Today, we will introduce three methods for estimating the population of pandas. The giant panda is a unique "national treasure" level animal in China. In order to timely understand the population size, habitat area, and living conditions of pandas in the wild, China began organizing a national field survey of giant pandas in the 1970s. Giant pandas are surveyed in the wild approximately once every 10 years. In order to obtain more accurate data, Chinese researchers have tried different research methods.
Panda Xi Lan
1. Estimate based on a certain area
Two giant panda surveys were conducted in 1974-1977 and 1988. At that time, researchers first selected a certain area as the survey range and searched along a certain route within that range. They estimated the approximate number of giant pandas in the area using mathematical formulas based on the information they found along the way, such as the number of giant pandas and the area. They can infer the situation of the entire protected area from this. However, wild giant pandas are extremely vigilant and can usually smell the scent of humans and hunting dogs from a distance, always hiding. For safety reasons, the visual distance of the staff should not be too close, so the accuracy of the conclusions drawn is relatively low.
2. Distance differentiation method and bite differentiation method
The research experience of researchers is constantly enriched, and their technical means are also constantly improving and perfecting. Starting from the third survey in 1999, researchers began to use a combination of "distance differentiation method" and "bite differentiation method". The objects studied by these two methods are various information elements left by giant pandas, such as feces, urine, hair, caves, paw prints, and footprints. After observing and recording these information elements, researchers use computers to determine the distance between two trace points. If the distance between two points exceeds the normal range of activity of giant pandas. Researchers have preliminarily concluded that there is more than one giant panda lurking here.
The territories of giant pandas may overlap. When the distance between two points is within the normal range of activity, researchers need to use the "bite joint differentiation method" to assist in the study. After eating bamboo, giant pandas will directly excrete the indigestible bamboo stems. Based on the depth and width of bite marks left on these bamboo stems, researchers can determine whether they were bitten by the same giant panda, and then calculate the number of giant pandas. This method is called the "bite joint differentiation method". But in some seasons, giant pandas only eat bamboo leaves and do not leave "bite joints" in their feces, so the "bite joint differentiation method" also has its shortcomings.
3. Deoxyribonucleic acid testing method
In the fourth survey that began in 2013, Chinese researchers continued to use the "bite joint differentiation method" while also using the deoxyribonucleic acid detection method. Researchers have started extracting deoxyribonucleic acid from collected giant panda feces. Due to the fact that different giant pandas almost never have the same deoxyribonucleic acid, this method can basically determine the number of giant pandas. However, using this method is relatively difficult as researchers must collect fresh, non contaminated feces extensively. So, the current numbers of wild giant pandas are estimated. (Source: Chengdu Research Base of Giant Panda Breeding)