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Archive for the ‘Passerines’ Category

Last week, on my birthday, I went out to bird along the Clarksberg Branchline Trail in West Sacramento, Ca. I was out on the trail at 6:30 just before dawn and wandered around for about an hour. The section of the trail that I was birding is really close to my condo and as such is a spot that I bird pretty frequently. This morning was one of those mornings that reminded me of why it so special, and important, to get out to places close to where you live and see what is happening in the world.

It was a great morning of birding. I saw a Red-breasted Sapsucker searching for food high in a oak, found many Varied Thrushes foraging in the leaf litter for insects and worms, watched a pair of Red-shouldered Hawks as they flew screaming across an open field straight towards me to land in a tree right over my head, and found a White-throated Sparrow (an unusual winter visitor to the west coast and my favorite member of the genus Zonotrichia) hanging out with a group of Golden-crowned Sparrows! The birds were wonderful, and I was right around the corner from my house, and only there for an hour! You do not need to work hard for great birding.

These small, local birding explorations are not grand adventures. They are not exhilarating chases to see some incredibly rare species. They do not generally produce stupendously high species totals. But what they are is the bread and butter of birding experiences. They keep us in touch with the movements and pulses of the natural world right around where we live. Pulses that can go unnoticed all too easily in our modern busy lives. These local explorations give us the one-the-ground knowledge of what creatures are living next door, of how the environment changes from season to season and year to year, of exactly where a given bird can be found and what they like in a habitat. This is not knowledge that can be obtained easily, and it is knowledge that can be of great import. So get out to visit the local spots that are close to you and keep an eye on what is going on. you never know what you are going to find!

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The Tricolored Blackbird (Agelaius tricolor) is a bird both fascinating and beautiful. One of its unique characters is that it is found nowhere in the world except California and a small portion of Baja California. This alone makes it pretty special to anyone from California! The glossy, black male Tricolors can be identified by the thin slice of white just below the red on their shoulders. This distinguishes them from the similarly plumaged Red-winged Blackbird because the later has a slice of yellow below the red, or sometimes just red.

Tricolored Blackbirds form huge flocks of many tens of thousands of individuals. These are larger than any other bird species in North America today. They can get so big and so dense, that they blacken the sky. However, while these flocks are big, they only rank as the second largest flocks of North American birds ever. The Passenger Pigeon was another sky darkening bird which once formed even larger flocks. However, the Passenger Pigeon when extinct in 1914. There are actually several parallels to be drawn between the Passenger Pigeon and the Tricolored Blackbird. Some of these parallels may give rise to concerns about the long term survival of the Tricolored, but these parallels may also give us a chance to save the blackbird where we were unable to save the pigeon.

One of these parallels between the Tricolored Blackbird and the Passenger Pigeon is that they are both highly social and nest in huge colonies. Tricolored Blackbird nesting colonies sometimes get as large as 50,000 birds! This colonial breeding lifestyle is one the factors that is thought to have been the downfall of the Passenger Pigeon. Social cues can play very important roles in controlling when birds come into breeding condition. It may have been that Passenger Pigeons could only breed if they were surrounded by other Passenger Pigeons that were also breeding. As populations of Passenger Pigeon were decimated by market hunting, the colonies may have fallen below some critical threshold where even though there were many individuals left alive, there were not enough to trigger each other into breeding. This would have resulted in practically no young birds being hatched and the total collapse of what was the most numerous bird species in the western hemisphere. The fact that Tricolored Blackbirds also only breed in very large colonies suggests that they may also need the social cues of having many breeding neighbors in order to reproduce. This makes the Tricolored Blackbird at risk of the same fate as the Passenger Pigeon.

Another parallel between the two species, that goes hand in hand with large numbers required to breed, is that the breeding colonies occupy a fairly small area. All those birds pile in to relatively small patches of suitable freshwater marsh habitat in the central valley. These patches of habitat are more and more often agricultural lands such as rice fields and the feed fields for dairy cows. This high density in a small area is one of the reasons that Passenger Pigeons were so profitable to hunt. Market hunters could go to a colony and bring down tremendous numbers of birds in a very short time. While not hunted, small and concentrated breeding colonies is a problem for the Tricolored Blackbird because nestlings are usually not ready to fly when harvest time comes around. As many as 20,000 nests were destroyed when a single 10 acre rice field was harvested.

