Dicromantispa interrupta

Dicromantispa interrupta
Mantisfly

Saturday, June 27, 2015

Are Texas Warthogs Coming?


As you may know, the USDA has been working on a national plan to control feral swine (hogs, pigs), and I did my civic duty and gave them my two cents worth. Now comes a blurb from the news media that warthogs are on the loose in Texas and, oh by the way, that’s old news. Here’s one example: tinyurl.com/ncpgwa8.

Well, maybe in Texas it’s old news. I follow the feral hog situation because of my involvement in the Emerald Pendant project, but never once ran across warthogs in my literature review. Evidently, most if not all of these burrowing barrows escaped from high-dollar sitting-duck hunting reserves, although a few may have also been released by exotic-pig faddists. Apparently, it is not common enough to be widely perceived as an invasive-exotic threat, and may not even be reproducing in Texas yet. What is its potential to become an over-abundant pest? Well, the leopard and the lion and the Lango have all been unable to control them in Africa, and their cousin, the Eurasian boar, well, you know…

The common warthog is a savannah grazer, which means it prefers grasslands to forests and focuses on eating graminoids, but also eats roots, tubers, berries, nuts, crops, insects, eggs, and carrion. For sure, it will eat any herp it runs across. These are exactly the same foods that feral hogs eat. The warthog lives in sounders, like feral hogs, but unlike them is said not to occupy territories. If the latter is true, then warthog sounders could be more difficult to trap with the whole-sounder approach than feral hogs. One obvious biological error in the article cited above is the idea that warthogs are not nocturnal like feral hogs. Actually, hogs are indeed naturally diurnal, but become nocturnal where humans hunt them. There is no reason to believe that warthogs would not similarly adapt the shroud of the night. The warthog can occur in densities of up to 77 per km2, or 1 per 3.25 acres, but a more typical density is 1-10 per km2, comparable to American feral hogs.

The warthog’s gestation period is 5-6 months, far longer than that of the feral hog, so while the latter can have two or more litters per year at 4-8 young each, the warthog has only one litter of 2-4 young per year. If warthogs become established and strong control efforts are used on them, would the number of litters per year and number of young per litter increase in the face of significant control pressure? Research shows that feral hogs become more fecund when hunted and trapped, so warthogs could easily follow suit. The genes are almost certainly present in warthogs, as humans have bred super-fecundity into domestic pigs, dogs, sheep, and chickens, among others. Warthog birthing occurs at the start of the rainy season, which happens at variable times throughout the warthog’s native range in Africa, so it would probably adapt to American rainfall seasons.

On the bright side, drought and hunting with dogs can extirpate the warthog locally. Furthermore, the warthog does not have subcutaneous fat and its hair is sparse, so the warthog suffers in the cold; hence, the burrows. However, sparse hair and absent fat layers are possibly controlled by a single or few genes each, and if one (set) is the only thing keeping warthogs from breeding in the US today, then a single mutation could be a game-changer. Environmental stresses can force mutations.

There are two species of warthogs in Africa: the common and the desert, or Ethiopian. I don’t know which one is on the hoof in Texas, but the native landscape of the desert warthog is arid brushland and thickets, which sounds a lot like the Texas Hill Country. Regardless, there appears to be potentially suitable habitat in Texas and Mexico for both species.

The prospects for extirpating warthogs from Texas appear favorable. First, outlaw their importation, breeding, keeping, and hunting. Second, send in specially trained professional exterminators/hunters using every reasonable trick in the book (e.g., hunting with warthog-trained hunting dogs, Judas warthogs, whole-sounder trapping, and aerial surveys and shooting). Third, fold warthog concerns into national and state monitoring and public education campaigns.

Perhaps the USDA should focus a sufficient chunk of its national swine control resources on warthogs before they become as abundant and destructive as feral swine. USDA could fund genomic research on the potential for mutations that enable subcutaneous fat and/or denser hair. Research into the likelihood of warthogs acclimating to a nocturnal lifestyle may be warranted, although I think that can be assumed. Cage experiments could be done to see if warthogs can over-winter and reproduce in parts of America that rarely if ever freeze, such as north Mexico and the southern-most tips of Florida and Texas. Would warthogs burrow more deeply in American freezing zones than in no-freeze African zones, and if so, would that protect them sufficiently here? How deeply does fencing have to be buried to keep warthogs from successfully digging under and out? Even if the warthog is not territorial in arid and semi-arid environments, perhaps it would become so in wetter climates like east Texas and south Florida. Are there any other non-African locales where warthogs have been released, and if so, what has been the experience of local control efforts? The Mexican government might want to participate in any or all such research.

