When did elephants disappear in Zhejiang?

In August this year, we were delighted to hear that a new life was born in the "Short-nosed Family" of Asian elephants (also known as elephants) in Xishuangbanna. The "Short-nosed Family" had migrated north to Kunming in 2021, attracting the attention of the world's media and netizens. Elephants are extremely representative land animals, and their long-term close interaction with humans has successfully attracted global attention to mountains, forests and swamps.

Recently, the TV series "The Lost Elephant" has been popular, which inspired me to think about the disappearance of elephants in reality. Historically, elephants were widely distributed in my country, and Zhejiang was once an elephant habitat (this article refers to the area where wild elephant populations reproduce and thrive). Later, it disappeared quietly. Exploring its time can fill the gap in academia, have sample significance for biodiversity conservation, and enhance understanding of current global climate change.

△ Asian elephant

1. Elephants live in Zhejiang

According to 14C dating and tree ring correction, 11,500 years ago, the Earth entered the Holocene epoch from the extremely cold Ice Age. The climate warmed significantly, glaciers melted, and mammoths, saber-toothed elephants and other mammals all became extinct, leaving only Asian elephants alive in China.

1. Elephants lived in Zhejiang 6,000 years ago

Archaeological and ice core studies show that the climate was warm, humid and stable during the Holocene heyday 7,200-6,000 years ago. Wild elephants are distributed across half of China, from Beijing in the north to the Leizhou Peninsula in the south. Ivory objects and remains of Asian elephants dating back 6,300-6,000 years ago were discovered at the Hemudu site. During the Neolithic period, remains of Asian elephants were also unearthed at sites such as Loujiaqiao and Majiabang in Zhuji, Zhejiang.

Elephants have high requirements for the range, sunlight, food, shade, water source, slope, temperature, etc. when choosing a habitat. This shows that the climate in Zhejiang at that time was warm and humid, with lush vegetation, which was an ideal habitat for elephants.

2. Zhejiang is a long-term and stable habitat for elephants

At the end of the Shang Dynasty and the beginning of the Zhou Dynasty, my country experienced its first "cold period" in its 5,000-year history. The temperature dropped significantly, and the northern boundary of the wild elephant habitat irreversibly withdrew from the Yellow River Basin. Due to the lack of understanding of climate change, the ancients explained this phenomenon as "Duke Zhou driving the elephants away." With the productivity level at the time, the habitat of wild elephants moved significantly southward, which was far beyond human control.

From the Spring and Autumn Period to the Northern and Southern Dynasties, the northern boundary of elephant habitat was between the Yangtze River Basin and the Huai River Basin. Wild elephants still lived in large groups in the vast area of ​​the middle and lower reaches of the Yangtze River (including Zhejiang). The elephants Cao Chong mentioned were given by Sun Quan, who had just taken over the six counties of Jiangdong. Judging from Cao Cao's curiosity and the scope of his activities, there were no wild elephants north of the Huai River around 202 AD.

British historian John Mauk believes that between 580 and 1050 AD, the northern boundary of elephants’ habitat in China retreated significantly southward (as shown in the figure below), migrating from the upper reaches of the Yangtze River, Huaihe River, and Qiantang River basins in the shape of a Chinese character "几" to the Lingnan region, which is highly overlapped with the jurisdiction of the Jiangnan Dao in the Tang Dynasty. Is this a coincidence or a necessity?

△Map of Jiangnan Road in the Tang Dynasty, with Yuezhou (now Shaoxing) as its capital

3. When was the last time an elephant appeared in Zhejiang?

The "Wu Yue Bei Shi" records that in 953 AD, "in that year, a large elephant came from the south to Dongyang and was captured in a pond or lake." Since then, there have been few records of wild elephants in Zhejiang.

The elephant sighting in Dongyang made national headlines and was recorded in the history of the Wuyue Kingdom as a national event. How rare was this! The people of Wuyue who were alive at the time had most likely never seen a wild elephant. Considering the relative limit of ancient people's lifespan of 100 years, the elephants may have left Zhejiang before 853 AD.

So when exactly will it be? Let's find out with this question.

2. Why did the elephants leave Zhejiang?

1. Zhejiang’s high population density is an important reason

Zoologists believe that the maximum population pressure threshold that elephants can tolerate is 20 people per square kilometer. From the first year of the Wude period of the Tang Dynasty (618 AD) to the end of the Tianbao period of the Tang Dynasty (756 AD), the national population grew rapidly, reaching its peak in 755 AD. During this period, Zhejiang's development efforts were unprecedented. The table below shows that around 713 AD, Zhejiang's population density reached 22.26 people per square kilometer, exceeding the elephant's tolerance limit. However, Zhejiang's overall excess does not mean that all local states have exceeded the limit.

In 742 AD, the total population of Zhejiang was about 4.89 million (the total population of each state is shown in the table below, Jiaxing is part of Suzhou and is not listed), which is four times that of the Southern and Northern Dynasties. Among them, Wenzhou was developed later and is located at the forefront of the loss of elephant habitat in Zhejiang. The total population reached 240,000 and the population density was 20 people per square kilometer. At this time, the population density of each state in Zhejiang reached the limit of elephants' tolerance for the population in their habitat.

