| 来源类型 | Monograph (IIASA Interim Report) |
| 规范类型 | 报告 |
| Mothers Adjust Egg Size to Helper Number in a Cooperatively Breeding Cichlid. | |
| Taborsky B; Skubic E; Bruintjes R | |
| 发表日期 | 2006 |
| 出版者 | IIASA, Laxenburg, Austria: IR-06-056 |
| 出版年 | 2006 |
| 语种 | 英语 |
| 摘要 | Mothers should adjust the size of propagules to the selective forces to which these offspring will be exposed. Usually a larger propagule size is favored when mortality risk or competition for young are high. Here we test two predictions on how egg size should vary with these selective agents. When offspring are cared for by parents and/or alloparents, protection may reduce the predation risk to young, which may allow mothers to invest less per single offspring. In the cooperatively-breeding cichlid "Neolamprologus pulcher", brood care helpers protect group offspring and reduce the latters' mortality rate. Therefore females are expected to reduce their investment per egg when more helpers are present. In a first experiment, we tested this prediction by manipulating the helper number. In "N. pulcher" helpers compete for dispersal opportunities with similar-sized individuals of neighboring groups. If the expected future competition pressure on young is high, females should increase their investment per offspring to give them a headstart. In a second experiment, we tested whether females produce larger eggs when perceived neighbor density is high. Females indeed reduced egg size with increasing helper number. However, we did not detect an effect of local density on egg size, although females took longer to produce the next clutch when local density was high. We argue that females can use the energy saved by adjusting egg size to reduced predation risk to enhance future reproductive output. Adaptive adjustment of offspring size to helper number may be an important, as yet unrecognized strategy of cooperative breeders. |
| 主题 | Evolution and Ecology (EEP) |
| 关键词 | cooperative breeding, maternal effects, maternal investment, offspring size, intraspecific competition, cichlids |
| URL | http://pure.iiasa.ac.at/id/eprint/8043/ |
| 来源智库 | International Institute for Applied Systems Analysis (Austria) |
| 资源类型 | 智库出版物 |
| 条目标识符 | http://119.78.100.153/handle/2XGU8XDN/125502 |
| 推荐引用方式 GB/T 7714 | Taborsky B,Skubic E,Bruintjes R. Mothers Adjust Egg Size to Helper Number in a Cooperatively Breeding Cichlid.. 2006. |
| 条目包含的文件 | ||||||
| 文件名称/大小 | 资源类型 | 版本类型 | 开放类型 | 使用许可 | ||
| IR-06-056.pdf（342KB） | 智库出版物 | 限制开放 | CC BY-NC-SA | 浏览 | ||
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