Bill Sheffield Interview, Part 1 of 2

  • DT: My name is David Todd. I'm here for the Conservation History Association of Texas. And it's March 5, 2008. We're outside of College Station, Texas. And we're at the home of, of Dr. Bill Sheffield who is an ecologist who received his PhD from, from Texas AandM and has done a variety of work in Texas and, and other states but has a special interest and, and expertise in, in exotics.
  • And we we're hoping that we could visit with him about that as well as some of his other work. And I want to thank you for taking time to talk to us.
  • BS: Certainly.
  • DT: I thought we might start by mentioning your, the two books that you worked on. Nilgai Antelope in Texas and the later a book called Exotics on the Range. And I was hoping that you could tell us why it was you decided to write these books and, and maybe tell us a bit about the process of writing them and what you found out.
  • BS: The monograph on exotics in Texas was a compilation of four initial studies done in the United States on nilgai and on free ranging nilgai antelope. I did the food habit study but I helped coordinate the other studies.
  • And then I left the university, came back as a research associate and to satisfy some of the requirements of the grant we were under, the Caesar Kleberg Research Program and Wildlife Ecology, that's, that's King Ranch.
  • We were prod, produced the results of our studies and I, and this was a compilation of those four initial studies on the, on exotics, nilgai particularly in Texas. There were other studies, there were other man, monographs, white-tailed deer, I mean, and axis deer, black buck antelope and a few other studies that weren't actually hooved animals, hooved exotics that we were done un, under that program.
  • DT: Just to, to give some context to this, I guess your, your study on nilgai was based on research that you started in 1969, is that right?
  • BS: Yes, I came to the University, AandM, and wildlife science department in '69 as a candidate, a PhD candidate and I was offered the opportunity to study nilgai on Norris division of the King Ranch in primarily their food habits and feeding interrelations with cattle and native deer.
  • So that's how I got involved initially with exotics and that was my first effort. And that was the first good habit study done in the United States on free ranging nilgai.
  • DT: Well, maybe you can help us find a, a starting point for understanding nilgai and, and all the other exotics that, that might have been found in Texas at various points by turning the clock back and, and telling us, when were the first introductions of, of exotic animals to Texas?
  • BS: To Texas?
  • DT: Yes, sir.
  • BS: Most, most records reflect that it was, 1930 was a popular time. There had been some animals purchased by various ranches in Texas even prior there, probably back in nineteen, the twenties.
  • Nilgai refers to the east in the 1930's as were a number of other exotics that were purchased by private ranches and then released on their properties and included some of the more popular ones now, the axis deer, the black buck, lets see, aoudad, aoudad sheep and a few others. They were, mouflon, they were some of the first animals that were actually studied in detail as a result of their release in Texas.
  • DT: And, can you tell us the sort of context for what was going on in habitat and wildlife in the late twenties, early thirties that might have influenced these ranch owners to release these exotics?
  • BS: Well, of course, most of the hill country ranches where most of the animals were released and probably still are today, were livestock operation, primarily cattle. There was an interest in hunting of course and initially I think they were purchased and released just as a matter of interest in something different, something to show people or something to enjoy, that was different than our native populations.
  • And from that, they be, the industry began to increase, the number of animals began to increase, and they began to find other uses, primarily hunting, for exotics.
  • Then it evolved as more and more exotics came on the scene, some very prolific, then their, I think that initiated a need to find some other way to deal with them to, to control their populations.
  • In addition to hunting, they began to consider meat sales, recreational opportunities such as drive-thru parks, photographing the animals, and that's primarily what they're used for today, other than just private enjoyment of the ranch owners.
  • DT: I've, I've heard stories that, that in the late twenties, early thirties, a lot of the native wildlife had become quite scarce and there was some interest in trying to repopulate the Texas landscape with with something and it happened to also be that's when these exotics were also introduced at the time. Is that, was there a connection with the fate of the white-tailed deer in particular?
  • BS: Well I think that's kind of two questions. One is I think you're right, example, classic examples I think are introduction of aoudad sheep in New Mexico, in the Colorado River gorge and again, in Palo Duro Canyon in Texas.
  • Those people were seeking another game animal to hunt. And I think maybe in New Mexico, they had some of their principal big game animals had declined and they were looking for something to substitute
  • and, and so they began to primarily in, introduce aoudad along with some other species I think gemsbok and I don't remember what all they ended up releasing as free ranging animals in New Mexico and then aoudad is free ranging animals in the Palo Duro Canyon in Texas.
  • DT: Can you tell us how they decided which animals might be viable here in Texas to import and introduce?
