The Tricolored Blackbird is a small, striking bird found primarily in California. With its black plumage accented by red and white markings, it is a distinctive species that was once common in the state. However, in recent decades, the Tricolored Blackbird population has declined significantly due to habitat loss and other threats. Many conservationists are concerned about the future of this unique bird and are working to study and protect remaining populations.
What is the Tricolored Blackbird?
The Tricolored Blackbird (Agelaius tricolor) is a medium-sized songbird that measures about 8.5 inches in length. Males are black overall with bright red shoulder patches bordered by white. Females are dark brownish-black with gray streaks and have a muted version of the male’s red and white markings. Their dark coloration distinguishes Tricolored Blackbirds from other blackbird species in California, such as the smaller Red-winged Blackbird.
Tricolored Blackbirds are highly social birds that nest in large colonies numbering in the thousands. They forage on the ground in open grasslands and agricultural fields, often far from their nesting sites. They mainly eat insects but will also consume seeds and grains. Tricolored Blackbirds are migratory within California, moving around according to seasonal food availability.
The Tricolored Blackbird has a distinctive musical call described as a mix of chatter, squeaks and croaks. They produce loud sounds when gathered in their dense breeding colonies. Tricolored Blackbirds nest from late March through early August, earlier than most other blackbirds. They construct nests low in emergent wetland vegetation near sources of water.
Where are Tricolored Blackbirds found?
The range of the Tricolored Blackbird is limited to California and neighboring regions. Over 90% occur in California’s Central Valley and nearby coastal areas. Small numbers extend into Oregon, Washington, Nevada and Baja California in Mexico.
Within California, Tricolored Blackbirds breed in two distinct types of habitat – wetlands and agricultural fields surrounded by grasslands. Traditional nesting sites are freshwater marshes dominated by cattails or tules. More recently, many have adapted to use agricultural fields such as triticale and other grain crops.
After nesting, Tricolored Blackbirds forage more widely over grasslands, scrub, pastures, dairies, and feedlots. They often range far afield from their colony sites while feeding. Winter habitat is variable, including both wetlands and a range of open habitats.
Why are Tricolored Blackbird populations declining?
Over the last century, the Tricolored Blackbird population in California has experienced a dramatic decline. In the 1930s, there were estimated to be over 700,000 birds. The most recent estimate puts the total population at less than 200,000. This represents a loss of over 70% in just a few generations.
There are several factors behind this steep population drop:
- Wetland loss – Over 90% of the original wetlands in California’s Central Valley have been lost to development and agriculture. This removes crucial nesting habitat.
- Disturbance of nesting colonies – Activities like harvesting grain crops before young have fledged can destroy entire breeding colonies.
- Lack of insect food sources – Habitat loss and pesticides have reduced insect populations that are a vital food source.
- Conversion of rangelands – Cattle ranching lands with good foraging habitat have been converted to vineyards or orchards unsuitable for the birds.
- Climate change – Drought stress has reduced nesting habitat in marshes and decreased productivity.
The combined effects of these threats have made it difficult for Tricolored Blackbird populations to stabilize, let alone recover to former levels. Without improved conservation actions, the species may continue to decline towards extinction.
What conservation efforts are underway?
Federal and state wildlife agencies classify the Tricolored Blackbird as a Species of Conservation Concern and monitor populations. The species is listed as Threatened under California’s Endangered Species Act, which prohibits take or possession without a permit.
Specific conservation actions include:
- Protection of breeding colonies – Colonies are monitored and protected from disturbances. Volunteers help discourage encroachment.
- Financial incentives – The Natural Resources Conservation Service partners with farmers to delay harvests and provide nesting habitat.
- Wetland restoration – Some degraded marshes have been restored to provide improved nesting and foraging grounds.
- Range expansion – New protected sites with water and foraging habitat have been established in arid regions like the Mojave Desert.
- Captive breeding – Zoos and wildlife centers have worked to establish captive breeding programs as a safeguard for the species.
