science

Sexing Roadrunners

/ Rowdy / 2 Comments

Greater Roadrunner (Geococcyx californianus), Kent County, Texas, 2018.

It seems everyone has a lot of questions about roadrunners (Geococcyx californianus) lately, including how to determine sex. Many observant people have noted that some roadrunners have a colorful post-orbital apterium  (the patch behind the eye) while others do not. It was once thought possible to determine sex depending on the presence of white or blue in this area(PDF warning), but current research indicates this method to be unreliable. The only reliable field method to visually sex a living roadrunner is to take measurements of the bill length and width as well as measurements of the foot. Besides the ethical concerns of chasing down a bird just to satisfy your curiosity, as you might imagine, they are difficult to catch! While it is unfortunate Roadrunners do not display as visible sexual dimorphism as many other birds (think of the white coloration of a male bobwhite and the tan coloration of a female bobwhite), it is still fantastic to observe the little differences between individuals.

roadrunner
Roadrunner with colorful post-orbital apterium, Mitchell County, Texas 2016.
roadrunner-1-4
Less colorful post-orbital apterium, Dickens County, Texas, 2016.

Another often asked question is whether roadrunners impact northern bobwhite populations through predation. The reasoning is that roadrunners are very successful predators of small animals including rodents, lizards, snakes, and even other birds. Since quail chicks start life the size of a marble and spend the first few weeks of their lives smaller than a golf ball, it is easy to imagine roadrunners quickly taking a brood of bobwhites. It doesn’t help that northern bobwhite are a species that have suffered a huge population decline in the last century, and biologists, landowners, hunters, and nature lovers are desperately exploring the driving forces behind that decline. This has led to some too quickly pointing fingers, and roadrunners have been a victim in the past. The truth is that there is no evidence to support the claim that roadrunners are negatively driving bobwhite populations. A Texas Parks and Wildlife Department project (PDF warning) examined the stomach contents of 118 roadrunners and found two bobwhite chicks out of many prey items. In a landscape plagued with drought, unmanaged grazing, and abundant mammalian nest predators, there is a long list of more likely culprits.

So, what do they eat then?

Roadrunner with Texas spiny lizard meal or bride-gift, Jones County, Texas, 2019.

The shorter list would be what roadrunners will not eat. From insects to rodents, lizards, snakes, birds, and plants, they are adapted to survive in the sometimes food scarce American Southwest. In 1998, I observed a roadrunner kill several cliff swallows by laying as flat as possible near a building and suddenly making an explosive jump to snatch a diving swallow from the air. After each kill, the roadrunner would carry the dead swallow to the base of a fence post and then return to hunt again. Later, the roadrunner carried off all of the swallows to a location I could not observe.

In addition to hunting for food for themselves, food plays a large role in roadrunner courtship. Males attempting to woo a mate will bring her bride-gifts. If she accepts the gifts, the new couple with build a nest together, with the male bringing the female nest material. While both sexes will incubate and tend the nest, the male will often bring the female food while she sits on the nest. This is another reason why causal observers make over estimate the influence of Roadrunners on prey species populations: while it may appear a single roadrunner is a blood thirsty killing machine, it may in fact be feeding half a dozen other roadrunners.

I may eventually write a full species account for the roadrunner for this blog, but a fantastic resource to learn more is Dr. Martha Maxon’s wonderful natural history book, The Real Roadrunner (paid link). It is very approachable by general interest readers while maintaining scientifically accurate information.

Greater Roadrunner, King County, Texas, 2019.
Greater Roadrunner, Hall County, Texas, 2019. While roadrunners seem to select for shorter cover to hunt in, they blend wonderfully into the midgrass prairie grasses of the Rolling Plains of Texas.


(Cover photo: Dawson County, 2017).

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Updated 2022.

A scalping at Fort Phantom

/ Rowdy / 1 Comment

Sunset at Lake Fort Phantom

Sunset at Lake Fort Phantom

In my previous posts I mentioned the three reservoirs which supply Abilene’s water, what it takes to fill them up, how that water gets to the lakes, and what happens to that water when we’re finished with it. There is one last source to talk about and that is the Clear Fork of the Brazos River, which is a tributary of the Brazos.

Clear Fork of the Brazos River

As you can see, the Clear Fork of the Brazos passes very close to Fort Phantom Lake, but does not fill it. Wouldn’t it be great for Abilene if it did? Apparently, over 65 years ago, someone thought so, because in 1950 construction began on a diversion dam across the Clear Fork of the Brazos near Fort Phantom Lake. This was nearly 20 years after the dam for the lake was built.

