An Interactive Quiz
about biology
PIGEONS
START
Read the passage below. For each question, choose the option that fits best.
¶1 Scientists have long been baffled by the uncanny ability of these small, 0.5 kg birds to make precise point-to-point flights over great distances and to hold their course whether the skies are clear or overcast. The answer to how pigeons home would undoubtedly provide a clue to the related mystery of how birds migrate — how, for example, some small songbirds fly 3 Mm without stopping and without going astray.
¶2 Ornithologists are becoming increasingly convinced that pigeons use multiple clues, some of which overlap, to navigate. Pigeons, like many migratory birds, apparently read the positions of the sun and stars in order to orient themselves. Furthermore, it is possible that pigeons have tiny magnetic substances in their brains which enable them to detect variations in the earth’s magnetic field and determine their course accordingly.
¶3 This general orientation does not, however, account entirely for the pigeon’s point-to-point navigation, which would seem to require another faculty. The pigeons do not locate their homes by keen eyesight, as evidenced by experiments in which the birds wear frosted contact lenses and still come home. Researchers in Italy believe olfactory cues play an important part such that the pigeons smell their way home.
¶4 Biologist Mel Kreither at Cornell University, where extensive research on homing pigeons is being carried out, has several theories. Pigeons can see and sense polarized light, says Kreither. Their ability to detect its direction and changes in its direction may help the birds to orient themselves. They are also sensitive to ultraviolet light, which may give a cue. Pigeons can sense an altitude change of as little as 3 meters because they can detect small changes in barometric pressure. This sensitivity helps to hold them on a steady course and to detect advancing weather fronts.
¶5 Another clue to the pigeon’s navigational skill stems from their ability to hear very low sounds, down to half a Hertz. These infra sounds, which are inaudible to humans without assistance, are generated by a variety of sources, including mountain ranges, ocean waves, and thunderstorms. The long waves, which sometimes travel hundreds of kilometres unbroken, may provide a pattern by which the pigeon finds its way home.
Ready? Let's begin.
The word “uncanny” in ¶ 1 most likely means:
Best choice: mysterious. ¶ 1: scientists are baffled by this ability in the birds. Strategy: infer meaning from use in context.
An ornithologist studies …
Positions of the sun and stars
Variations in the Earth’s magnetic field
Best choice: birds. ¶ 2: “Orinthologists” used in relation to study of pigeon senses. Strategy: infer meaning from use in context.
Which title fits best?
Sensory perception of homing pigeons
Best choice: how homing pigeons find their way home. Strategy: infer the point from events as a whole.
Which of the following could not be concluded?
Biologists are not certain how pigeons navigate
Homing pigeons fly at altitudes of at least 3 meters
Humans cannot detect polarized light
Some birds may be able to detect changes in air pressure
Best choice: humans cannot detect polarized light. Other options are stated in text. Strategy: infer from supporting evidence.
Mel Kreither would most likely enjoy teaching which subject?
Best choice: science. Mel Kreither taught biology at Cornell University, researching homing pigeons. Strategy: infer from supporting evidence.
Information from the passage could be used in the study of …
Developing devices for blind people
Helping people find their way around shopping malls
How homing pigeons survive and fit in the food-cycle
Best choice: developing devices for blind people. The passage pertains to non-sight navigation of living beings. Strategy: transfer content to another context.
The lowest sound a human can hear is 20 Hertz, which is ___ times louder than what a pigeon can hear.
Best choice: forty. A pigeon can hear half a Hertz; a human can hear 20 Hertz; 20 = 40 * 0.5. Strategy: transfer content to another context.
Which claim could not be supported from the passage?
Barometric pressure is related to altitude
Hertz is a measure of frequency
Pigeons can be fitted with contact lenses
Songbirds have long migratory paths
Best choice: songbirds have long migratory paths. This is too general; the passage only mentions that some do. Strategy: infer from supporting evidence.
Which of the following could not be concluded?
Something audible makes a sound
To orient is to figure out direction of travel
Best choice: Mel Kreither is a professor. He is a biologist and associated with a university, but it is not indicated that he is a professor.
Barometric pressure most likely varies with …
Attitude (relaxed / determined)
Best choice: altitude. Pigeons sense an altitude change because they can detect extremely small changes in barometric pressure.
This concludes the comprehension quiz on pigeon navigation. The reading passage is based on “How do homing pigeons find their way home?” in Caroline Sutton, How Do They Do That?, 1982.