Part of the basic seabird monitoring work we do on the Farallones involves tracking the reproductive history and lifespan of Cassin’s auklets that were given uniquely marked metal leg bands as chicks. Just over 400 wooden nest boxes were installed across the island in 1983, which mimic the natural burrows used by the auklets, and birds quickly started breeding in them. Over the past 35 years, each box that contained a known-age pair was checked every 5 days to note when an egg was laid, whether or not that egg hatched, and whether or not the chick reached fledgling age. Some of these chicks from known parents recruited into their own nest boxes and started breeding, resulting in multiple generations of birds all within close proximately to each other. Above is a family tree created with the kinship2 package in R, showing the largest pedigree in the known-age dataset that spans 6 generations from 1987 up until 2018. Click HERE for a higher resolution version.