Final answer:
The information provided does not directly answer the question about livestock loss, but sheep are typically the most vulnerable to predators among common livestock animals. Livestock farming has major ecological impacts including habitat loss and climate change.
Step-by-step explanation:
The direct answer to which livestock accounts for more than three-quarters of all livestock lost to predators is not available from the provided information, but based on common farming practices, sheep are often the most vulnerable to predators compared to other livestock animals such as chickens, cattle, and goats. This is due to their size and the way they are often grazed on open pastures.
Loss of livestock to predators can significantly impact agricultural livelihoods and the ecology of areas where these animals graze. Livestock farming, representing a considerable amount of deforestation, has deep environmental impacts, including the loss of habitats for numerous species, an increase in greenhouse gases, and changes in soil erosion and rainfall patterns. Moreover, the loss of large mammal species, often due to indirect human actions like habitat destruction, can have profound effects on biodiversity and the associated economic activities like tourism.