  • BS: Yeah, I think primarily it was a comparison of their native ranges with similar ranges in Texas, ranges that, that were had mild climates. Most of them, most of the animals that had been released here, at least animals like black buck, nilgai antelope; they cant tolerate extreme cold weather so they did quite well in South Texas.
  • And then black buck as well as other animals were released on ranges that had a temperature range and an environmental range and, and food supply that was pretty well suitable and matched some of their ranges in their native countries. (misc.)
  • DT: Can you tell us what areas a lot of these exotics typically came from? You're talking about sort of the climate and the, the type of habitat. What, what countries were they from?
  • BS: Primarily Asia for the, for the deer species which there are many, and Africa. That's where most of the, most of the animals came from.
  • The most successful ones seem to have come from Asia and Asia Minor and the less successful ones, with exception of a few, are, were from Africa. Most of those that came from Asia and Asia Minor were deer species and antelope species and those that came from areas such as Iran and North Africa are, were the sheep and goat species.
  • DT: And were some of these animals becoming rare in their native countries? Is that one of the reasons they were brought here (inaudible)?
  • BS: Well, yeah, yes, that's one reason given. The black buck is an example. They say now that there are fewer black buck in India than there are in the United States, than there are in Texas. And their ranges have, were destroyed, have been reduced from development and so they're declining as well as nilgai antelope.
  • They're declining in India where they're primarily from and in Pakistan and some of them were released in Nepal. And part, particularly in India and Pakistan their habitat is, is being reduced and they're being hunted and over-utilized,
  • despite the fact that nilgai, for example, are, are in the Bovidae family, they're in the same can, family as cattle and then, of course, in India cattle are sacred animals. But even so they're declining and they're being probably hunted and use, over utilized.
  • DT: Maybe you can walk us through how some of these introductions were done, how the, the animals were captured and then transported to the United States.
  • BS: Well, I don't know how they captured them in the foreign countries. They were shipped to the United States and, and for a number of years, they've had to go into quarantine. And that problem for private landowners has some, been somewhat bypassed by, by acquiring animals from zoos and that is a principal resource for animals being initially imported in the United States, certainly in more recent times.
  • They came from zoos and some directly from foreign countries but those are the ones that had to go into quarantine. And, and I think there's a law now that says once a hooved animal, a herbivorous ungulate comes in the United States from a foreign country, it can never leave quarantine, only the progenies. So zoos have some exemption from that and consequently, a lot of animals have been acquired from zoos.
  • DT: And, and are some of the folks who or the origins of these animals, are they paid for selling these animals to, to the private landowners or are they gifts or how are they transferred?
  • BS: I think it's probably both in the United States and I'm speaking of animals that come from the zoos. An example is Norris division of King Ranch. The King Ranch acquired nilgai antelope primarily from San Diego Zoo in California. And they were gifts.
  • They were somewhat overpopulated I think with nilgai. And the owner of the San Diego Zoo who was William Randolph Hearst was good friends with Mr. Caesar Kleberg, who was one of the prominent people for the King Ranch in those days
  • and Mr. Kleberg envisioned stocking the Norris division of the King Ranch with an animal whose food requirements and ecology was intermediate between their livestock and their native deer. And William Randolph Hearst recommended to him nilgai and in fact, they are intermediate in size and in food habits and what have you.
  • So they began to stock the Norris from the San Diego Zoo with small numbers of nilgai. To, to carry this farther and to get beyond your question, the first introductions were in small numbers, four and six animals shipped from California and, and they were released on the Norris and they didn't, they didn't take, they disappeared.
  • So finally after several introductions, they acquired about twelve animals and pinned them in, in a corral and kept them together there for, for quite some time and then opened the gate and let them leave on their own accord and from that release, all the nilgai antelope in Southeast Texas (inaudible) evolved. And that's, that's, that was a gift initially. Other animals are purchased I, I'm sure.
  • DT: Well, maybe you can elaborate a little bit more about how these animals would get released and established because it seems like they're, they're moving say they came from a foreign country, it's probably new forage or they've come from a zoo where they probably had food brought to them.
  • BS: That's true.
  • DT: Or pelletized or something. How did they make that change?
  • BS: Well what I understand is, and an example I'm familiar with, is that these animals are first confined and, and sort of settled, and, and get to be acclimatized and then, then they're released sort of allow, allowed to move out on their own. A lot of the exotics have a tendency to, to travel. Once they're released, they just start exploring the countryside looking for a habitat, I guess, that they,they require.
  • And where ranches are or where or where ownerships are under high fence, that's no problem but where they're not, these animals can escape and be free ranging onto contiguous ownerships and that's how a lot of exotics have expanded throughout the hill country, particularly in South Texas.
