Transcript e.6.4 outline two examples of how foraging behavior

OPTION E
E6
FURTHER STUDIES OF BEHAVIOR
SOCIAL BEHAVIOR
 Social Behavior –
May benefit animals by allowing cooperation and
division of labor (ex. insects)

– an actively cooperating group of
individuals belonging to the same species and
often closely related (bee hive, flock of birds, pack
of wolves)


Examples of social behavior includes:
schooling of fish
 herds of zebra (confuses predators)
 social foraging (a pack of wolves has more success
hunting)

 Communication
is necessary for social
behavior

Communication –

Communication is important in finding food,
warning of danger, indicating social status,
identifying members of same species, indicating
sexual maturity or readiness
 Animals communicate in a wide variety of
ways including auditory, visual, tactile,
chemical or electrical signals (ex. bird songs,
alarm responses, and hierarchal dominance
patterns in wolves)

Pheromones –
may result in immediate or long term effects
 often involved in sexual responses

Communication in an ant colony – Lord of the Ants – The Ant
Whisperer
http://www.youtube.com/watch?v=5HKl8Luuotw
 Dominance
hierarchies –

Suppresses aggression –

Many factors affect dominance – often influenced by sex
hormones
 Many animals defend





a territory
most animals have a
–a
geographical area that they seldom leave
some animals exhibit
– defend a
section of the home range from other organisms
territoriality is well studied among birds
Territoriality
territoriality is closely tied to
E.6.1 DESCRIBE THE SOCIAL ORGANIZATION OF HONEY
BEE COLONIES AND ONE OTHER NON-HUMAN EXAMPLE.
Social
Insects
 Elaborate societies are found among
the social insects – ex. ants, bees, and
wasps – most studied is the honeybee
These societies show four main
characteristics:
Cooperative
Overlapping
division of


E.6.1 DESCRIBE THE SOCIAL ORGANIZATION OF HONEY
BEE COLONIES AND ONE OTHER NON-HUMAN EXAMPLE.

Honeybee Society

The honeybee society generally consists of:
(only fertile female)



up to 80,000
at certain times, a
Worker
Drone
Queen
http://westmtnapiary.com/bee_castes.html#
E.6.1 DESCRIBE THE SOCIAL ORGANIZATION OF HONEY
BEE COLONIES AND ONE OTHER NON-HUMAN EXAMPLE.

Members are divided into different groups
called
,
(care for young, find food, defend
colony, remove dead members) – different
castes allows for
E.6.1 DESCRIBE THE SOCIAL ORGANIZATION OF HONEY
BEE COLONIES AND ONE OTHER NON-HUMAN EXAMPLE.
Composition of bee society is controlled by



She secretes an
If queen dies or leaves,
E.6.1 DESCRIBE THE SOCIAL ORGANIZATION OF HONEY
BEE COLONIES AND ONE OTHER NON-HUMAN EXAMPLE.
 Honeybee

Communication
Communication is accomplished through a
series of body movements called a dance:
If a scout bee finds a rich food source within 50m of
the hive, the scout performs a
which excites the other bees and causes them to fly
short distances in all directions from the hive until
they find the nectar
 If the food is distant, the scout performs a
which follows a figure-eight pattern


Dances
http://www.youtube.com/watch?v=lE-8QuBDkkw
E.6.2 Outline how natural selection may act at the level
of the colony in the case of social organisms.
 Natural
selection can act at the colony
level

Natural selection selects for



Those individuals with these traits will have a
better chance at surviving and therefore a
better chance at living long enough to pass on
these favorable traits
Within the honey bee colony, the
workers seem to work “unselfishly”
Survival of the colony; however,
E.6.2 Outline how natural selection may act at the level
of the colony in the case of social organisms.

Workers share
with
Dad is drone who is
they
 Queen is


of their genes
so
so they each receive
Arrangements in the bee colony favor
survival of the genes of the workers!

