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The idea of a wetland that can move from place to place is an odd one, but in many ways it is not a new one. Basically, a walking wetland is when someone floods a piece of land and lets a wetland grow there for a while. Then, after some pre-determined amount of time has passed, that piece of land is drained and a different piece of land is flooded. A wetland is then allowed to grown on the new piece and, viola, the wetland has walked!

This technique is a lot like crop rotation schemes that have been around for just about as long as agriculture. Letting land lay fallow lets that land recharge some of its nutrients and so be more fertile the next time a crop is grown on it. Walking wetlands are just another type of rotations, but this rotation is to cover the land with shallow water. Not much water is needed to make this work. Generally, about 4 inches is the average depth! Letting the land be flooded in those 4 inches for from 1 to 4 years lets amazing things happen!

Walking Wetland 01

First year walking wetland in the Klamath Basin.

For one, a lovely wetland springs up quite quickly. In the first year, the area is generally covered in grasses and other fairly short plants that only raise above the water a relatively short distance and that grow in a fairly open pattern with lots of space for shorebirds to walk around and forage. In the second year, tules and cattails grow up. This form tall and dense stands. The small open patches are preferred by a wide range of duck species though the shorebirds don’t tend to like this habitat as much. In subsequent years, some habitat modification, such as mowing, is generally needed to keep the tules and cattails at a level that still allows for birds and other wildlife species to access the wetland. Otherwise the stands of tules and cattails grow so dense that only a few species will utilize them.

Another amazing thing is that some crop pathogens that live in the soil drown. Many pathogenic microbes cannot survive a year or two of being submerged. Impressively, many beneficial soil microbes actually can survive this long underwater, so when the land is drained, the good microbes are still present and many of the bad ones are gone! This has an economic benefit because growers then need to buy less pesticides. This has an environmental benefit because grower need to apply less pesticides.

A third amazing thing is that all the birds that come and use the wetland leave their waste behind! Bird guano is fantastic fertilizer, and having a few thousand ducks, geese, and shorebirds wandering around can result in the grower needing to buy and apply less fertilizer and also lead to a boost in crop production!

Walking Wetland 02

An older walking wetland in the Klamath Basin.

Along the Pacific Flyway, walking wetlands have been really pioneered in the Klamath National Wildlife Refuge along the California-Oregon boarder, which is home to the first officially titled Walking Wetlands Program. It has since also been adopted in the Skagit Valley in northern Washington state. Additionally, several groups in central California, including the Sacramento-San Joaquin Delta Conservancy where I work, are looking at using walking wetlands in the California Delta.

For better or for worse, setting aside habitat exclusively for wildlife use is not going to be able to secure enough land to protect that majority of species. Instead, finding ways for agriculture and wildlife to both succeed is the only way that longer-term conservation is going to be successful, and walking wetlands are a terrific example of what that can look like.

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I was walking along the edge of a plowed field along the Clarksberg Branchline Trail in West Sacramento a couple of days ago when I saw a hatch year Northern Harrier quartering back and forth, low over the ploughed earth. The raptor was not very far from the edge where I stood, so I was able to get a really great view as I watched it coursing along and staring at the ground intently as it hunted for its breakfast. Suddenly, it made a sharp turn, almost flipping over itself, and dove for the ground. It landed on something and after a moment standing on the ground, it took off. As it did so, I saw a small, brown object in its talons. I assumed at first that it was a small mammal, and that the Harrier had made a successful hunt, but when the bird was about 20 feet off the ground, it dropped the brown object. As the thing dropped back to the earth, I was able to see that it was not an animal at all, but was actually a clod of dirt.

What had happened here? Did the Harrier make a mistake and attack a mouse-shaped bit of dirt thinking that it was, in fact, the makings of a meal? Given how amazingly keen the eyesight that raptors possess this seems unlikely. And it seems especially unlikely given that the bird was only about 20 or 30 feet off the ground when it started the dive. Making that big a mistake at that close a range is hard to believe. So what was the hawk doing? Was it practicing? This was a young Harrier. Perhaps, not seeing any actual voles or mice at that moment, it decided to do a little target practice. I don’t think of raptors needing practice, but of course that is probably kind of silly. Young songbirds need to practice their song, and often sound amusingly bad at first. However, of the course of a few weeks, they practice and hone their vocal abilities and end up producing songs that sound like the other adults of the species. So, raptors practicing their hunting skills seems pretty understandable. The amount of skill required to be a predator is rather impressive, and even when you consider that many of these skills are hard-wired instinct, that still leaves a lot of room for learning and improvement: practice. Here was a raptor that, perhaps, just picked a particular earth clod on the ground and wanted to see if it could hit it at high speed, just to see if it could. It did, so that practice run was successful! Practice does make perfect!

