Animal Behavior Module 9

Define "Piloting."

The ability of an animal to find its way using landmarks.

What distinct types of sensory input can serve as landmarks during piloting?

Visual, olfactory, and magnetic inputs.

How does the Black rhinoceros successfully achieve rapid movement despite its poor vision?

By memorizing its home territory (piloting via landmarks).

What specific sensory mechanism do salmon use to identify and find their natal streams?

Olfaction (smell).

Define "Compass Orientation."

The ability of an animal to find its way without using landmarks by keeping a specific angle toward an external reference system.

List three external reference systems used by animals as a compass.

Magnetic fields, the stars, or the sun.

What consequence occurs if an animal relying strictly on compass orientation is physically displaced?

Because its angle of reference is fixed, the animal will end up in the wrong location.

Describe the landmark experimental outcome when immature starlings were captured and moved 150 km east of their normal migratory starting point.

Upon release, they flew south using their preset compass angle and ended up exactly 150 km east of their normal migratory end point.

Over what distances can compass orientation be utilized?

It can be used for both short-distance and long-distance navigation.

Define "Vector Navigation."

An inherited program that instructs an animal which compass direction to head in and exactly how long to travel.

In what specific scenario do certain bird species rely heavily on vector navigation?

During their very first migration event.

How did a cross-breeding laboratory experiment with blackcap warblers definitively prove that vector navigation is inherited?

Cross-breeding individuals from two populations with different migration destinations resulted in offspring that migrated to a point located directly between the destinations of the two parental populations.

Define "Path Integration" (also known as dead reckoning).

The process where an animal integrates information on the sequential direction and duration of each leg of an outward journey to calculate its position relative to home, then uses its compass to return.

Define "True Navigation."

An animal's rare ability to maintain or establish reference to a goal, regardless of its location, without the use of landmarks.

What is the alternative term used for true navigation?

Homing.

How does displacement by a researcher affect an animal capable of true navigation versus one using vector navigation?

The animal capable of true navigation will not get lost if displaced, whereas the vector navigator will end up in the wrong location.

Name five specific animals or groups of animals that possess true navigation abilities.

Homing pigeons, certain long-distance migratory birds (such as swallows and oceanic bird species), sea turtles, and the spiny lobster.

Which bird holds the record for the longest known non-stop flight of any migrant, and what is its route?

The Bar-tailed Godwit; it flies 11,000 km non-stop from Alaska to its non-breeding areas in New Zealand.

What are three common organizational themes found inside animal orientation systems?

The use of multiple cues, a hierarchy of systems, and the transfer of information among various systems.

Can a single navigational system involve more than one sensory system?

Yes

Define a visual "landmark."

An easily recognizable cue that can be stored quickly in an animal's memory to guide it on a later journey.

Describe the visual landmark experiment involving digger wasps and a ring of 12 pinecones.

Researchers placed 12 pinecones around a wasp's new burrow. When she left, she circled the site in flight to learn the landmarks. When researchers shifted the ring a few feet, the returning wasp searched inside the pinecone circle, missing her actual burrow.

Why does navigation using a "Sun Compass" strictly require an organism to possess an internal biological clock?

Because the sun constantly changes its position in the sky throughout the day; the internal clock allows the animal to adjust for this movement to maintain its circadian rhythm and heading.

List three external reference systems used as a compass by animals.

Magnetic fields, the stars, or the sun

What happens to an animal relying on compass orientation if it is physically displaced by a researcher?

It will end up in the wrong location because its angle of reference is fixed.

Describe the experimental result when immature starlings were captured and displaced 150 km east of their normal migratory starting point.

They flew south anyway and ended up exactly 150 km east of their normal migratory end point.

Define "vector navigation."

An inherited program that tells an animal the compass direction to head in and how long to travel

When do certain bird species typically use vector navigation?

During their first migration event.

How did cross-breeding experiments with blackcap warblers prove vector navigation is inherited?

Cross-breeding two populations with different migration destinations resulted in offspring that migrated to a point located exactly between the destinations of the two parent populations

Define "path integration" (also known as dead reckoning).

The process by which an animal integrates information on the sequence of direction and duration of each leg of an outward journey and uses that information to return home.

How does an animal use path integration to calculate its way back home?

It tracks information from its outward journey to know its current position relative to home, then uses its compass to find its way back.