These characteristics have contributed to a dramatic decline in Tricolored Blackbird numbers over the last two decades including a particularly sharp drop in the last six years from an estimated population of 395,000 in 2008 to a population of 145,000 in the 2014 breeding season. This severe drop has led the U.S. Fish & Wildlife Service to grant this species temporary status as Endangered under the Endangered Species Act. This temporary listing, the first of its kind, means that the Tricolored Blackbird will be treated as a fully listed species but only for six months with the potential for a six month extension after that. This is to help protect the breeding colonies into and through the 2015 breeding season. If numbers respond well in 2015, it seems likely that this will provide impetus to list the species permanently.

Only time will tell if we have been able to learn the lessons taught by the Passenger Pigeon at so high a cost. The Tricolored Blackbirds surely hope that we have.

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On the morning of the 19th, I was out birding in the early morning along the Clarksberg Branchline Trail in West Sacramento. I was poking around the section of trail just north of Lake Washington Blvd. from about 6:20am to 7:30am. It was one of those morning where I decided to not worry about covering a lot of ground. Instead, I wanted to take my time, relax, and covered the ground thoroughly really investigating each bird I heard or saw and taking my time to enjoy it. I was rewarded by some lovely views and fun finds. My species list is at the end.

Right as I started my walk, I saw a long, slim animal run out from the edge of the blackberry tangle along the trail ahead of me. It stopped out in the open for a short moment and then continued on towards the large pond just east of the trail. To my surprise, I realized that it was a Mink! I have seen River Otters at this location before, but never a Mink. What was it doing here? As I scanned the pond, there were no birds swimming in the water except three domestic ducks that were probably dumped here to become feral. As I stood by the water’s edge, I head several birds in one of the willows that grow right on the bank. I walked that way, and found a Marsh Wren singing in the cattails and my first White-crowned Sparrow of the fall for West Sacramento! It was a really good looking  adult bird that was sitting in, and calling from, that willow. Soon the Central Valley will be covered in millions of White-crowned Sparrows back from their breeding grounds in Canada and Alaska to spend a comparatively warm winter in lovely California.

As the sun rose, beautifully tinged blood red by the smoke from the King Fire that is burning just east of Sacramento, I stumbled my way into a mixed insectivore flock. At this time of year, with migrants and vagrants wandering all over the country, mixed insectivore flocks are always worth spending some time with. Often, many birds will come together to forage, and this can attract individuals of species that you might not get to see otherwise. In this case, the bulk of the birds were Bushtits, maybe 25 of them, which were streaming from oak tree to oak tree giving their high pitched contact calls as they told each other where they were. As I watched these tinny birds, I started to notice the other species in the flock. A Western Scrub-Jay, a coupe of Northern Mockingbirds, and a lovely pair of Black-throated Gray Warblers which came low in some small trees and afforded me some great looks! The day ended with a total of 5 of these warblers which is a lot compared to what I am used to seeing in winter, which is just one or two.

After I left the mixed flock, I walked out into an open field that had been mowed and tilled. As I walked along the line of tree that marks the edge of this field I was treated to a fast triple-raptor encounter. First, a Swainson’s Hawk took off from one of the tree tops and doove down into the field. It pulled up before landing, apparently the prey animal it had seen got under cover in time to avoid becoming breakfast for the hawk, and returned to its perch. right after that a Red-tailed Hawk came barreling of the line of trees and cruised over the field and away. As I was watching the Red-tail, a Red-shouldered Hawk started calling behind me. It was circling at about tree top level and proclaiming dominion over this patch of ground. The Red-shouldered Hawk is a resident bird that I see almost every time I bird this area. The Swainson’s Hawk breeds nearby somewhere, but then leaves, with the rest of it’s species members, to head south in winter which is something that will be happening soon. The Red-tail could go either way in that it could be a resident or a migrant just here for the summer. How these different hawks interact and adjust to one another is a question that has long interested me. Take the Red-shoulder, for instance. It has a territory that it defends year-round. Suddenly, in mid-March this Swainson’s Hawk shows up trying to find a place to settle and nest. How does the Red-shoulder respond? Does it simply move out of the larger hawks way? Do the birds compete and adjust their territory boundaries to one another? Do these birds eat different enough foods that they don’t really care about each other? And then, how does the Red-tailed Hawk fit into all this? How resident birds adjust to the comings and goings of migrants is not something that has gotten a lot of attention and I think could make for a really cool research project.

