Birds Flashcards
(93 cards)
1
Q
Q: Key developments in the ancestors of birds leading to modern birds
A
> 200 MYA, after major extinction event, dinosaurs began rapidly diversifying in body size to fill new ecological niches
Over 50 M year period, theropod ancestors of birds continuously shrank
Small size, light weight allowed escape from predators by climbing trees, gliding, flying
66 MYA, K-T mass extinction, end of Cretaceous– their small size, efficient insulation (feathers), and ability to fly may have helped birds survive the dinosaur extinction event.
Underwent explosive adaptive radiation, forming the diverse group of birds that we see today.
2
Q
Q: How are birds related to dinosaurs?
A
Birds are closest living relatives to all extinct dinosaurs
Birds evolved from theropods, a group of meat-eating dinosaurs
Archaeopteryx may be the evolutionary link between dinosaurs and birds
3
Q
Q: Physical/behavioral similarities between birds and theropods?
A
Walking on two legs, scales on legs, pneumatized (air-filled) bones, having feathers, laying eggs, nesting and brooding.
4
Q
Q: Primary function of early dinosaur feathers
A
Insulation
5
Q
Q: What species is commonly considered the first bird?
A
Archaeopteryx
Discovery of this feathered fossil provided evidence that birds are flying dinosaurs and diverged from small, bipedal theropods.
6
Q
Q: Theropods
A
Two-legged, carnivorous dinosaurs
Include Tyrannosaurus rex, velociraptors
Ancestors of birds
7
Q
Q: Bipedal
A
Form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs.
8
Q
Q: Where are birds classified taxonomically?
A
Birds are one of the five (actually >5 because multiple fish classes) classes in the Vertebrata subphylum.
Kingdom: Animalia; Phylum: Chordata; Subphylum: Vertebrata; Class: Aves.
9
Q
Q: What has driven many of the major characteristics of birds?
A
Adaptation to flight
10
Q
Q: Bird adaptations to flight
A
Reduced weight (pneumatized bones, lack of teeth)
Strengthened skeleton with several specific adaptations (details on separate card)
Strong flight muscles, attached to keeled sternum
Fast metabolism (can’t store heavy foods for long periods of time; also need energy for flight)
Large eyes (avoiding collisions in flight, spotting prey from a distance)
Efficient, one-way respiration system (details on separate card)
Missing/reduced organs decrease weight (e.g., no bladder, urethra, only one ovary in some birds; reproductive organs reduce in size outside of breeding season)
11
Q
Q: Bird skeleton adaptations to flight
A
-reduced in weight and strengthened (pneumatized bones)
-bones are reduced in number
-some bones are fused to increase skeletal strength
-keeled sternum (breastbone); attachment point for powerful flight muscles
-The “wishbone” (furcula)
–found only in birds
–strengthens thoracic skeleton to withstand the rigors of flight
–provides flexible attachment site for the breast muscles
-ribs have boney extensions that go from rib to rib
–serve as attachment sites for scapula muscles
–strengthen the rib cage overlapping with the rib behind them
–increase effectiveness of muscles involved in inspiration (yes, birds are inspiring, but this refers to intake of breath)
12
Q
Q: Name some examples of birds that cannot fly
A
Penguins
Ratites (ostrich, cassowary, emu, rhea, kiwi).
13
Q
Q: Bird characteristics
A
Feathers (defining characteristic)
Hard-shelled, amniotic eggs
Scales on legs
Beaks or bills
Tails
Wings (though not all can fly)
Relatively large eyes
Bipedal
Endothermic
Vertebrates
Pneumatized bones (except penguins, loons, and puffins)
14
Q
Q: Endothermic
A
Dependent on or capable of the internal generation of heat. The animal is able to maintain a relatively constant internal temperature, irrespective of the temperature of the surroundings.
15
Q
Q: Do any living animals have feathers besides birds?
