ANIMAL BEHAVIOR EXAM 2 UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS
Question:
1. Cross-fostering has different imprinting effects in two
related song birds (BLUE TITS & GREAT TITS)
Answer:
the special effects of imprinting could not have occurred without a "prepared
brain", one whose genetically influenced the development enabled it to respond
in special ways to particular kinds of information available from its social
environment;
-a group of Norwegian researches provided evidence that there is a genetic
contribution to learning when they performed a cross-fostering experiment and
switched brood from blue tit nests into the nests of closely related great tits, and
vice versa. Some of the cross-fostered chicks grew up and survived to court and
form pair-bonds with members of opposite sex
-of the surviving fostered great tits, only 3 of 11 found mates--all of which were
blue tit females that had been fostered by great tits. Of the surviving fostered
blue tits, all 17 found mates, although 3 of these were females that socially mated
with cross-fostered male great tits
-the researches found that none of the cross-fostered great tits mated with a
member of their own species whereas most of the cross-fostered blue tits did
-however each blue tit female that had a great tit as a social partner must have
mated with a blue tit male on the side, because all 33 offspring produced by
those females were blue tits, not hybrids
**THUS ALTHOUGH MISIMPRINTING OCCURRED IN BOTH SPECIES, THE
DEVELOPMENTAL EFFECTS OF BEING REARED BY MEMBERS OF ANOTHER
SPECIES WAS FAR GREATER FOR GREAT TITS THAN BLUE TITS, AN INDICATION
THAT THE GENETIC BASIS OF THE IMPRINTING MECHANISM WAS VERY
DIFFERENT FOR THESE TWO CLOSELY RELATED SPECIES
, Question:
2. selection favors investment in the mechanisms underlying learning only when
there is environmental unpredictability that has reproductive relevance for the
individuals--thus we have a cost benefit argument, one that presupposes that any
proximate mechanism that enables individuals to learn comes with a price tag;
-the brains of male marsh wrens living in the western United States should be
larger than those of their East Coast counterparts because young West Coast
wrens learn nearly 100 songs by listening to others, whereas East Coast wrens
have much smaller learned repertoires of about 40 songs--when the birds brains
were examined, the song control systems of West Coast wrens weighed on
average 25 percent more than the equivalent nuclei of East Coast wrens
-this can be caused by other environmental differences between East and West
Coast birds
-to further examine the role of environmental variation on brain size, a group led
by DANIEL SOL used remotely sensed climatic data (measures such as temp and
rain) and the comparative approach to examine more than 1200 species of birds
**THEY FOUND THAT LARGER BRAINS ARE MORE LIKELY TO OCCUR IN
SPECIES THAT EXPERIENCE SEASONAL ENVIRONMENTS WITH GREATER
ENVIRONMENTAL VARIATION ACROSS THEIR GEOGRAPHIC VARIATION.
MOREOVER, THE RESEARCHERS DEMONSTRATED THAT LARGER RAINS
EVOLVED WHEN SPECIES INVADED THESE MORE SEASONAL ENVIRONMENTS,
PERHAPS ALLOWING THEM TO COGNITIVELY BUFFER THESE HARSHER
ENVIRONMENTS THROUGH INFORMATION GATHERING AND LEARNING
-as we have seen, Clark's nutcracker is a food-storing specialist and it has a large
pouch for the transport of pine seeds to storage sites--the pinyon jay also has a
special anatomical feature, an expandable esophagus, for carrying large
quantities of seeds to hiding places however, the Florida scrub-jay and the
Mexican jay lack special seed-transport devices and appear to hide substantially
less food than their relatives
-Individuals from these four species were tested on two different learning tasks in
which they had to peck a computer screen to receive an award (non-spatial
learning task), and the other required them to remember the location of a circle
on the screen (spatial task). When it came to the nonspatial learning test, pinyon
jays and Mexican jays did substantially better than the Florida scrub-jays and
nutcrackers--but in the spatial learning experiment, the nutcracker went to the
head of the class, followed by the pinyon jay, then the Mexican jay, and finally the
Florida scrub-jay
**TO THE EXTENT THAT NUTCRACKERS AND PINYON JAYS REALLY ARE
ESPECIALLY GOOD AT SPATIAL LEARNING ONLY, WE CAN CONCLUDE THAT
BIRDS HAVE NOT EVOLVED ALL-PURPOSE LEARNING ABILITIES, BUT RATHER
THAT THEIR LEARNING SKILLS ARE DESIGNED TO PROMOTE SUCCESS IN