Pumps at the diversion dam “scalp” some of the water from the river and divert it into the lake. Permits dating from 1949 indicate that the City of Abilene was originally authorized to divert 30,000 acre-feet per year. That is approximately 9.7 Billion gallons of water! I reached out to Howdy Wayne Lisenbee, Assistant Director of Water Utilities for the City of Abilene and Mr. Lisenbee confirmed that the city is still permitted up to 30,000 acre-feet per year.

The diversion dam and pump station. Aerial photography courtesy Rocky White

The diversion dam and pump station.
Aerial photography courtesy Rocky White

There are conditions that have to be met before that water is allowed to flow. First, it has to rain on the upstream watershed of the Clear Fork of the Brazos. Once the water is flowing, the city of Abilene is obligated to allow 600 acre feet of water through the dam for downstream users, and must allow some water to flow through the dam while they are pumping. Many Abilene residents show frustration when the City of Abilene does not pump water from the Brazos after a rain, but we are under legal and ethical obligations to let people downstream from us have some of the water.

How does it happen?

When the conditions mentioned earlier are met, water is impounded behind the dam shown in the lefthand side of the above photo. Eight pumps (located on the righthand side of the same photo) push the water a little over 300 yards through a pipeline into Fort Phantom Lake. Of the eight pumps, five are 1,500 horsepower and are capable of moving roughly 100 million gallons per day. the other three, while smaller, are not lightweights: they are 1,000 hp and can pump 50 million gallons of water per day! If all of these pumps were running at the same time it would be possible to fill 984 olympic sized swimming pools in a single day.

Due to permit restrictions and maintenance reasons, usually only a few pumps are utilized at any one time. If during a pumping session one pump were to break pumping could continue with the other pumps. Mr. Lisenbee stated that during the scalping in May the city used a combination of two to four large pumps and a couple of the smaller pumps to add 651 million gallons to Fort Phantom reservoir over the course of three days.

The pipeline which carries water from the Brazos to Fort Phantom Lake

The pipeline which carries water from the Brazos to Fort Phantom Lake

Aerial view of Brazos diversion pipeline. Water flows straight up from this pipe.

Aerial view of Brazos diversion pipeline. Water flows straight up from this pipe.

What is an “acre foot?”

 An acre foot is the amount of water it would take to cover an acre of land (43,560 square feet) with 12 inches of water.

Once the water reaches the end of the pipeline it flows straight up out of the large pipe shown on the right.

This water comes roaring down the into the lake:

The same type of scalping occurs on a smaller scale on the east side of the lake. In 1954 the City of Abilene acquired a permit to divert up to 3,000 acre-feet of water per year from Deadman Creek when conditions allow. In return for this use Abilene is obligated to release a certain amount of treated wastewater back into Deadman creek.

Same as it ever was

This additional water security did not come easily for the citizens of Abilene. Before the Clear Fork of the Brazos diversion dam was even completed landowners downstream began to complain and seek legal action. According to articles from the Abilene Reporter-News from the 1950s, an argument raged between Abilene and the landowners near Albany throughout the ’50s.  These battles echo the new arguments over some of Abilene’s projected water projects.

As the population of the area grows and as climate change continues to alter our landscape, these arguments over water will also continue. In my final article on Abilene water I will explore what the search for new water in the past was like as compared to the searches in our near future.

Your water is in detention (ponds)

/ Rowdy / 3 Comments

[This is part of a series of posts exploring how a midsized Texas city gets its water. For the first post, click over to see what it takes to fill up a lake.]

In the broadest sense, Abilene has two sources of water: recycled and surface water. Surface water is the water that we draw from the three lakes (Fort Phantom Hill, Hubbard Creek, and O.H. Ivie) as well as the water we scalp from the Clear Fork of the Brazos river. We’ll look at scalping in another post.

How does the water get to these lakes?

Of course rain falls on the watershed of these lakes, but it then has to find its way to the lake. In the case of Fort Phantom Lake, it actually flows through Abilene. While driving around
town, the water (and trash) you see in the ditches and creeks is on its way to your tap.

Abilene_drainage2

Besides creeks and ditches, rain that falls downtown flows into the stormwater sewer system through the drains built into curbs. This water flows straight into the nearest creek to be transported to the lake and thus receives no treatment. This is why you should never dispose of anything but water into sewer drains; it is going straight to your drinking water!

The scenic route

Along the way, the water is diverted in various ways including ponds, detention ponds and riparian wetlands. The latter are the marshy areas often found along the edges of creeks and other water bodies. You might see reeds and cattails along the edges of these places. These wetlands (often ephemeral in this part of the country) provide important ecosystem services to use all. While I’ll let Bill Nye explain it better than I can, you should know that these areas help prevent erosion, fight pollution, provide valuable urban wildlife habitat, and help slow down water to prevent downstream flooding.