While these initiatives have had some success, experts say they have not been enough to reverse ongoing declines. The conservation focus remains on maintaining as robust and resilient a population of Tricolored Blackbirds as possible while continuing to restore habitat across their California range.
How many Tricolored Blackbirds remain today?
Due to their fluctuating nesting locations and nomadic lifestyle, accurately surveying Tricolored Blackbird numbers poses challenges. Teams of researchers monitor known nesting sites each year and track concentrations of wintering birds to produce population estimates.
In 2017, a statewide survey conducted under a rigorous protocol estimated the total population at 177,656. This was down sharply from a similar 2014 survey that estimated over 400,000 Tricolored Blackbirds. Reasons for the sudden decline are not fully clear but may include recent drought impacts.
The 2018 statewide survey detected about 147,000 birds. Numbers for 2019 have not yet been synthesized but individual site surveys suggest they remain below 175,000 adult birds.
About 50% of the current estimated population nests in grain fields in the San Joaquin Valley. Much of the remainder nest at wetland sites like Tricolored Blackbird State Reserve and wildlife refuges. Winter surveys find most birds in the Sacramento Valley, including the Rice Belt and Sacramento National Wildlife Refuge.
Largest current breeding colonies
Location | 2017 Estimate |
---|---|
Tule Lake National Wildlife Refuge | 30,000 |
Delevan National Wildlife Refuge | 20,300 |
Winter site near Williams | 17,000 |
The Tricolored Blackbird population was distributed across only 23 counties in California during the 2018 breeding season. This highlights the geographic concentration of remaining birds in certain areas of the Central Valley and surrounding foothills.
What does the future look like for the Tricolored Blackbird?
The Tricolored Blackbird faces ongoing threats from habitat loss, nesting disturbances and food shortages. While concerted conservation efforts have so far prevented its extinction, the population remains far below historic levels and continues to decline overall.
Most experts believe the Tricolored Blackbird has a high risk of extinction within the next 50 years if current trends continue. However, if wetlands can be restored in the Central Valley, croplands managed to be more compatible with nesting, and insect prey populations enhanced, there is hope the species’ decline could be reversed.
More aggressive legal protections may be warranted if the population drops under 100,000 total birds. Captive breeding flocks could provide an insurance population if Tricolored Blackbirds disappear from the wild entirely, though maintaining birds in captivity long-term is challenging.
Efforts to maintain healthy breeding colonies across a variety of habitat types will remain a focus of conservation groups over the coming decades. The unique and iconic Tricolored Blackbird persists for now in California, but its future is tenuous without redoubled recovery efforts supported by sufficient funding and favorable agricultural policies.
Conclusion
The Tricolored Blackbird was once among the most abundant bird species in California, nesting in vast marshes in flocks numbering hundreds of thousands. Habitat loss and degradation have driven the population down to fewer than 200,000 total birds confined to a small portion of the state. Intensive recent survey efforts estimate there are currently between 147,000-177,000 adult Tricolored Blackbirds, found in just 23 California counties.
Ongoing monitoring and protection programs have prevented the extinction of the Tricolored Blackbird thus far. However, the species remains at serious risk due to continuing losses of wetlands, disturbance of nesting colonies, dwindling insect food supplies, climate change impacts and other factors. Restoration of nesting and foraging habitats, incentives for farmers who provide habitat, captive breeding and increased legal protections may be needed to stabilize this unique species and eventually recover it from the brink.
The fate of the Tricolored Blackbird ultimately depends upon human choices about land use and conservation in California. With sufficient resources and policy changes to manage landscapes in a bird-friendly way, the bright plumage and noisy choruses of this social blackbird may once again become a common sight in the state. The alternative is to let short-term economic interests continue to erode vital habitats until Tricolored Blackbirds disappear forever outside of zoos. The birds remain for now, barely clinging to existence in a few spots – but for how much longer?