I reject the argument that their current status in Texas indicates that we should not make a meaningful effort to extirpate warthogs right now. I believe that their shaky toehold plus our experience with feral swine give us reasons enough to nip warthogs in the bud.


USDA spent a million bucks on an experiment to control feral pigs in New Mexico. Let me say that again, “A million-dollar experiment…” I think it was worth it, too, and believe that a program to eliminate warthogs from Texas costing less than a million bucks might be a bargain in the long run. I would also support passing the cost of warthog control onto Texas sitting-duck hunting reserves, as they are certainly the fount of the problem.

Tuesday, June 16, 2015

From Ditch to Creek

I previously posted two reports about erosion control measures taken on my North Carolina house lot driveway. One was to this blog on September 12, 2010, about the stream crossing culvert (tinyurl.com/pt82u5r) and the other to my On Rappel blog on October 29, 2013, about the driveway ditch efforts (tinyurl.com/omgb8ve). The goals were to control erosion while simultaneously creating potential landscaping water features. I really won’t have time to do any serious landscaping until the house is built, but my efforts seem to have paid off. I hope this is apparent in the following before-and-after photos.

This is what the stream culvert crossing looks like now:


But this is what it started out looking like:


Ugly! You can see a lot of dirt exposed, with stream banks cut nearly vertical. I used a shovel to “bevel” the sides a little by removing the loose dirt and taking the overhanging root mat back away from the stream a foot or so on each side to reduce erosion. (Incidentally, there were a couple of ringneck snakes in the undersides of the root mat). I then placed small logs along both banks in the hope that not only would they retard the tendency to wash out the culvert but also provide a substrate upon which ferns, mosses, liverworts, and other plants could take root in and armor the ground:


The idea was that plants would grow on and between the rotting logs and form a web of roots extending back into the creek bank dirt. Indeed, the first photo shows that the plants readily took root in the logs.

Driveway ditch erosion was of equal concern, and since the driveway runs straight up the hill, so do its flanking ditches. This is part of the west ditch right after I added short split logs to create riffles and pools (and after a rain):


And this is what it looks like today:


You cannot hardly even see the ditch anymore, as it has silted in and the split logs are completely buried. Much of the initial storm water now sinks into the grassy, sediments in and beside the ditch, and what does runs off will sheet flow until reaching an open-top culvert (bottom of photo).

This is the east ditch right after construction:


After several years of vegetative growth, the east ditch looks even better. It gets more runoff than the west ditch, which keeps silt from clogging the ditch, although leaf litter sometimes has to be cleaned out as is evident in the foreground:


Overall, I’m pretty happy with the results. 

Saturday, May 30, 2015

Northern Red Salamander

I am back in North Carolina for the warm months and preparing to start construction on my mountain house. While clearing the house pad of trailers, tools, and trash over the last few days, I have run across some cool critters. Scrap boards were set on the ground next to the portable sawmill so Uncle Ralph and I could mill logs without slipping in the mud. These had to be moved. I knew from previous experience that untreated wood set an inch or two in the ground was good resting/hiding habitat for the northern red salamander (Pseudotriton ruber ruber), so I kept an eye out for them. Sure enough, a 6-7 inch long specimen had burrowed under a grounded board, so I snagged it and this is the best pic of the lot:


After wrestling with an unsatisfactory photo setup with the last red salamander I caught here, I had been giving some thought to upgrading my salamander photo setup. But, having done nothing so far but cogitate, this new Sally required immediate construction. First, I drilled small holes in the bottom of a $2 plastic salad bowl and then lined it with a mat of sphagnum moss scalped from a rotting log:


Placing it in the bowl amongst the moss, new Sally settled right down and let me take a dozen or so pics. The previous Sally squirmed around throughout its photoshoot, but that was probably because the bowl was bare glass and Sally had no place to hide. Perhaps Sally feels more secure in its native element of leaves and moss. Whatever, this time was different. After the photography was completed, I placed the bowl in the ground within an old stump hole in the heavily shaded forest:


And then camouflaged the blue plastic with detritus:


The plan is to leave the bowl in the ground where it will incubate in a natural Appalachian forest environment. Hopefully, the sphagnum moss will live and grow in the bowl well enough to look like a moss-covered hollowed-out stump and be good for small-animal photography.

