Wednesday, August 31, 2011

Texas Bridge Bats

I've been fascinated with bats for a long time.  I've gone down to Town Lake to see the bats emerge from the Congress Avenue Bridge. I've been to the Old Tunnel Wildlife Management Area and seen the bats emerge a number of times.

If I'm on I-35 in Pflugerville or Round Rock at dusk, I've seen bats emerge from the Wells Branch Bridge, the Howard Lane Bridge, and the McNeil Bridge.

I've gone out a couple of times to try to get some good bat photos. The first time I tried, I couldn't get the right angle for the shot I visualized - the silhouettes of the bats against a colorful sunset sky.  I've been helping with the bat interpretation at the McNeil Bridge, but if I'm talking to people, I'm unlikely to be taking time to photograph.

But Friday night things came together, the clouds in the eastern sky took on a pinkish hue, the bats were a little later than normal coming out, and another picture that I had visualized looked promising.  When the bats emerge from the bridge, they fly to the east to forage over the agricultural fields and pastures in eastern Williamson County.  They make beautiful patterns in the sky as they disperse.  I wanted to capture those beautiful and actually mathematical patterns.

It takes over several hour for the 1.8 million bats to leave their roosts.   But it is an amazing spectacle.
It is amazing to me how the flow of bats weaves itself across the sky, at times almost moving as though there is a common intelligence guiding the patterns. 


Late summer is a good time to view the bats because this year's pups have joined the flow.  

My article about the free-tailed bats is in this week's Hutto News.

Henry has a new app for his phone, Radarscope.  He came into my office near sunset asking what time the bats come out.  It turns out that you can see the images on the radar from this app that show the density of the bats emerging from a number of places around us in Central Texas.  Check out his blog and see the video he made of the radar images this evening.

Monday, August 08, 2011

Couch's Kingbird vs Western Kingbird

With a Couch's kingbird in my neighborhood,  I wanted to get better at distinquishing the Couch's from the Western kingbird.  I knew that I had western kingbird photographs from an Amarillo trip.  I wanted to compare them side by side.

Western Kingbird

This picture of the western kingbird was taken at Lake Tanglewood in Amarillo.  These birds swarm the area behind lawnmowers catching tons of insects.  In comparing the two species, the western kingbird has a dark, blackish square tipped tail with obvious white outer feathers.  While it is a beautiful yellow bird, the yellow is not as bright as the Couch's kingbird and the top of the breast is more gray.  The beak is smaller and thinner than the Couch's kingbird.  The western kingbird is found throughout the western United States during the summer and winters in Central America. It prefers open habitats of grassland, desert shrub, pastures and even urban areas.  

Couch's Kingbird

This photo of the Couch's kingbird was taken in Central Texas in Hutto.  The Couch's kingbird is a vibrant yellow, much brighter than the Western kingbird. The yellow extends all the way to the neck.  The bill is stouter and larger and the tail is lighter in color and slightly forked but  without the white tail edges of the western kingbird.  The Couch's kingbird has a gray head with a dark eyeline.

The northern range for the Couch's kingbird is the far southern tip of Texas in the Rio Grande Valley and it extends south through the eastern coast of Mexico down through Central America.   It prefers woodland boarders and brusy streamside thickets but is also found in abandoned overgrown agricultural fields and  urban areas. 

This sighting in Williamson County is only the second record for this species in the county. The first sighting was back in 1993.  It is the first record of nesting Couch's kingbirds in Williamson County.  This summer there are nesting Couch's kingbirds in both Williamson County and Bastrop County.  

Saturday, August 06, 2011

Couch's Kingbirds in Williamson County

I am grateful to a local birder who gave me a head's up about the nesting Couch's kingbirds in my neighborhood.  I went out a couple of days ago and located them easily, but it was mid-day, not the right time of day for photography not to mention the heat.

I got out tonight with my big lens, hoping they would be cooperative.  Henry and I saw them immediately upon parking. One was even in good position for a photograph, but before I could get it located in the lens, it flew to the top of the tree.  The adults were vocal when we first arrived, so I was glad to hear their call.

These birds are listed in TEXBIRDS on the Austin Rare Bird Alert. This is only the second record of this species in Williamson County.  They are normally found in Texas only in the Rio Grande Valley.

I had another opportunity when one of the birds landed in the interior of the tree.  I suspect this is near the nest, although I have not seen the nest itself yet, although I have looked for it.

I have pictures from the Texas Panhandle of Western Kingbirds so I am anxious to dig them out and compare so that I will be better able to distinguish between the two species.