  • DT: Maybe you can go into that a little bit more. I, as you say these exotics started in isolated ranches, I guess, in South Texas on the King properties and then in various ranches in hill country. How did they spread? Where did they go? What are their numbers now?
  • BS: You know, their numbers have definitely increased. I don't have any current information. I've been retired for quite a while. But the last information I got, which probably relates to populations in the mid eighties, were probably, for one thing, probably fifty or sixty percent of the State of Texas has animals now.
  • So they expanded, a lot of them expanded on their own. They moved and moved and moved and crossed fences and what have you until they found habitat that suited them.
  • I don't know if I'm answering your question direct but that's one way they expanded. Then, of course, there were private sales where one ranch or one owner, ownership would acquire animals from another and transport them to their properties and, and, they would build a population and then they would expand and so on.
  • And I really don't know the total number of exotics, but it's well over two hundred and some odd thousand in Texas alone now. And about fifty-five or sixty percent of, percent of the counties have them and the species, I always just have to take a wild guess and say there are probably twenty-five or thirty species or more.
  • And, and, and more recently, animals have been released that weren't among the herbivorous ungulates, that were first popular such as nilgai and black buck and axis deer. They, there's been an effort to establish a commercial enterprise with exotic birds, ostrich, emu, rhea from South America from Ar, Argentina.
  • Those efforts failed but those are some of the more recent exotics that were intro, introduced into the States. We have so many now, so many species probably don't need to go (laughs) outside the United States to get more.
  • DT: You said that some of these animals were successful in their release. They got established, they, they have viable populations and survive on their own. And then some failed. Can you help us understand why some might have been successful and some failed?
  • BS: Well I think it primarily had to do with, with, where they were released. There was such a di, disparity between their native environments or when they came from zoos, they were just unable to, to develop a viable population. Another thing is some of the species are more prolific than others.
  • Black buck doesn't take much to get a heck of a black buck population going and the same way with nilgai, they're very prolific. Same way with aoudad sheep. Some are just hardy, more prolific animals then when they're released into an environment that's mild, with a mid climate and adequate vegetation, then they're successful.
  • Others that have been released in, into Texas, in environments that just either the weather gets too cold or gets too dry or they just didn't make it.
  • DT: I'm, I'm confused about something that I hope you can help me understand better. These exotics were, were largely released by private individuals?
  • BS: Initially. DT: Or were there also state releases?
  • BS: No, no they're, it's mostly been by private individuals. And, and in fact the state is more concerned about native species and, and, and is probably concerned about the exotics and their impacts on native species.
  • And so most of the releases, in fact, just about all of the releases have been by private individuals although there's an example of that aoudad sheep in Palo Duro Canyon where there was enough influence by landowners and in the counties contiguous to the canyon who wanted some exotic animals, some additional species for hunting coordinated with the state and the state was involved in that release.
  • But they're not in many, I don't think, that they were involved in.
  • DT: And, and what sort of roles does the state have now in, in ownership or game regulation for these exotics?
  • BS: As I understand, they've changed it. At one time it reached a point where certain species such as axis deer in Bexar county and Kindle County and some of the other counties, were the free ranging ones, the ones that escaped from their ownership, owners land were protected. You had, had to have a valid hunting license and, and, and you could hunt them then.
  • I understand now that there has been so many in order, and in order for the state to control these, these exotic species, that they have lifted that restriction and that all you have to have now is a valid hunting license and permission from the landowner who's, who has the animals to take animals any time of year.
  • They're not treated as our, our native game animals. They're treated more as a private property of the landowner as are livestock.
  • DT: You said that, that the state attitude about these exotics has been some, somewhat of concern about the impact on native animals. I was hoping that you could explain what the concern is about how exotics and, and natives interact.
  • BS: Well, for one thing, exotics can out-compete and when we say native animals primarily we're talking about white-tailed deer in Texas. There's some, you know, maybe some mule deer out in West Texas but where most of the exotics are in hill country in Edwards Plateau and in South Texas, we're talking about white-tailed deer primarily as the, the principal hunting animal, native.
  • And exotics can out-compete white-tailed for food. And on ranges where there, it is, that are overstocked, white-tails suffer. They can out-compete white-tail for two reasons. One is exotics don't have the fidelity to their home range that white-tailed deer do.
  • White-tailed deer have been known to starve to death rather than leave their home range to go to other areas and find food. Exotics don't have that problem. They're, they're perfectly willing to travel to find food if if food is scare on their range.
