Pigeon

Thurman’s English name is a rollerball, obtained for the ability to perform numerous somersaults in flight. They are very hardy birds with excellent flight and decorative qualities. During the Second World War, the population suffered greatly, and work is currently underway to restore the population.

The Fastest Birds on Land

Fastest Birds In The World

4/Damask Pigeon

The Damascus pigeons are types of racing pigeons that come from Syria or Turkey. Some researchers claim that the breed was known to the ancient pharaohs 5000 years ago. The synonymous name of the bird is Jerusalem dove. Another, eastern name of the breed is the dove of Muhammad, and the name “Damascus” was fixed due to the fact that these birds were brought to England from Damascus.

The body of this racing homers is proportional, squat, the chest is protruding, with developed muscle mass, the tail is of medium length, the legs are unfeathered. The bird has a large round head with a short break. The colour of the pigeon is very original – the icy white colour on the wings turns into dark, almost black feathers. The top of the tail is decorated with a wide black stripe.

Damask Pigeon

3/Tula Hot Turman Pigeon

A feature of this racing homer pigeons breed is its plumage – its colour is called cherry. The ends of the tail feathers are decorated with a white stripe and white mirrors on the flight feathers. In-flight, the plumage shines brightly with green and lilac highlights, which provided him with the epithet – “hot”.
According to some reports, the Tula Turman was removed from the Ribbon Turman in the 17th century. These are small, oblong birds. The head of a pigeon is decorated with a crest. The head is not large, the neck is long, proportional. The bird has developed muscles, short, fledgeling legs.

Tula Hot Turman Pigeon

2/Kalot Pigeon

Kalot is a type of chasing pigeons and a racing pigeon. They do not set flight records, but we’re used to intercepting “outsiders”. Race pigeons fly in groups at an average altitude. The bird is medium in size, its body is harmonious, proportional, with a rounded full chest. The elongated back of a sloping shape passes into a magnificent tail. Most often, the plumage of these pigeons is white.

1/German Elster Pigeon

German Elster’s are decorative breeds it’s one of the Fastest Birds in The World. The two-tone colour gave rise to another name – the Armored Pigeon since the plumage of the head and chest can be of dark shades – coffee, bluish-black, etc. The colour is saturated, without extraneous shades. The body is large, proportional. The head is small, narrow, with a long, thin neck. The wings are medium, wide, well covering the body. The tail is narrow. There is no data on the origin of the breed. it’s one of the fastest racing pigeons in the world .

German Elster Pigeon

Preening

  • Ask who has seen birds clean themselves. Feathers protect birds&apos skin and keep them warm, so they have to take care of them. Birds clean their feathers by preening.
  • Who knows how many neck bones we have. (7) To help preen, God gave most birds 13-25 neck vertebrae, more than any other animal.
  • They run each feather through their beak which straightens the feathers kind of like when you have to straighten and clean the Velcro. The barbs and barbules fit together like Velcro. Run your fingers across the feather and try to separate the barbs and barbules. Now rub your finger over it and try to have them fit back together.
  • Another thing they do when they preen is to coat their feathers with a light layer of oil from their oil or uropygial gland (at the base of their rump above their tail). This is especially helpful for water birds. The oil keeps the feathers dry and light. Sometimes you can see birds preening, similar to a cat or dog licking their fur.
  • Pour a little bit of water on a paper towel. What happens? The paper towel gets soaked. What would happen if that happened to a bird when it was flying? (It wouldn&apost be able to fly.) What do you think will happen when we pour water on contour feathers? [Allow students to work in groups to pour a little water over the feather. Have paper towels under them.] What happened? (It just slid right off and doesn&apost even feel wet.)
  • That&aposs not all that the oil gland does. The oil also inhibits the growth of bacteria and fungus, contains a Vitamin D precursor that changes into Vitamin D, and preserves the protein (keratin) in the feathers.

You will need:

  • Velcro (we used the velcro straps on backpacks) (optional)
  • contour feathers for each group of 3-5 students
  • water
  • paper towels


Watch the video: structure of contour feathers (September 2022).


Comments:

  1. Templeton

    This very good phrase has to be precisely on purpose

  2. Eteocles

    Be not deceived in this respect.

  3. Hieronim

    It is remarkable, very amusing play



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