A
No
16
Q
Q: Functions of feathers
A
Thermoregulation (more efficient than fur), flight, waterproofing, protection from the elements, camouflage, mating displays, aid in egg incubation
17
Q
Q: Common ancestor of modern reptiles, birds, and mammals
A
A scaled reptile
Over 300 MYA
18
Q
Q: Benefits of birds having relatively large eyes?
A
avoiding collisions in flight
spotting/capturing fast-moving or camouflaged prey
19
Q
Q: Two general differences between birds that tend to be predators vs. prey
A
Predators: maintain a more vertical stance (egrets, hawks); eyes more forward-facing
Prey: more horizontal posture (eat seeds, plants, and insects off the ground) (jays and finches); eyes more side-facing
20
Q
Q: Key difference between bird eggs and reptile eggs
A
Bird eggs have a hard shell. Stronger and can support the embryo inside through harsher conditions (i.e. like rolling out of a nest).
21
Q
Q: Endothermic vs. ectothermic animal food consumption
A
To sustain their higher metabolism, endothermic animals typically require several times as much food as ectothermic animals.
22
Q
Q: Pneumatized bones
A
Air pockets within the bones
Reduced weight
Have criss-crossing struts or trusses for structural strength
23
Q
Q: Compare bones of flighted and flightless birds
A
Birds that have lost their ability to fly have heavier bones than flighted birds but they are still comparatively lighter than a similar sized mammal bone.
Ostriches and emus need the heavier bones to meet the demands of running.
Penguins need heavier bones to dive for food otherwise they would bob like corks near the surface.
Many flightless birds lack keeled sternum.
24
Q
Q: Bird foot vs dinosaur foot
A
Classic bird foot that separated birds from the dinosaurs was three toes in front and a hallux in back (homologous to human big toe)
Dinosaurs had three toes. [In theropods, hallux was non-opposable and too short to touch ground.]
25
Q: Name some parts of a bird that can tell us about their lifestyle
Beak, feet, wings (details on separate cards)
26
Q: Modern bird feet, and reasons for the different adaptations
Foot type can indicate lifestyle
Two to four toes on each foot
Most perching birds and raptors have anisodactyl foot- three forward toes and hallux in back (homologous to human big toe). "Anisos" means unequal.
Some perching birds have zygodactyl foot- two toes forward and two rear facing. Good for clinging to and climbing through trees. "Zygo" prefix originates from "yoke," and as a prefix, means "paired" or "union".
Runners like the ostrich have a reduction in the number of toes and all their toes facing forward. Ostrich is only bird w/2 toes. Cassowary, rhea, and emu all have 3.
Webbed feet (useful for swimming and sure footing on wet ground):
-palmate: front 3 digits are webbed. Most common type of webbed foot. Ducks, geese, swans, gulls, and other aquatic birds.
-totipalmate: all four toes united by web. Pelican, cormorant, boobies, gannets.
Birds' legs and feet are covered in scales, a holdover from their reptile ancestors.
Raptors (birds of prey) have long, strong digits w/ heavy claws for catching, holding, and killing prey. Owls, hawks, eagles, and falcons.
27
Q: Two most common types of feet in perching birds
Anisodactyl- having the hallux behind and the other three toes are in front as in a thrush. "Anisos" means unequal.
Zygodactyl- having the toes of each foot arranged in pairs, with two toes in front and two behind as in a woodpecker, parrot, osprey. "Zygo" prefix originates from "yoke," and as a prefix, means "paired" or "union".
28
Q: Words for two of the types of webbed feet
Palmate- front toes are united as in ducks and gulls.
Totipalmate- fully webbed; all four toes are united by ample webs, as in a pelican or cormorant.
29
Q: Raptorial toes
Bird toes that are deeply cleft, with large, strong, sharply curved nails (talons), as in hawks & owls.
30
Q: What is sexual dimorphism?
When two sexes of the same species exhibit different characteristics aside from differences in sexual organs.
31
Q: What is sexual dichromatism?
