Twice a day, as the tide recedes, vast expanses of mud are exposed. Although it may not look like it, mudflats are a banquet table for birds. Within a square meter of mud, there may be up to 50,000 individual invertebrates! More than 90 percent of these tiny animals occur within the top five centimeters of mud. This abundant food resource enables shorebirds to gain up to 30 percent of their body weight in fat prior to resuming their travels. The tide refreshes mudflats with nutrients.