Editing Behavioral ecology (section)

====Parent–offspring conflict resolution====
Parents need an honest signal from their offspring that indicates their level of hunger or need, so that the parents can distribute resources accordingly. Offspring want more than their fair share of resources, so they exaggerate their signals to wheedle more parental investment. However, this conflict is countered by the cost of excessive begging. Not only does excessive begging attract predators, but it also retards chick growth if begging goes unrewarded.<ref>{{cite journal|last=Kilner|first=R. M.|title=A Growth Cost of Begging in Captive Canary Chicks|journal=Proceedings of the National Academy of Sciences of the United States of America |year=2001|volume=98|pages=11394–11398 |bibcode=2001PNAS...9811394K|doi=10.1073/pnas.191221798|issue=20|pmid=11572988|pmc=58740|doi-access=free}}</ref>  Thus, the cost of increased begging enforces offspring honesty.

Another resolution for parent–offspring conflict is that parental provisioning and offspring demand have actually coevolved, so that there is no obvious underlying conflict. [[Cross-fostering]] experiments in [[great tit]]s (''Parus major'') have shown that offspring beg more when their biological mothers are more generous.<ref>{{cite journal|last=Kolliker|first=M. |author2=Brinkhof, M. |author3=Heeb, P. |author4=Fitze, P. |author5=Richner, H.|title=The Quantitative Genetic Basis of Offspring Solicitation and Parental Response in a Passerine Bird with Parental Care|journal=Proceedings of the Royal Society B: Biological Sciences|year=2000|volume=267|pages=2127–2132|doi=10.1098/rspb.2000.1259|issue=1457 |pmid=11416919 |pmc=1690782}}</ref> Therefore, it seems that the willingness to invest in offspring is co-adapted to offspring demand.