Unfortunately, Abilene has removed many of these wetlands in favor of straightening creeks. This is because it is easier to remove trash and treat for mosquitoes in wide straight ditches lined with short grass than in wetlands. It is also an attempt to reduce flooding. Abilene, like many other cities, use detention ponds to slow flood water, collect trash, slow pollution, and other services provided by wetlands. There are approximately 200 detentions ponds scattered through Abilene, though the Abilene Storm Water Department only inspects and maintains slightly under 50 of these ponds.

Detention pond in eastern Abilene before a rainstorm.

Detention pond in eastern Abilene before a rainstorm.

As I will mention in the following video, part of Abilene’s stormwater management plan is to allow water to flow down certain secondary streets, and these small holding areas are crucial to slowing the water down enough to prevent flooding.

2015-07-08 17.32.51

Detention pond after a rainstorm

You might be surprised that there are so many of these ponds scattered across Abilene, since there are so few bodies of water. Many of these ponds are just a few feet deep and spend most of the year as open grassy areas. You may have seen children playing in a detention pond and didn’t realize it was a pond! These ponds provide a place for water to collect during heavy rains to prevent flooding and they slow the flood water down, allowing some trash and debris to fall out of the water before it gets to the lake.

And there is one source of your drinking water. Next week we’ll take a look at another source of water.

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What does it take to fill up a lake?

/ Rowdy / 6 Comments

UPDATE: After reading this post to find out why it seems the lake rises so slowly, check out this post where I discuss the recent rain.

Most of Texas has been in exceptional and extreme drought for the past five years. Now due to  el niño, we are finishing spring with cool, wet weather. For the first time in what seems like forever much of Texas is officially drought-free. In fact, some areas are experiencing severe flooding; however, that is not the complete story. What I would like to do today is discuss the flooding and drought issues here in Texas on a watershed level.

Despite these floods and despite the fact that overall Texas reservoirs are 78% full, many lakes are at less than 50% of capacity. People living in the Rolling Plains and Edwards Plateau ecoregions of Texas are still experiencing drought conditions. I built this map below to give an idea of the land area in Texas suffering from drought conditions and to show the number of lakes that are less than half full.

drought_d

In the areas still in drought above live approximately 3.5 million people and all of the lakes shown are water sources for these people. There are other water sources, some lakes which have received some water, and other areas depend upon aquifers (a nonrenewable source), but these empty lakes remain important.

What does it take to fill up a lake?

When it rains, the water does several things. On pervious surfaces, such as lawns and fields, it soaks into the ground to provide soil moisture needed for plants. If the rate of precipitation is greater than what can be absorbed, or if the rain lands on hard surfaces, it begins to run off. Take a parking lot for example: rain runs off of the parking lot into a drainage ditch (or storm sewer), the ditch runs into a gully, that gully runs into a creek, that creek runs into a river, and that river may run into a lake before it ends at the ocean. Cities will then pump water from the lake, treat it, and then citizens will use that water in their houses.

Every lake has a certain area from which it will collect water. This area is called a watershed. Since most of my readers are from the Abilene area, I will use Lake Fort Phantom as an example. This lake is currently at 37% capacity. The watershed of Fort Phantom is approximately 500 square miles. If this entire area were to receive a 1 inch rain and if it were all run into the lake, it would receive 8.66 BILLION gallons of water! That is enough water to last 26,600 families for a year. This also happens to be roughly the amount of water in Lake Fort Phantom right now, and there are 10 times as many people depending upon that water.

Using the example above it would take 2.6 inches of rain over the entire watershed to completely fill up Lake Fort Phantom. Recently much of the Big Country has received lots of rain; the nearby town of Merkel has received 11 inches of rain in the last six weeks, but as I mentioned above, Lake Fort Phantom is only 37% full.

So, where did the water go?

Examine this map I made of the Fort Phantom watershed:

Phantomshed

The rain has to fall into the red shaded area in order to reach the lake. While the lake has 500 square miles to draw from, in reality that is not a lot of area. Merkel may have received a lot of rain, but that water will end up in the Brazos river and not Lake Fort Phantom. Another issue is that not all the rain that falls in the watershed actually ends up in the lake. As I mentioned before, some water is absorbed, but a sustainable amount of water is also diverted into ponds, ephemeral wetlands, rainwater collection catchments and flood control basins. Once it is in these areas the water is used by many people and animals, and these areas should not be considered a waste of water.

The drought may be over for most of Texas, and in the coming weeks the drought may be over for us on the Rolling Plains, but please keep in mind that it takes rain falling in exact areas to refill our water supplies. Though it may seem like we are receiving a lot (and in some areas too much) water, we should not back away from water conservation efforts. We may have a cool wet summer, but then again, we may not.

It is a long time until September.

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