Orn Exam 1
Lek
communal area in which two or more males of a species perform courtship displays. Females visit the lek briefly to select mates and to copulate, but they do not form lasting pairs bonds with the males. Ex: Sage grouse
Altruism
cooperation in birds (Acorn woodpeckers) led to ideas about kin selection. It is basically the bird not thinking of its own survival and promoting the survival of its relatives regardless of whether it leads to diminished fitness for itself.
Island biogeography
created by MacArthur and Wilson. Island biogeography is the study of the species composition and species richness on islands. Island biogeography is a study aimed at establishing and explaining the factors that affect species diversity of a specific community. An island in this context is not just a segment of land surrounded by water. It is any area of habitat surrounded by areas unsuitable for the species on the island.
morphology of vocal apparatus
• Bird vocalizations originate from the syrinx, an elaboration of the junction of the base of the trachea and the two bronchi. The syrinx is made up of tracheal tissues (woodcreepers, antbirds) bronchial tissues (owls, nightjars) or both tracheal and bronchial tissues (most birds) • The main element of the syrinx are its vibrating tympaniform membranes, the muscles that control tension in these membranes and the supporting cartilage
Diversity of the types of birds.
• Birds can be very colorful (Rainbow Lorikeet, Peacock), • their songs can be very elaborate (Common Loon, Winter Loon)
Powderdown
• Feathers that grow in dense, distinctly arranged patches on birds such as herons. They disperse a dustlike substance from the surface of their barbs • Disputed-functions may include the waterproofing of feathers
Filoplumes
• Hair-like feathers that monitor movement and position of adjacent vaned feathers. They are attached to bases of (especially) movable feathers like flight feathers. Inconspicuous. Lots of nerve endings at their follicles (bases) that signal the adjacent muscles to adjust a feather's position when the filoplume's tip (which is a small tuft) is disturbed
Semiplumes
• Intermediate between vaned and down feathers, has a rachis longer then the longest barb. Primary role is thermal insulation.
Bristles
• Modified vaneless contour feathers. Usually on head to aid in prey capture, protect eyes/nostrils, tactile sensation. Ex: open flycatcher's bill to see its 'bug net'
Anisodactyl
• Most perching birds have Anisodactyl feet, it is the prevalent order of toes. It is the 'classic' toe arrangement. • The hallux is behind and the other three toes are in front. o Ex. Great blue heron, eagles and vultures
What are cons? Thecodont
• No feathers on the thecodonts
Semibristles
• Similar to bristles but have more side branches o EXCEPT for those on the knees of the Bristle-thighed Curlew and on the toes of some owls
Heterodactyl
• Similar to the zygodactyl foot except the inner toe is reversed (digits 3 and 4 face forward and 1 and 2 face backward) o Only found in trogons
What are two major lineages of birds that diversified during the cretaceous?
Enantiornithes and Ornithurae
What is a feather?
Feathers, the most distinctive feature of avian anatomy, are an extraordinary evolutionary innovation. They provide insulation for controlling body temperature, aerodynamic power for flight, and colors for communication and camouflage.
What is monophyletic
Monophyletic-a group that contains all the descendants taxa of a single common ancestor
What kind of information does systematics use to classify birds?
Morphology, Behavior, and parasites and molecular techniques
Speciation
derived largely from avian examples. An example of speciation is Darwin's Finches and the adaptive radiation of bird bills. This corresponds to a diversity of diets use a diversity of bills. A bird's bill is its key adaptation for feeding. The size, shape and strength of the bill prescribe the potential diet. The land carnivores- eagles hawks, falcons and owls- have strong, hooked beaks with which they tear flesh and sinew. Other bill types tear meat, spear fish, crack seeds, probe crevices or strain microscopic food from the mud. Other bills for different types of birds enable them to be nectar feeders, digging into trees for insects, or marine predators (penguins) have bills with curved projections that direct fish toward the esophagus.
What is parsimony?
The simplest explanation. The parsimony principle is basic to all science and tells us to choose the simplest scientific explanation that fits the evidence. In terms of tree-building, that means that, all other things being equal, the best hypothesis is the one that requires the fewest evolutionary changes.
What is speciation? Give example of speciation event
The splitting of a single phyletic line into two or more lineages (adds species) Allopatric, Peripatric, Parapatric, and sympatric
What is Ornithology?
The study of birds that includes their physiology, classification, ecology and behavior.
What is cladistics?