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This past weekend a friend, my wife, our 7 week old daughter, and I went birding in the Sacramento Bypass Wildlife Area.  It was a beautiful day with bright sunshine and just a little coolness in the air.  The Cattails (Typha spp.) in the central portion of the bypass were letting go of their fluffy seeds and the Mugwort (Artemisia spp.) were just starting to send up their spring growth, resprouting from their roots.  As we walked along the northern channel among the willows and oaks and cottonwoods I heard a flock of Bushtits.  Wanting get a look at them, and not wanting to miss any other birds foraging with them, I found the little flock of about 6 birds and started to sift my way through the group.  But, I stopped in my tracks when I got the first bird in my binoculars.  It was a small bird with a bright yellow belly.  At first my mind jumped to male Lesser Goldfinch, but it just as quickly rejected that option.  The bird I was looking at had a long tail and no dark patch on the forehead.  It looked like a Bushtit, but it was really, really yellow!  Is it a Yellow Warbler?  No.  Is it an Oragne-crowned Warbler?  No.  American Goldfinch?  No.  And then I see another one, and another, and another.  They are acting like Bushtits.  They sound like Bushtits.  But the whole flock is comprised of birds that are bright yellow!  Finally, I realize what is going on.  They are indeed Bushtits and they are foraging in a willow tree that is in full bloom.  Every time one of the birds jumps to a new twig to search for insects it is dowsed by the bright yellow pollen from the willow.  Since Bushtits are very active foragers and often hang upside down to find the insects they eat, even the bellies of these birds were coated in pollen.  They looked amazing!  Bright yellow Bushtits!  The flock finished searching through the willow tree and moved on to a nearby oak where they stood out even more.  Just goes to show you that when you see something odd, there is often a perfectly sensible explanation, just not one that anyone would guess.

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One facet of my research on the Evening Grosbeak (Coccothraustes vespertinus) that I am hoping to put together is a much better survey of where the different flight call types occur, what they are doing, and what they are eating.  To give a bit of background, five different variants of Evening Grosbeak flight call have been observed.  These different variants have been labeled Type 1 through Type 5, and while the differences are subtle to the human ear, they are distinct enough that with practice they can be identified in the field.  They are also different enough that the grosbeaks themselves can almost certainly tell them apart as well, and so may play an important role in group membership identification.

The geographic ranges of birds that make these different flight call types has been generally worked out.  Type 1 is found mostly in the Pacific northwest and central Rocky Mountains, Type 2 is mostly found in the Sierra Nevada and southern Cascade Mountains of California and Oregon, Type 3 is mostly found around Great Lakes and in New England and southeast Canada, Type 4 is mostly found in the southern Rocky Mountains of Colorado and New Mexico, and Type 5 is mostly found in the mountains of central Mexico and southern Arizona.  I say mostly a lot in that description because there is a lot that we don’t know.  It is known that there is a fair bit of overlap in where the different flight call types have been observed.  In the Sierra, while most of the birds give Type 2 flight calls there are birds that give Type 1 flight call as well.  In Wyoming, where Type 1 would be expected, Type 1 birds are the most commonly observed, but Type 4 birds occur there in smaller numbers as well.  There are also parts of the continent where it is not well understood what type might be the most common.  The area in central Canada that is between Type 1 and Type 3 is filled with question marks.  Nevada and Utah are between the Type 1, Type 2 and Type 4 regions.  This area does not have a lot of Evening Grosbeak habitat, but it seems likely that these birds do occur on high mountain ridges.  They may or may not breed there, but even knowing what birds pass through the area would be interesting.  Another huge area of unknowns surrounds Type 5.  Very little research has been done on where these birds occur, exactly.  Even the portion of the range that is in the USA in Arizona and possibly New Mexico is not well established.