Also note, while disassembling and burning a cord or so of sawmill scrap, two copperheads, a ringneck snake, a blue-tailed skink, a slimy salamander, and an American toad were uncovered and released unharmed. Only the smaller copperhead was photographed but technical issues prevent me from retrieving the pic, so this older image of a copperhead on that wood pile will have to do:


Monday, April 13, 2015

Terror Lizards

One of my fav jokes when hanging out with my friends next to the lake is to tell them, “Don’t turn your back on the water.” It’s an African saying of gaily dressed people who live in mud-and-wattle huts in crocodile country. I, of course, am far more sophisticated wearing drab polyester in a trailer park and doing my best to turn as many trailers into beer cans as possible. Heck, I don’t have to worry about stepping outdoors into a flock of Terror Parakeets or Terror Muslims!

So, on this cloudy morn after breakfast, I stepped outside to drink the last dregs of my first cup of coffee while standing on the banks of the dinosaurian Orange Lake. One of the pair of moorhens that lives right outside my door immediately spotted me, let out its worried cut-cut-cutting call, and swam slowly away toward the more varied habitats to the east. I think these moorhens have their nest at the east end of the levee that extends from my lot, based on a false-wound theatrical ploy the two gave me last week. So, I imagine the second moorhen was on the nest this morning.

No big deal, just a nice daybreak in cool weather without the sun in my eyes, veg omelet in my stomach, and delicious coffee (ask me to make you a cup some time) on my lips. Then I looked down at my feet at the lakeside floating mat:


Good thing it’s only three feet long!

Sunday, April 12, 2015

ACT - Saarinen Preserve

Arthur and Phyllis Saarinen donated a 78-acre tract to the Alachua Conservation Trust, a non-profit land conservancy, for conservation purposes. Today was the preserve’s grand opening, attended by 30-40 people including the Saarinens and ACT personnel Hutch Hutchinson and Mark Larson.

Now called the Saarinen Preserve, it has 2.6 miles of trails open to the public, all of which are used for hiking, horseback riding, and bicycling. I walked 2.3 miles of them today.



Preserve trails are well-worn and have been recently bush-hogged to widths of 6-12 feet. Other trails connect into the Saarinen Preserve trails from adjacent properties that have been developed by neighbors over the past several years. I don’t know about the access policy for off-preserve trails, but there are markers along the trails where they exit the preserve.

The property is almost entirely forested. There is a small area adjacent to the parking lot dominated by planted slash pine in the overstory and laurel oak and live oak in the understory. Most of the site is cloaked in hammock vegetation dominated by laurel oak and live oak, with a small area in the southeast having abundant sweetgum. The central and southern parts of the preserve’s hammock also have longleaf pine and the remainder of the site has loblolly pine mixed in with the hardwoods. Other species of upland hammock trees are rare. I saw only one small Southern magnolia, one Southern red oak, and a couple of mockernut hickories, but there are also a few small sugarberry and winged elm trees. Interestingly, Carolina buckthorn (Rhamnus caroliniana) is common in the preserve’s southern reaches; I see this shrub only rarely, so it was a treat. Ebony spleenwort is common. Several species of invasive exotic plants also occur, Ardisia and camphor being abundant in certain areas and Japanese climbing fern occasional. The Ardisia is loaded with berries:


The soils are derived from the Miocene-aged Hawthorne formation rather than the usual Plio-Pleistocene sands in this region. This does not surprise me, however, because the preserve is on the same ridge that Warrens Cave, Dead Man’s Cave, and Breath of the Rock Cave are located on and they too have the dark Hawthorne clay soils. ACT representative Mark Larson told me that every time they dug a hole for a fence post, they hit rock about 18 inches down and the rocks were boulders, not bedrock. What I can’t figure out is how those boulders got themselves imbedded in the Hawthorne formation in what Mark basically described as a layer of rocks. Curious, that.

