In Sapzurro bay on the Colombia-Panama border, the blue land crab can be found scuttling around human infrastructure, burrowing in the nooks and crannies of the coastal settlement. The species, which can grow up to 15cm and ranges in colour from violet to bright cerulean blue, is considered critically endangered or vulnerable in this region, although it can be classed as invasive elsewhere. It traditionally lived in the region’s rich mangrove forests, many of which have now been urbanised – habitat loss that scientists have blamed for the crab’s decline.
But when scientists studied the distribution of the species around Sapzurro bay, they were surprised to find it was still thriving in areas where vegetation had been eliminated: crawling in pastures, banana and coconut plantations, and scurrying below concrete structures. While burrows in urban areas were fewer and smaller, it had successfully built homes along sewage canals and among houses.