Sexual dimorphism involving a difference in coloring or marking patterns between male and female members of the same species.
32
Q: Example of sexually dimorphic birds at the zoo
Eclectus parrot is unusual in that both the male and the female display bright colors
Extreme sexual dimorphism
Male is mostly green whereas the female is red
Both the male and female have multiple mating partners; they are both trying to attract the opposite sex.
33
Q: Why are birds so much more colorful in the tropics than in the temperate areas?
Outside of the tropics, bright colors would often make a bird too vulnerable to predators.
Birds in trees in tropical areas are actually well-hidden because of their bright colors. Green feathers blend into the trees which are green all year-round in tropical climates. As the birds dart through the flashes of light in the forest, their colors actually make them harder to see.
34
Q: General features of flight feathers
Flighted birds have asymmetrical feathers.
Wings curved convexly over the top edge, which creates a greater pressure underneath the wing and produces lift, just like an airplane.
35
Q: What can we learn about a bird from its wing shape?
Indicates lifestyle.
Fast flyers, like swifts and falcons, have long pointed wings.
Soaring birds have broad, large wings to gain lift from thermal air pockets.
Long wings could be problematic in a forested area.
36
Q: What's special about owl feathers?
Specialized feathers reduce noise of air rushing over the wing.
Silence helps them both to hear prey, and to remain undetected.
Owls are night predators with a keen sense of hearing.
More details from National Audubon Society: Comb-like serrations on the leading edge of wing feathers break up the turbulent air that typically creates a swooshing sound. Those smaller streams of air are further dampened by a velvety texture unique to owl feathers and by a soft fringe on a wing's trailing edge.
37
Q: Bird feather anatomy
Made of keratin.
Light-reflecting pigments
Not living tissue.
When growing, have blood supply that enters through the calamus, or quill end.
Rachis: Main shaft.
Barbs: Branches coming off rachis that form a flat surface.
Barbules: Tiny parts on each barb that lock together to give feather its stiffness.
Hooklets: Tiny parts that lock the barbules [of adjacent barbs?] together.
Vane/blade: Smooth surface formed by interlocked barbs that come off the rachis.
38
Q: Bird feather maintenance
Preening, important maintenance of feathers, where birds clean, reshape, and add oil (from a gland near the base of their tail called the uropygial gland)
The vane of a contour feather unzips, and can be rezipped with preening. (see feather anatomy on separate card)
39
Q: Name some parts of a bird where keratin is a major component
Feathers, bill, talons
40
Q: Features of keratin that make it a good material for feathers
light-weight, strong, flexible
41
Q: Contour feathers
Feathers that cover most of the surface of the bird, providing a smooth appearance.
Individual barbs are hooked together, giving the feather its overall shape. (see feather anatomy on separate card)
42
Q: Do birds keep the same feathers forever?
Feathers are shed in a seasonal molt that usually occurs once a year after breeding season.
An adult bird will typically replace all of its feathers during a molt
Loss of feathers is staggered, often over several months, so the bird has enough feathers for flight and insulation.
Some birds also have a partial molt in winter or spring.
43
Q: Bird species living in what type of habitat have an oil gland that is especially developed?
Water environments.
To maintain their waterproof effect.
Examples: pelicans, penguins, ducks.
44
Q: Do any birds lack oil glands?
Oil glands are absent in doves, pigeons, Amazon parrots, and Hyacinth macaws, for example.
These birds have specialized feathers that disintegrate into powder down, which serves the same purpose as preen oil.
Birds that produce powder down are less likely to bathe or immerse themselves in water and do not require the stronger waterproofing that preen oil provides.
45
Q: What does a penguin do before molting? Why?
When a penguin goes into premolt, it puts on a lot of weight before it loses all of its feathers.
The extra weight helps maintain its body temperature in the cold water until the feathers come in.
46
Q: Do all parts of a bird's skin have feathers?
Birds feathers are laid down in tracts to reduce weight. (Some exceptions noted on different cards.)