Looking at the open field with the naked eye, I did not see anything out there, but just on a whim I decided to give it a scan with my binoculars. As I looked slowly across the field I saw no less than 15 Killdeer scattered about foraging. So much an empty field! It reminded me that a lot can be hiding and go unnoticed when only a cursory inspection is done.

This was a really nice morning birding. I saw some beautiful birds that got me thinking about interesting ideas and taught me a thing or two all at the same time.

Double-crested Cormorant (1)

Turkey Vulture (1)

Canada Goose (12)

Red-shouldered Hawk (1)

Red-tailed Hawk (1)

Swainson’s Hawk (1)

Killdeer (15)

Western Gull (3)

Rock Pigeon (70)

Mourning Dove (20)

Anna’s Hummingbird (3)

Belted Kingfisher (1)

Nuttall’s Woodpecker (4)

Black Phoebe (3)

Western Scrub-Jay (11)

American Crow (12)

Oak Titmouse (4)

Bushtit (25)

Bewick’s Wren (3)

Marsh Wren (1)

Blue-gray Gnatcatcher (1)

American Robin (5)

Northern Mockingbird (2)

European Starling (30)

Cedar Waxwing (8)

Orange-crowned Warbler (5)

Black-throated Gray Warbler (5)

Spotted Towhee (2)

California Towhee (1)

White-crowned Sparrow (1)

Red-winged Blackbird (30)

Mink (1)

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A few days ago, I found myself in Blackwood Canyon on the west coast of Lake Tahoe. It is a beautiful spot where Evening Grosbeaks have been reported regularly over the last couple of weeks. The day was lovely, and the birding was terrific with lots of classic mountain birds all around. Warbling Vireos and Hermit Warblers were foraging in the poplars that grow along side the stream that runs down the middle of the canyon. MacGillivray’s and Wilson’s Warblers were leading young birds around through the willows. Spotted Sandpipers were walking and bobbing their tails as they foraged along the rocky stream edges. Female Mallards lead broods of ducklings from pool to pool.

I did find a flock of Evening Grosbeaks, though they were not particularly cooperative in terms of my research plans. However, while I did not get the experimental trials I had hoped for accomplished, I did see something new and cool. I was stopped along the side of a road at around 9:30am beside a small group of spruce tree when I heard an Evening Grosbeak giving really loud flight calls. They were actually kind of spectacularly loud! As I watched, I saw the grosbeak, a male, flying from tree top to tree top and continuing to give these high amplitude calls. After standing below him recording for a few minutes, I figured out why he was behaving this way. There was an adult Red-tailed Hawk perched in the top of one of the spruce trees and the grosbeak was mobbing it. Now, Evening Grosbeaks are known to use their flight calls to coordinate the movement of a flock and they are also used by birds to locate other individuals over long distances. Further, they may possibly play a role in mate choice decisions and in population identification. However, to the best of my knowledge, this is the first time flight call have been observed being used in a predator harassment context! After a few more minutes, the Red-tailed Hawk flew off. The Evening Grosbeak, having succeeded in annoying the predator into leaving, quieted down and then departed on his own business.

