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MISSION STATEMENT
Our fundamental mission is to assemble, synthesize, and distribute information
and expertise gained from cowbird research and ongoing management to those needing
to consider, establish or maintain cowbird management programs as options for
the enhancement and maintenance of songbird populations, including those for endangered
species.
Under this mission, our specific goals are to:
(1) provide a central bibliographic database to reference published and unpublished
information on the biology of cowbirds and the results of cowbird management activities.
(2) summarize the current diversity of perspectives and opinions for assessing cowbird/host interactions and conducting cowbird management activities.
(3) summarize, synthesize, develop and update the most current and appropriate considerations and protocols for:
a. initiating cowbird management options at local or regional scales,
b. implementing and conducting specific cowbird management activities, and
c. sampling and analyzing data establishing a need for management, and monitoring effectiveness of such management.
(4) develop effective education and outreach for the above to the public, academicians, resource managers, consultants, and conservation groups.
ISSUES AND POSSIBLE SOLUTIONS THAT THE COUNCIL WILL ADDRESS ARE GROUPED UNDER FIVE GENERAL HEADINGS, AS FOLLOWS:
I. Public Education and Outreach to Managers
An informed public is essential for developing sound management policy. Some information
will be made available through web postings or hard copy handouts of policy or
research papers that can be mailed out or published. Some information is best
imparted by consultation with informed individuals or presentations to certain
groups. Hence, the Council will undertake the following:
a. Promote the synthesis and distribution of existing data on cowbird numbers, host numbers, and cowbird management
b. Serve as a central clearinghouse and authority as to what conclusions can and can't be made from existing information.
c. Use this internet web site to publicize the criteria for evaluating the need, initiation and operation of cowbird control programs. We will also prepare hard-copy materials where appropriate to assist state and federal government agencies in determining how and when to support cowbird management efforts.
d. Serve as a resource to managers with questions.
e. Give presentations or lead workshops or discussion groups about the need for
and the activities of this advisory council at ornithological conservation society
meetings, as well as local planning commissions entering into Habitat Conservation
Plans and similar management approaches.
f. Provide educational material to conservation organizations such as the Audubon Society and contribute to public education regarding the need for a scientific basis and appropriate procedures for cowbird management.
II. Defining the Extent of Cowbird Problems that are Candidates for Management
Actions
The Council will assemble and make available information identifying candidates for management, and specifically will:
a. Identify which additional data are most critically needed and at which particular sites to guide management decisions either about cowbird control, habitat protection/augmentation, landscape-level approaches or other mitigation activities.
b. Evaluate what management actions might be needed for issues dealing with non-endangered
species, such as actions to benefit eastern and midwestern forest species or western
riparian species.
d. Prepare concise guidelines to improve decision-making about when to initiate cowbird control -- and when NOT to initiate cowbird control programs.
e. Be available to consult with managers about the collective options and considerations for managing songbird populations affected by cowbirds that can be used in concert with, or as alternatives to, local and/or direct cowbird control (e.g. landscape measures, predator control, etc.).
III. Criteria for Justifiying Initiation and Termination of Cowbird Control
Issues related to cowbird control are complex and require careful analysis
and judgement. Cowbird parasitism is highly variable in space and time, and
high rates of parasitism of a particular host species at one site over one
sampling period do not necessarily reflect impacts at other sites and
times. Furthermore, cowbird parasitism is a naturally occurring phenomenon,
as are other processes that reduce avian numbers, such as nest predation.
Cowbird parasitism is not a new impact on North American birds as fossils
of the Brown-headed Cowbird date to 500,000 years ago and DNA sequence data
indicate that parasitic cowbirds have been in North America for at least
800,000 to 1,200,000 years. Despite its ancient nature, cowbird parasitism
may today be a significant factor in the survival of some hosts due to
recent increases in the cowbird's range and possibly abundance. Potentially
even more significant, is widespread anthropogenic destruction of habitat,
which has reduced some bird populations to such low levels that they may
not be able to sustain additional stresses such as cowbird parasitism.
Despite cowbird impacts, cowbird control may not always be the best
management action for a wide range of reasons (it has resulted in increased
host populations for only about half of the species it has been designed to
protect and uses scarce resources that might be better spent on other
actions). The Council is preparing guidelines to address these and related
issues, which are dealt with in the following questions:
a. What baseline data should be collected and analyzed prior to
implementing cowbird management?
b. Can we define trigger points (based on frequency of parasitism and
degree of host losses when parasitism occurs) that should lead to cowbird
management, especially cowbird control?
c. What are the downsides to cowbird control that one needs to consider
(such as the possibility that cowbird control will be presented as a
management action that negates the need for other, possibly more
efficacious management measures)?
d. What criteria should be used for assessing the efficacy of cowbird
control?
e. Can we determine when cowbird control can be terminated?
IV. Means of Assessing the Efficacy of Cowbird Management
The ultimate measure of success of cowbird management is an eventual
increase in a host's breeding population, not the numbers of cowbirds
killed or even increases in a host's reproductive output. The latter is a
reasonable short-term goal or measure of success. However, those
contemplating cowbird control programs should keep in mind the fact that
although cowbird control typically results in large increases in host
output, there are sometimes no concomitant increases in the numbers of
hosts that breed, apparently because factors other than reproductive output
are limiting the host populations. The following questions summarize the
Council's commitment to ensuring that cowbird management is conducted
within a scientific framework and executed in a cost-effective manner.
a. What monitoring data and analyses are needed to assess the efficacy of
cowbird management?
b. How can management and monitoring be couched into local and regional
assessments of benefits to host populations?
c. How can management and monitoring be evaluated relative to other
processes affecting the managed systems?
d. Can cowbird control programs be designed as structured experiments that
can show whether control actually increases the breeding populations of
hosts?
e. What are the specific administrative problems in initiating, maintaining
and monitoring control policy and programs?
V. The Best Procedures to Use for Cowbird Trapping
[Under development]
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