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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

what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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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