Migratory Bird Program
Conserving the Nature of America

APPENDIX E

SUMMARY OF BIOTA/NATURAL COMMUNITIES BREAKOUT SESSION

Dave Capen, University of Vermont, Chair

 

Participants in the Biota/Natural communities breakout session identified 22 issues of concern, and then consolidated them into four categories: impacts on habitat of other species; interspecies interactions; cormorant population issues; and health and safety issues. Discussion of key elements for all categories combined are summarized below, along with five recommended strategies.

ISSUES

IMPACTS ON HABITAT OF OTHER SPECIES

  • Habitat destruction: degradation, ecosystem collapse
  • Aesthetic impact of habitat destruction
  • Restoration
  • Protection of sites

INTERSPECIES (SPECIES/SPECIES) INTERACTIONS

  • Rare plants
  • Other animal species
  • Nongame and game fish
  • Positive contribution to biodiversity

CORMORANT POPULATION ISSUES

  • Consistent methods for survey
  • Response thresholds
  • Geographic issues: because species is migratory
  • Population objectives need to be regional and local

HEALTH AND SAFETY ISSUES

  • Potential human health issues
  • Threats to health of other species
  • Water pollution and affected air quality

ELEMENTS OF DISCUSSION:

SCOPE OF THE PROBLEM

  • Consider where populations of double-crested cormorants (DDC) have persisted for a long time.
  • In the Northeast, islands protected from predators are most important nesting sites.

WHY IS IT IMPORTANT?

  • Aesthetics of habitat alteration.
  • Displacement of other species.
  • There is a limited number of predator-free vegetated islands in the Northeast.
  • Domino effects of species replacement.
  • Direct mortality of plants.

BARRIERS TO ADDRESSING THE ISSUES

  • Laws and policies of regulatory agencies.
  • Private ownership.
  • Public ownership.
  • Lack of information on carrying capacity of cormorant habitats.
  • Varying public values and opinions.
  • Public resistance to certain control methods.
  • Political intervention.
  • Costs.
  • Inability to totally exclude cormorants from islands.
  • Funding of population monitoring.
  • Lack of coordination of management activities among management agencies (population information).

OPPORTUNITIES

  • Public opinion.
  • Visible aesthetic degradation raises public awareness.
  • Cormorants can actually be used as a surrogate monitor for prey populations.
  • Cormorants may actually control overabundant fish populations.

COMMUNICATION/EDUCATION NEEDS

  • Public totally unaware/need basic information.
  • Public involvement in management process.
  • Need to convey that management goals are reasonable.
  • Need to convince public that we are responsible (need to take responsible actions so public doesn=t act first).
  • Inform public of potential health hazards of double-crested cormorant colonies.

RESEARCH AND INFORMATION NEEDS

  • Ability to predict population growth and expansion.
  • Ability to predict future impact on the environment and other species.
  • Ability to identify potential colonization sites.
  • Determine population thresholds for significant impacts to habitat (may be different for different resources).
  • How many double-crested cormorants are too many?
  • Know more about the potential spread of Newcastle disease to domestic poultry.
  • Potential impact of DCC in life cycle of parasites.
  • Potential for reducing gull/airport problem by displacement.
  • Habitat evaluation studies.
  • How to restore habitat (e.g., effects of guano on soil).
  • Need to establish repository for information (Colonial Waterbird Registry).
  • Better understanding of general biology of double-crested cormorants.
  • Need accurate long-term population estimation methods.

RECOMMENDED STRATEGIES:

1. Conduct studies that will provide additional demographic information to support population modeling. (Information lacking on reproductive success on northern breeding areas and survival in southern wintering areas).

2. Initiate and coordinate surveys of DCC populations and monitoring of productivity throughout the Northeast; develop more standard methods for such surveys.

3. Manage DCC populations on a flyway basis: 1) establish DCC Flyway Technical Committee and

2) establish regional population objectives for DCC, but continue to address local issues at the local level.

4. Inventory islands and assess habitat suitability in Northeast (to reflect on potential for expansion of nesting colonies).

5. Develop plans to protect known colonies of colonial nesting birds from DCC invasion.

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Last updated: April 11, 2012