This was yet another reminder that calls can have many different functions even when it is basically the same call, and even when that call is has a fairly simple structure. What subtle differences communicate different information to a receiver? Was the volume of these calls an important component of harassing a predator? Are there other differences (speed of delivery, frequency range, something else) between flight calls that are used in different contexts? I have this one recording, and so will certainly examine it to see if there is anything that jumps out at me, but with only the one occurrence, it will be hard to identify smaller differences, even though such small differences may be quite important to the birds involved. This also served as a reminder that exciting things can happen, but you have to spend time out with your study subjects to see them!

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This week I began my summer field season. I am planning weekly excursions up into, and throughout, the Sierra Nevada mountains to find Evening Grosbeaks, my study species. My first day in the field was a modest start. I left West Sacramento at 3:00am and drove up highway CA-49 to the San Francisco State Field Campus just outside of the tiny town of Bassetts, CA. When I arrived, at around 6:00, it was lightly misty and on the cold side. I walked around the field camp a little and heard the forest wake up. It was not long before I heard my first Evening Grosbeak of the day and setup my equipment. As the weather cleared, I got some work done testing how Evening Grosbeaks respond to recordings of various kinds, but there were not that many grosbeaks around. There were a bunch of other birds around that gave me some great looks, including several near collisions. At various points in the morning, I was nearly hit in the head by a Western Tanager, a Red-breasted Sapsucker, a White-headed Woodpecker, and a Mountain Chickadee! I also got to see an Osprey circling high overhead with its breakfast, a moderate sized fish, in its talons. But, since the grosbeaks were not especially cooperative I decided to try a new spot. I continued east on CA-49 to Yuba Pass where I was happy to find more grosbeaks along with a few Red Crossbills, lots of Cassin’s Finches, and several Chipping Sparrows, one of which landed on the side of the road not five feet from me and sang and sang. Delightful! After a while, and grosbeaks only showing up few and far between, I headed back down towards Bassetts where I saw Townsend’s Solitaire, which were a real treat for me, and a very lovely pair of Fox Sparrows. Then, after a brief stop in at the Sierra Skies RV Park in Sierra City, I was homeward bound. Odd as it sounds, the RV park in Sierra City was a great field site for me during my Master’s work. All in all, it was great to get out into the field and shake the dust off my methodology. I only got 5 actual trials, and since I am aiming for 10 each day, that was a bit lower than I would like. But there is a lot of summer ahead, so the work will get done. Next week I am planning on heading to the area around Quincy, CA and Bucks Lake to poke around, and hopefully fine more Evening Grosbeaks who will listen to my recordings and let me know what they think of them!

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While camping last week in the Sierra foothills, I got to witness a wonderful event; the first flight of a Common Raven. I have been fortunate enough to have seen many birds leave their nest for the first time and venture out in to the world. It always excites and inspires me. It is a view of the future, what will this new life include? It is a continuation of the past, linking each individual to their ancestors. It is a reminder that on this great web of evolving lineages, we are all connected to one another.

This particular first flight was, admittedly, not wildly successful. The ravens had built their nest in a large spruce tree that was just a dozen or so yards from where we were camped with a group of our friends. On Tuesday, the 17th of June, one of the young ravens decided that the time was right. It spread its wings and leaped out of the nest. It did not get far, as it glided right over our campground and crashed clumsily into a tree. it then attempted to flap its way higher up the tree, but only succeeded in knocking itself lower and lower until finally it fell out of the bottom branches of the tree and onto the ground about 4 feet from where my 1.5 year old daughter was playing with her friends! They all looked at each other for a moment. The kids looked at the raven with surprise and the raven look at the kids with the same expression. After a few seconds just staring at each other, the bird turned and hopped off through the trees. Rather soon, one of the adult ravens had found the wayward youngster and commenced yelling at the young bird until it found a tree with a lot of low branches and was able to scramble awkwardly up off the ground.

Over the next couple of hours, two more young ravens dropped out of the nest ending up scattered around that patch of forest. All seemed healthy and strong and began to explore their, suddenly expanded, world. The adults certainly had their work cut out for them as they tried to feed and keep track of the three young birds wandering through the trees, and the forest was loud with all of them calling back and forth to one another.

A pretty exciting and memorable event for all concerned!

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I just read an article, and then the paper it was based on, about songbird migration. It was published by a group from the Cornell Lab of Ornithology (including one person I used to work for). They used eBird records to examine where and when songbirds migrate and how these migratory movements correlate with weather patterns. What they found was that songbirds use different migratory routes in spring vs. fall,  moving in a roughly clockwise pattern. This makes the routes match wind patterns such that the birds take advantage of the strongest tailwinds in spring as they head north to their breeding grounds and face the weakest headwinds in fall as they move south to their non-breeding grounds.

I really like this study for several reasons. One is that much of our understanding of migratory movements in birds is based on waterfowl banding results. This is because there is a huge waterfowl data set due to hunters who report the bands on birds they shoot. This results in something like a 10% recovery rate for banded waterfowl (in comparison, songbirds banding has something like a 1%, or less, recovery rate for bands). However, any information that is gained by studying waterfowl movements may or may not be applicable to other birds. For example, most waterfowl are fairly strictly limited in the type of habitat they can use. Other birds are much more general, so the patterns may well be different. As our abilities to track bird movement have increased, our understanding of migration has also increased, and (as in so much of life) the picture is more complicated the more we learn. So this new analysis broadens our understanding of what migrating birds do. Waterfowl generally use one of four fairly narrow migratory corridors, called flyways, as they move north and south each year (the four flyways are the Pacific, Central, Mississippi, and Eastern). Songbirds, it turns out, use much wider swaths of the landscape which can be roughly divided into three flyways (Western, Central, and Eastern), and the areas used within each swath are different in spring (more to the west) than in fall (more to the east).

Another reason that I like this study so much is that is relies on citizen scientist. The records that the authors used were from eBird, which is an online database run by Cornell that anyone can add to. It is a way for birders to post their sightings and then see how those sightings fit into the larger picture of what birds are doing across the state, country, continent, or even hemisphere. By tapping into this vast knowledge base, the authors were able to examine where birds were being seen and when at a broader geographic scale, finer resolution, and including more species then ever would have been possible if the authors had tried to collect the data themselves. So, this study stands as yet another example of how important individual birders are to bird research and conservation. It is also another reminder of how much value there is in birders and ornithologists talking to each other!

So, a great study with interesting results and creatively using a citizen science data set. What could be better?

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It has been 14 years since the first printing of the first edition of David Allen Sibley’s Sibley Guide to Birds. It was a wonderful book and stood out, at least in my mind, as the best guide to come out since Roger Tory Peterson’s guides to eastern and western birds. Now Sibley has produced his second edition, my copy just arrived in the mail yesterday. And this new edition has a lot of changes from he old one.

The first thing that struck me were the colors. This new edition has generally bolder, darker, richer colors than the first edition. This change may serve to highlight plumage characteristics and draw attention to color contrasts, and so may make the guide more user friendly. However, there is always a danger when attempting to improve on reality and the result will be distorting reality. Overall, I really like the richer colors, but I do think that on some of the birds, such as the California Towhee, it may have gone a bit too far.

A second major change is that the families of birds now appear in a very different order. Traditionally, bird guides have been formatted so that they present the groups of birds in an order that follows the evolutionary history of birds. In most guides this has meant that the first groups are the Loons then the Grebes then the Albatross and Petrels. However, with ever more detailed and accurate DNA sequencing abilities, the evolutionary history of birds has been going through several rounds of shake-ups, and Sibley’s second edition reflects the more current understanding of how birds have evolved. Now, the first groups shown are the Ducks and Geese followed by the Gallinacious birds and then the Loons, and the altered order of bird families continues throughout the rest of the book. I really like that the order of bird families has been changed. It means that we all have a better understanding of evolution. I am sure that some people will be annoyed at the new ordering, and may feel a bit disoriented when having to re-learn where to find a particular group of birds, but our knowledge is always changing, and the resources we use should reflect those changes.

