Wildlife census is the process of estimating the population size and structure of wild animals in a given area. Wildlife census is important for various reasons, such as:
- To monitor the status and trends of wildlife populations and their habitats.
- To evaluate the effectiveness of conservation and management interventions.
- To identify the threats and challenges faced by wildlife and their ecosystems.
- To inform policy and decision-making for wildlife conservation and sustainable use.
There are different methods of conducting wildlife census, depending on the objectives, resources, and characteristics of the target species and area. Some of the common ways are:
Direct count method
This method involves counting all or some of the individuals of a species that are visible or audible in a sample area or along a transect. This method can be applied to species that are conspicuous, abundant, or have distinctive features or sounds.
For example, the vehicle transect or road count method is widely used in India to count large herbivores like deer, antelope, and elephants. However, this method has some limitations, such as:
- It may not be feasible or accurate for species that are rare, elusive, nocturnal, or cryptic.
- It may be affected by factors such as weather, visibility, observer bias, and animal behaviour.
- It may require a large sample size and effort to achieve a reliable estimate.
Indirect count method
This method involves counting the signs or traces left by animals, such as tracks, scats, nests, burrows, or camera trap images, and using them to infer the population size and structure. This method can be applied to species that are difficult to detect directly but leave identifiable marks or evidence of their presence. For example, the pugmark method and camera trap method are widely used in India to count tigers. However, this method also has some limitations, such as:
- It may require a high level of expertise and training to identify and interpret the signs correctly.
- It may be influenced by factors such as sign availability, persistence, detectability, and sampling design.
- It may require complex statistical models and assumptions to estimate the population parameters.
Miscellaneous count method
This method involves using other sources of information or techniques to estimate the population size and structure of animals. This may include methods such as:
- Capture-recapture method: This method involves marking or tagging a sample of animals and recapturing them after a certain period of time to estimate the population size and survival rate .
- Distance sampling method: This method involves measuring the distance of animals from a line or point transect and using it to estimate the population density and abundance .
- Genetic analysis method: This method involves collecting DNA samples from animals or their signs and using them to estimate the population size, structure, and diversity.
These methods can provide more accurate and reliable estimates than direct or indirect count methods, but they may also require more resources, skills, and technical support.
Conclusion
Wildlife census is a vital tool for wildlife conservation and management. It helps to assess the status and trends of wildlife populations and their habitats, evaluate the impacts of conservation interventions, identify the threats and challenges faced by wildlife, and inform policy and decision-making for wildlife conservation and sustainable use.
There are various methods of conducting wildlife census, each with its own advantages and limitations. The choice of method depends on the objectives, resources, and characteristics of the target species and area.
