 The Purple Martin became known as America's most wanted bird because of the idea it ate lots of mosquitoes. We now know it's insects in general that the Purple Martins eat, says Ben Westfall. One Purple Martin will, on average, eat 17 pounds of flying insects. That's their consumption in one season. Purple Martins overwinter in Brazil and other parts of South America and then begin flying north, reaching Florida by late December or January.