It will be interesting to see what ACT comes up with in their land management plan for the preserve. I imagine they will figure out how to replace the laurel oaks with quality hardwoods. The cave properties mentioned above indicate that the Saarinen Preserve historically supported a species-rich mixed forest dominated by live oak, Southern red oak, Southern magnolia, mockernut hickory, redbay, sugarberry, American ash, and winged elm, among many others. But 78 acres of laurel oaks will be tough to battle!


Monday, March 2, 2015

Birdsbesafe Collar Covers



A so-called conservation biologist at St. Lawrence University in Canton, New York, named Susan Willson has five cats, two that live outside and three indoors. One of the outdoor cats, named “the Gorilla,” is an admitted “serial killer” cat, one that is “especially adept at killing birds.” She tried but decided not to keep this cat indoors because it gets into “a peeing war” with her three indoor cats, so she is willing to accept her cat killing a lot of birds because she does not want to euthanize her cat. All things considered, she would fall under what many conservation biologists call a “cat lady.”

But she evidently feels at least some guilt over the needless loss of wildlife at her hands because she bought a Birdsbesafe Collar Cover that is claimed to reduce bird kills, and then conducted a study to at least partly justify the collar cover as adequate mitigation for those wildlife kills. Her study is reported in Birdsbesafe: Can a novel cat collar reduce avian mortality by domestic cats (Felis catus)? S.K. Willson, I.A. Okunlola, and J.A. Novak. Global Ecology and Conservation 3(2015) 359-366.

Birdsbesafe’s product consists of a tube of brightly colored cloth enclosing a break-away nylon collar and having a reflective edge trim to make it easier to see by motorists at night. Collar covers are brightly colored so that birds and some other prey species can more easily spot cats stalking them. Reds and oranges are used extensively along with yellows; however, they noted that reds, oranges, and yellows can match autumn leaf colors and thus might camouflage cats somewhat and be responsible for the increase observed in autumn bird predation. Many mammals, including nearly all nocturnal mammals, cannot see red colors, rendering Birdsbesafe’s product of little value to them. Conversely, reds and yellows possibly come across as camouflage to color-blind mammals under certain conditions. Also, collar covers reflecting ultraviolet could provide additional visual warning to some wildlife, but this was not addressed.

Willson et al. found that 71% of tested cats got used to collar covers within 5 days. That means the collar covers will be problematic for 29% of the kind of cats they tested. Since all tested cats were fully domesticated human-owned animals, it is probable that feral cats would exhibit significantly lower collar cover acceptance rates. In combination with the difficulty in trapping and then re-trapping feral cats to install and replace lost break-away collars, effective use rates are likely to be quite low and thus ineffective mitigation. This point was not reported by authors or noted by Birdsbesafe on its website.

Birdsbesafe collar covers are made of an unidentified “fabric” and designed to enclose a nylon collar, both of which will absorb and hold water and other liquids. If the product is never washed, such as with feral cats, cat hoarders, and other low-quality cat owners, collar covers can become stiff with embedded algae and dirt (and age). This could result in open sores on the cats from abrasion and could snag on brush and fencing when running from predators. This may not be an issue in a fenced-in suburban back yard, but both issues could constitute cruelty when applied to feral cats whose collars cannot be replaced due to trap-shyness. Willson et al. and Birdsbesafe do not address this issue even though authors suggest that collar covers be used on feral cats.

Willson et al. tested the successfulness of collar covers only on serial killer cats like “the Gorilla.” They placed collar covers on 54 cats in the fall and 19 cats in the spring for twelve weeks each, and claimed that collar covers reduced bird kills by a factor of 19 times in the spring and 3.4 times in the fall and decreased small mammal predation by about half in the fall but had no effect in the spring. In comparison, belled collars were shown by a second research group to reduce bird and mammal kills by 50%, although a third study revealed that cats can compensate for the bells and develop different hunting strategies. A fourth study showed that the CatAlert product, which produces a beeping sound every seven seconds, resulted in cat kill reductions that were not significantly different from bells. The CatBib is a large piece of colored cloth attached to a collar that not only visually warns birds and color-vision enabled mammals but also places a physical barrier between cat paws and wildlife victims. A fifth study found that 81% of CatBibbed cats stopped catching birds and 45% stopped catching mammals, but noted that owner acceptance would likely be small because the CatBib is bulky and appears awkward.