Define "true navigation" (also called homing).

An animal's ability to maintain or establish reference to a goal, regardless of its location, without the use of landmarks.

How does true navigation differ from vector navigation when an animal is displaced?

An animal capable of true navigation will not get lost if displaced; it can adjust and find its goal, whereas a vector-navigating animal ends up in the wrong place.

What are three common organizational themes found in animal orientation systems?

The use of multiple cues, a hierarchy of systems, and a transfer of information among various systems.

Name three animal groups capable of learning and using environmental landmarks for navigation.

Insects (such as bees and wasps), mammals, and birds.

Describe the experiment that proved digger wasps use visual landmarks.

Researchers placed a ring of 12 pinecones around a wasp's burrow. When the ring was moved a few feet away, the returning wasp searched inside the pinecone circle instead of the true burrow location

Why must navigation by a sun compass be paired with an internal biological clock?

Because the sun constantly moves across the sky throughout the day

Describe the experiment that demonstrated the sun compass in sand fleas.

Sand fleas were acclimatized to an artificial light cycle 12 hours out of phase with nature. Released on a beach in natural sunlight, they moved 180° in the wrong direction (up the beach instead of down to the sea)

What two things did the sand flea experiment imply they use to find their heading?

The sun and their internal biological clock.

Who established that bees accurately identify the direction and range from the hive to a food source?

Karl von Frisch.

How does a worker bee signal the range and sun-relative direction of a food source to other workers?

By performing a waggle dance

What orientation cues do honeybees use in sunny weather vs. largely overcast weather?

Sunny: The sun or remembered visual landmarks.

Overcast: Polarized light.

Define "polarized light" with respect to light wave vibration.

Light whose electric field vectors are restricted to a single plane by filtration, causing all waves to vibrate in the same plane.

How does natural sunlight become polarized in the atmosphere?

By passing through particles and water molecules in the air.

What causes the degree and direction of atmospheric light polarization to vary?

The position of the sun.

What are the two ways polarized light can be used for orientation?

1) As a direct axis for orientation

2) to determine the sun's position when it is blocked from view (e.g., below the horizon at dawn and dusk)

Which animal group primarily relies on a star compass, and when do they fly?

Many bird species that migrate at night.

Describe the planetarium experiment that proved warblers use a star compass.

Warblers in a planetarium oriented south. When the planetarium sky was slowly rotated, the birds adjusted and maintained their orientation relative to the moving stars.

Why do birds navigating by stars need a "sextant and chronometer"?

They require a built-in ability to read patterns of stars (sextant) paired with an accurate time-of-day clock (chronometer).

What do night-migrating birds do if a specific star constellation is obscured by cloud cover?

They switch focus to an alternate constellation.

What did researcher William Keeton demonstrate regarding the cue hierarchy in homing pigeons?

Time-shifted homing pigeons misoriented on a clear sunny day (relying on the sun) but oriented correctly on an overcast day (relying on magnetic fields).

How was the homing pigeons' reliance on magnetic fields on overcast days confirmed?

When magnets were used to disrupt the magnetic field on overcast days, the pigeons could no longer orient correctly.

State two distinct advantages of using magnetic fields for orientation over celestial cues.

1) It allows for navigation when visual or celestial cues are missing/limited

2) magnetic cues are constant year-round.

At what angle is the Earth's magnetic field tilted relative to the planet's rotational axis?

11 degrees

Define the positive and negative poles of the Earth's magnetic polarity.

Magnetic North Pole: Positive pole.

Magnetic South Pole: Negative pole.

What is a polarity compass, and what does it allow an animal to do?

A compass system that uses field polarity to allow an animal to distinguish north from south.

Give an example of a large mammal behavior driven by a polarity compass, and state when it fails.

Cows and wild deer tend to align their bodies north-south while relaxing; this alignment fails when they are under high-voltage power lines.

Define "angle of inclination."

The angle that the magnetic line of force makes on the horizon.

What is an inclination compass, and which animal groups use it?

A compass that distinguishes between poleward (steepest lines of force) and equatorward (parallel lines of force); used by some amphibians, reptiles, and birds.

Name four animals capable of responding to tiny differences in the intensity of the magnetic field.

Bees, sea turtles, alligators, and homing pigeons.

What is a "magnetic map" and what does it allow an animal to do?