SOLVING ECOLOGICALLY RELEVANT PROBLEMS
QUESTIONS AND CORRECT ANSWERS
Question:
1. Cross-fostering has different imprinting effects in two
related song birds (BLUE TITS & GREAT TITS)
Answer:
the special effects of imprinting could not have occurred without a "prepared
brain", one whose genetically influenced the development enabled it to respond
in special ways to particular kinds of information available from its social
environment;
-a group of Norwegian researches provided evidence that there is a genetic
contribution to learning when they performed a cross-fostering experiment and
switched brood from blue tit nests into the nests of closely related great tits, and
vice versa. Some of the cross-fostered chicks grew up and survived to court and
form pair-bonds with members of opposite sex
-of the surviving fostered great tits, only 3 of 11 found mates--all of which were
blue tit females that had been fostered by great tits. Of the surviving fostered
blue tits, all 17 found mates, although 3 of these were females that socially mated
with cross-fostered male great tits
-the researches found that none of the cross-fostered great tits mated with a
member of their own species whereas most of the cross-fostered blue tits did
-however each blue tit female that had a great tit as a social partner must have
mated with a blue tit male on the side, because all 33 offspring produced by
those females were blue tits, not hybrids
**THUS ALTHOUGH MISIMPRINTING OCCURRED IN BOTH SPECIES, THE
DEVELOPMENTAL EFFECTS OF BEING REARED BY MEMBERS OF ANOTHER
SPECIES WAS FAR GREATER FOR GREAT TITS THAN BLUE TITS, AN INDICATION
THAT THE GENETIC BASIS OF THE IMPRINTING MECHANISM WAS VERY
DIFFERENT FOR THESE TWO CLOSELY RELATED SPECIES
, Question:
2. selection favors investment in the mechanisms underlying learning only when
there is environmental unpredictability that has reproductive relevance for the
individuals--thus we have a cost benefit argument, one that presupposes that any
proximate mechanism that enables individuals to learn comes with a price tag;
-the brains of male marsh wrens living in the western United States should be
larger than those of their East Coast counterparts because young West Coast
wrens learn nearly 100 songs by listening to others, whereas East Coast wrens
have much smaller learned repertoires of about 40 songs--when the birds brains
were examined, the song control systems of West Coast wrens weighed on
average 25 percent more than the equivalent nuclei of East Coast wrens
-this can be caused by other environmental differences between East and West
Coast birds
-to further examine the role of environmental variation on brain size, a group led
by DANIEL SOL used remotely sensed climatic data (measures such as temp and
rain) and the comparative approach to examine more than 1200 species of birds
**THEY FOUND THAT LARGER BRAINS ARE MORE LIKELY TO OCCUR IN
SPECIES THAT EXPERIENCE SEASONAL ENVIRONMENTS WITH GREATER
ENVIRONMENTAL VARIATION ACROSS THEIR GEOGRAPHIC VARIATION.
MOREOVER, THE RESEARCHERS DEMONSTRATED THAT LARGER RAINS
EVOLVED WHEN SPECIES INVADED THESE MORE SEASONAL ENVIRONMENTS,
PERHAPS ALLOWING THEM TO COGNITIVELY BUFFER THESE HARSHER
ENVIRONMENTS THROUGH INFORMATION GATHERING AND LEARNING
-as we have seen, Clark's nutcracker is a food-storing specialist and it has a large
pouch for the transport of pine seeds to storage sites--the pinyon jay also has a
special anatomical feature, an expandable esophagus, for carrying large
quantities of seeds to hiding places however, the Florida scrub-jay and the
Mexican jay lack special seed-transport devices and appear to hide substantially
less food than their relatives
-Individuals from these four species were tested on two different learning tasks in
which they had to peck a computer screen to receive an award (non-spatial
learning task), and the other required them to remember the location of a circle
on the screen (spatial task). When it came to the nonspatial learning test, pinyon
jays and Mexican jays did substantially better than the Florida scrub-jays and
nutcrackers--but in the spatial learning experiment, the nutcracker went to the
head of the class, followed by the pinyon jay, then the Mexican jay, and finally the
Florida scrub-jay
**TO THE EXTENT THAT NUTCRACKERS AND PINYON JAYS REALLY ARE
ESPECIALLY GOOD AT SPATIAL LEARNING ONLY, WE CAN CONCLUDE THAT
BIRDS HAVE NOT EVOLVED ALL-PURPOSE LEARNING ABILITIES, BUT RATHER
THAT THEIR LEARNING SKILLS ARE DESIGNED TO PROMOTE SUCCESS IN
SOLVING ECOLOGICALLY RELEVANT PROBLEMS
