Here we provide downloads of literature related to tricolored blackbirds. This literature includes the Tricolored Blackbird Conservation Plan, the annual reports of tricolored blackbird researchers, a special edition of the Central Valley Bird Club Bulletin devoted to the tricolored blackbird, and additional documents that have resulted from efforts to conserve the species.
This is the species account for the tricolored blackbird that appears in the publication "California Bird Species of Special Concern: A ranked assessment of species, subspecies, and distinct populations of birds of immediate conservation concern in California."
This publication should be cited as:
Shuford, W. D. and Gardali, T., editors. 2008. California Bird Species of Special Concern: A ranked assessment of species, subspecies, and distinct populations of birds of immediate conservation concern in California. Studies of Western Birds 1. Western Field Ornithologists, Camarillo, California, and California Department of Fish and Game, Sacramento. This volume is available from Allen Press at the location below.
Thank you to Dave Shuford and Tom Gardali, editors of the California Bird Species of Special Concern, and Ted Beedy, the species account author, for providing the pdf of this document and for permitting us to provide it for download.
|62_BSSC_Tricolored Blackbird.pdf||426.4 KB|
This report, by Ted Beedy, Susan Sanders, and Debra Bloom comprehensively reviews what was known about tricolored blackbirds up to 1991, summarizing the relevant literature and providing a comprehensive catalog of breeding colonies.
|Beedy, Sanders, and Bloom 1991.pdf||7.46 MB|
Jon Feenstra's survey during May, 2013 of 20 sites in Baja California, Mexico known or potentially suitable for occupation by breeding tricolors. Of these, only 3 sites were occupied and breeding was documented or suspected at all 3 sites. One of these sites was confirmed as a breeding location for the first time. Many sites were unsuitable due to sustained drought conditions.
This manuscript by Richard W. DeHaven summarizes his work with tricolored blackbirds, reports on a 2000 survey of sites studied during the 1970's, provides perspectives on the dependence upon nesting near dairies in the San Joaquin Valley, and offers suggestions for stabilizing the population of the species.
The report is geographically restricted to the Central Valley and does not consider the needs of the southern California population segment.
|DeHaven 2000 quarter-century perspective.pdf||1.35 MB|
Today the California Department of Fish and Wildlife (CDFW) issued an appeal for public comment on a proposal to list the Tricolored Blackbird as a threatened or endangered species. CDFW is soliciting public comment regarding the species’ ecology, biology, life history, distribution, abundance, threats and habitat that may be essential for the species, as well as recommendations for management of the species. Comments, data and other information can be submitted by email to firstname.lastname@example.org. If submitting comments by email, please include “Tricolored Blackbird” in the subject heading.
Comments may also be submitted by regular mail to:
California Department of Fish and Wildlife
Nongame Wildlife Program
Attn: Neil Clipperton
1812 Ninth St.
Sacramento, CA 95811
All comments received by June 1, 2016 will be evaluated prior to submission of the CDFW report to the Commission.
This publication by U.C. Davis ecologist Bob Meese, which appeared in the journal Western Birds in summer, 2013, summarizes the results of 6 years of field work designed to evaluate the role of insect abundance on tricolored blackbird reproductive success.
A total of 47 colonies was studied and relative insect abundance and reproductive success at each was estimated. In only rare instances was reproductive success estimated to be 1 young/nest or greater, and in each case higher reproductive success was correlated with unusually high insect abundance in foraging habitats surrounding colonies.
Tricolor reproduction appears to be food-limited and few locations in the Central Valley appear to have the abundance of insects necessary to support reproduction by a colonial insectivorous bird species.
The Tricolored Blackbird Working Group was formed to voluntarily develop and implement actions that would help to ensure the long-term survival of the tricolored blackbird. Working Group members produced a Conservation Plan to guide their efforts.
The Conservation Plan was signed in September, 2007.
Available for download is the version 2.0 update to the Conservation Plan, January, 2009.
The Conservation Plan should be cited as:
Tricolored Blackbird Working Group. 2009. Conservation Plan for the Tricolored Blackbird (Agelaius tricolor). 2.0 Update. Susan Kester (ed.). Sustainable Conservation. San Francisco, CA.
|Conservation Plan MOA 2009 2.0 update.pdf||772.38 KB|
This report summarizes the costs and benefits of conserving tricolored blackbird breeding colonies located in grain fields in the San Joaquin Valley from 2005 through 2009. Report prepared by Bob Meese and submitted the U.S. Fish & Wildlife Service, 2800 Cottage Way, Sacramento, CA 95825.
|Contribution of the Conservation of Silage Colonies to Tricolored Blackbird Conservation.pdf||105.93 KB|
This is the final report, submitted to the California Department of Fish & Game and the U.S. Fish & Wildlife Service, of the field activities of Dr. Robert Meese and provides a summary of the colonies detected, their characteristics and fates, and estimates of the number of young produced by successful colonies.