There are portions of the bird's skin with no feathers.
47
Q: Types of feathers
Contour feathers- cover most of the surface of the bird, providing a smooth appearance. Include flight feathers.
Flight feathers (remiges)- long, stiff central shaft, asymmetrical (leading edge has shorter barbs, narrower vane), used for flight, found on wings and tail.
Tail feathers (rectrices)- flight feathers found on tail, fairly uniform.
Down- small, fluffy, soft, no barbules, used for insulation.
Other types- semiplumes, filoplumes, bristles
48
Q: Powder down
Form of down feathers.
Grow continuously and disintegrate at their tips into a fine keratin powder.
Some birds use this powder to protect their feathers from parasites and feather-degrading bacteria.
Found in many birds where the preen gland is absent.
Found in some parrots, some cockatoos, herons, tinamous
49
Q: How do peahens choose mates?
Based on quality of their tail feather display.
Peacock turns his back to the peahen, displays tail, then turns around to catch her attention.
Note: peacock sheds most tail feathers after breeding season is over.
50
Q: Bird egg characteristics
Hard-shelled (calcium carbonate), amniotic eggs.
Color added as it moves through the genital tract. Serves a camouflage.
Provide protection, gas exchange, and a yolk for nourishment.
Note: excretory products remain within the shell; they are crystalized from solution and stored harmlessly from the developing chick.
51
Q: Bird egg rearing
Most birds lay eggs in nest that they construct from various materials such as wood, mud, grass, feathers, moss, or even spider silk.
Eggs require incubation to keep at optimal temperature.
Nurturing the eggs and young after they hatch requires dedicated parental care. One or both parents care, depending on species.
52
Q: Examples of natural predators of bird eggs
Foxes, raccoons, opossums, other birds (e.g., many corvids), snakes.
53
Q: One reason ostrich eggs are very strong
Large flightless birds are heavy. Shells must be strong enough to support weight of brooding parent.
A 200 lb. person can stand on an ostrich egg without breaking it.
54
Q: Bird hatchling characteristics and needs
In many species, hatchlings are *altricial*: helpless and requiring significant parental care.
-Altricial young in birds: blind, featherless, poorly developed, cannot regulate body temperature so must be brooded on nest, must be fed by parents.
-Mostly in songbirds, raptors, parrots.
In other species, hatchlings are *precocial*: relatively mature and mobile from the moment of hatching.
-Born with a downy feather covering, eyes open, and are able to walk or swim within a few hours.
-Some can forage and feed on their own shortly after hatching.
-Waterfowl and gamebirds such as grouse, turkeys, and quail have these type of offspring. Also domestic chickens.
55
Q: Altricial
Helpless at birth or hatching and requiring parental care for a period of time.
56
Q: Precocial
Young that are relatively mature and mobile from the moment of birth or hatching.
57
Q: How does a parent bird keep their eggs/hatchlings warm?
Parent bird broods their young, keeping them warm by spreading the feathers out, umbrella-like, so the young can maintain contact with the skin of the adult through a brood patch, a featherless section below the breast of many birds used to incubates egg(s) and keep hatchlings warm.
58
Q: Which kinds of chicks tend to fledge earlier?
Altricial chicks develop rapidly and tend to fledge earlier than precocial chicks.
Parents of altricial chicks have to work much harder but for shorter periods of time.
Birds that nest on the ground tend to produce precocial chicks. Birds that nest in trees or off the ground tend to produce altricial chicks.