The study of evolutionary branching sequence-enables ornithologists to separate primitive characters from common derived characters. Phylogenetic studies require homologous characters, which can be traced to the same feature in the intermediate common ancestor of both organisms and which exist in both their original and their changed states.
What is binomial nomenclature? Who came up with this?
The system of nomenclature in which two terms are used to denote a species of living organism, the first one indicating the genus and the second the specific epithet. It is used in biological systematics, when scientists try to determine the evolutionary relationship between organisms. Carl Linnaeus (1707-1778) Swedish physician and botanist is the founder of modern taxonomy.
Territortiality
form of aggressive spacing, most of the major theoretical advances in the idea of territoriality came from Ornithologists, Fretwell, Lucas, Brown, Nice
Give some advancement in each lineage over Archaeopteryx. Enantiornithes:
• Sinornis santensis was a signature species of this radiation discovered in China by Dr Ji Shu'an (1987) • Toothed, sparrow sized bird with many features of theropod dinosaurs and Archaeopteryx. Sinornis also exhibited features intermediate between archaeopteryx and modern perching birds. • Advances: strengthening and modifications of the hand, forearm, and pectoral girdle for flight functions -The ability to raise the wings high over the body as well as to fold them - A large pygostyle for the support of a tail fan, which improves steering and braking for flight -A perching foot with an opposable rear toe, the hallux
plumage patterns
• The plumage patterns provide clues to evolutionary relationships, such as in downy shorebirds
Pamprodactyl
• All four toes directed in the front which typically characterizes the mousebird and some swifts. • EXCEPT the dashed lines on the drawing which indicate the positions of toes 1 and 4 are not fixed and all four toes may or may not all point forward
What kind of function do feathers provide?
Locomotion-flight (duck wing) Thermoregulation-by shielding from cold or heat (ptarmigan) Communication-between individuals either visually (color and pattern, steller's jay) or acoustically (snipe) Protection-from predators (cryptic plumage; nighthawk) and elements (waterproofing; eifer) crypsis as feeding adaptation.
Morphological Species Concept
MSC: Classifies organisms based on observable phenotypic traits (such as the color of the bird, patterns of spots etc)
Sexual selection can arise from two different methods
1) male rivalry: One male could deny access by other males to a female. For instance, territoriality would be a form of acquiring beneficial resources that would allow them better success in mating. 2) Female preference: if females prefer some character of males, as a form of better fitness, they can greatly affect breeding traits.
Why do we study Ornithology?
1. Evolution, ecology and sociobiology 2. Population and Community Ecology 3. Behavioral ecology 4. Animal communication 5. Orientation and navigation
What are the pros? Theropods
1. The bone morphology and shoulder sockets are similar to modern birds. This can be seen in the Chicken versus the Theropod 2. Theropods ( i.e. the Oviraptor) and birds have eggs in nests that were (are) incubated. This was proven with a fossil of a Oviraptor and compared to a piping plover and nest. 3. This is a hypothesis by Thomas Huxley. He used the Archaeopteryx as missing link to support evolution of birds and reptiles (Compsognthaus- theropod dino) PROS: • Evolved from theropod dinosaurs 180 mya • Curasorital • T Rex DNA sequencing similar to chicken and ostrich, not crocs • Presence of protofeathers on many theropods but not on the thecodonts.
What are the PROS? Thecodont
1. The transition from gliding thecodonts to flying birds is more likely than for ground-running theropods to flying birds 2. Feathers more likely evolved as stabilizers in gliding species rather than for insulation in ground running species PROS: • Evolved from thecodonts 230mya • Arboreal • Fossils of thecodont avian ancestors that resemble theropods b/c of convergent evolution • Feduccia-digits of bird hand equal dinosaur hand • Microraptors not theropods • Flight should have evolved in arboreal species yet all theropods cursorial
What is shared derived character?
A shared character is one that two lineages have in common, and derived character is one that evolved in the lineage leading up to a clade and that sets members of that clade apart from other individuals. Shared derived characters can be used to group organisms into clades
What is Altruism
Altruism is the cooperation in birds led to ideas about kin selection. Altruism is basically the bird not thinking of its own survival and promoting the survival of its relatives regardless of whether it leads to diminished fitness for itself. Ex: the superb fairy-wren of Australia has non-mated helper birds that make sure the young of mated birds are taken care of. Those young that have additional help get 20% more food than wrens fed only by parents
Arrangement of toes
Anisodactyl, Syndactyl, Pamprodactyl, Zygodactyl, Heterodactyl
What time period do we see avian history begin?