A map system that allows an animal to obtain positional information from the earth's magnetic field to determine its position relative to its goal.

Define "magnetic signposts."

Innate abilities to respond to specific magnetic landmarks that trigger a directional change.

Explain the programmatic path changes driven by magnetic signposts in pied flycatchers.

They fly southwest from Central Europe to Iberia, then change direction to southeast toward Africa to avoid the Alps, Mediterranean Sea, and Sahara. They use Iberia's unique magnetic field as a landmark to trigger this turn.

What combination of two magnetic features do sea turtles use to navigate during oceanic journeys?

The angle of inclination and the strength (intensity) of the magnetic field.

Define "magnetoception" (or magnetoreception).

A sense that allows an animal to detect a magnetic field to perceive direction, altitude, or location

What chemical mediator is responsible for light-dependent magnetoception?

Cryptochrome

Explain the chemical activation process of cryptochrome under light.

Exposure to blue light activates cryptochrome to form a pair of two radicals whose electron spins are correlated. The surrounding magnetic field alters this correlation (parallel or anti-parallel), changing how long cryptochrome stays activated.

What is the sensory result of cryptochrome activation on retinal neurons?

It alters their light-sensitivity, allowing the animal to effectively "see" the magnetic field.

Name two organisms in which light-dependent cryptochrome magnetoception is believed to occur.

The fruit fly Drosophila melanogaster and certain bird species like garden warblers.

What is the chemical formula for magnetite, and what mechanical effect does the Earth's field have on it?

Fe3O4. The Earth's magnetic field physically affects this magnetically sensitive oxide, generating a transducible nervous signal

Where exactly is magnetite located in birds like homing pigeons and Australian silvereyes?

In their beaks

Where are the specialized vestibular neurons that encode magnetic field direction and intensity located in the pigeon brain?

In the lagena of the inner ear.

Provide an example of an animal that utilizes both magnetite and cryptochrome systems.

The eastern red-spotted newt (Notophthalmus viridescens

What inductive sensing organ do sharks, stingrays, and chimaera (Chondrichthyes) use for magnetic and electrical sensing?

Ampullae of Lorenzini

What type of electrical currents do the ampullae of Lorenzini detect?

DC currents.

Name the two proposed models for olfactory navigation.

Papi’s “Mosaic” Model and Wallraff’s “Gradient” Model.

Detail Papi’s “Mosaic” Model of olfactory navigation.

Animals map a limited area (e.g., a 70–100 km radius for pigeons) by associating environmental odors (like pine forests, coastlines, or city pollution) with specific directions over time. Homing requires only detecting the presence or absence of these odors

Detail Wallraff’s “Gradient” Model of olfactory navigation.

It proposes long-range, stable atmospheric odor gradients where two or more scents vary in intensity along different axes. The animal compares the scent intensity at its current location to its known home concentration

What is the primary scientific criticism of Wallraff's gradient model?

Meteorologists deny that stable odor gradients actually exist in nature

Where is the natal location of the American eel?

The Sargasso Sea.

How do migratory fishes coordinate olfaction with other orientation cues?

They use other long-range cues to get close to their goal, then switch to olfactory cues when they are close enough for olfaction to be feasible.

Why is electrolocation observed exclusively in aquatic or amphibious animals?

Because water is a much better conductor of electricity than air.

How do weak-electric fish map their surroundings for orientation?

They generate weak electrical fields (under 1 volt) and identify the location of objects relative to themselves by interpreting distortions in that field.

Provide the common and scientific names for the two best-known weak-electric fish species.

1) Peters' elephant nose fish (Gnathonemus petersi) and 2) Black ghost knife fish (Apteronotus albifrons).

How do echolocating animals orient within their environment?

They bounce sound waves off objects to identify them and build a spatial map based on auditory cues.

Name the two genera of shrews that use echolocation.

Sorex and Blarina.

How does the function of echolocation in shrews differ from its function in bats?

Shrews use echolocation strictly for simple, close-range spatial investigation of their habitat rather than for pinpointing food.

Provide the common and scientific names of the nocturnal bird species that use echolocation.

1) Oilbirds (Steatornis caripensis) and 2) Swiftlets (Aerodramus sp.).

Where do oilbirds and swiftlets use echolocating calls to navigate?

Through the trees and caves where they live.