59
Q: Bird digestion adaptations
Gizzard
-birds lack teeth, need extra grinding mechanism in their digestive system
-thick-walled, muscular pouch, often filled with swallowed sand or pebbles to help break down tough material
-captures bones in many carnivorous birds, which are regurgitated (e.g., owl pellets)
-allows them to consume food that is harder to digest such as insects, seeds, other plant material
-is the second chamber of two-chambered stomach (first chamber has gastric juices to soften food)
Crop
-expanded pocket off esophagus of some birds that bulges visibly against the bird's neck when full
-adaptation for taking food in in large quantities quickly; helps avoid staying in one place too long to avoid predation
-pigeons, flamingos, and some penguins have evolved "crop milk", a secretion from the crop, to feed their young
Waste excretion with reduced water content; also combines liquid and solid
-uric acid, the nitrogenous waste product of birds, requires less water than the excretion of urine by mammals
-eliminates 2x more nitrogenous waste than urea
-no bladder, no urethra
-weight reduction
60
Q: One way a bird benefits from its lack of teeth?
weight reduction
61
Q: What is bird waste called? Why is it multicolored?
Waste is excreted as guano.
The white pasty material is urine, which is mixed with fecal material that may be darker in color.
62
Q: Bird respiratory adaptations
Need efficient extraction of oxygen for breathing at high altitudes and for powering flight
-Large, 4-chambered heart pumps at a relatively high rate
-One-way airflow respiration, where air goes through lungs in one direction, aided by system of nine air sacs which act by negative pressure to move air through the lungs. Inspired air -> posterior air sacs -> lungs -> anterior air sacs. Takes two cycles of breathing in+out to get air through system.
-Highly efficient
-Lungs fairly small
63
Q: Name one bird adaptation for avoiding heat loss while standing in cold water.
Countercurrent heat exchange- arrangement of blood vessels (arteries adjacent to veins) that allows peripheral cooling particularly of appendages and at the same time maintains an adequate blood supply without excessive heat loss. Arteries and veins exchange their heat content without mixing. Heat that would have otherwise exited the body is carried back toward core.
E.g., penguins, flamingos, ducks.
64
Q: Besides bird legs/feet, where else does countercurrent heat exchange occur?
In nasal turbinates. Turbinates warm/moisten the air going into lungs and captures heat/moisture of exiting air. Warm air carries more water; turbinates cool it as it exists and reduce water loss.
65
Q: Bird senses and uses
Excellent vision (keenest sense)
-essential for safe flight, locating prey, navigation
-predators have forward-facing eyes and superb depth perception
-bird eyes largest relative to body size in animal kingdom
-can see wider range of wavelengths than humans; many species can see UV light
-eyes have almost no range of movement in sockets; compensate by having a greater range of neck rotation or different eye placement/shape.
Excellent hearing
-used to communicate, find mates, detect danger, locate prey at night (owls)
-no external pinnae but ear openings are covered by specialized feathers to allow efficient sound transmission and protect against turbulence in flight
-owls have offset ear openings to better determine direction of sound.
Poor sense of smell
-a few species, such as the turkey vulture, kiwis, and albatrosses, use smell to locate food (old world vultures rely on their eyesight)
Some birds can sense Earth's magnetic field.
66
Q: Adaptation that protects bird eyes during flight?
Third eyelid: nictitating membrane
-Lubricates and cleans the cornea of debris
-Clear, protects open eye from insects and debris while flying
67
Q: Nictitating membrane
Transparent or translucent third eyelid present in some animals that can be drawn across the eye for protection and to moisten it while maintaining visibility.
68
Q: To what extent are bird songs learned vs. built-in?
Songs are species specific, but the attributes of song that characterize individual species appear to result mostly from differences in the learning process rather than from differences in the structure of the vocal apparatus.
69
Q: Anatomy used to produce bird songs
The passerines or songbirds are known for their songs produced by the bird's voice box.
Birds can vary both the intensity (loudness) and frequency (pitch) of sounds with their syrinx.
Some birds do not have a voice box and clatter their bills such as the stork.
70
Q: What is one way birds without voice boxes communicate?
Some birds do not have a voice box and clatter their bills such as the stork.
71
Q: Purposes of bird songs
Communicating over long distances or among the trees where there's no direct line of sight.