Avian history starts more than 150 mya during the Mesozoic period
Biological Species Concept
BSC: defines a species as a population or group of populations who's members have the potential to interbreed in nature and produce fertile offspring.
What is the primary chemical that makes up the feather?
Beta Keratin a fibrous protein polymer that forms microscopic filaments that have a strong mechanical properties. The beta Keratins are unique to reptiles and birds. They make up most of the hard structure of reptilian skin and leg scutes, claws and beaks of birds. These Keratins are also classified by a small deletion in their molecular sequence
Form of the nostril
Birds have different arrangement of the elements of bony palate. The bony palate of the Rhea has a complex bone arrangement that is a unique paleognthous palate of ratite birds
What are the cons? Theropods
CONS: • Feet unlike modern birds, like theocodonts • Collagen fibers rather than protofeathers • Microraptors not theropods • Flight should have evolved in aroboreal species • Impossible to reach running speeds • Reversed hallux not for running
2. Population and Community Ecology
Competition theory and island biogeography
What is the structure of a feather?
Comprised of beta keratin (mostly protein); distinct chemically from reptilian keratin (scales). In the form we typically see (not growing), they are dead. Typically morphology (contour feather)- calamus (quill) rachis (central shaft) with emanating barbs, barbules and barbicels that interlock to form vane and give a feather its strength and structure, with very little weight
Polygynandry
Males pair with many females and females pair with several males. Basically a mixed mating system. It's common in fishes but not with birds. Its characteristic of tinamous, and flightless ratites
Who were David Lack, Robert MacArthur and G. Evelyn Hutchinson?
David Lack was a British evolutionary biologist who made contributions to ornithology, ecology and ethology. His 1947 book, Darwin's Finches, on the finches of the Galapagos Islands was a landmark work. He developed Lack's principle. Robert Helmer MacArthur was co author of island biogeography and island biogeography theory. G. Evelyn Hutchinson There had been studies of the biology of lakes for centuries, but Hutchinson wrote the first major treatise in which the biology, chemistry and geology of lakes were considered extensively in the same work. He thereby essentially established modern limnology, the science of lakes, as an important field. He was the first to use radioactive phosphorus in a lake to demonstrate the rapid utilization of this vital element in natural waters and thus founded another important field, radioecology.
What are some things that make birds so fascinating and influential?
Diversity of the types of birds, Easily observed,Easily they can be studied
What type of feather is good for insulation?
Down feathers, natural light weight thermal insulation
Ecological species concept
ESC: defines a species by its ecological role or niche
Polyandry
Females pairing with several males. (1 percent) Found predominantly in shore-birds. Often occurs in sexual reversal (one sex is larger than another)
What type of feather is good for monitoring movements and position of adjacent vaned feathers?
Filoplumes
Sexual Selection
Form of natural selection in which variation in fitness among individuals is generated by different mating success
What kind of characteristics need to be added to the taxonomic tool kit by succeeding generations of ornithologist?
Form of the nostril, structure of the leg muscles and tendons of the feet, Arrangement of toes, morphology of vocal apparatus, plumage patterns
5. Orientation and navigation
Many species migrate, but studies on birds have proven to be some of the most insightful in understanding what determines the onset of migration, how species navigate, and how they prepare physiologically for their arduous journeys.
Compare and contrast Homology and Analogy
Homology-traits inherited by two different organisms from a common ancestor Analogy-similarity due to convergent evolution, not common ancestry. Just bc they look and act alike does not mean they are related closely on the tree of life. An Example analogous structures is the wings of bats, flying insects and birds. All three organisms use their wings to fly, but bats are actually mammals and not related to birds or flying insects.
What is convergent evolution?
In evolutionary biology, convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches
Promiscuity
Indiscriminate sexual relations. Males though may be willing to copulate with as many females as possible.
Phylogenetic Species Concept
PSC: defines a species as a set of organisms representing a specific evolutionary lineage.
What is the American Ornithologist's Union? What purpose do they have?
It establishes and regularly revises a list of valid names, both English and scientific, for birds in North America.
What is Archaeopteryx lithographica? Why is it an important bird? Where was it found?
It is the complete skeleton of a small reptile like animal with feathers. The first link between birds and reptiles. It is a fossil record. Discovered in a limestone quarry of central Europe. Dates back to late Jurassic period (135-155 mya)
What is sexual dimorphism? Do birds exhibit it?
It is the distinct difference in size or appearance between the sexes of an animal in addition to difference between the sexual organs themselves. Birds do exhibit it. The males are typically more colorful and perform elaborate dances to entice the females to mate.