An even less understood aspect of Evening Grosbeak life is that of diet.  Most bird books give the very general “eats seeds and insects” with little or no explanation of what seeds and what insects.  Do birds that make different flight call types eat different foods in their respective different ranges?  No one knows.  When individuals that produce different flight call types find themselves in the same place, do they then retain any differences in diet, or do they all simply eat whatever is around?  Again, no one knows.

So here is my call for aid.  I want to collect information on the calls and diet of Evening Grosbeaks across North America.  This will take a very long time if I do it all myself, but I am hoping that you might be willing to help.  If you are willing to help there are two ways you can.  One is if you see Evening Grosbeaks any where, take a moment to observe what they are eating.  What I am looking for is information on what these birds are eating in the wild, so bird seed out of a feeder may not give the most interesting information, although you never know.  The second way to contribute is if you hear an Evening Grosbeak vocalizing.  If you do, and have any recording device (this does not have to be fancy, I have gotten useful recordings off the recorders in digital cameras), then make a recording.  These recordings will be best if they have the vocalizations of only one bird calling for as long as possible, but any recording will be useful and this includes birds at feeders.  After you have made an observation or recording make a note of the date, time of day, location (be as exact as possible.  GPS locations would be great), and any notes on behavior or habitat that seems interesting to you.  Then send them along to me at anhaiman@ucdavis.edu

This is going to be a long and slow accumulation of knowledge which is why I am starting now.  I will be collecting this information for years.  As you find birds and can pass the information along to me, don’t worry about being too late.  Thanks in advance!

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A bit after moving into our new place I cleared out the dead plants from the back yard and, on the 5th of September, I set up our bird feeders.  I was very eager to see what birds found the feeders and of what species they might be.  I waited and waited, watching the feeders every morning, but no birds found them.  Brewer’s Blackbirds, Red-winged Blackbirds, Western Scrub Jay, American Crows, and House Finches (all of which visit seed bird feeders at least occasionally) fly over our yard daily, yet none explored our yard.  I was quite surprised when a week passed without a single visitor.  I had fully expected the birds to search over their habitat regularly and thoroughly enough to find a new food source much faster than this.  To make our yard more attractive to passing birds I placed a few handfuls of seeds on top of garden wall that is near the spot where the feeders are hanging.  A couple more days passed without incident.  Then, two days ago, I say a Western Scrub Jay on our roof looking at the seeds on the wall.  It considered them briefly before flying off without coming down.  Yesterday, I saw what I am guessing to be the same bird on our roof again.  It flew back and forth from of the roof of the house to the roof of the garage a few times looking at the seeds from every angle, but again it flew away without coming down.  This morning, I again saw a Western Scrub Jay on the roof of the garage.  It perched there for a few minutes, and then made the decision to drop down onto the top of the wall where the black oil sunflower seeds lay scattered.  One by one, it quickly picked out about a half dozen in its bill and then departed to eat them elsewhere!  Our first avian visitor!  I wonder what will happen next!

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I went out to the Fremont Weir National Wildlife Refuge this morning and spent a lovely few hours before the heat of the day began to sink in.  Saw lots of great birds including, but not limited to, Western Kingbirds that are still paired up even though most have finished breeding, Blue Grosbeaks singing all over the place, a hatch-year Red-shouldered Hawk that flew right in front of me, and an adult Red-tailed Hawk being harassed by a Red-winged Blackbird.  Among all these bird sightings I did have one really notable mammal sighting.  I was poking around through the underbrush near the edge of a small water way that runs through the refuge and came across a number of small trees that displayed the clear tooth marks of having been chewed through by a Beaver.  A few steps farther, and I saw the Beaver itself standing on the far bank at the waters’ edge.  It was eating some greenery, and when it was finished it walked up the bank, picked another plant, brought it down to the water and swam in pulling the plant in with it.  It only swam for a few seconds before it turned around, came back to shore, and began munching on the, now wet, plant.  I have no idea why it did this rinsing behavior, but it was interesting to see!  After it finished its’ breakfast, the Beaver returned to the water and swam off down the channel.  It really was a very nice morning indeed.

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