  • Another problem is that white-tailed deer don't have a lot of feeding flexibility. They require high quality food and they're pretty selective. Exotics are not. If their, if the preferred foods of the exotics run short, they don't have a lot of problem to switch over, in other words, if they're grass eaters and the grass runs short, they don't have a problem to go to browse or to forbs.
  • White-tailed don't have that flexibility. So where ranges are overstocked and the carrying capacity is low, white-tailed deer are going to suffer. And as the exotic game population expands, the more and more, the more dense the species get and the more diversity in, in species, the the worse it is for white-tailed deer.
  • DT: You talked about the, the interaction between some of these exotic ungulates and the white-tailed deer, is, is there any interplay between the predators, the mountain lions, bobcats, coyotes and some of these exotic ungulates or
  • BS: Well, I'm sure that these predators you mentioned prey on, on sick animals and on young animals. But I, I really don't know the de, the intensity, the degree by comparison with white-tail.
  • Of course, white-tail are native and our predators that prey on them are native and I would imagine that, that, they're, they tend to prefer to go for young animals and, and white-tails, for example, coyotes and deer, than some of the other some of the exotics, many of which are pretty large animals. An animal would have a hard time pri, bringing down a 700 pound nilgai but maybe not the young.
  • DT: Another aspect that occurs to me about how there might be competition or some kind of influence between these exotics and natives is, is parasites, viruses. Are there things that the exotics might play host to would have a bad impact on the native wildlife?
  • BS: This has been studied and I don't know all about that. I can give you my personal experience with nilgai antelope on the King Ranch. One thing I did was to, we collected these animals and we necropsied them and we took samples of their viscera and we observed for ectoparasites, ticks and so forth.
  • We sent those to vet school at AandM and the parasitologist there examined them and actually there was not a high number of, of endo or ectoparasites among the nilgai. One can, one thought is that these exotics are, didn't evolve with these, our local parasites. They're not natural hosts. So they're for the most part they, they're not apt to be infested.
  • I found a couple of species of ticks on nilgai but I never found any sick ones that were apparently sick as a result of some disease. And another thing, we have protection. We have, these animals are required to go to, into quarantine when they're shipped from other countries and they can never leave if they're herbivorous ungulates. And that is a protection.
  • And I think, in general, I'd be safe to say that the exotics really don't pose a serious problem and don't carry the dangerous diseases that they do in other countries such as rendered pests, and, and among animals and, and, in Asia and places like that.
  • DT: One other connection that comes to mind for me at least is, is that there might be hybridizing going on between some exotics and, and natives. I think I've read about mouflon and red deer having possibility of
  • BS: Not mouflon (inaudible). Red deer can hybridize with elk, our native elk; they've been known to do that. Fallow deer, no sika deer, have hybridized with elk I think. But in, in a natural environment and among free ranging animals and animals that have domestic livestock and, and whatever, I think hybridization other than those examples is, is pretty rare.
  • And now thereve been attempt there have been hy, there have been hybrids produced by capturing animals such as banteng cattle hybrid, the native Europe, Asian animal that's endangered. They have crossed that animal with livestock cattle successfully. And, and lets see, what else. They have crossed buffalo.
  • Of course buffalo are, are not exotics, they're native. But those there's been hybridization there and some other cases but that's not prevalent on a open range where they're free ranging animals. That's mainly among animals that are pretty well confined. Let me back up and mention one more thing.
  • You asked about parasitism or diseases. They, these animals might, parasitism and disease might increase as dense, as these animals density increases on, on given areas. You know, diseases are density dependent. So we don't know what is coming in the future where there is a high density of, of exotics and native animals.
  • DT: We talked about the, the connection between exotic wildlife and native wildlife and I was wondering if you could talk now about the connection between the wildlife, exotics and the habitat in North America.
  • I, I've read peoples, who've said that, that with the loss of a lot of the Pleistocene large mammals that there was a niche that was opened up for introduction of more kinds of wildlife, large, large mammals. Do you see truth to that?
  • BS: Well, with the decline of, and I've read that the wooly mammoth, for example, possibly became extinct because of over-hunting by prehistoric man. There's a possibility that these animals can be ju, bringing in new animals, foreign animals to occupy the niches of animals that have become extinct in this country that have some justification and some consideration. I don't know much about that.
  • DT: Something else that I've thought would help us give some context to this is that I imagine a lot of the exotics that are here in Texas are, are actually livestock as opposed to free ranging animals. Is there any way to compare the impact of these exotic ungulates that, that we've been talking about earlier and say cows or sheep or goats or horses?
  • BS: Yeah, in, in the first place, they're not livestock (laughs). They, they animals influence the vegetation complex and animals that come in and utilize vegetation classes and, and parts of vegetation classes can influence what evolves there in the way of plants.
