(by Dr. Suzanne Valente)
This is an addendum to my comment previously submitted to the GGNRA with respect to the 2008 closure of a section of Ocean Beach referred to as the “Plover
Protection Area”. This addendum is intended to supplement the previous comment and respond to the new plover issues
as outlined in the 2011 DEIS for the GGNRA.
As noted in my original comment, this 2011 DEIS again fails to mention a 2007 study by Warren that found plovers’ feeding was not negatively impacted by recreational activities of humans and dogs. This
is critically important because the plover does not nest or breed at Ocean Beach or Crissy Field; its’ primary activity
here is feeding and foraging for food. Instead of acknowledging the Warren study, this DEIS relies in large part upon a study by Matthew Zlatunich and Michael Lynes of the Golden Gate Audubon Society. This new study, like the Warren study, was conducted in cooperation with the GGNRA.
The new Zlatunich-Lynes study was conducted in 2009/2010 at Crissy
Field in San Francisco. This study exhibits many of the scientific shortcomings noted in my original comment:
- This study was merely an observational study
- The observational collection of data was performed by Audubon volunteers who had
a bias—the GGAS has publicly advocated the banning of dogs to protect the plover
- This study made no attempt to ascertain comparative effects on the plover. There
is no discussion of the disturbance level perpetrated by other sources, even though they tell us that data was collected
- Raw data is not provided to the reader
- The analysis appears to be biased because it is based upon incomplete data. For
example, the level of disturbance is not categorized in the analysis even though we are told they were categorized in their
- Assumptions are made in this analysis without supporting explanation. For example,
they decided to assign the disturbance to an on-leash dog if he was closer to the plover than his guardian. This ignores the
possibility the disturbance was due to the number of bodies—e.g. two people walking would disturb a plover to the same
extent as a leashed dog and a person.
To clarify the issue of comparative disturbance, it seems odd that although known
predators of the plover are acknowledged to be at Crissy Field, no attempt is made to analyze the disturbance they create
for the plover. The Common Raven and American Crow are present, yet ignored in the analysis. Beyond this, the California Gull
is noted as being present. This is of interest because a recent study using surveillance cameras at plover nesting sites in
San Francisco Bay documented California Gulls as being responsible for 25% of all predation of plover nests. (Robinson-Nilsen,
Caitlin1, Jill Bluso Demers1, Cheryl Strong2, and Scott Demers 3; 1 San Francisco Bay Bird Observatory, firstname.lastname@example.org;
2 U. S. Fish and Wildlife Service, Don Edwards San Francisco Bay National Wildlife Refuge; 3 HT Harvey and Associates DETERMINING
THE EFFECTS OF HABITAT ENHANCEMENTS AND PREDATORS FOR WESTERN SNOWY PLOVER). California Gulls are new to some of these areas—could
the decline in the number of plovers at Crissy Field be related to an increase in the presence of California Gulls? This study
makes no attempt to ascertain if there is any such correlation.
The Zlatunich-Lynes study notes the number of plovers
has been steadily declining since 2005/2006 records. They choose to rely upon previous conclusions that the greatest disturbance
impact to wildlife within the Wildlife Protection Area at Crissy Field is caused by dogs, joggers and walkers. The data from
this study showed the number of dogs and humans in the plover area spiked in 2008/2009, and declined dramatically in 2009/2010.
The number of plovers continued to decline, despite the reduction in recreational disturbance in 2009/2010. This could lead
one to conclude that there is no correlation between the number of dogs and people and the number of plovers present. There
is no discussion of this possibility in the data analysis of this study.
The Zlatunich-Lynes study is without merit because it deliberately
misleads the reader about the GGNRA’s legal obligations to protect the plover. Ocean Beach and Crissy Field are not
designated as critical habitat by the USFWS. Therefore, the GGNRA is obligated only to prevent the harassment or taking of
the plover within its boundaries. Appendix B contains the legal definition of a disturbance which would constitute harassment
and be a violation of the law: “If the observer witnesses a blatant violation of the law, such as a dog owner knowingly
and without regard allowing his dog to harass wildlife, the observer shall make note on the comment sheet and shall, upon
completion of the survey, file a wildlife harassment report at the park police station…” There is no indication
in this study analysis that any observer EVER witnessed this type of harassment of a plover during their observations.
Alternatively, the Zlatunich-Lynes study records “disturbances”
which they define as minor, moderate and major—none of which rise to the level of the legal and accepted definition
of a disturbance that is utilized by USFWS and other studies. For example, the Zlatunich-Lynes study states:
“a minor disturbance will cause a resting bird to stand”. A clear thinking individual can conclude that
a minor “disturbance” as defined by this study is really no disturbance at all. Worse yet, when analyzing the
number of “disturbances” observed, there is no acknowledgement as to how many of these “disturbances”
are actually minor, moderate or major based upon these authors’ criteria. It is entirely possible (and I believe probable)
that each of the disturbances recorded and utilized to justify the restriction of recreation were merely minor “disturbances”.
This would be consistent with the conclusions of other studies including the following which states: “…snowy plovers
in other areas have become habituated to relatively constant and non-threatening human trail use.” (Trulio, Lynne1 ,
Caitlin Robinson-Nilsen2, Jana Sokale3 and Kevin Lafferty4 1 San Jose State University; Lynne.Trulio@sjsu.edu ; 2San Francisco
Bay Bird Observatory; 3 Sokale Environmental Planning; 4 Western Ecological Research Center, US Geological Survey NESTING
SNOWY PLOVER RESPONSE TO NEW TRAIL USE.)
In summary, the Zlatunich-Lynes study and its recommendations
are flawed, dishonest and biased. The DEIS advocates recreational restrictions based upon this study. Clearly, the failure
in this study to find any violation of the law with respect to the protection of the plover, and the omission of studies that
contradict the need for recreational restrictions should render this aspect of the DEIS invalid and discredit the conclusion
that recreational restrictions must be implemented to protect the plover in the GGNRA.