|2008 Final Report.pdf||446.57 KB|
This report documents the results of field work conducted in 2009 by Bob Meese.
|2009 Final Report.pdf||288.33 KB|
This report documents the results of field work conducted in 2010 by Dr. Robert Meese, discusses the significance of these results, and provides recommendations for the conservation of tricolors.
|2010 final report.pdf||224.06 KB|
This is the final report of the 2015 field season submitted by Bob Meese, under contract to the California Department of Fish and Wildlife and with financial support provided by the JiJi Foundation.
|Meese 2015 TRBL Final Report.pdf||233.05 KB|
This is the final report of William J. Hamilton III submitted to the California Department of Fish and Game (now Fish and Wildlife) and the U.S. Fish and Wildlife Service that describes field work conducted on tricolored blackbirds during their 1993 breeding season.
|Hamilton 1993 Tricolor Report to FWS.pdf||1.81 MB|
This is the final report for the 2005 field season of William J. Hamilton III and Robert J. Meese of the University of California, Davis. This report contains the results of the authors' detection and monitoring efforts, reproductive success estimates, a study of the foraging habits of birds at several colonies, GIS analyses of the landcover types within the foraging radius of breeding birds, and management recommendations.
|Hamilton and Meese 2005 final report.pdf||3.51 MB|
Results of Kelly Weintraub's 2011 field season in the Tulare Basin determining the nesting success rates of Tricolored Blackbird colonies in various nesting substrates. This report was prepared for the Fish and Wildlife Service as an annual report.
Methodology, results, and discussion of Tricolored Blackbird nesting success are included.
This report summarizes a field survey of 44 known and potential tricolored blackbird colony locations conducted by Richard A. Erickson, LSA Associates, Horacio de la Cueva, Biologia de la Conservacion, and Mark J. Billings, LSA Associates, in northern Baja California, Mexico from January through August, 2007. Breeding was confirmed at only one of the sites surveyed.
Extreme drought conditions were observed in this region during the survey interval and are believed responsible for depressing prey abundance and resulting in poor reproductive performance in most terrestrial bird species, including the tricolor.
|2007 Baja California Tricolored Blackbird Survey.pdf||246.26 KB|
This report summarizes a field survey of 26 known and potential tricolored blackbird colony locations conducted by Richard A. Erickson, LSA Associates and Horacio de la Cueva, Biologia de la Conservacion in northern Baja California, Mexico from March to June, 2008. Tricolors were observed at 7 locations and breeding was confirmed at 4 of the sites surveyed.
Extreme drought conditions were observed in 2007 persisted in this region in 2008 and are believed responsible for depressing prey abundance and resulting in poor reproductive performance in most terrestrial bird species, including the tricolor.
|Tricolored Blackbird 2008 Baja Survey.pdf||40.52 KB|
Finding the Perfect Balance, by Stephanie O'Neill, appears in the September - October, 2008 issue of Outdoor California magazine. This article highlights efforts to take a co-operative, non-regulatory approach to conserve the tricolored blackbird.
|Outdoor California 2008 TRBL Article.pdf||5.61 MB|
This report, by Tom Paulek, former Area Manager of the San Jacinto Wildlife Area in Riverside County, and his wife Susan Nash, an attorney, summarizes their survey of southern California tricolored blackbird breeding colony locations in Orange, Los Angeles, Riverside, and San Diego counties during the 2007 breeding season.
Prior to their survey, they contacted several prominent southern California biologists, including Kimball Garrett of the L.A. County Museum, Pete Bloom, formerly of the National Audubon Society, and Phillip Unitt of the San Diego Natural History Museum, to assess existing knowledge and to learn the locations of previous colonies.
Their survey resulted in the detection of one colony of 800-1,000 adults in San Diego county and this was supplemented toward the end of their survey with information provided by Tyler Grant of the U.S. Fish & Wildlife Service, Carlsbad, California, of a second colony in San Diego county of approximately 100 adults.
These were the only tricolored blackbird colonies documented in southern California in 2007, a year of record drought and a near-complete reproductive collapse throughout the range of the species (Meese, 2007; Erickson, de la Cueva, and Billings 2007).
|Paulek and Nash 2007 Colony Survey.pdf||28.52 KB|
This report, by Elena Berg, John Pollinger, and Tom Smith of the Center for Tropical Research at UCLA, provides the results of their analysis of the genetic structure within tricolors to help evaluate whether there is a single genetically homogenous population to conserve, or instead whether there are indeed two (or more) distinct populations that should be managed separately. Their analysis showed that there were some unique alleles in southern California but that there was not sufficient genetic differentiation to consider the southern California population a genetically distinct evolutionary unit from the Central Valley or Kern River Valley populations.
|UCLA TRBL Genetics Study Final Report.pdf||631.16 KB|
|Tricolored Blackbird RCPP Report to NRCS April 1 2016 - June 30 2016.pdf||186.73 KB|
Report by Audubon California to the Natural Resources Conservation Service, May 19, 2015 to September 30, 2015.