  • So, you know, these exotics, if they're heavily grazers or something, they may reduce the grass pop., grass classes, classes of grass and something can supplant that and first thing you know that system, that ecosystem has changed from the standpoint of vegetation complex and that can have an impact on native animals. I guess that's as close as I can answer that one.
  • DT: I think that there have been concerns about these exotics exceeding what their habitat can support in some places and there've been efforts to, to control them or even remove them. Can you talk about some of those (inaudible)?
  • BS: Well, yeah. Uses is the main thing, you know, find some use. And it seems to me, it seems to be that the most successful or the most feasible use is hunting and that ha, and that's how a lot of these ranches have evolved toward selling hunting, either lease hunting or guide hunting, to augment their livestock income,
  • for example, as well as to help control the number of animals (?) ungulates on the range, on the ranges. The, there have been other uses. Meat studies have been done and it's been found that a number of the exotics by comparison with the livestock have nutritious lean meat that's, that's a benefit for today's meat market.
  • But it just seems that and there is some of, there are some entities that process exotic meat and sell them, sell it. Axis deer, by the way, is the most popular and the most palatable. But they're they're they don't take enough animals to be that, to have that much impact on,on the reduction of the species.
  • I would imagine if someone could come up with a system whereby surplus animals, exotics, could be captured, processed and fed to organizations that take care of needy people and things like that, that would, that would be something that I don't think a lot of, is done a lot now, but that's a thought. But it's a problem and right now it seems that hunting is the most effective way to re, to control the numbers.
  • DT: I think when we were speaking off tape earlier you were telling me about trapping, the fur trade with respect to, to nutria. Can you explain your experience with trying to find a use for those animals and...?
  • BS: Well, we're talking about Louisiana now and nutria are an exotic that became leased, released in the Louisiana marsh as a result of a hurricane from the famous, what is it, the, the, what's the name of that salt dome? Adri, Avria Adria
  • DT: Avery Island? BS: Avery Island. They first had nutria pens and it's said that nutria inoculated the Louisiana marsh as a result of the storm that tore the pens up and the animals escaped and nutria are very prolific and they began to take over the marsh and they out-competed the, the popular muskrat fur animal.
  • And subsequently, were just, they're quite a pest, quite a pestful exotic in the Louisiana marsh. And it was decided that unless they could develop a fur industry or a meats industry, that, that, that could use the muskrat, I mean the nutria for, they would have a real problem and they did.
  • They found a way to process nutria pelts so that now they're very valuable. They developed factories that processed the meat for animal foods and those are the uses in Louisiana that have been made of the, of this exotic. It was really proliferating and plaguing the Louisiana marsh.
  • DT: How do they taste?
  • BS: Great, taste like rabbit (laughs). Love them. When I was a student at LSU, I had to, I was in a class with a professor, a marsh ecologist, whose chore was to find out, to develop an in, a market for nutria, that was one of his projects. And we used to have to go to the marsh and trap nutria and we examined them for endo and ectoparasites.
  • Incidentally, they were found to be one of the cleaner animals in the marsh and that aided the, the effort to sell them for meat. And our professor used to tell us that unless we tested those animals and ate them when we were camped in the marsh, that we'd flunk (laughs).
  • So, so we were forced to do that as students and come to find out, they weren't bad eating. But I don't think a lot of that's done now. Mainly it's used for dog food, for animal foods and I understand nutria pelts make one of the more valuable fur coat, fur coats.
  • DT: Another exotic, I believe it's exotic that we haven't talked about in much detail yet is, is the feral hog.
  • BS: I hate to talk about the feral hog (laughs). It in my opinion, and I don't think I'm by myself, is undoubtedly the most detrimental exotic that was ever released into this country. They, of course, are crosses between domestic hogs and European wild boar that had been brought in and introduced into this country.
  • And they have just, they're very prolific and they have just expanded everywhere throughout the south, all through Texas, all through Louisiana, Mississippi I'm sure and into Arkansas. And it is a tremendous problem to control their numbers now. In fact, I don't think they can ever be eliminated.
  • They can only be controlled. So that is a major management effort in Texas to control feral hogs. And they, they are omnivorous. They eat anything. So they're, they're competitive with our native animals. They destroy crops and they, they render some pastures and what have you in pretty bad condition.
  • It looks like they've been plowed in some areas where hogs have come in and eaten. And they're very wily. They're, they're, have become mainly nocturnal and they're difficult to control and hunt. But it, it's, it's a popular sport.