As they work to ensure the
, they are also ensuring
E.6.3 DISCUSS THE EVOLUTION OF ALTRUISTIC
BEHAVIOR USING TWO NON-HUMAN EXAMPLES.
 Altruistic
Behavior
An animal’s primary mission is to live long
enough
 Some animals spend time and energy helping
others – this type of helpful behavior is
mutualism.
 Other times,

.
This is called altruistic behavior.
E.6.3 DISCUSS THE EVOLUTION OF ALTRUISTIC
BEHAVIOR USING TWO NON-HUMAN EXAMPLES.

How could altruistic behavior have evolved?

Natural selection may favor animals that help a
relative because

This concept is known as
because it includes the genes an animal perpetuates in
its kin as well as the genes it perpetuates in its own
offspring
E.6.3 DISCUSS THE EVOLUTION OF ALTRUISTIC
BEHAVIOR USING TWO NON-HUMAN EXAMPLES.

Kin selection –


ex. Low ranking prairie dogs act as sentries (guards),
risking their own lives to protect their siblings and
ensure that the genes they share in common continue
to the next generation  Kin-directed altruism
Reciprocal altruism –
E.6.3 DISCUSS THE EVOLUTION OF ALTRUISTIC
BEHAVIOR USING TWO NON-HUMAN EXAMPLES.
EXAMPLES OF ALTRUISTIC BEHAVIOR
1. Naked Mole Rats
 Live in colonies of up to 80 individuals in burrow systems
in parts of East Africa
 One female is dominant and is the only one to reproduce
 “Frequent workers” dig the tunnels and bring food
 “Infrequent workers” are larger and occasionally help with
heavier tasks
 “Non-workers” live in the central nest and protect
breeding female and offspring
E.6.3 DISCUSS THE EVOLUTION OF ALTRUISTIC
BEHAVIOR USING TWO NON-HUMAN EXAMPLES.





If a predator threatens the colony, workers are sent out to
be sacrificed so that the queen and her young can live
Mole rats in a colony are almost genetically identical
Good example of
Burrows are a very harsh environment to live in –
probably could not survive in that environment without
A colony of social organisms is sometimes considered to
be one “super-organism”
Naked mole rats of Africa http://www.youtube.com/watch?v=5yRzFZRiTjg
E.6.3 DISCUSS THE EVOLUTION OF ALTRUISTIC
BEHAVIOR USING TWO NON-HUMAN EXAMPLES.
2. Vampire Bats of Costa Rica
 Live in groups and feed at night by sucking blood from
larger animals
 If one bat in group fails to feed for more than 2
consecutive nights, it may die of starvation
 Bats that have fed successfully regurgitate blood for a bat
that has failed to feed
 Good example of
because
 There is an advantage for the whole group, because
E.6.4 OUTLINE TWO EXAMPLES OF HOW FORAGING BEHAVIOR
OPTIMIZES FOOD INTAKE, INCLUDING BLUEGILL FISH FORAGING FOR
DAPHNIA.
 Foraging

behavior –
Optimal foraging – foraging by animals which

Animals may adopt varying foraging strategies to
optimize reward
E.6.4 OUTLINE TWO EXAMPLES OF HOW FORAGING BEHAVIOR
OPTIMIZES FOOD INTAKE, INCLUDING BLUEGILL FISH FORAGING FOR
DAPHNIA.
EXAMPLES OF OPTIMAL FORAGING BEHAVIOR
1. Starlings (Sturnus vulgaris)
 Feed their young mostly crane-fly larvae obtained
by probing their beaks in the soil
 Starlings become less efficient at probing for
larvae as the number of larvae they are holding in
their beaks increases
http://iz.carnegiemnh.org/cranefly/images/Photos/Starlings_feed_on
_tipula_larva_by_Frode_Falkenberg.jpg
E.6.4 OUTLINE TWO EXAMPLES OF HOW FORAGING BEHAVIOR
OPTIMIZES FOOD INTAKE, INCLUDING BLUEGILL FISH FORAGING FOR
DAPHNIA.

