<< Chapter < Page Chapter >> Page >

Choosing when to reject eggs

Acceptor versus rejector strategies

a chart showing the rejection rate of parasite eggs at different clutch sizes.
Rejection frequency of cuckoo eggs by the great reed warbler at various clutch sizes.
Redrawn from Moskat and Hauber 2007.

As previously discussed, cowbird and cuckoo hosts exhibit different responses to learning their own eggs due to the specialist and generalist strategies of the two parasites. The result is that some species are far more willing to accept a parasitic egg than to reject it. Stokke et al. (2007) constructed a model to show how variation in egg appearance can affect whether a host species adopts an acceptor or rejecter approach. While acceptors accept all eggs, regardless of whether they are their own, rejecters will attempt to discriminate and reject parasitic eggs, risking misrecognition and rejection of own eggs. The model predicts that hosts that may potentially suffer greater losses from mistakes in recognition and rejection will be more likely to adopt an acceptor strategy. However, in cases where clutches have very similar eggs, hosts are more likely to reject since they are less likely to mistake their own eggs for a parasitic egg. The authors conclude that an increased learning period is more adaptive for clutches that have high variation between eggs since there is a greater risk of mistakes. A similar experiment corroborates these findings, revealing that females were much more successful at rejecting false eggs when mimicry is low and their eggs are more similar, situations in which learning one’s own eggs becomes more advantageous and the cost of losing an own egg is much lower (Rodriguez and Lotem 1999).

The effect of intraclutch variation

This dynamic ability of hosts to adjust their thresholds for egg acceptance or rejection is well-illustrated in one experiment by Moskat and Hauber (2007). Reed warblers reject cuckoo eggs more often when they had only laid one egg, but less often when several eggs or no eggs existed in the clutch ( [link] ). The authors hypothesized that reed warblers adjust their acceptance thresholds , or point at which eggs are accepted as own, based on the traits of the eggs in the clutch. When no eggs have been laid, the birds have no criteria on which to base their acceptance behavior. When only one egg has been laid, there are only a few traits that the hosts have to recognize as characteristic of their own eggs, so parasitic eggs that fall outside of this narrow range of traits are quickly rejected. However, as more eggs are laid by the host, variation between eggs results in a greater number of acceptable traits, and it becomes easier for a parasitic egg to slip in. To protect against mistaken rejection of their own eggs, hosts expand their acceptance thresholds to allow eggs with a greater variety of traits, resulting in greater acceptance of parasitic eggs as well. As predicted by Stokke et al., greater intraclutch variation , a greater difference between the eggs in the same clutch, prompted hosts to accept more eggs because the costs of misrecognition and misrejection increased. As a result, the birds were more willing to accept parasitic eggs than risk the loss from rejecting their own eggs

Questions & Answers

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
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
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
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
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?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Berger describes sociologists as concerned with
Mueller Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Mockingbird tales: readings in animal behavior. OpenStax CNX. Jan 12, 2011 Download for free at http://cnx.org/content/col11211/1.5
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Mockingbird tales: readings in animal behavior' conversation and receive update notifications?