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a male bird feeding a baby bird in a tree.
Male Tree Swallow feeding a baby swallow. Courtesy of Steve Byland and Flickr.
The probability of high paternity or low paternity does not impact how often the male visits the female nor when he visits her in the egg laying cycle.

How yellow-headed blackbirds attract mates

In the yellow-headed blackbird ( Xanthocephalus xanthocephalus ), males attract mates by adopting broods of others’ offspring. In this species, females choose where to nest based on the number of females living on the territory and the number of active nests. The more females with active nests on a territory, the more resources the territory must have and the safer it must be from predators. These factors will lead females to nest in the same area. Replacement males, thus, may be able to attract new females ready to settle if they accept the presence of unrelated offspring in nests made by previous territorial males. In this case, adoption and not infanticide is the behavior that yellow-headed blackbirds choose as a tool to actually increase eventual fitness (Gori et al . 1996).

Female infanticide in the house sparrow

Due to gamete dimorphism, sperm is cheaper to produce than eggs. Males can, thus, copulate with many more females and father more children than females can produce. Females, however, will devote more resources into the care for the young to compensate for the fewer number (Queller 1997). This allows for males to be more mobile. This, and the fact that because of the internal fertilization of eggs males can never be sure about their expected paternity in a brood, usually leads to males being the sex typically faced with the decision to adopt or kill a brood. However, females are presented with this dilemma too. In the house sparrow ( Passer domesticus ), females have to compete with each other for limited nesting space (Veiga 1990). This competition leads to the selection of behaviors that will increase the chances of a female taking over a nest and her raising her offspring up to fledge. Many times when a new female takes over a previously used nesting site, the other females’ young are still there. This new female now has to decide whether she should raise these offspring or if she should kill them. As expected, infanticide is not rare. In one study, female house sparrows committed infanticide over 20% of the time when females replaced other females (Veiga 2004). Moreover, because this nest is visited by the male that was helping to raise the other young, the female will kill off the other young in order to focus more of the male’s time and resources on the caring of her own young. She will mate with this male and lay a clutch of eggs where he expects high paternity.

Female infanticide can also occur without a female’s taking over a used nest site. In house sparrows, because the females are mated with a polygynous male, they are more likely to kill their rival’s offspring in order to get more of the male’s energy and time devoted to her and her offspring. When a polygynous male had other nests full of fledglings that needed care, female behavior that would give more, needed attention to her own offspring would be favored. Nearly 90% of these females committed infanticide (Veiga 2004).

Questions & Answers

do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit 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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