In addition, I also found that the prosperity of Zhejiang is in stark contrast to that of Fujian in the south. Fujian is the last province to be developed in the south. Due to the policy of Emperor Wu of the Han Dynasty to "force all the people in southern Fujian to move out", it has been sparsely populated for a long time.

In 742 AD, the total population of Fujian was about 410,000 (the highest during the Tang Dynasty was only 600,000). The population density of Zhejiang and Fujian was 46.4 people/square kilometer and 3.3 people/square kilometer respectively. Whether in terms of total population or population density, there is an order of magnitude difference between Zhejiang and Fujian (see the table below).

2. The conduction effect of the cold climate is the driving force

The academic community generally believes that the reason for the elephants' southward migration is also due to the cooling of the climate. Let's look at the climate of the Tang Dynasty. There are different opinions in the academic community on whether the climate of the Tang Dynasty was warm or not. There are the "warm theory" represented by Zhu Kezhen, the "cold theory" represented by Yao Tandong, and the "warm at first and cold later theory" represented by Man Zhimin.

Comprehensive analysis shows that the climate warmed up in the early Tang Dynasty. During the first hundred years of the Tang Dynasty, the climate was warm, humid and stable, much like the heyday of the Holocene. Good weather and good harvests brought peace and prosperity to the country, which was an important reason for the Tang Dynasty to prosper.

Starting from the middle of the eighth century, the climate in the late Tang Dynasty turned noticeably colder. The climate during this period was far less stable than in the previous period. Various extreme cold weather events such as the freezing of the Yangtze River and ice formation in coastal waters occurred frequently. There was also a significant increase in records of natural disasters in Zhejiang, such as the drying up of Jinghu Lake in Shaoxing and cannibalism caused by drought in Quzhou.

Paleoclimatologists such as Zhang Deer studied the ancient climate of the Ming and Qing dynasties for 500 years and found that cold winters often correspond to rainy summers. In the middle and late Tang Dynasty, 90% of cold winters corresponded to rainy summers. Frost and snow in spring and autumn will freeze seedlings, and floods are not conducive to plant growth. Floods often alternate with droughts. In the late Tang Dynasty, elephants in Zhejiang had limited food and water sources, and their habitats were obviously deteriorating further.

In the late Tang Dynasty, the direct cause of the sharp decline in population was war, and the underlying cause was the cold climate that led to poor agricultural harvests, which became more sensitive in densely populated Zhejiang. Rapid climate change (warming or cooling) or instability has a transmission effect, which will lead to chain reactions in politics, economy, and military. The Syrian war originated from a refugee crisis caused by drought. Of course, climate change does not only bring disadvantages. For example, the current global warming is conducive to opening up the Arctic route and reshaping the new international geopolitical pattern.

In summary, the elephants quietly left Zhejiang in the early Tang Dynasty. The existence of Fujian helped Zhejiang avoid the tragic "human-elephant conflict". The high population density in Zhejiang and the relative vacuum in Fujian meant that the actual time when the elephants left Zhejiang was earlier than the theoretical time. Considering the population underreporting and household registration concealment in the Tang Dynasty, the exact time when the elephants left Zhejiang was probably around 700 AD.

From the Hemudu period to 700 AD, elephants lived in Zhejiang for about 5,000 years, and finally disappeared with heavy steps during the heyday of the Tang Dynasty. The Tang Dynasty benefited from climate change but was helpless against it.

In the long history of the earth, climate change has never stopped. Unchanged is unexpected, and change is the norm. The consequences of rapid climate change or instability may be beyond our imagination. The elephants leaving Zhejiang have brought us a lot of thoughts!

References:

[1] Zhu Kezhen, “A Preliminary Study of Climate Change in China over the Past Five Thousand Years”, Acta Archaeologica Sinica, No. 1, 1972.

[2] Zhang Deer, “Questioning the theory that the monsoon caused the fall of the Tang Dynasty based on China’s historical climate records”, Progress in Climate Change Research, Vol. 4, No. 3, 2008.

[3] Wen Huanran, Research on the Changes of Plants and Animals in Chinese Historical Periods, Chongqing Publishing House, 2006.

[4] Yi Maoke, The Retreat of the Elephants: An Environmental History of China, translated by Mei Xueqin et al., Jiangsu People’s Publishing House, 2014.

[5] Ge Quansheng, Zheng Jingyun, Fang Xiuqi, et al., “Temperature changes in the winter half year in eastern China over the past 2000 years” [J]. Quaternary Sciences, 2022, 22(2).

[6] Lan Yong, “Climate Changes in the Tang Dynasty and the Rise and Fall of Tang Dynasty History”, Chinese Historical Geography Series, No. 1, 2001.

[7] Man Zhimin, “Discussion on the Issue of Cold and Warmth in the Tang Dynasty”, Quaternary Studies, No. 1, 1998.

(Author: Tang Weiping, a junior high school science teacher in Ningbo, a member of the China Science Exploration Association, a member of the China Forestry Society, and a member of the editorial board of the Zhejiang Science Popularization Federation; Yan Yuanbo, a student of Ningbo Xiaoshi Middle School.)