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At the heart of the Fort Funston fight is protection of the bank swallows. Although there are pro-dog and anti-dog advocates,
EVERYONE is in favor of protecting the Bank Swallows. Green Friends believe in science-based decisions. What does the scientific
data indicate?
Test your knowledge by answering "true, false, or don't know" to the following questions
1) Bank swallows (Riparia riparia) are threatened with extinction.
FALSE. In spite of what some GGNRA sign states, bank swallows are not an endangered species, nor are they likely to become
extinct if the Fort Funston population continues its decline. Bank Swallows are a threatened species only in California. They
are considered common in the North America range, and they are also common world-wide, including Europe, where they are called
"sand martins."
2) Bank swallows commonly nest on coastal cliffs.
FALSE: Dwelling on coastal cliffs is rare. That is why there are only two coastal colonies in California. The scientific
name, Riparia riparia, refers to riparian ecosystems, that is, to rivers. In California, 75% of the population is confined
to the Sacramento and Feathers rivers. The remainder is found in the counties such as Yolo, Shasta, Lassen, Modoc, Siskiyou,
and Mono. There are only two coastal colonies, in San Francisco and San Mateo.
3) Native plants are necessary for the Bank Swallows.
FALSE: Native plants are not a criteria for the colony location, nor necessary for food. In facts, the Fort Funston
Bank Swallow population declined after the existing ecosystem was disrupted and native plants were substituted. In general,
bank swallow nests, because of their placement on verticals faces of banks and bluffs, are generally devoid of vegetation
around othe burrow. Vegetation on the top of the cliff can range from grassland, coastal scrub communities, coniferous forests,
under irrigated pastures, riparian forests, and desert shrub habitats.
Almost 100% of the bank swallow diet is comprised of insects. However, bank swallows are not picky eaters requiring "native
plant insects." They have diverse dietary habits, and will forage in any area that has large amounts of any insect biomass.
Fort Funston bank swallows' favorite cafe is at Lake Merced.
4) Recreational users at Fort Funston are a threat to bank swallows.
FALSE: Bank Swallows appear relatively insensitive to moderate levels of human-induced disturbances. The bank swallows
are cool if you're not climbing on the cliff face, or hovering directly above the burrows. There is no evidence that recreational
users otherwise disturb the behavior of the swallows or the swallow burrows.
Successful bank swallow colonies occur on bank under farmland, near recreational boat traffic, car and pedestrian traffic,
hydoelectric generators, livestock grazing, etc. California Department of Fish and Games states that land uses don't seem
to matter as long as the integrity of the nesting bank remains.
The Fort Funston colony, first recorded in 1905, has existed for decades first in a military installment,and then in an
urban park. To reach their feeding grounds, Lake Merced, the swallows fly over a state highway and noisy gun range.
What is a threat to the bank swallows in California? According for California Fish & Game, the major threat is in
central California, flooding and erosion disturbances during the breeding season. For the coastal colony, the GGNRA biologist
identified predatory birds, such as kestrels, and graffitti vandalism as the major threats to the Fort Funston colony. There
was NO evidence that dogs presented a threat.
In addition, At Fort Funston, the major cause of erosion is ocean and storm activity. The numerous landslides are evident.
However, unless a landslide happens during breeding season, it isn't necessarily detrimental, since bank swallows will build
new burrows if the old ones are gone.
| Raven hunting in the upper colony. |
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| Ravens prey on young swallows perched at the mouths of the burrows. |
| Graffiti vandalism |
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| A GGNRA study identified graffiti vandalism as a threat to the bank swallows. |
| Graffiti on the lookout below bank swallow colony |
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| The sign says "Please Stay Back," but this doesn't prevent vandals from climbing and spraypainting. |
| Erosion south of the colony |
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| Waves from winter storms and high tides are the major cause of erosion at Ocean Beach. |
5) The GGNRA was established to provide recreational open space, i.e. the "R" in GGNRA stands
for "recreation."
TRUE. In the 1950's a congressional commission, the Outdoor Recreation esources Review Comission reported that outdoor
opportunities were urgently needed near cities. The most popular outdoor activities were walking, hiking and picnics. The
committee recommended the establishment of national recreation areas located in or near urban areas, designated primarily
for outdoor recreation use rather than natural or historical preservation. This led to the establishment of parks
such as the Golden Gate National Recreation Area.
Urban park or wilderness, an important goal at all national parks is the conservation of natural resources. With good
park management, recreational use and conservation are compatible.
Current park management has concentrated all off-leash dog recreation into limited areas. During the 1990's, most SF GGNRA
off-leash areas were closed. This was correlated with a huge increase in visits to Fort Funston. In addition, 20% of
FortFunston is now closed. Rather than protecting natural resources, NPS policies may contribute to degradation
of natural resources by exceeding the carrying capacity of Fort Funston. Furthermore, lack of recreation space in urban parks
may lead city dwellers to drive to outlying, sensitive habitat for recreation, or to move from the city and contribute
to urban sprawl (a major threat to biodiversity).
| Loss of recreational space |
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| Red=closed area. Green=beach access pathway. Orange=closed area. |
| Dogs (little criminals) playing at Fort Funston |
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| For over 40 years, dogs and wildlife have peacefully co-existed at Fort Funston. |
FortFunstonDOG: Rebuttal to 12-Acre Closure. Includes excellent analysis of Bank Swallow threats by L. Cavaluzzo
California Department of Fish and Game: Bank Swallows
US Distribution of bank swallow (sand martin) population.
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