  • I'll add this, a gentleman named Mike Hughes who processes and sells exotic game animals at Ingram, he has a company there or he did, I guess he still does. One day I asked Mike of all the animals he processed and sold which, which species did he sell the most of?
  • He said feral hogs (laughs). But the most popular is axis deer for meat and they're sold in gourmet restaurants all over the country. And that's about all I know about that.
  • DW: And how does that one taste?
  • BS: Huh?
  • DW: Axis deer, can you tell us a little about (inaudible)?
  • BS: About the taste?
  • DW: Yeah, if you can.
  • BS: Axis deer, it's, it's a good meat and it, it's not a dark meat like our venison. And it's, it's tender and it's, it's very, it's, it's, has it's high in protein. It's, it's, it's the most palatable meat among people who have been, who, who ask about it and have tried it. I have. I've tried it in a gourmet restaurant in Houston and I found it was excellent.
  • Nilgai meat is not bad but if you don't process it right, being Bovidae, in the Bovidae family, nilgai meat looks a lot like beef but it can be tough.
  • And I think most of the mistakes that probably individuals make processing game meat is they overcook it and you have to cook nilgai meat just right, better to get younger animals. But it's not bad but it doesn't hold a candle to axis deer, the tenderness, the, the, and nutritional quality, the taste, the appearance is, is good.
  • DT: Well, we've talked so far about everything from nilgai to axis deer to fallow deer and then some of the other animals that maybe don't fall in that, that large ungulate category, the feral hogs and the, the nutria.
  • I was hoping that you, you might have some comments about some of the other exotics that have become part of the Texas landscape. One is an insect, fire ant. What do you think the role of the fire ant is and, and how did it come to be in this state?
  • BS: That's as tough a question as, as the one about the feral hog. Well fire ant, they have what they call the Formosan and I think it's the most fierce. It's the big, black one that can really sting you. And they, they're the ones you see so prolific and so expansive over a lot of the pasturelands and what have you and along the gu, the coastal states.
  • Fire ants are, I don't think well ever eliminate them. I think we can only control them. They came from South America, some other species. We have a native species. It's not good but it's not, it doesn't just cover large areas and, and present the problems that, that the Formosan does.
  • They're a problem for our li, our wildlife and particularly ground nesting birds. And often in South Texas and along the coast and in Louisiana where they're so prolific, they're given major credit for the demise or the reduction in numbers of bobwhite quail.
  • And they no doubt have an impact. But they're, they're not the only impact on the, has reduced bobwhite quail in the south and in a lot of Texas where they've been extirpated.
  • I think land use practices by man have done the biggest damage, farming, large scale monocultural farming, foreign grasses on pasturelands, those don't do, those don't do quail much good. And, but fire ants are one of the many predators that ground nesting birds have.
  • DT: You mentioned the grasses that are found. I imagine that some of them would fall into the category of the exotics some of these turf grasses and
  • BS: Yeah, most of them. DT: Most of the old world blue stems. Can you help us understand what the role of, of these grasses might be?
  • BS: Well, these grasses such as species of Bermuda, varieties of Bermuda, bahia grass, these are real popular pasture grasses for livestock but they're not productive. They don't, they don't produce se, seeds and, and they don't, they're, they're not usable by our native deer and, and birds.
  • They just, they take good care of cattle but they don't take good care of our native animals and so they're, they're undesirable as far as ecologists are concerned, wildlife ecologists.
  • DT: Do, do you know the origins of things like the K.R. bluestem and
  • BS: Well, King Ranch bluestem came from Africa so, so does Kleberg bluestem I'm, I'm sure. Johnson grass, I think it's a South American grass that's a popular weed species.
  • K.R. [King Ranch] bluestem was disseminated significantly in Texas as I understand it as a result of the highway department planting that grass along the rights of ways because it doesn't get high in its uniform height and you don't have to mow it as much and so it cut highway maintenance expense.
  • The problem was that it, it expanded into contiguous pastures and it spread and it, it can compete, out-compete native grasses and, and is not a valuable wildlife food plant. So, in essence, for wildlife it, it has not been productive.
  • DT: Well, you told us some about exotic mammals and insects, vegetation. How about birds? You mentioned quail and, and I understand that, that there are some exotic birds and I would think of English sparrow, house sparrow, starlings, can you explain from the view of an ecologist what that means to the native birds (inaudible)?
  • BS: Well, yeah, they compete for food and space and nest sites and they're very prolific. Most of them, the ones you mentioned such as the house sparrow which used to be called the English sparrow and starlings, a bird form England, were brought over here to, I think out of sentiment for people who were immigrating to the United States and wanted something of their original homeland.
