historic trestle flume

Wondering if the trestle form of historic elevated flumes might provide some additional sculptural interest…

'flume' refinements

Focusing in on the primary site at 74^th and Cedar, trying to figure out what is the best way to configure ‘flume’. 

Is it a simple rolled pipe-like form that opens to the sky or something that’s conical with some more sculptural intrigue?  Should it frame an entire landscape scheme or simply be placed as a sculptural object within a field of green?  Should it function as a walkway or a stage?  Is interactivity desirable or should it be more of a standalone object to be contemplated from a distance?  Should the piece be illuminated at night or have some luminous feature?  How detailed should we make the flora/fauna fenestration along the top of the piece?  How readable would this fenestration be against existing foliage?  Should the piece be painted or left as rusting relic?  More visibility issues…also questions and concerns about maintenance and vandalism.  What is the ground plane interface?  Should it be buried in earth, placed on a footing or supported by stones? 

These are a few of the issues I’m thinking about as I try to refine the approach…

bluebird boxes

This is a proposed prototype for bluebird boxes to be sited in Oak Tree Park and along Water Flume Line Trail.  Anticipate making them out of steel pipe (and a removable ABS inner sleeve insulator).  Could be powder-coated blue to tie into other park elements.

additional information on bluebird boxes

As far as box construction and structure goes, there are a number of aspects to keep in mind for any bluebird box. These are listed on the Cornell website (http://nestwatch.org/learn/all-about-birdhouses/features-of-a-good-birdhouse/), and include no perch, ventilation available, correct hole size for western bluebirds (1 9/16"), ample depth to reduce predation, a door for cleaning out the inside of the structure (not located on the underside of the structure), a roof that will shed rain and reduce rain from getting into the hole, and a design on the inside of the box to allow young to leave the box. On this last point, as the young are just learning to maneuver and fly, there should be interior grooves to allow young to grip onto the inside of the box enough to be able to exit. As we use wooden boxes on base for our bluebirds, we use the rough side of the wood board for the inside of the door leading to the hole, which allows enough grip for the young to leave. We have seen designs where very small sections of mesh-hardware were attached to the inside of the door leading to the hole, however, in one instance an adult bluebird died after her tongue (which is forked in the back of the mouth) somehow got caught on the wire. This was a freak accident, but still something to consider, as some birds tend to get their tongues stuck (especially woodpeckers).

For box materials, I have not heard of anyone making boxes out of metal, nor do I know about success rate correlated with specific materials. I would note, though, that metal boxes pose a number of concerns, including insulation and rust potential. We have seen PVC pipe designs, and those seem to work fine. As for coloring the boxes, I don't necessarily think that this would deter birds from nesting in them, as long as the paint is free of any toxins. One concern I would have with having a very colorful box is the increased potential for them to be disturbed by people - this could always be remedied by having the boxes high enough on trees, but that makes checking the boxes or cleaning them at the end of the season more challenging.

For the grouping of boxes, bluebirds are not colony nesting birds (like purple martins, where you would have at least 24 boxes within one colony site). We tend to have about a 100-200 meter distance between each bluebird box, as this significantly reduces competition between individuals. If you are going to have boxes near each other, I would suggest only two within a 100 meter space, minimum of 10-15 feet apart. You may get bluebirds nesting in one of these and swallows nesting in the other. If they are too close, the birds will spend more time defending their territory than is necessary. It looks like you would be able to fit about 6 boxes maximum within the space you're working in.

A bluebird box can be placed on an oak tree trunk or on a pole that is cemented into the ground. For orientation of the boxes, we have seen success in boxes that are oriented any direction; however, we tend to place ours in a Southeasterly direction, as they get more insolation from the sun facing south and are not facing directly into our wet, Westerly winds we often get in the area.

As Jerry mentioned, depending on the structure and which species are drawn to the habitat, you may get other birds nesting in your boxes. For your initially suggested design, those longer structures are typically used for purple martins, though swallows will nest in them too. The hole you would want to use to attract bluebirds would be too small (typically) for purple martins to nest in them. Thus, height is a big consideration here, as more birds will be able to nest in a deeper box.

Christa LeGrande-Rolls, Biologist, DPW/ED

Audubon Society meeting 12.12.16

Immediately following committee review was a meeting with South Tacoma Neighborhood Councilmember Beverly Bowen-Bennett, Tacoma Parks representative Mary Anderson and Executive Director Emily Kalnicky and Jerry Broadus of Tahoma Audobon Society.  This was an opportunity to receive technical background on bluebirds and explore the feasibility of pursuing the bluebird box project.

A potential environmental education tie-in with Arlington Elementary partnering with Audobon was floated…along with mention of a docent program with Parks.  Possible projects included habitat study, youth bird drawing, bird/nature hikes, birdbox design and an ongoing docent/stewardship program.  There was also the possibility of surveillance cameras in the boxes so students could observe bird behavior.

Jerry provided a font of information about bluebirds and their habits and habitat.  Apparently they prefer the open meadows and prairie that typically surround groves of Garry Oak.  They are insect-eaters that pounce and require a steady supply of easily-seen prey.  To bring a bluebird population to a new area requires creating a habitat corridor that provides a migration path.  Bird banders ‘seeded’ a new population on South Vancouver Island that’s been highly successful.

Setting up a bluebird box program involves a number of parameters being met.  The first is the aforestated open meadow or prairie conditions.  The birds really prefer an open area where they can look down and hunt insects below while being able to see any predators (like raccoons) in their immediate surroundings.  They really dislike dense foliage typical of evergreen stands and thick groundcover for these reasons. 

The boxes that they live in should be 4-8 ft off the ground (a box on a pole or fence post typically works).  Wood, plastic or metal will work as a material, though metal would require some insulation from cold.  Entry hole size, location of hole,  size of box and orientation of box in relation to the sun are all critical.  Boxes should not crowd each other, allowing the birds to have their own area without significant competition for food from other birds.  Tree swallows, sparrows, chicadees, starlings and grey squirrels often compete for bird boxes.

While it can be a challenge to get bluebirds to nest in a new area, there are several successful programs in the area.  There’s 35 boxes at Nisqually Refuge, another program in Cle Elum and a very successful bluebird box program at Eagles Pride Golf Course near Joint Base Lewis McChord.  We make a plan to meet in January with Christa Legrande who manages that program.

contemplation of committee feedback & a conceptual direction

So I’ve given the feedback provided by the committee on December 12^th considerable thought and am starting to shape a conceptual refinement of what was offered.   I need to winnow the number of elements from 7 down to a maximum of 3-4.  And make sure those elements cohere as an esthetic statement.

What I heard from all the comments was mixed.  Before I left the room for committee deliberations was some real enthusiasm for the stonework (boulders, bike racks and benches).  Also considerable enthusiasm for blue tree and bird boxes.  Several comments about ‘flume’ as an iconic landmark that could draw folks to the park. 

After deliberations, it seemed like there was some sort of consensus around ‘flume’ and interest in the bird boxes (if they were funded/handled as a separate project/budget).  Also enthusiasm for blue tree (with paint concerns noted).  Enthusiasm for boulder, bike rack and benches had cooled and the representative from Tacoma Water tossed cold water on the pump house murals. 

So it seems a direction has been determined.  Focus on developing an iconic ‘flume’ piece and do further research on blue tree and bird boxes.  This seems like a clear conceptual direction for the project, particularly if we can develop a sense of visual connection and ‘flow’ between the iconic ‘flume’ and the multiple bird boxes.  Nice conceptual link between the depiction of flora/fauna and a mirror flora/fauna rehab project (plants & birds).

Onward...