Mate attraction, evaluation of potential mates, bond formation, claiming and maintenance of territories, identification of other individuals (such as when parents look for chicks in colonies or when mates reunite at the start of breeding season), warning of predators (sometimes with specific information about the nature of the threat).
72
Q: How do birds that live in colonies recognize their mates/chicks?
Colonial birds have voices which differ greatly from one individual to another.
When the chick has hatched, the parents recognize its call and are able to find their chick in a large group.
E.g., Chilean flamingo, Magellenic penguin.
73
Q: Examples of bird intelligence
Corvids use tools, employ teamwork to solve problems. Crows have been observed using traffic for cracking nuts.
Burrowing owls use dung as a decoy. They scatter clumps of animal feces near their nest and wait for dung beetles to arrive at their trap.
Palm cockatoo will use a stick as a drumstick to thrum a hollow tree for territorial display or to attract a female.
Multiple species mimic calls of other animals, and use that ability to elicit desired behaviors from other animals.
Blue jays, green jays, and woodpeckers store seeds in the fall and at a later date are able to find them (critical for their survival as food becomes scarcer).
74
Q: What is migration? What is the benefit?
A regular seasonal movement made in response to changes in food availability, habitat, or weather.
Typically made in the fall following either the start of cold temperatures (moving toward warmer areas) or the start of dry season.
Takes advantage of the abundant food supply during the summer months.
Allows birds to avoid climatic extremes.
Increases the amount of space available for breeding and reduces aggressive territorial behavior.
75
Q: What might trigger migration in an animal?
Hormonal changes, change in day length[, changes in food supplies, changes in temperature].
In birds, coincides with an accumulation of a layer of fat.
76
Q: How far do birds migrate?
Many birds undertake seasonal migrations of thousands of miles including songbirds and waterfowl.
Arctic terns fly up to 44,000 miles each year.
77
Q: How do birds know where to go when migrating?
Navigation and orientation involves the birds' own internal clock.
Position of the sun, moon, and stars.
Can detect the earth's magnetic field.
Learn landmarks and other distinctive features of the path. Major migration routes, or "flyways", where many species are observed making the trip, usually follow easily found landmarks such as mountain ranges, or coasts. The San Francisco Bay is a major Pacific Flyway.
78
Q: What is a behavioral adaptation that can be a significant factor in bringing about speciation?
Migration. When different populations of a species follow different migratory paths, it can open the door to creating a new species as they have different selection pressures.
79
Q: Who are the ratites?
Subset of the flightless birds with a common ancestor, including ostrich, cassowary, rhea, emu, and kiwi.
Recent studies have shown that tinamous are closely related to the ratites and are among the most ancient of birds. Although now considered among the ratites, tinamous have a keeled breastbone and can fly short distances on their short, rounded wings. Nonetheless, they spend most of their time on the ground, where strong legs help them get around and find food.
80
Q: Ratite characteristics and adaptations, particularly those that distinguish them from flighted birds.
Flat, NOT keeled, sternum.
Wings tend to be small or rudimentary.
Developed adaptations for running.
-Relatively strong legs.
-Tend to have reduced number of toes; ostriches are only bird with two toes; cassowary, rhea, and emu have three; kiwi has four.
Feathers not adapted to flight.
-Not grouped in tracts. Evenly distributed.
-Lack barbs and have no feather vanes, which means they do not have to oil them, hence no preen gland.
-For thermal regulation and display, not flight, so weight is not an issue.
Thicker egg shells (withstand weight of heavier parent, also more protective since not high up in nest).
Young are precocial and can run or walk soon thereafter.
Most have communal nests, share incubating duties. Ostriches are the only ratites where the female incubates (share duties, with male incubating at night).
81
Q: Why does it make sense that ratites don't have a keeled sternum?
A keel provides sites for strong flight muscle attachment. Ratites don't fly.
82
Q: What defensive feature makes cassowaries a dangerous target for would-be predators (and humans who are not careful)?
