The One-Legged Warbler

I spent this past weekend camping with family and friends. We camped at a spot that I have not been before called Upper Blue Lake in Alpine County, California. This site is about 45 min south of Lake Tahoe, at around 8,200 ft in elevation, and just off the Pacific Crest Trail. It is a pretty spot set in pine and fir trees, and we had a really nice and relaxing time.

The birds around the campground were pretty entertaining. We had Brown Creepers, Red-tailed Hawks, Williamson’s Sapsuckers, Audubon’s Warblers, Mountain Chickadees, Steller’s Jays, and a Cooper’s Hawk in the trees surrounding out campsite.

But one bird was particularly memorable. As several of our group were watching a Williamson’s Sapsucker, when I heard a warbler chip in the trees above me. I found the warbler and saw an adult male Wilson’s Warblers flitting in the branches. As I and a few others watched, I noticed that the bird seemed significantly more clumsy than most. It was very active hoping from twig to twig looking for, and catching insects. Each time it landed, however, it would wobble around, loose it balance, and need to flap its wings a bit to regain its perch. I was starting to really wonder about this odd behavior when something caught my eye. As this warbler was just landing on a twig, and attempting to hold its position, I saw that one leg was gripping the twig. There was only a stump where the other leg should have been!

The one-legged Wilson’s Warbler (photo courtesy of Erin Hess).

From what I could see, it looked like the leg ended cleanly at the distal end of the tibiotarsus, or where the “ankle” joint would have been. Most of the time the tibiotarsus was held up in the feathers, tucked out of sight. It was only visible when the bird lost its balance a bit and instinctively reached out with the incomplete leg. A friend of mine was able to snap a few pictures, and in them you can see the bird standing on a branch and only one foot gripping the bark.

Clear view of the one-legged Wilson’s Warbler standing on one leg (photo courtesy of Erin Hess)

I have no idea if this was an injury (seems more likely) or a birth defect (seems much less likely especially for an adult bird). Regardless of how it happened, the bird seemed to be doing ok. It was very active, the feathers looked to be in good condition, and it was vocalizing normally as well.

This was an impressive example of how resilient birds are. I have seen numerous wild birds that have injuries that were severe enough to cripple a mammal, but the birds have healed and are still able to function at a survivable level. For how fragile they seem, birds a tough!

 

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Point Blue 2018 Bird-a-thon!

Dear Sponsor (I hope!),

About twenty years ago, the Point Reyes Bird Observatory (PRBO) founded a new bird-a-thon team named the Drake’s Beach Sanderlings. The Sanderlings was particularly noteworthy because it was the first youth Bird-a-thon team that PRBO had ever organized. It was an exciting event! I remember, because I was one of the first youth members of the Sanderlings.

In the years since, the Sanderlings (myself included) have continued a very successful tradition of taking to the field every fall to crisscross Marin County, finding as many bird species as possible in twenty-four hours, and raising money for bird research and conservation. This makes the Sanderlings the longest running youth bird-a-thon team I am aware of! It is certainly the longest running such team in California. The team has included a shifting variety of members as our youths have gotten older, moved away, and/or gone to college. Wherever they have spread to, they have carried with them a passion for birds and nature that was, in part, nurtured by the Sanderlings.

The team’s namesake, a Sanderling

Until his death, the Sanderlings were led by the legendary Rich Stallcup along with former PRBO board member Ellen Blustein. After Rich passed away, I was invited to co-lead the team with Ellen, and I have been honored to do so every year since. This year Ellen has decided to step down as a team leader which marks the latest change in the history of the team. PRBO has changed as well, including a name change to Point Blue Conservation Science.

In this modern age, youth participation in conservation, both globally and locally, has never been more important. However, there is growing concern that birds will not be able to compete with digital sources for the attention of what could be the next generation of conservation leaders. Teams like the Sanderlings help to engage youths with birds and the natural world.

