Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.
Biol Lett. 2012 Aug 23;8(4):657-9. doi: 10.1098/rsbl.2011.1180. Epub 2012 Feb 22.
Both field and laboratory studies demonstrate that hummingbirds (Apodiformes, Trochilidae) have exceptional spatial memory. The complexity of spatial-temporal information that hummingbirds must retain and use daily is probably subserved by the hippocampal formation (HF), and therefore, hummingbirds should have a greatly expanded HF. Here, we compare the relative size of the HF in several hummingbird species with that of other birds. Our analyses reveal that the HF in hummingbirds is significantly larger, relative to telencephalic volume, than any bird examined to date. When expressed as a percentage of telencephalic volume, the hummingbird HF is two to five times larger than that of caching and non-caching songbirds, seabirds and woodpeckers. This HF expansion in hummingbirds probably underlies their ability to remember the location, distribution and nectar content of flowers, but more detailed analyses are required to determine the extent to which this arises from an expansion of HF or a decrease in size of other brain regions.
野外和实验室研究都表明蜂鸟（雨燕目，蜂鸟科）具有出色的空间记忆能力。蜂鸟每天必须保留和使用的时空信息的复杂性可能由海马体（HF）提供支持，因此，蜂鸟的 HF 应该得到极大的扩展。在这里，我们比较了几种蜂鸟物种的 HF 相对大小与其他鸟类的 HF 相对大小。我们的分析表明，相对于端脑体积，蜂鸟的 HF 明显更大。当以端脑体积的百分比表示时，蜂鸟的 HF 比迄今为止检查过的任何鸟类的 HF 都要大两到五倍。这种蜂鸟 HF 的扩展可能是它们能够记住花朵的位置、分布和花蜜含量的基础，但需要更详细的分析才能确定这种扩展是来自 HF 的扩展还是其他脑区的缩小。
