Ecotourism helps conserve wildlife by increasing the value of wildlife conservation for local people. In Argentina, the world's largest breeding colony of Magellanic penguins is visited by thousands of tourists every year, causing the penguins to become habituated to the presence of people. Has ecotourism affected the penguins' ability to respond to stressors? Has it affected the penguins' secretion of corticosterone? In response to a visit by tourists, which penguins—habituated or non-habituated—would show a greater change in expression of genes for liver enzymes involved in converting amino acids to glucose? Explain.

Verified step by step guidance

1. Understand the concept of habituation: Habituation is a process where an animal decreases or ceases its responses to a stimulus after repeated exposure. This is important to determine how habituated and non-habituated penguins might react differently to stressors such as human presence.
2. Review the role of corticosterone: Corticosterone is a hormone involved in the stress response in birds. It helps mobilize energy by promoting gluconeogenesis, the process of converting amino acids to glucose in the liver. This is crucial for understanding how stress affects penguins at a physiological level.
3. Consider the impact of ecotourism on stress response: Habituated penguins are used to human presence and might show a reduced stress response compared to non-habituated penguins. This could mean lower corticosterone secretion and possibly less activation of the genes involved in gluconeogenesis.
4. Predict gene expression changes: Non-habituated penguins, experiencing higher stress from human presence, would likely show a greater increase in corticosterone levels. This would lead to a higher expression of genes for liver enzymes involved in gluconeogenesis, as their bodies respond to the need for more glucose under stress.
5. Connect ecotourism to wildlife conservation: Understanding these physiological responses helps in assessing the impact of ecotourism on wildlife. It's crucial for developing guidelines that minimize stress for animals, thereby supporting both conservation and sustainable tourism.

Key Concepts

Habituation

Habituation is a form of learning in which an organism decreases or ceases its responses to a stimulus after repeated exposure. In the context of wildlife, habituation can lead to animals becoming less responsive to human presence, which may affect their natural behaviors and stress responses. For example, habituated penguins may not react as strongly to tourists, potentially altering their physiological stress responses.

Corticosterone

Corticosterone is a steroid hormone produced by the adrenal cortex in response to stress. It plays a crucial role in the stress response by regulating energy, immune reactions, and metabolism. In penguins, increased levels of corticosterone can indicate heightened stress, which may be influenced by human interactions, such as ecotourism, leading to changes in their behavior and health.

Gene Expression and Stress Response

Gene expression refers to the process by which information from a gene is used to synthesize functional gene products, like proteins. In response to stressors, such as the presence of tourists, certain genes may be upregulated or downregulated, affecting physiological processes. For penguins, the expression of genes related to liver enzymes that convert amino acids to glucose may vary between habituated and non-habituated individuals, reflecting their differing stress responses.