What does nature vs nurture mean?
Nature refers to all the evolutionary factors that have shaped the genetics that birds have inherited from parents and ancestors. Nurture refers to all the things that have influenced the birds since they were conceived (environment) This was studied by Konrad Lorenz among others that have studied bird communication and how it is influenced by heredity and the environment
4. Animal communication
Nature vs nurture- ornithologist and ethologists (Konrad Lorenz) have studied bird communication and how it is influenced by heredity and the environment.
What are some scientific advancement that has been discovered using birds as a model organisms?
Observation of speciation, heritability, molecular analyses of phylogeny, competition theory, island biogeography, territoriality, mating systems, altruism
What are three processes that species change by?
Phyletic evolution, speciation and extinctions
What is the technical name for feather tracts?
Pterylae are the feather tracts, the location in which feathers grow. Such as ventral and central tracts
What is the study of feather tracts?
Pterylography or pterylosis
Where would you find coverts?
Rows of smaller feathers that overlap the bases of the remiges and cover the gaps between them. The long shafts of the outer remiges (primaries) attach to the bones of the hand and the second digit. • Provide forward thrust on the downstroke of the wing during flight
1. Evolution, ecology and sociobiology
Speciation, heritability and Molecular analyses
Why do we study Ornithology? Definition
Studying birds have led to many scientific advancements or a deeper Understanding to key ecological aspects in biology.
3. Behavioral ecology
Territortality, Altruism and types of mating
Which of the two gave rise to modern birds?
The Ornithurae gave rise to the modern bird because not all of its members went extinct at the end of the Mesozoic era, unlike the enantiornithes, which all died off.
What are Remiges?
The flight feathers of the wing (singular remix) are large, stiff, pennaceous feathers. • They primarily serve aerodynamic functions and have little importance in insulation.
What is phyletic evolution?
The gradual change of a single lineage (does not alter species number, but changes species identity) probably rare
Who was Thomas Huxley?
The great evolutionary biologist of the nineteenth century he was a herbotologist by trade, asserted that birds were "merely glorified reptiles" and accordingly classified them together in the taxonomic category Sauropsida. He was advocate for Darwin's theories and became known as "Darwin's Bulldog". He is the one that really started people looking at the link between reptiles and birds.
Which of the two is more heavily supported and is accepted as the current hypothesis?
The more heavily supported and accepted current hypothesis is the Theropod
About how many species worldwide exist?
There are about 9700 species worldwide, about twice as many mammals (30 orders)
How do we define what a species is?
There are many ways to define a species. MSC, BSC, ESC PSC
What are the two hypotheses for birds evolving from dinosaurs?
Theropod and Thecodont
Vane feathers
These are your typical flight feathers, retrices (tail feathers) and remiges (wing feathers) as well body feathers, called contour feathers. They are usually asymmetrical with degree of asymmetry roughly correlated with strength of flight.
What are Retrices?
They are flight feathers of the tail (Singular rectrix) attach to the fused caudal vertebrae or pygostyle. • Usual 12 function primarily in steering and braking during flight • Exception are anis and grouse with 18 tail feathers and snipe with 24.
What are the different types of feathers?
Vane feathers, Down Feathers, Semiplumes, Filoplumes, Bristles, Semibristles, powderdown
Speciation define 2
allopatric, sympatric, and parapatric modes of speciation derived largely from avian examples, in fact natural selection itself was initially seeded in part from Darwin's Finches on the Galapagos Islands.
Kin selection
is the evolutionary strategy that favors the reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction. Kin altruism is altruistic behavior whose evolution is driven by kin selection.
Monogamy
it is the prolonged pair bond with a single member of the opposite sex for purposes of raising young. Birds are classically among the most monogamous. Monogamy (90 percent of birds): Birds have one mate. Ex: Pie babblers
Competition Theory
it is the theory there is competition between all organisms, animals, individuals, groups etc for territory, location of resources, goods, mates, prestige, recognition or group status for leadership. It arises whenever at least two parties strive for a goal which cannot be shared or which is desired individually but not in sharing or cooperation. Naturally occurs in organisms that co-exist in the same environment. Ex. Food source, mates and water. Can have beneficial and detrimental effects. It is the driving force of adaptation and ultimately evolution.
Polygyny
males pair with two or more females (2 percent).