The serial killer cats that were employed in the Bridsbesafe collar cover study habitually brought home killed but allegedly “intact” prey. Obviously, this protocol does not account for kills that were simply left in the field, stolen by other predators, or eaten. This could be a significant flaw in the data because large numbers of uncounted kills could go unreported:

Assume that an uncollared cat over a week’s time kills 10 birds, eats 2 of them, and brings 8 home. Assume that a Birdsbesafe collar cover is then put on that same cat and it then kills only 2 birds but eats both of them over the next week. Willson et al.’s conclusions would then be that collar covers reduced kills from 8 to 0, or by 100%, when the real rate would be 80%.

Alternatively, assume that the uncollared cat over a week again killed 10 birds, ate 2 of them, and brought 8 home, but a collar cover used over the following week resulted in only 4 bird kills, 2 of which were eaten and the other 2 brought home. This would result in a calculated 75% reduction in kills when the actual number would be only 60%.

Birdsbesafe and Willson et al. can play with the numbers and come up with any success rate they want, but any way that I look at the numbers, authors’ results are optimistic and may actually be gross overestimates of success because they do not contain a correction factor to account for kills not brought home. Has any research been done on quantifying such a correction factor? I did a lot of literature reviewing on this subject a few years ago and do not remember any such correction factor being published in the scientific literature, but if a correction factor does exist, I am sure that a scientist like Willson at an institute of higher learning like St. Lawrence University would have applied it. If a correction factor does not exist and if it is potentially important, then why do Willson’s and other research groups not ascertain it? It would clearly be a significant gap in our knowledge of cat kills and cat prey mitigation.

Willson et al.’s data collection occurred during two seasons, spring and fall. There were no reasons cited for those seasons nor for not sampling during other seasons. I suspect it had to do with summer college vacations and winter cold, but authors should have addressed whether these two seasons are representative of a full year or else should have pointed out that their results may not be indicative of an annual period. Birdsbesafe’s 87% reduction claim implies an annual basis, which I think is misleading.

Willson et al.’s tested cats brought home 19 species of birds from 12 families and 11 species of mammals from 8 families, totaling 50 birds and 136 mammals. Unfortunately, authors did not include a raw-numbers table of before-and-after kills, so we cannot scrutinize the actual data ourselves. The only raw data provided by authors was a list of kill numbers by species, and the only reduced data provided is a bar chart of average kill numbers per cat per week. They then report their results in terms of reduction multiples, stating that uncollared cats killed 19 times more birds in the spring and 3.4 times more in the fall. Similarly, uncollared mammal kills were twice as high as collar-cover kills in the fall but were equal to collar-cover kills in the spring. In other words, if I have done my math correctly in the absence of raw data, collar covers reduced bird kills by 77-95% and mammal kills by 0-50%. However, considering the uncounted-kills flaw, those numbers may be overestimates by 10%, 20%, or even more.

Willson et al. reported that only one herpetofaunal (herp) prey item was brought home, a spring peeper frog. They claimed that the reason for this low number is that the study was done in northern New York, implying that this locale has low herp populations. I am not sure if that is true, but even if it is, the implication should have been clearly stated as a fact and should have been referenced.

They quote a sixth report that free-ranging cats wearing kitty-cams caught more herps than any other type of animal. Additional reports have found that cat owners are more likely to bag and freeze certain animals than others. Owners (1) readily collect small birds and intact (non-bloody) mammals and lizards, (2) are less likely to handle shredded carcasses, (3) are unlikely to even see, much less collect small herps half-eaten and left by the cat in the lawn, and (4) snakes of any kind or size. Therefore, it is likely that Willson et al.’s tested cats did bring home more herps than owners were willing to collect and report, so authors were correct to eliminate herps from their study.

The generally accepted and most often way in the biological literature to convey before-and-after changes is to report percent changes, whereas Willson et al. reported only reduction multiples. The latter are indeed fine to impart, but only if percent changes are also reported. Authors’ peers cannot otherwise confirm the original findings, which is important if herps or other prey items are left out of the equation.