A third big change is the addition of 111 rare species. These are species that are generally found on other continents, and that have been recorded a very small number of times in North America. At first, I thought that this would simply clutter up the guide with a bunch of birds that basically no one sees, and that they would distract from the birds that people are generally looking for when they open their bird books. But, on further reflection, I have actually really like having all these new birds. It gives us all a better understanding of, and exposure to, what birds are out there. I think that if we as birders, all have a more global understanding of our favorite taxa, that can lead to nothing but good.

One very minor bone to pick is something that was pointed out to me by the late, great Rich Stallcup. He noticed that the Wrentit had a somewhat worried expression and that this was not really representative of the fierce Wrentit spirit. In the new edition, the Wrentit still looks worried.

So, overall, I really like the new Sibley Guide to Birds a great deal and am looking forward to my next opportunity to use it. If I find a White-crested Elaenia I will now be able to identify it!

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My mom recently asked me about the migratory habits of the Western Meadowlark (Sturnella neglecta).  I gave her what I knew off the top of my head, but realized that I did not know all that much detail on the subject, and so I went reading.  What surprised me most in what I found was just how little there was to find.  For being such a common species, there is a great deal that has not been recorded about their migratory biology.  For example, even the sizes of the flocks that Western Meadowlarks migrate in are not well documented.  This is a common situation for short and medium distance migrants, as much more focus has been on the study of long distance migrants.

Here is some of what is known.  After the breeding season, small loose flocks start to assemble.  This is usually in September and October depending on location.  These flocks can overwinter if conditions are mild, or they may migrate together if conditions are harsh.  In the northern and central portions of their range, Western Meadowlarks are diurnal migrants, and they can travel as far south as central Mexico.  While this can include individuals moving a distance of up to 1000 km (as indicated by a small number of band recoveries), most Western Meadowlarks seem to follow a pattern where the whole population moves a bit south as a loose unit, so the northern most breeding population will remain the northern most non-breeding population.  Birds that breed at higher elevations tend to be altitudinal migrants moving downslope during winter.  During migration and the non-breeding season, they generally seek out suitable habitat in sheltered valleys during periods of harsh weather.  Western Meadowlarks are actually non-migratory in much of the southern portions of their geographic range, a belt that stretches from Kansas to California.  Even less in known about the spring migration of this species, but migrants generally return to breeding grounds in March and April.

So, keep your eyes out for Western Meadowlark flocks.  You never know what you may learn!

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On Saturday, I spent about an hour-and-a-half with my three-month-old daughter wandering around a giant shopping center in Roseville, CA.  My wife was spending some time with some friends, and so my daughter and I took the opportunity to have a look around.  As we walked between huge box stores and along expansive parking lots I was impressed, as I often am, at how much animal life was finding a way to live in and amongst all the human impacts that exist in very urban areas.  House Finches were in the bushes all over the place and White-throated Swifts and Lesser Goldfinches were frequently flying and calling over head.

During our rambling, my daughter and I made two particularly exciting discoveries.  The first was finding a bee hive!  The swarm had built their hive in the nooks and crannies of a potion of a wall that have been made to look like pile rocks.  The bees were industriously visiting the wisteria vines, blooming not far away, and also coming in from much greater distances as they foraged for food for the colony.  I was pretty thrilled to find this hive, but was careful not to make too much a big deal about it when people were passing by because I was worried that someone would freak out and that the property managers would find out and spray the colony.  This was weird for me because I usually like to share sightings like this with anyone who is willing to listen, but here I figured that the best thing for the bees would be secrecy.  The second exciting discovery was a Bushtits nest!  The pendulum nest of lichens and spiders web was hanging in a small ornamental tree only about 6 feet above the ground.  The tree was in a little ally way between two humongous stores.  The two adults were very busy searching through the landscaped plant and bringing caterpillars and other insects they found back to the nest to feed their chicks.

Even though this was not a bird walk through some wild place it yielded some wonderful nature experiences, and was a wonderful way to spend some time.  It served as a terrific reminder that there is wildlife to be seen everywhere, and I look forward to continuing to share similar experiences with my daughter.

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