Polygamy
mating system where an individual may associate with many different members of the other sex. Ex: Red-winged black birds
Heritability define 2
phenotype (outward manifestation of the individual) is a product of genotype (genetic make-up) and environmental influence
Heritability
phenotype is a product of genotypes and environmental influences. Example: Subtle or slight advantages in egg quality, camouflage, or agility increase in prevalence in a local population. This is b/c the surroundings have changed and the birds are having to adapt camouflage and etc so they are better able to survive in that area.
Molecular Analyses of Phylogeny
the process of studying the evolutionary relationships of species (ie phylogeny) using molecular techniques. This method (DNA-DNA Hybridization) was developed by Charles Sibley and Jon Ahlquist. It is a technique for comparing the DNA of different species to find out just how genetically different they are. It is used to estimate the amount of genetic change that has taken place in the entire genome since the time at which two groups diverged from their most recent common ancestor. The estimates of genetic change between species are then used to cluster pairs of species that are most similar. To build a phylogeny, the estimates of genetic change are converted into standardized "distance" that form the basis of a hierarchical branching diagram, or evolutionary tree.
What is polyphyletic
those that do not share a common ancestor
What is paraphyletic
those that share a common ancestor but not all descendants are included
What are key characters that are shared between birds and reptiles?
• The skulls of both articulate with the first neck vertebra by means of a single ball and socket device (occipital condyle). Mammals have two occipital condyle. • Have a simple middle ear with only one ear bone (the stapes). Mammals have 3 middle ear bones. • The lower jaw or mandibles of both birds and modern reptiles are composed of 5 or 6 bones on each side. Mammals have only one mandibular bone. • The ankles of both birds and modern reptiles are sited in the tarsal bones, NOT between the long lower leg bones, or tibia and tarsi as in mammals. • The scales on the legs of birds are similar in structure to the body scales of modern reptiles • Both birds and modern reptiles lay a yoked, polar egg in which the embryo develops by shallow divisions of the cytoplasm on the surface of the egg. • In birds and some reptiles, females have two different sex chromosomes, Z and W and are referred to as the heterogametic sex; males are the heterogametic sex in mammals with X and Y chromosomes • Both birds and reptiles have nucleated red blood cells, whereas the red blood cells of mammals lack nuclei.
Zygodactyl
• The toes are arranged in pairs, the second and third toes in front, fourth and hallux behind, as in a woodpecker o W/ two foward-pointing toes and two rear-pointing toes, has been achieved in different in different ways nine times
Easily they can be studied
• They can easily be caught in nets (mist net) • The caught birds will be banded and then can easily be observed in the field (overnbird's leg, white-crowned sparrows) • Relatively short life spans and generation, moderate rates of production (Dunnock nest) • Community level ecological studies are possible, since many species co-exist in a given habitat (Pelicans and boobies) • Conspicuous evolutionary curiosities, especially with regards to sexual selection (pin tailed whydah)
Syndactyl
• This foot has two front toes (second and third digits) partially joined or webbed for much of their length (fused basally) They also have a broad sole • Characterizes the Order Coraciiformes o Ex. Kingfishers, hornbills and rollers
Give some advancement in each lineage over Archaeopteryx. Ornithurae:
• Toothed, small finch sized, arboreal species in the early Cretaceous. • Later members had advanced wing structure and flight ability and fully developed perching foot. • By late Cretaceous, exhibited a wide range of sizes and life styles that mirrored those of modern wading birds, perching birds and diving birds. Also had semi flightless birds that were large and carnivorous (Diatrymas) -Hesperornis, Ichthyornis
Down Feathers
• Usually lack rachis; they have flexible three b's and so don't interlock tightly, forming a floppy feather that is soft and traps air. Perfect for light weight thermal insulation for young birds (nearly all have it) and adults-those that live in cold climates have the most. Down is the best weight-to-warmth ratio, as long as you keep it dry. That's what the contour feathers do.
structure of the leg muscles and tendons of the feet
• When a perching bird squats, the leg tendons, which are located on the rear side of the ankle, automatically cause the toes to grip. • When the bird stands, the tension relaxes and the toes open. • A special system of ridges and pads between the tendons that flex the toes and the insides of the toe pads acts as a natural locking mechanism and permits the birds to sleep while perched.
Easily observed
• they are mostly diurnal, gather in groups (secretary bird), • vocalizations can easily distinguish species. It is easy to do audio surveys. • They are territorial, usually fairly easy to relocate (Barred Owl) • Sexual dimorphism- sexes can be differentiated easily in the field for many species. (Humming birds, Cardinals) • Build discrete nests (humming birds, barn swallow, whippoorwill)