Agreement No: 68-9104-5-261
|Narrative Tricolored Blackbird RCPP Report May 19 - Sept 30 2015.pdf||733.5 KB|
This is the annual report of Dr. Robert Meese of the Dept. of Environmental Science & Policy at the University of California, Davis and summarizes his field work in detecting, monitoring, and estimating the reproductive success of tricolored blackbird breeding colonies in the Central Valley of California. This report integrates 7 years of field work, provides evidence for insect limitation as among the factors causing the 35% reduction in abundance of tricolors from 2008 to 2011, and provides conservation recommendations that may help to sustain the species.
|Reproductive Success of Tricolored Blackbird Colonies in 2011.pdf||197.45 KB|
This report, by Keiller Kyle and Rodd Kelsey of Audubon California, provides a summary of the 2011 statewide survey.
|Results of the 2011 Statewide Survey.pdf||921.5 KB|
This report, authored by Rodd Kelsey, Audubon California ecologist and coordinator of the 2008 Statewide Census, summarizes the results of the 2008 census and provides perspectives on population trends as documented in previous statewide censuses dating back to the first census conducted in 1994.
|Tricolored Blackbird 2008 Status Report Final.pdf||3.58 MB|
This report summarizes field work conducted by Dr. Robert J. Meese during the 2006 field season, including colony detection, monitoring, descriptions of colony fates, estimates of productivity, and recommendations for additional conservation actions. This report was submitted to the U.S. Fish & Wildlife Service and Audubon California, who supported the field work.
|2006 Final report.pdf||248.34 KB|
This report summarizes field work conducted by Dr. Robert J. Meese during the 2007 field season, including colony detection, monitoring, descriptions of colony fates, estimates of productivity, color-banding, and conservation recommendations. This report highlights the near-complete reproductive failure of the species in California in 2007. This report was submitted to the U.S. Fish & Wildlife Service and Audubon California, who supported the field work.
|2007 Final Report.pdf||3.12 MB|
This report by Dr. Jonathan Feenstra summarizes the results of his efforts to estimate the number of tricolored blackbirds in southern California during the 2009 breeding season.
|Status of tricolored blackbird in southern California 2009.pdf||673.81 KB|
This report provides a summary of efforts made by Dr. Robert Meese and collaborators in 2010 to trap and band tricolored blackbirds at five sites in the Central Valley, from Kern National Wildlife Refuge in the south to Delevan National Wildlife Refuge in the north, and includes a summary of records of previously banded birds recovered, recaptured, and re-sighted during the field season.
|2010 banding final report.pdf||595.83 KB|
Tricolors were trapped and banded at 4 locations in 2011 and hundreds of previously banded birds were recaptured. This report summarizes the trapping and banding results of U.C. Davis ecologist Dr. Robert Meese.
|2011 banding final report.pdf||780.14 KB|
This report provides a summary of the 2007 efforts to trap and band tricolors at three colonies in the Sacramento Valley.
|2007 banding summary report.pdf||153.23 KB|
This report provides a summary of 2008 efforts to trap and band tricolors at three colonies in the Central Valley, and includes a summary of records of previously banded birds recovered, recaptured, and re-sighted during the field season.
|2008 tricolor banding summary report.pdf||198.74 KB|
W.J. Hamilton III's annual report from the 2000 Survey.
|Hamilton 2000 TRBL breeding census & survey in 2000 observ and recs2.pdf||4.44 MB|
Ted Beedy and Bill Hamilton's 1997 report that summarizes a vast amount of literature and provided an update on the status of tricolors throughout their range up to 1997.
|Beedy & Hamilton 1997.pdf||1.02 MB|
This new study by Emilie Graves, Marcel Holyoak, and Bob Meese of U.C. Davis and Rodd Kelsey of The Nature Conservancy (formerly with Audubon California) analyzes over 100 years of colony occupation data to help to understand the contributions of breeding habitats and regional variation to population trends in tricolored blackbirds. Temporal trends differed between breeding habitat types and were associated with regional differences in population declines. A relatively new nesting substrate, triticale (a wheat x rye hybrid grain), has since the 1980's produced colonies 40× larger, on average, than other breeding habitats, and contributed to a change in regional distribution since it primarily occurred in the San Joaquin Valley. The mechanism for such an effect is not clear, but could represent the local availability of foodstuffs in the landscape (i.e. stored grains) rather than something specific to triticale crops. While variation in trends among habitats clearly occurred, they could not easily be ascribed to source-sink dynamics, ecological traps, habitat selection or other detailed ecological mechanisms.
It was published in the open access journal Ecology and Evolution.