Willson et al.’s data is based on kills that were collected by cat owners and saved for seasonal pickup, thus relying on the cat owner claims that they saved all the brought-home kills. It is known from other studies that many prey items brought home are in varying states of intactness and that owners will leave a particularly stinky mess on the lawn rather than bag and freeze it. This was not mentioned by the authors even though it is a known flaw of owner-based data collection and will underestimate predation rates.

Willson et al. initially used collars that easily broke away and were lost approximately 50% of the time. They replaced that model with one that broke away less than 10% of the time. Obviously, different break-away rates will produce different efficacy rates, but authors neither gave different efficacy rates for the two collar models nor reported whether the two data sets were determined separately or lumped together. This should have been clarified. Regardless, authors did not name the brands/models of the tested collars, contrary to standard methods. This failure means that their experiment cannot be independently repeated by others.

Willson et al. did not address whether any of the tested cats learned how to open a break-away collar or if the broken collars were accidentally separated. Although not integral to their study, cats may find it easier to learn how to disengage some collar models than others, and this might be why one of their two models broke away so often. This is yet another reason why authors should have listed the collar models tested.

Only 26% of Willson et al.’s participating cat owners said they would buy and use cover collars in the future. Their reasons were break-away losses, cat comfort, and owner dislike of the product. It is good to note that Birdsbesafe developed a new break-away collar from stretchy nylon fabric in order to lessen the break-away issue.

Willson et al. focus on bird kill reductions and discuss mammal kill reductions but little. This is perplexing, since mammals are as ecologically valuable as birds and cats evidently kill more mammals than birds. It is obvious to conservation biologists that it is at least as important to protect mammals as birds. True, Birdsbesafe collar covers are only claimed to reduce bird predation, but the correct goal is to protect all wildlife from free-roaming cats, so a birds-only mitigation device is woefully inadequate. It begs the question of why authors expended resources on a product with such limited value.


In summary, Willson et al.’s report is flawed in terms of (1) its reason for being, which was to assuage guilt, (2) non-standard and misleading methods of reporting kill reductions, (3) failure to admit to probably low feral cat use rates, (4) failure to recognize potential cruelty to feral cats from dirty, stiff collars, (5) failure to compensate for uncounted kills in efficacy rate estimates, (6) failure to justify projecting results from two seasons out over the entire year, (7) inadequate reporting of raw data, (8) failure to justify using a product designed for bird protection even though it is evidently unsuitable for other taxonomic groups such as herps and mammals, (9) failure to list the tested collar models despite very different loss rates, and (10) failure to admit that low owner acceptance means that collar covers can mitigate only for relatively small numbers of prey items. The cat kill reduction values reported by Willson et al. and highlighted by Birdsbesafe are therefore unwarranted at best and deliberately misleading at worst.

Monday, February 9, 2015

Great Blue Heron Method for Eating Catfish

The camera trap last night produced nothing, a surprise considering that it has videoed wildlife every night since being set out. Perhaps the critters are tired of dried instant rice, or maybe they aren’t interested in tomato peelings and spoiled blueberries. New bait is in order – more banana chips at the very least will be set out tonight.

But the day’s Orange Lake wildlife viewing has started out much better. While on telephone hold, I noticed a Great Blue Heron standing on the bank maybe 50 yards from me, so I put binoculars on it to see why it was not in the marsh. The bird had a 6- or 7-inch brown bullhead (Amieurus nebulosus) in its mouth. While I watched, the heron dropped the fish, turned it over belly up, and used its beak to stab into the head through the fish’s softer chin. Each stab involved the top and bottom bills slightly agape, so that it actually made two wounds with each thrust. This happened repeatedly, with the fish slowly showing less and less life over time.

Ordinarily, we see a heron snag a fish and swallow it right away, but the catfish’s three long spines prevent quick ingestion and the poison gland at the base of each spine is also a deterrent. After 15 or 20 minutes of this, the fish was lifeless and the heron began pecking at the bases of the spines to break them. It returned to the water several times during the procedure to wash off dirt and grass adhering to the fish’s sticky skin. After killing the fish and removing its spines, the heron returned to the lake to wash it one last time and then swallowed it.

Contrast this heron’s method of removing catfish spines to that of a Double-Crested Cormorant I reported on February 22, 2008 at tinyurl.com/lljuy2o.


I figured the heron would loaf for a while to wait for the fish to pass through the gizzard, but no, it went right back out to forage for more prey, catching another little victim or two: