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From an evolutionary perspective, as a bird gets older the cost of reproduction increases. At some point in the bird’s lifecycle it will no longer be beneficial for it to breed its own offspring. Older females can thus maintain greater reproductive benefits by increasing the reproductive success of their relatives, rather than breeding themselves (Williams 1957; Hamilton 1966). In this manner they are still able to pass their genes on to a limited extent, similar to the sibling helpers in Micronesian kingfishers.

Often the dominant female is deposed by related individuals. In 57% of displacement cases among Seychelles warblers, the new dominant female was identified as being a daughter, sister, or niece of the deposed female (Richardson et al. 2007). Since deposed females tend to help the nest they were originally breeding in, this observation indicates that in most cases the grandparent helper ends up increasing the reproductive success of a closely related warbler. In accordance with Hamilton’s theory, this behavior maximizes a grandparent’s gene dispersal and as a result, is evolutionarily favorable.

White ibis

Non-breeding female White Ibises ( Eudocimus albus ) have been observed tending to multiple nests with which they are not necessarily related (Herring&Gawlik 2007). The females were noted as visiting up to 5 different nests. They would rearrange eggs, weave fresh material into the nest, and shade nestlings. These birds did not brood or feed chicks; this responsibility was fulfilled by the direct parents of each nest. Interestingly, attendant male White Ibises exhibited aggressive behavior to these assisting females, forcing them to abandon their efforts (Herring&Gawlik 2007). This suggests the behavior is concurrently innate and not necessarily based in helping to raise related young. Whether or not this behavior is truly cooperative is thus debatable because these Ibises do not directly assist in nurturing the young and their assistance is not readily accepted by the direct parents.

However, reproductive fitness benefits of helping in these cooperatively breeding warbler communities include more than just the chance to indirectly pass on genes. Subordinate females also have the chance to breed offspring of their own. Unlike other bird communities, such as the Micronesian kingfisher where helpers completely forfeit the opportunity to reproduce, 44% of Seychelles warbler helpers, during every breeding season, are able to directly increase their reproductive fitness by having offspring of their own (Richardson et al. 2002).

In light of these advantages, it is strange that deposed females ever choose to become floaters, a role that provides neither direct nor indirect reproductive fitness. This mystery is accounted for by considering the quality of resources available in different territories. As illustrated by [link] , it has been observed that the quality of territories on which ousted breeding females become subordinates is consistently higher than the quality of territories where they become floaters (Richardson et al. 2007). Thus, similar to how ecological factors determine the level of cooperative breeding in the Azure-winged Magpie, the probability a displaced warbler will adopt a helping role is dependent upon whether or not the territory holds enough resources to support an additional member.

