Peromyscus guardia

# Angel Island Mouse (Peromyscus guardia) The Angel Island Mouse is a small rodent endemic to Isla Ángel de la Guarda in the Gulf of California, Mexico. This deer mouse species measures approximately 8-10 cm in body length with a similarly sized tail, displaying typical grayish-brown fur with lighter underparts. As a nocturnal omnivore, it feeds on seeds, fruits, and vegetation, playing a crucial role in seed dispersal across its island ecosystem. **Geographic Range and Habitat** This species exists exclusively on Isla Ángel de la Guarda, Mexico's second-largest island, covering roughly 895 square kilometers. The mouse inhabits diverse terrain including desert scrubland, rocky outcrops, and areas with sparse vegetation dominated by cacti and desert shrubs. **Threats** The primary threat stems from introduced black rats (Rattus rattus), which compete for resources and potentially prey on native mice. Habitat degradation from feral goats has historically impacted vegetation structure, though goat populations have been reduced. Climate change poses additional risks through altered precipitation patterns affecting food availability. **Conservation Measures** Mexican authorities have implemented biosecurity protocols to prevent further invasive species introductions. Goat eradication programs have been partially successful, allowing some habitat recovery. Research efforts focus on population monitoring and ecological studies to better understand the species' requirements. **Current Outlook** The species remains critically endangered with population trends unknown due to limited recent surveys. The restricted range makes the population extremely vulnerable to environmental changes and invasive species impacts. Without intensive management of invasive species and continued habitat protection, the Angel Island Mouse faces significant extinction risk.