Since 1970 we have established a database of standardized monitoring for spring and fall migrant landbirds at Manomet. There are very few such standardized long-term data sets and none provide a better window on ecological changes. Overall, migrant bird cohorts sampled showed a 50% decrease from 1970-1995, but more encouragingly, overall numbers are stable from 1996-2010. Our published papers and continuing internal analyses confirm the species by species changes.
With recent spring warming trends, leafout, invertebrate larval emergence and spring migration timing of many bird species are all occurring significantly earlier. Our studies, and now several others, suggest that long distance neotropical migrants may not have the ability to show this response to such rapid warming trends. Long-term results indicate rapid population declines of some migrant birds and we expect Manomet data to be a consistent source of historic and current data on population change and migration timing effects.
