The great is a small bird that originally adapted to live in the forest, but it has an extraordinary ability to adapt to the human environment. Nowadays, urbanization is proceeding at an increasing rate, which also affects the lives of animals. However, researchers from Lund University recently found that great living in urban environments have lower levels of stress hormones than their forest-dwelling counterparts.
Anders Brodin, a biologist at Lund University, said: "The great's high cognitive ability makes it highly adaptable, while the great in the city seems to have adapted to the new environment so that they don't feel stressed by the high population density. Another possible explanation is that the smartest and most flexible individuals were the first to successfully settle in urban environments. ”
The most common stress hormone in birds is cortisol. The researchers compared hormone levels between great from various urban environments, such as parks and private gardens, with those that inhabit woodlands. Typically, researchers do this by measuring hormone levels in the bird's blood when they are captured. For the study, however, Anders Broding and his colleague Hannah Watson chose to measure hormone levels in bird tail feathers.
Hannah Watson explains: "The tail feathers grow for two to three weeks in late summer and early fall, so they can be a good measure of average hormone levels over a continuous period of time. During this time, birds form winter flocks based on their eating habits, and having a high ranking in the flock is essential for survival during the winter months. This leads to many fights as individuals try to establish themselves in the group. ”
Extensive winter breeding in our community means that populations of great are denser in urban settings, which one might think could lead to higher stress levels. However, the opposite seems to be true - the big living in the city do not suffer as much as their counterparts living in the countryside.
Anders Broding concludes: "It's important to understand the impact of urbanization on different species, and the great is interesting because it frequents our breeding stations. The presence of small birds in the garden is a pleasure for many, and our research shows that it is especially important for species like great to keep birds so that they can be in close contact with our lives. ”
The great's ability to adapt well in urban environments is inseparable from its highly flexible cognitive abilities. Cities offer a wealth of resources and opportunities, such as human buildings and artificial breeding stations, which provide a rich food source for the great. This makes it easier for big in cities to access food, reducing the level of competition and stress.
At the same time, great in urban environments also benefit from relatively low predator pressure. Compared with the big in the forest, the food chain and ecological balance in the city are relatively simplified, and the big faces less predation pressure. This also helps reduce their stress hormone levels, making them more relaxed and comfortable with city life.
The researchers' findings have important implications for our understanding of how animals adapt to urban environments and the stability of urban ecosystems. By understanding the impact of urbanization on animals, we can take appropriate conservation and management measures to ensure the harmonious coexistence of cities and nature.
In conclusion, the great, as a highly adaptable bird, has shown amazing adaptability in urban environments. Studies have shown that urban great have lower levels of stress hormones, possibly because they are more capable of finding food and avoiding predators in urban environments. This research reminds us of the importance we place on protecting urban ecosystems and creating more livable and shared environments for us and wildlife.