The most recent statewide surveys documented a rapid decline in the number of Tricolored Blackbirds, from about 400,000 in 2008 to about 250,000 3 years later. Annual monitoring and research into the relationship between reproductive success (RS) and insect abundance by ICE ecologist Bob Meese has shown a chronic low RS in dozens of colonies studied since 2007 and relatively high RS only in instances when colonies were surrounded by landscapes with unusually high insect abundance. Thus, the recent decline in the numbers of tricolors is believed to be due to chronic low RS (the number of birds recruiting into the population has been much smaller than the number dying) due to insufficient insect abundance. For the full story, please visit the Tricolored Blackbird Portal.
