Many small birds have been noted to have larger relative brain sizes. This help them survive harsh seasonal changes and unpredictable habitats.
Using a global sample of 2,062 species, two-member team of researchers from Germany and the U.S. showed that some birds cope with extreme winter conditions by investing in large brains. This helped them in better planning and developing new, innovative survival strategies. Others with smaller brains invested in traits like large body sizes and high reproductive output. The resident birds in the higher latitudes of Earth exhibited these two alternative strategies for coping with environmental fluctuations. The study ( Nature Communications, August 2019) was able to highlight how climate plays an important role in shaping the global distribution of brain size in birds.
They also found a relationship between reproductive output and brain size in the global sample of resident birds. Large-brained species typically required long, costly periods of parental care, limiting ability to raise a large number of young. Small-brained species are able to produce large number of offspring either frequently or slowly. Small brain, slow reproductive output strategy was common in stable tropical regions but was not seen in high-latitudes environments.
It was earlier shown that large-brained birds evolved in relatively stable environments and subsequently colonised variable environments. Bigger brains allowed corvids, owls and woodpeckers to colonise highly variable environments.
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