  • And they brought these birds over and they did quite well here and they became very prolific and they exist in urban areas as well as wild areas and they compete with our native an, birds for food. There is an animal that I don't think is exotic. It's the brown-headed cowbird. It's parasitic on nest sites.
  • It moves through the countryside and lays the female lays eggs in other birds nests and let the other birds hatch them and then they move on. And the, it tends to be larger, the young tend to be larger than some of the native young birds, hatchlings. And they sometimes boot the younger birds out (laughs).
  • And, and the surrogate parents end up raising the brown-headed cowbirds instead of their, instead of their own kind and, and this has caused a lot of detriment to a lot of our valuable songbirds.
  • I think the bluebird, Eastern bluebird is one that has suffered from parasitism by the brown-headed cowbird but I don't think it's native, it's exotic. I think it's a native bird. I may be wrong, I was wrong once. That's when I thought I was wrong and I wasn't. You might want to strike that.
  • DT: Well, we've talked about exotics in, in a number of regards the, while were talking about exotics, I was hoping you might be able to tell us about undergrowth in, and some, I guess, small trees and the ones that come to mind are things like Chinese tallow and ligustrum, nandina. Do you know much about their history and their impacts?
  • BS: Well, they're exotics of course and, and the Chinese tallow, I think came here as a garden variety or, or a landscape tree for yards and you see a lot of it. And it produced, is very productive of its, of seed. A lot of birds like it.
  • Someone I know, a biologist who did a little study on the use of tallow trees seed by birds and it found that about thirty-five species of birds in the East Texas area use the seed and they would disseminate those seed, those hard seed and that, that causes it to spread and it competes, of course, in, in dense stands with more productive plants and native plants.
  • It's, it does real well along Texas Gulf coast prairies where in some areas, it just literally has taken over. And in Louisiana where they've had to, had to spray the trees to kill them back to get their pastures back and their native species.
  • Well, actually ligustrum there's, there are two, three species of ligustrum. There's Chinese ligustrum, wax leaf ligustrum, I guess there are others. They're used, too, in landscaping in yards as hedges and, and what have you.
  • I see they're, they've escaped here on my property, I see a lot of Chinese ligustrum here and it's pretty prolific, it expands, it grows, it competes with sp, for space and water and light with native plants.
  • So I don't think there are very many exotics that were brought here that have, had, where we've had positive results. There are so many examples of plant and animal exotics that, that have also been, been detrimental to the ecosystems.
  • DT: What would you say about, about plants in particular that are, that are native but maybe it's spread because of land use changes. The one that comes to mind is maybe ash juniper, maybe huisache or mesquite or (inaudible).
  • BS: Well, yeah those plants, some of those plants have become increasers as, as the range science people say as a result of land use practices. And some of them that are, that are not resistant to fire, for example, such as yaupon in East Texas primarily.
  • In the absence of fire and with woods cattle grazing to reduce the low, low vegetation, it has, it has just taken over in some places. There are other species that have done it. I don't know about ash juniper but the eastern red cedar, juniperus virginiana is not fire tolerant.
  • So where you have an absence of fire, landowners have tended to keep fire out. These trees have begun to proliferate. I know there are a number of varieties like mesquite comes in as, a, as an increaser on, on habitat that's been overgrazed or abused by, by overgrazing in a lot of areas.
  • Mesquite will come in and just take over and it's an opportunity for these plants to, without competition from other plants to, to proliferate and that's usually, often can be attributed to poor land use practices.
  • DT: When you, when you look at the landscape or wildlife populations and you see exotics or, or formerly native trees and creatures that have been able to expand their niche, do you say well that's, that's just a dynamic landscape or does it have some sort of other meaning to you?
  • BS: The meaning it has to me is I envision so many ownerships, so many ranges that have been abused by overstocking. And when I see all these varieties of animals, I tend to want to take a look at the balance between forage production and the classes of forage and animal demand and, and where animal demand is exceeding forage production.
  • In other words, you don't have, you're not meeting carrying pests then you have detrimental effects. You, you have animals that are not getting what they need. You, you have invader species coming in that are undesirable. It all relates to poor land use practices.
  • DT: I believe you've done some studies even quite recently about models that help understand what carrying capacity allows. And can you explain the idea of carrying capacity and these models (inaudible)?
  • BS: Yeah, shortly after I take a break. (misc.)
  • DT: When we broke we were talking about carrying capacity and trying to model what, what's acceptable or not.
  • BS: Well, it, it's been a practice that, carrying capacity for ranches primary recommendations had, had cattle in, native and our livestock in mind. And most livestock are grass eaters and some of the exotics are but some of them aren't and our native deer are not grass eaters.