The fewer journeys back to the nest,

Optimum number of larvae for starlings to catch
and carry back to nest depends on

In observed starlings,
E.6.4 OUTLINE TWO EXAMPLES OF HOW FORAGING BEHAVIOR
OPTIMIZES FOOD INTAKE, INCLUDING BLUEGILL FISH FORAGING FOR
DAPHNIA.
2. Bluegill Sunfish (Lepomis macrochirus)

Feed on Daphnia (“water flea”)
E.6.4 OUTLINE TWO EXAMPLES OF HOW FORAGING BEHAVIOR
OPTIMIZES FOOD INTAKE, INCLUDING BLUEGILL FISH FORAGING FOR
DAPHNIA.



At low densities of Daphnia,
fish will eat all sizes of prey
At medium densities, fish will
eat moderately sized prey
At high densities, fish eat
mostly larger prey

Consuming small numbers of larger prey

At lower densities, smaller prey has to be consumed to
E.6.5 EXPLAIN HOW MATE SELECTION CAN LEAD TO
EXAGGERATED TRAITS.
 Sexual



selection
In many species individuals actively compete for mates
Sexual selection –
in hierarchy may indicate a
E.6.5 EXPLAIN HOW MATE SELECTION CAN LEAD TO
EXAGGERATED TRAITS.
 Females may choose
mates based on
Ex. Male Peacock’s Tail
Feathers

Those males with the biggest, brightest tail feathers
have the best chance of being chosen by a female for
mating
 These males successfully mate and pass on their genes
 Those males with less elaborate tail feathers do not
mate and therefore, do not pass on their genes
 The long-term outcome has been the


Mating systems:
– males mate with many females

– female mates with several males

– organisms have only one mate for
the breeding season (very common in birds) or
for a lifetime (much less common)

– stable relationship between two
animals of the opposite sex that may ensure
cooperative behavior in mating and rearing of
young (common in birds)

 Courtship
– specialized behavior that precedes
the fertilization of eggs by a male –
(Ex. Sticklebacks)
Stickleback Partnership – start at 3:13
http://www.youtube.com/watch?v=cBX8hWuiHTk
 Many organisms care
for their young

benefit is

cost includes

natural selection favors parental care in species in
which the benefits to offspring survival outweigh
the costs of decreased opportunities to produce
additional offspring
E.6.6 STATE THAT ANIMALS SHOW RHYTHMICAL
VARIATIONS IN ACTIVITY
affect behavior
A variety of behavioral cycles occur
among organisms:

E.6.6 STATE THAT ANIMALS SHOW RHYTHMICAL
VARIATIONS IN ACTIVITY
 Circadian rhythms –
Controlled by an internal, biological clock
that is adjusted or reset by

Biological clocks seem to result from the
interaction of a number of biochemical processes

is thought to play a role in
timing systems of birds, rats, humans, and some
other vertebrates
 regions of the
also are part of
biological clocks in mammals

E.6.6 STATE THAT ANIMALS SHOW RHYTHMICAL
VARIATIONS IN ACTIVITY
Circadian rhythms (daily):

animals most active during
the

animals are active during
the

animals are active during

E.6.7 Outline two examples illustrating the adaptive
value of rhythmical behaviour patterns.
The time period favored could show to
provide


Ex: Cockroachs are nocturnal scavengers.
Feeding at night provides them with a more
humid environment (favored) and possibly
protection from predation.
E.6.7 Outline two examples illustrating the adaptive
value of rhythmical behaviour patterns.

Lunar cycle (monthly) –

Ex: Marine organisms, such as grunions, beach
themselves to deposit eggs and sperm at precisely
the high point of the tide
Grunion spawning
http://video.nationalgeographic.com/video/ani
mals/fish-animals/bony-fish/us-grunionspawning-vin/
http://grunion.pepperdine.edu/
E.6.7 Outline two examples illustrating the adaptive
value of rhythmical behaviour patterns.
 Migration
–

Migration –

– adaptation to environmental
change (moving from an area that
becomes less hospitable)
Environmental cues trigger physiological responses that
lead to migration (ex. changes in day length)
Direction of migration may be according to celestial,
magnetic, or olfactory cues

 Examples
of migration include arctic terns,
swallows, white stork, blue whale, grey whale