Tricolored Blackbird
Agelaius tricolor
Photo: California Department of Fish and Wildlife
Introduction
Status
Ecological Requirements
RCIS Regions: All terrestrial regions
RCIS Natural Communities: Freshwater Emergent Wetland, Agriculture, Annual Grassland (CDFW 2020)
Breeding habitat: Large, dense breeding colonies (March to August) in emergent wetlands with tall, dense cattails or tule (CDFW 2008, 2019; Hamilton 2004). Often associated with dairies and ripening grain heads (Hamilton 2004). Requires open water within 500 meters of colonies (Hamilton 2004).
Foraging habitat: Croplands, grassy fields, flooded lands, irrigated pasture, dry rangelands, dairy operations and along edges of ponds, may be up to 4 miles from breeding areas (CDFW 2008, 2019; Hamilton 2004); particularly attracted to ephemeral pools (Hamilton 2004)
Wintering habitat: Open rangeland, grasslands, and agricultural fields with low-growing vegetation, and dairies and feedlots (Hamilton 2004; Shuford and Gardali 2008).
Colonies make extensive migrations and movements during the breeding season and in winter within their range (Shuford and Gardali 2008)
Full species account available: Tricolored Blackbird (Agelaius tricolor). The Riparian Bird Conservation Plan: a strategy for reversing the decline of riparian-associated birds in California (Hamilton 2004)
RCIS Conservation Priority: High (steeply declining, breeding areas require management)
Associated Non-Focal Species
Range and Modeled Habitat
Climate Change Vulnerability Assessment
Gardali et al. (2012) conducted a species-specific climate change vulnerability assessment for the tricolored blackbird (TRBB) on exposure and sensitivity factors:
Exposure Factors
- Habitat suitability-Moderate
- Extreme weather- Moderate
- Food availability- Low
Sensitivity Factors
- Habitat specialization-Moderate
- Dispersal ability-Low
- Physiological tolerances- Low
- Migratory status- Low
Though tricolored blackbirds are projected to experience a 10 to 50 percent decrease in habitat suitability and some increase in exposure to extreme weather events, they can tolerate some variability in habitat types (Gardali et al. 2012). With a high ability to migrate and disperse to new habitats as well as an ability to successfully use appropriately managed agricultural lands, tricolored blackbirds are not included on the Climate Change Vulnerability Priority list (top 25 percent of highest assessed scores) (Gardali et al. 2012; Hamilton 2004).
Conservation Strategies
Tricolored Blackbird Goals, Objectives, and Actions
There are 35 proposed actions. For complete goals, objectives and actions explanations see the complete table of conservation strategies in the RCIS PDF.
Species Goals, Objectives, and Actions
Goal TCBB 1
Promote persistence of tricolored blackbird populations in the RCIS area through protection, and enhancement of habitat.Objective TCBB 1.1
Protect known occurrences and allow for expansion by protecting suitable habitat. Measure progress towards achieving this objective by the number of breeding locations, acres of adjacent foraging habitat and associated/equivalent acres protected.Action TCBB 1.1.1
Promote persistence of active breeding colonies by conducting community outreach programs to encourage private protection and appropriate management of occupied habitat (Tricolored Blackbird Working Group 2007).
Objective TCBB 1.2
Enhance occupied and suitable tricolored blackbird breeding, wintering, and foraging habitat. Measure progress towards achieving this objective by acres of habitat and adjacent/equivalent acres enhanced and occupied by tricolored blackbirds.Action TCBB 1.2.1
Maintain suitable vegetation structure in tricolored breeding and foraging habitat, including biennial burning of breeding habitat with heavily flattened cattails and modified grazing practices in irrigated pastures (Hamilton 2004; Shuford and Gardali 2008).
Action TCBB 1.2.2
Manage water levels in breeding habitat to prevent flooding of nests and increased predator accessibility (Tricolored Blackbird Working Group 2007).
Action TCBB 1.2.3
Conduct studies on gaps in basic life history information such as distribution, resource utilization, and survival of wintering birds (Shuford and Gardali 2008).
Objective TCBB 1.3
Restore occupied and suitable tricolored blackbird breeding, wintering, and foraging habitat and create new habitat. Measure progress towards achieving this objective by acres of habitat and adjacent/equivalent acres restored and occupied by tricolored blackbirds.Action TCBB 1.3.1
Restore/create appropriate densities of nest substrate species in suitable breeding habitat near productive foraging habitat (Shuford and Gardali 2008) using appropriate vegetation management practices and active revegetation, where needed.
Action TCBB 1.3.2
Create ephemeral pools with appropriate native vegetation densities to encourage presence of breeding and foraging tricolors where their absence limits tricolored blackbird settlement (Hamilton 2004).
Objective TCBB 1.4
Protect grain and silage-nesting tricolored blackbirds until enough, permanent breeding habitat is available (Tricolored Blackbird Working Group 2007). Measure progress towards achieving this objective by acres of silage and grain habitat and adjacent/equivalent acres restored and occupied by tricolored blackbirdsAction TCBB 1.4.1
Fund and carryout silage buyout with willing private landowners (Tricolored Blackbird Working Group 2007).
Action TCBB 1.4.2
Promote awareness of tricolored blackbird nesting behavior and conservation options on ranch and farmlands, such as deferring harvest of grain and silage crops when possible until after the breeding season (Tricolored Blackbird Working Group 2007).
Regional Goals, Objectives, and Actions
Goal RC 1
Sustain resilient, connected natural communities for the full range of native species, habitats, and ecological functions in the RCIS area through the protection of large blocks of continuous habitat supporting sensitive species.Objective RC 1.1
Protect and preserve existing intact non-marine habitats and resources and allow for expansion of habitat by protecting suitable or occupied habitat. Measure progress towards achieving this objective by the number of acres of habitat and adjacent/associated acres protected.Action RC 1.1.1
Acquire parcels with suitable habitat through fee title purchase or conservation easement.