Cassowaries have developed long inner toenails (up to 10 cm), used defensively with powerful kick.
83
Q: Compare penguin adaptations to other birds
-Most flightless birds lack the keeled sternum, but penguins have a keeled sternum and use strong chest muscles for swimming ("flying" through water)
-Penguin feathers are not arranged in tracts, more evenly distributed (as are many flightless birds). Why? Need densely packed feathers to stay warm in extreme conditions. Also don't need to be light enough to fly.
-Feathers are short, stiff, and symmetrical. Comprised of an outer vane region and a 'downy' inner 'after-feather'.
-Feather shafts are flattened to enable the close packing. The shafts of flighted birds are rounded. (Magellanic penguins have 70 per sq. in.)
-Land based flightless birds need heavier bones to meet demands of running. Penguins have heavier bones (though not as dense as mammals) to dive for food (rather than floating on surface).
84
Q: Which birds are considered raptors?
Blanket term used for birds of prey like hawks, falcons, eagles, and owls.
The word 'raptor' comes from the Latin word, "rapere", which means to seize or take by force.
85
Q: Characteristics of raptors
Long, powerful, curved talons to grasp and kill prey
Hooked beak for tearing apart meat
Keen vision
Males tend to be 1/3 smaller than females
Cast regularly (regurgitate indigestible items in wad of feathers, fur, and bones)
86
Q: Size difference between male and female raptors, and possible reasons for this.
Males tend to be a third smaller than females.
Various theories:
-Prevailing theory: Raptors are aggressive because they kill active prey, and with formidable beak and talons, the male could pose a threat to the female during mating.
-Size may have also been influenced by the female spending more time incubating and caring for young and thus defending her nest. Male spends more time foraging and the smaller size makes him more agile in pursuing prey.
87
Q: Are turkey vultures birds of prey?
Turkey vultures are often grouped in with birds of prey, but are more closely related to herons and storks.
They are scavengers and do not hunt live prey.
88
Q: Roles of birds in maintaining healthy ecosystems
Pollinators, seed dispersers, consumers of insects, predators (maintaining healthy populations of their prey), prey.
Birds also serve as barometers of the health of ecosystems; they are an indicator species.
In the continental United States, hummingbirds are key in wildflower pollination, so their absence would have an impact on the wildflowers.
89
Q: One way to grab a visitor's attention when promoting birds.
Asserting that "birds are flying dinosaurs!"
The shared evolutionary history of birds and dinosaurs promotes a better understanding of the importance of birds and avian conservation.
90
Q: Threats to birds
Pesticides and poisons
-Kill directly and indirectly.
-DDT kills directly by poisoning their nervous systems. Also reduces reproductive success by causing thin eggshells and reducing hormone levels necessary for egg laying. Toxins accumulate up food chain, so raptors are particularly susceptible.
-Ranchers have left poisoned animal carcasses out for wolves, which also killed eagles and other bird scavengers.
Global warming
-Long-distance migrants are particularly susceptible. Depend on precisely timed, once-a-year blooms of food to fuel breeding. Warming can change timing of food availability.
Habitat degradation
Pet trade (e.g., Bali Mynah, critically endangered)
Use of ornamental feathers (less common now)
91
Q: Actions to help birds
Educating the public on the effect of poisons and pesticides.
Reduction of greenhouse gas emissions.
Help birds in your yard: clean your bird feeders and baths; install nesting boxes; add insect-friendly native plants; remove invasive plants; eliminate use of insecticides.
In northeast India and Borneo, Indian hornbill feathers are used in traditional ceremonies. Many zoos, including the SF Zoo, collect molted hornbill feathers and send them to these native lands.
92
Q: Indicator species
An organism whose presence, absence, or abundance reflects a specific environmental condition. Indicator species are used to monitor the health of an ecosystem.
93
Q: Plumage
The entire feathery covering of a bird; plumage refers both to the layer of feathers that cover a bird and the pattern, color, and arrangement of those feathers.