To support and continue to encourage youth engagement in the natural world, I would like to invite you to become a sponsor of the Sanderlings. Your support sends a powerful message that a team like the Sanderlings should continue to be taken seriously and continue to grow. This year, the Sanderlings bird-a-thon will be on September 29^th, and if you do choose to become a sponsor, I will be sure to let you know how the day goes.

To become a sponsor, go to: http://pointblue.blueskysweet.com/teampage.asp?fundid=800#.W3xRM-hKi70 and click the DONATE NOW button. I hope you think we are worthy of your support. Please feel free to contact me with any questions you might have.

Sincerely,

Aaron

Drake’s Beach Sanderlings Team Leader

510-289-7239

agincourt82@hotmail.com

 

 

 

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Bats Under the Bypass

If you are in the Davis or West Sacramento area in the late summer or early fall, and have an evening to spare, go and find a spot where you can sit beside the Yolo Bypass Causeway. This is where highway I-80 crosses over the Yolo Bypass.

Streams of Mexican Free-tailed Bats over the Yolo Bypass

Just as the sun begins to set, you will see an amazing sight. Columns of bat will flood out from under the bypass and stream across the sky in sinuous ribbons. About a quarter of a million Mexican Free-tailed Bats (Tadarida brasiliensis) live under the bypass this time of year, and every night they pour out and spread across the surrounding area to find small flying insects to eat.

These bats are incredible! They can fly about about 100 miles per hour, making them among the fastest mammals in the world! Remember that Cheetahs are the fastest land-mammal, but bats have them beat by a healthy margin. These bats can fly as high as a mile above the ground, and can forage out distances of several miles from their night roost before returning around dawn to sleep. Using their sonar they can detect and pinpoint the exact position of little insects flying through the air and then capture those insects on the wing, at speed!

My wife, daughter, and I joined some friends and went out for an evening visit to see the bats about a month ago. I was a spectacular evening in the Yolo Bypass Wildlife Area. We saw lots of Swainson’s Hawks; herons, egrets, and ibis galore; some of the biggest Western Saddlebags (which is a species of dragonfly) I have ever seen; and then we got to the causeway.

When we arrived, the sun was still a touch above the horizon, so we had some time to stand around the dirt road that runs parallel to I-80 and chat and watch the sunset. We got a very nice surprise when an adult Peregrine Falcon flew past and landed in the top of a tree a little ways to the west of us. I was so excited to see this bird that, in turning around for a better look, I clumsily stepped on my wife toes (sorry sweetheart)!

Mexican Free-tailed Bats as they leave from under the Yolo Causeway.

As the light began to fade, we started seeing little movements under the causeway. The first bats were starting to move. Interestingly, the bats do not wake up, take flight, and simply fly out from under the causeway wherever they happen to be. Instead, they wake up, take flight, and then fly directly under the causeway for a few hundred yards before turning a sharp left, and lifting up into the open sky. I have no idea why they decide to do this, but volunteers at the Wildlife Area know it is gong to happen so consistently, that they can tell you exactly which tree the bats will fly out near.

The numbers of bats moving under the causeway built and built until there were bats streaming along between the support pillars. Then they made that left, and out in to open they came! A snaking stream of bats began raising and twisting into the sky! Thousands and thousands of bats following one another out from where they had been sleeping to look for food. As we watched the seemingly endless flow of bats, we got a very cool surprise. That Peregrine Falcon that we had seen earlier came back. It started strafing through the flow of bats. It was hunting bats!

I have seen this behavior of raptors hunting bats as they leave their night roost on video before, and it is pretty spectacular to see on a screen. Seeing it in real life was thrilling! After a couple of passes, the Peregrine made a quick move to one side, and suddenly it had a bat in one talon! It flew off and out of sight carrying it’s dinnertime snack.

The rest of the bats were generally nonplussed by the Peregrine attack, and keep streaming and streaming into the coming night.

Finally, the last bat that was going to leave had departed, and the darkness was getting deep enough that we would not have been able to see the bats fl by even if they were there, so we piled back into our cars and headed for home.

All in all, a terrific way to spend and evening!

 

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