In situ vs. Ex situ: Two ways to save a species

When a species is in trouble, conservationists have two main approaches to protect it: in situ and ex situ conservation. Both are essential tools for preventing extinction, but they work in different ways, and often complement each other. Understanding these approaches helps explain how we can safeguard wildlife, from endangered rainforest tenrecs to declining urban hedgehog populations.

What Is In Situ Conservation?

The term in situ means “in the original place.” In situ conservation focuses on protecting species in their natural habitat, ensuring they can survive and reproduce where they evolved. This approach maintains the natural relationships between species and their environment.

Key strategies include:

• Protecting and restoring habitats (e.g., replanting native vegetation, reducing pesticide use).
• Creating wildlife corridors to connect fragmented habitats.
• Controlling invasive species that threaten native wildlife.
• Enforcing laws against poaching and illegal logging.

Example for hedgehogs: Creating safe road crossings, restoring hedgerows, and making gardens wildlife-friendly so hedgehogs can thrive in the wild.

Example for tenrecs: Preserving Madagascar’s forests through community-led land management and reforestation projects.

Advantages:

• Species continue to evolve naturally.
• Protects entire ecosystems, not just single species.
• Often more cost-effective in the long run.

Challenges:

• Requires large-scale, long-term commitment.
• May be difficult in areas with intense human activity or conflict.

What Is Ex Situ Conservation?

The term ex situ means “outside the original place.” Ex situ conservation involves protecting species by moving them out of their natural habitats into controlled environments.

Key strategies include:

• Breeding programs in zoos, wildlife parks, or specialised breeding centres.
• Keeping living genetic material (such as seeds, gametes, or embryos) in storage for future use.
• Reintroducing individuals into the wild once threats in their habitat have been reduced.

Example for hedgehogs: Wildlife rescue centres that rehabilitate injured or orphaned hedgehogs and release them back into the wild.

Example for tenrecs: Captive breeding programs for rare species like the Lowland Streaked Tenrec (Hemicentetes semispinosus) to ensure a safety net population.

Advantages:

• Can protect species when their wild habitats are no longer safe.
• Allows for close monitoring of health, reproduction, and genetics.
• Acts as an insurance policy against extinction.

Challenges:

• Does not protect the species’ natural habitat.
• Captive-bred animals may lose survival skills.
• High costs and need for specialised care.

How In Situ and Ex Situ Work Together

The most effective conservation strategies often combine both approaches. In situ efforts address the root causes of decline, while ex situ programs provide a safety net and help rebuild wild populations when conditions improve.

For example:

1. In situ work might involve restoring hedgehog habitats in rural and suburban areas.
2. Ex situ rescue and rehabilitation programs can support injured hedgehogs until they are ready to return to those restored areas.

Similarly, for tenrecs, reforestation projects in Madagascar can be combined with ex situ breeding to bolster population numbers before reintroduction.

In Summary

In situ and ex situ conservation are not competing methods, they are two sides of the same coin. Saving species like hedgehogs and tenrecs means protecting their wild habitats and having backup plans in controlled environments. By combining these approaches, conservationists give wildlife the best chance to survive and thrive.