  • So when you base carrying capacity on a, on a piece of property that is, has a variety of herbivorous ungulates, it may not be accurate if you base it on grass eaters alone.
  • So we've come up with a way to take into consideration the various food requirements of the different species of animals and model that so that you can say well if you have this particular species of animals and you have this much production, forage production, grasses, forage and browse, your major forage classes,
  • then you can have x number of these critters and x number of those critters and x number of these critters. And that is a more accurate way to determine carrying capacity because you're taking the food habit requirements, the food requirements of all the species that are on a given area. And that model is being worked on and it will come out some time next year I guess.
  • DT: Well while were talking about species, I'd like to ask you a couple of questions about, about some of the exotics and (?) some unusual animals that are, that are making inroads on Texas landscape and one group would be the, the some of the African or I think Australian birds, the ostrich and the rhea birds.
  • BS: Emus.
  • DT: Emus. Can you tell about how those got introduced and they had their spike and then the industry has had in trouble since?
  • BS: Well I think they were introduced by private purchases or maybe, and either from individuals, other individuals or from zoos, with the idea that they could be used commercially. And in fact I don't know if you're familiar with ostrich leather but it is a, you know they make cowboy boots out of ostrich hide and, and I've had belts and billfolds and it is very durable, much more durable than, than cattle cowhide.
  • But apparently there wasn't enough demand to keep the industry going and it just faded away. I don't know of any other, I don't know of any other sources other than local stock using maybe foreign animals.
  • They probably don't have the problem getting foreign birds in he, into this country that they do with herbivorous ungulates because the quarantine restrictions. Birds probably can eventually, after quarantine and proven healthy, can, can be, can be handled or sold or bought.
  • DT: There's another class of animals that I was curious about your opinion on and, and they're pets that have gone feral. I understand that, that dogs that are, you know, when they become wild and they move in packs, can have quite an impact and that cats as well can have an impact on bird populations. Can you talk about those two aspects?
  • BS: Well you mentioned dogs. Dogs can pack, become feral and take up with coyotes and, and the, the hybrid that comes from that is called co, coy dogs. And they're, they're considered to be every bit as predacious and maybe even more so than, than the coyo, than a pure bred coyote.
  • With respect to cats, they're hunters. Cats are natural born hunters and, and they take a toll of our bird populations particularly and are considered to be a major enemy, a major predator on bobwhite quail, particularly where they're contiguous to urban and suburban developments.
  • So cats, cats are considered to be a top predator on bobwhite quail and where, bobwhite quail are diminishing rapidly in, in our country except possibly for South Texas but through East Texas and Southeast Texas and in Central Texas bobwhite quail has just declined tremendously. And part of it is probably because of development and the cats and pred, and pets that are associated with, with these developments.
  • DT: I, I've got sort of an ethical question for you. I, I had read recently that there was a birder who lived out on Galveston Island who got concerned about the effect of feral cats on piping plovers. And so he started trapping and shooting these cats and the humane society and some of the friends of the cats got upset.
  • But then there was another group, sort of bird lovers, who felt like, well, these are endangered birds, you know, you need to protect them. How would you come down on a, an issue like that?
  • BS: I'd take care of the cats (laughs). I, I believe that I'd give first priority to, to, of course, our birds but I can understand why people wouldn't want to lose their pets but I would admonish them to keep their animals at home and, and keep them at a reasonable population density and that might require some close coordination among the two factions.
  • We've had a similar problem and few years back where sandhill cranes were beginning to leave the Aransas Wildlife Refuge and here and there, not all of them but little groups and, and the feds got, the Federal, The U.S. Fish and Wildlife Service got particularly concerned because they we're afraid if they got off of the protected Aransas, the federal refuge that they might begin to lose some of the birds.
  • So they offered to, to purchase lands where these birds seemed to be going, these offshoot groups. And that became, became a point of contention between the state and, and the fed, and the U.S. Fish and Wildlife Service because the state didn't want to just indiscriminately bop here and there and,and sell land, land to the federal government.
  • You know, Texas has the fewest, the least amount of federal, federally owned land I think of any of the states and they have a thing about that. So, it was finally some of the ecologists began to realize that what was happening, for one thing, was that the vegetation was changing on the Aransas Wildlife Refuge and it was getting more dense and it was more difficult for some of the sandhills, I mean
  • the whooping cranes to feed and nest and so that was one reason they were, some of them, were moving to other areas because the ecological change and I think they might have gone in and tried to, tried to correct that. But that was several years ago and I don't know what the outcome is now, although the birds are increasing in numbers I think. (misc.) [End of Reel 2439]