Questions & Answers

wat improvement do economic has with our life
Aminata Reply
it help us how to use our limited resources to satisfy our unlimited wants
Pagnol
Economics is the social Science in which we study how scarce resources are allocated for the betterment of human being.
Ali Reply
what is equilibrium point
Happiness Reply
where price and quantity demanded meet
Pagnol
is the point where price an quantity demanded meet
Aminata
why do consumer demand curve tend to move downward slope
Aminata
What is monopoly
Ezekiel Reply
what is economics
BUKENYA Reply
economics us behavior. Of people, nations, markets etc. It has much to do with reactions. watch MSNBC. Bloomberg. everyday they talk about how the markets react to an piece of news, legislation, interest rates etc. Interesting volatile stuff
TOM
but, it also react with science
ezhilarasan
economic is a science with study's the behavior of people,market and price
Bertilla
it's a science which study the behavior of people ,market n price
Bertilla
What is opportunity cost?
Junior
opp. cost~a benefit, profit or value of something that must be given up to acquire or achieve something else
Kim
or something that you foregone
Kim
who is the father of economic
Yirtutey Reply
Adam smith
shaikh
modern father is Adam smith
Bilal
Adam smith
Nazifi
what is backward bend
Florence Reply
It's a curve that reverses direction
Ajibade
Good evening friends
Kojo
Evening
Ajibade
evening
Emmanuel
hi
Lawrence
Any Nigerian lady to meet here Well on eco ground
Suleiman
Good morning ooo I hope everyone is fine
Kojo
hello
James
yeah
Kojo
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Kojo
how time
James
cool
Kojo
Ok
James
Good morning
Junior
morning all
Emeka
Morning
Ajibade
😶g
Maaz
moaz taha u r egyptian aren't u ?
Marwa
marwa no
Maaz
how economic effect the Market
Abdikarem
what is the difference between statistic and statistics?
Shafiu
it can can be described as when the demand is insufficient
Amaan Reply
high Dublin divino through Higginbotham
Shubham Reply
How does exchange rate affect the demand and supply?
austine
You mean demand and supply of currency ?
Jahangir
Hello
Hann
Hi
Jahangir
Am debby
Hann
am jahangir
Jahangir
how are you
Ogunsola
I am All fine Wbu ?
Jahangir
doing great
Ogunsola
Hw r u all
Mudassar
Am gud
Hann
Gd
Mudassar
Ogunsola
are you help for your country of economy leavel
Mutha
hi
Hammed
Hello
Assan
hi
Pranshi
Hello
Kamal
hi
Pranshi
hi
Abbas
hi
Abdirazak
ki sah botine
Neyshawn
hi
Nasir
Hello Economist
Nasir
hello
Victor
Hie... may anyone give me examples of countries that successfully implemented import substitution industrialisation.
Thabo
Nigeria
Junior
hey I'm emma from Uganda
niwagaba
Hello
Abraham
What is the difference between Demand and Quantity Demanded?
Weedh
Demand refers to how much a product is desired by buyer mean while quantity demanded refers to the amount of product a buyer is willing to buy at a certain price.
Junior
Good evening
Ajibade
Evening
Junior
evening
Ogunsola
someone wat is d textbook to read for banking and finance course
ayomide
Evening
Anjorin
Hw r u doing
Faku
yh
Benj
I'm good, u?
Anjorin
demand is the various quantity of goods or services a consumer is Willing and able to buy at a particular price over s given period of time while quantity demanded is the amount of goods or services being paid for
Florence
Good
Awudu
1.it allows producers to learn and invent 2.it allows agent to take advantage of economic scale 3.it allow agents to focus in areas of
oyebola Reply
can someone explain the motive of money to me?
Alemogho Reply
ask the question you don't know
ojo
opportunity cost
Sylvo
the motive of money is to pay for goods or services. it's also for transaction purposes bet it ordinary or unforseen
Silke
Money helps to reduce our scarcity problems. It can satisfy your wants to an extent
Okwori
transactive motive
Aminata
money help as a store of value for future uses
Pagnol
it also serve as a medium of exchange
Pagnol
How dose economics use science methods to explains it problems
Edmond Reply
according to Jhon Robinson the main problem of economics is what to produce? how to produce? whom to produce? economics tries to solve these problem scientifically by using its theories which are scientific in nature,basically micro and macro theories which just explain what the problem is...
Lavkesh
and now the solving techinique is also changed. only theories or its matematical +statistical version is not sufficient so the economist had developed Econometrics which includes economic theory+mathematical economics+statistics, for solving economic problem. This method treats economics as a pure
Lavkesh
..pure science so this technique is based on pure scientific methods.
Lavkesh
Economics is the scientific study of human behavior so there for science is used to solve economics problems using economics theories
Florence
economic is not higly subject of taminadu ...
Mutha
measurement of elasticity of demand
John Reply
Price elasticity of demand= Percentage change in quantity demanded/ Percentage change in price
Jale
For example, suppose that a 10 percent increase in the price of an ice-cream cone causes the amount of ice cream you buy to fall by 20 percent. We calculate your elasticity of demand as
Jale
Price elasticity of demand =20 percent /10 percent = 2
Jale
In this example, the elasticity is 2, reflecting that the change in the quantity demanded is proportionately twice as large as the change in the price.
Jale
what is economic
Samuel Reply
economics is a social science that studies the relationship of human behavior between ends and scare...
Lawrence
Why is economics as a subject is so important to human being?
austine
it's significant in study of managing available resources to satisfy human needs and wants
mohamed
economics is the science of wealth
Aamir
it is also said that it is the science of scarcity
Aamir
why study economic
Neo
Economic helps to meet our needs and wants nd to make choices.
Abraham
careers or jobs associated with economics
Neo
Economics is more than choices, scarcity, resources etc. It has a lot to do with psychology, social psychology. Understand motivation for consumer decisons.
TOM
okey
Neo
I what to study economic understand education what subject will I take in my jamb
DIRIOHA
English.mathematics.economics and one other social science subject
Ogunsola
economic is life start to end
Mutha
Plz help in lectures job for economics
Mudassar
acc to robbin . "Economics is a science that studies human behaviour as a relationship between scarce means and ends which have alternative uses"
Jahangir
Economics is important to man "human wants are insatiable
Hann
pleas explain circular flow of income
Eagle
what is economic growth
Samuel
Economic growth is an increase in the real output leading to a growth or a rise in the nations gdp.
Charles
Economics is the study of wealth or money and it's an economic activity which has almost three terms divided into them, production consumption and Distribution of wealth.
Zahid
Economics is the study of wealth or money and it's an economic activity which has almost three terms divided into them, production consumption and Distribution of goods and services.
Zahid
plz what is econometrix
saheed
How does commercial banks create credit
Penda Reply
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Source:  OpenStax, Mockingbird tales: readings in animal behavior. OpenStax CNX. Jan 12, 2011 Download for free at http://cnx.org/content/col11211/1.5
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