Silly Rabbit

I took this photograph of a small cottontail rabbit earlier this year. It's actually an Eastern Cottontail (Sylvilagus floridanus), one of the most common rabbit species in North America.

We have ideal habitat for them and we see them frequently. They like open, grassy areas with shrubs along the edges for cover. This one was near our house, inside the fence and that is normally deadly territory for them, but our dogs were inside at the time.

They have a two-stage defensive strategy. First, they will freeze, which is what this one has done. Then if you approach closer, they will run away in a zig-zag pattern. They are quite fast and you never get really close.

They are mostly vegetarian although they sometimes eat insects. In turn, they are predated by coyotes, racoons, hawks, and owls.

There is another species of rabbit which we see on our property too, the black-tailed jackrabbit. They are larger, have longer ears with a black trim and have a long rear legs.

Texas Persimmon

I went on a short hike this afternoon even though it is quite hot. The current temperature is 101. It's not bad if you're in the shade, but the sun is a killer.

I've been indoors all weekend, working on the Naturescapes contest and the Hays County Master Naturalist newsletter, so I just had to get out.

I've noticed the Texas Persimmons (Diospyros texana) have put out fruit and wondered if they were ripening yet. The mustang grapes are. I'm surprised that these plants produce any fruit at all, given the drought, but there must be enough water for them to do it. The persimmons are shrubs or small trees, usually multi-trunked, about 5 to 15 feet tall. I noticed today that when they grow in the understory of trees they can get quite tall, probably because they're reaching for the light. When they're out in the open, they are more compact.

Here's a typical one, in the shade of some live oaks. It's about 10 feet tall.

They have beautiful, peeling gray - white bark.

The fruit are small berries, about 3/4 inches in diameter. They're green at first, but turn a deep blue, almost black, when ripe. I've eaten them before and they're quite good - very sweet. They are a favorite of birds and mammals. The juice leaves a stain on your fingers and lips for a while.

It's nice to know that even in the middle of this deep drought, the plants keep producing fruit, propagating into the future.

Prickly Pears

The Prickly Pear cactus (Opuntia) fruits are ripening right now. The fruits are edible and you can find many recipes for preparing them. They can be eaten raw and also made into jelliies and drinks. The pads are also edible and can be purchased at local grocery stores as nopales.

The prickly pear are also known as nopales or paddle cactus and there are 200 species in the genus, distributed throughout most of the Americas. They are native to the New World but have been distributed throughout the world.

We have many on our property, although I would not say they are so widespread as to be a problem. They are indicators of land which has been over-grazed, becoming more frequent as grass is grazed away, so they may be a sign of damage done to our land before we bought it. Although there are cattle grazing on our land, they are very few and not confined to only our property, and are definitely not over-grazing at this point.

We've taken a few out, by digging them out, but you have to be careful to remove all the plant material. If a pad lays on bare soil, it will root and a new plant will grow. They grow in clumps, usually only a foot tall and a foot in diameter, but some are larger: three feet tall and three or four feet in diameter.

I'm not sure exactly what species we have. The Wildflower Center lists two for our area and we probably have both: the Plains Prickly Pear (Opuntia polyacantha) and the Tulip Prickly Pear (Opuntia phaecantha).

They have beautiful, large blooms, which are about 3 inches in diameter and usually yellow. The cactus bloom right after a good rainfall. In this photo you can see a fully-opened flower and two others which are not yet open.

Some of the cactus have red in the flowers as you can see in this photo. You can also see the green, unripened fruit just below the spent flowers on the left.

Here's a photo of a large plant with many fruits. The photo was taken today, just outside of the fence around our house. The fruit turn a deep red, almost purple color, when ripe.

Finally, this photo, taken at the San Marcos Nature Center, was in the Naturescapes Exhibition in 2009. I like the clean, smooth curves of the pads and the texture provided by the short, almost knobby needle clusters.

Onion Creek Karst

A couple of years ago we were able to go on a guided hike along Onion Creek to see the karst features.

Our tour guide was Kevin Thuesen, Ph.D., Program Manager for the City of Austin Water Quality Protection Lands. The Onion Creek WQPL is located in central Hays County and was purchased by the City of Austin to help protect the Barton Springs recharge zone. The property is being managed to restore it to a grassland which will improve the quantity and quality of the water that makes it into Barton Springs.

The hike was in November of 2009 and the creek was dry in many places. This provided an excellent opportunity to see the karst features up close. Karst is a geological feature, basically a hole or cave, that allows rain water to enter directly into an aquifer. They are formed by water percolating through limestone and are widespread throughout our part of Texas. There are several right in the Onion Creek bed and many scattered throughout the WQPL property. They're an important resource for recharging Bartons Springs and the City of Austin is mapping them. They're also monitored regularly. A die is injected in one and then the length of time it takes for the dye to reach Barton Springs is measured. The duration is typically on the order of a few days.

Here's Kevin discussing a large karst. You can see that it's in the middle of the creek bed. The grate was installed to try to keep too much debris from entering. The grate has to be cleaned regularly and sometimes it's under water, but that is easier than cleaning debris out from the karst itself. 

Here's Kevin at a smaller karst. It's about 1.5 feet long and who knows how deep?

Here's another small one, about 1 foot in diameter.

This photo was taken in March, 2010 and the spring rains have filled the creek. The grate is about 5 feet under water. Although it's hard to tell from the photo, the water is actually forming a whirlpool as it enters the karst, kind of like water draining out of a bathtub. The leaf debris you see on the surface is swirling around.

Katy Lied

The katydids (Tettigonidae) are out right now although not nearly in the numbers of recent years. They start calling in the evening and will go all night. Their calls are a chirping sound, similar to crickets. They seem to go in waves as if a group is calling in one tree and then being answered from a different tree. To me, nothing says summers in central Texas like the katydids droning into the night. Along with the high temperatures, of course!

There are more than 6400 species in the Tettigonidae family. They look similar to grasshoppers but are more closely related to crickets. They closely resemble leaves.

The central Texas Leaf Katydid (Paracyrtophyllus robustus) has two forms, a green and a red, shown below.

There was an outbreak in central Texas in 2007, and I took these photos in June of that year. The katydids live in the oak trees and during an outbreak can defoliate major areas. We didn't see that happen around our house. The red form seems to predominate during outbreaks and I haven't seen a red one since then.