钥匙丢了? 不记得你把车停在哪了? 要是你有山雀的记忆力就好了. 

这些半盎司重的鸟, 大脑比豌豆略大, 在树皮里藏成千上万的食物，比如种子, 在枯叶下，在山上的松果里. 当冬天来临, 它们能回忆起藏匿物的确切位置, 这项技能帮助它们在严寒和深雪中生存. 

在一个 新的研究 发表在4月17日的《博彩app推荐》杂志上, 博彩平台推荐和内华达大学的研究人员, 里诺 identify nearly a hundred genes associated with the birds’ spatial memory, 或者回忆物体位置的能力. The paper also suggests a potential trade-off may exist between having a solid long-term memory and being able to quickly ditch old memories to form new ones.

The findings could help biologists better understand the evolution of spatial memory in animals, 包括人类, 说 格奥尔基Semenov, the paper’s lead author and a research associate in the Department of Ecology and Evolutionary Biology. “What we observed also provides valuable insight into how species may adapt to rapidly fluctuating conditions, 尤其是在气候变化的背景下.”

“山雀是令人印象深刻的鸟类，”他说 斯科特•泰勒他是博彩平台推荐的主任 山地研究站 and associate professor in the Department of Ecology and Evolutionary Biology. “Their spatial memory is much more developed than many other birds that don't have to have this strategy to survive cold winters.”

评价野生山雀的空间记忆能力, 泰勒在内华达大学的合作者, 里诺, 由生物学教授领导, 弗拉基米尔•Pravosudov, 设计了一个巧妙的测试. 他们悬挂了多个馈线阵列, each with eight bird feeders with seeds in California’s Sierra Nevada mountains. Each feeder has a gate with a radio frequency reader that can detect a tag researchers put on chickadees. 然后，该团队将每个门编程为只对某些鸟类开放, so that the chickadees had to remember the location of the feeders that would open to them. 

Pravosudov and his team then counted how many times each chickadee landed on the wrong feeders before they recalled the right one. The theory is that birds with better spatial memory would have a lower error rate. 

使用血液样本, the team at CU Boulder also sequenced the entire genome of 162 tagged chickadees, creating the largest dataset ever collected for evaluating the genetic basis of chickadee cognitive ability. 通过比较这些鸟的基因组和它们在喂食器测试中的表现, the team identified 97 genes associated with chickadees’ spatial learning and memory. Birds with specific genetic variants at these genes made fewer wrong attempts before landing on their designated feeders. 

A large proportion of these variants are associated with neuron formation in the hippocampus, 大脑中负责学习和记忆的部分, 根据论文合著者 莎拉Padula, a doctoral student in the Department of Ecology and Evolutionary Biology. Padula conducted a literature review on chickadees' spatial memory for the paper along with Ajay Patel他是泰勒实验室的博士生. 

"We found in previous literature that many of these genetic variants in chickadees are associated with behavioral disorders in other animals. So this finding can help us better understand animal behaviors in general," Semenov 说.

Understanding what genes are associated with the bird's spatial memory can help biologists track how the trait evolves, 据泰勒说. He adds that the common ancestor of all North American chickadees cached food. 但在这里发现的七种山雀中，有两种没有. “They live in a milder environment where food is generally available year-round. 现在博彩平台推荐知道了构成空间记忆的基因区域, we can look at what variation looks like in these species that have lost caching,他说.  

一个平衡

具有非凡空间记忆能力的山雀可以活到9年, 对于一只小鸟来说，这是一段很长的时间. But the study suggests that having good long-term memory may come at a price. 

After running the initial task for a few days, Pravosudov’s team assigned new feeders to the birds. 

令团队惊讶的是, chickadees that performed better in the initial test tended to struggle with switching to the new feeder. They seemed to have a harder time abandoning their initial memories and creating new ones.

“在一个更加多变的环境中, what our collaborators found suggests that chickadees with good long-term memory may have a disadvantage. 例如, 如果有意外的暴风雪, these birds may keep trying to visit caches that have been buried in the snow, 而不是忘记它们，去寻找其他的宝藏,帕杜拉说. 

变化的气候

Facing a rapidly changing climate, birds that can quickly form new memories may survive better.

“We hope to track how chickadee's spatial memory evolves under pressure from climate change. The good news is that these birds appear to have genetic variations in the population that could potentially allow them to adapt. 缺乏这种变异的物种可能无法做到这一点，”谢苗诺夫说.

这个冬天, Semenov, Taylor and the team set up the same type of feeder array at the university’s 山地研究站 west of Boulder. 

在过去的一百万年里, the mountain chickadees in the Rocky Mountains have evolved independently from those in the Sierra Nevada Mountains. The team hopes to investigate whether the two groups of birds have evolved spatial memory in the same way across different geographic regions. 

研究小组也对黑冠山雀是否, 它们与落基山脉的山雀共存, 表现出不同的空间记忆能力. They’ll continue the feeder experiment at the 山地研究站 during the upcoming winters to collect more data.

“We don't have to travel to a remote part of the world like Antarctica to study how animals might respond to climate change. We can do it with these birds that most North Americans are familiar with. 我认为这是山雀的特别之处，”泰勒说.