Action RC 1.1.2
Conduct surveys using eDNA and/or traditional survey methods in suitable or potentially suitable habitat to locate undocumented occurrences of focal species and other conservation elements and opportunities for habitat protection, enhancement, restoration, and creation (USFWS 2008).
Action RC 1.1.3
Create and sustain long-term funding for protected areas maintenance.
Action RC 1.1.4
Establish an incentive program for private landowners to protect occurrences and manage habitat.
Action RC 1.1.5
Protect populations from impacts from construction, vegetation management, and/or activities, including by surveying areas such as roads/trails and implementing species protection measures.
Objective RC 1.2
Enhance occupied and suitable habitat. Measure progress towards achieving this objective by number of acres of habitat enhanced and/or occupied.Action RC 1.2.1
Manage current and future recreation access including off-road vehicles, biking, equestrian, foot traffic, and unleashed pets to reduce impacts and disturbance to sensitive species and habitats. Ensure recreation is compatible with suitable and future potentially suitable habitat and adjacent areas, and areas of known occurrences. Enforcement and fencing may be used to prevent illegal off-road vehicle use (USFWS 2010).
Action RC 1.2.10
Work with private landowners and stakeholders to research species biology, threats, populations, densities, and/or ranges.
Action RC 1.2.11
Create/enhance connections between ecologically required habitat types, such as between aquatic breeding and upland dispersal habitats.
Action RC 1.2.2
Control non-native invasive species from occupied and/or suitable habitat, and areas designated by the U.S. Fish and Wildlife Service as critical habitat throughout the RCIS area.
Action RC 1.2.3
Reduce/eliminate pesticide, rodenticide (especially first- and second-generation anticoagulant rodenticides), and herbicide use, including for roadside vegetation removal projects as part of integrated pest management efforts in identified suitable habitat, and sensitive natural communities. Promote alternative pest reduction methods, such as promoting natural predator populations (Ventura County Public Works Agency 2017).
Action RC 1.2.4
Minimize impacts from native and non-native predator populations that have increased due to anthropogenic factors, including through educational outreach and trainings on how to safely coexist with native predators and predator removal programs where appropriate.
Action RC 1.2.5
Reduce anthropogenic impacts on habitat, including infrastructure construction and maintenance, inappropriate grazing, uncontrolled grazing, or overgrazing, off-road vehicles, foot traffic, fire suppression, recreational development and activities, non-native plants, and sand mining
Action RC 1.2.6
Manage infrastructure construction and maintenance projects, including transportation, solar energy facilities and projects on military properties, to be compatible for sensitive species.
Action RC 1.2.7
Manage grazing, including the installation of wildlife-friendly fencing, to ensure it is compatible with suitable and future potentially suitable habitat and adjacent areas, and areas of known occurrences. Grazing in sensitive natural communities, public lands should be reduced.
Action RC 1.2.8
Reduce trash dumping in areas with suitable and future potentially suitable habitat and adjacent areas, and areas of known occurrences.
Action RC 1.2.9
Enhance and restore native vegetation in occupied habitat and suitable but unoccupied habitat.
Water Goals, Objectives, and Actions
Goal Water 1
Improve conditions of water resources, aquatic and riparian habitats, and connectivity throughout the RCIS area through enhancement and restoration.Objective Water 1.1
Improve freshwater aquatic and riparian habitat conditions in areas with sensitive species and habitats. Measure progress towards achieving this objective by the improvement and restoration of aquatic and riparian conditions (inundation duration, water depth, water chemical composition, stream substrate composition and/or stream characterization, habitat structure, native species diversity, percent cover), water quality, and connectivity of water resources.Action Water 1.1.1
Reduce water pollutants such as fine sediments, pesticides, herbicides, sewage effluent, and other non-point and point source waste discharges, including through development and implementation of stormwater policy and infrastructure.
Action Water 1.1.3
Improve quality of wetland habitats and create new wetland habitats, including through invasive species control, increased water period, and recontouring to enhance proper elevation, etc.
Action Water 1.1.5
Minimize impacts to water resources from construction, military activities, and agricultural practices.
Action Water 1.1.6
Reduce introduction of sediments in creek channels from bank erosion, livestock grazing, timber harvestings, unpaved roads and trails, and recreation.
Action Water 1.1.7
Improve and expand existing riparian and upland buffers and create new buffers where they are lacking around stream and wetland habitats, as well as connectivity corridors between heterogeneous habitats. A qualified biologist and the best available science should determine buffer distances.
Action Water 1.1.8
Preserve and protect intact aquatic and riparian resources where protection is lacking.
Objective Water 1.2
Improve appropriate hydrology and hydrological functions to support sensitive species and habitats. Measure progress towards achieving this objective by the improvement of hydrological indicators such as water depth, stream flow, water temperature and chemical composition.Action Water 1.2.1
Moderate extreme water temperature fluctuations by controlling water flow regimes downstream of impoundments, water diversions, and residential or industrial developments.
Action Water 1.2.2
Ensure releases from water storage and diversion facilities maintain surface flows necessary for all life history stages of sensitive species (NMFS 2013).
Action Water 1.2.3
Maintain appropriate management of flood-control activities (both routine and emergency) to be compatible with sensitive species (NMFS 2013).
Action Water 1.2.4
Restore hydrological functions of waterways to mimic natural flow, temperature regimes, and sediment loads where feasible (Hayes et al. 2016).
Action Water 1.2.5
Develop and implement operating criteria to ensure the pattern and magnitude of groundwater extractions and water releases provide essential ecological functions.