Reptile & Amphibian Forums

Hey from Utah,

at the cost of much energy and I thought well planned searching I have found no sign or scale of the elusive Rubber Boa.

Any tips or advice would be grand ! No secret spots just general suggestions?

thanks ever so much,

Dr. G

Dr. G.:
My son Ryan lives in Utah and has some knowledge about the species in that state. If you check his web site at www.rubberboas.com you can send him an email message.

If you searched during the daytime at this time of year, I can understand you coming up empty handed as this is the next worst time to find the species during the day (only worst time is the dead of winter). During warm weather, the species in much of its distribution is more readily observe at night by driving roads through suitable habitat. In many regions, it also helps if it has rained recently or at least there is cloud cover.

If you still wish to make diurnal searches, if mid day temperatures reach into the 80's and above, I suggest going out early in the morning, say 8 to 8:30 and turn cover, mainly in the form of rocks in suitable habitat. The species has a very extensive north to south distribution in the mountains immediately east and adjacent to the major cities in the Salt Lake Valley, from Logan and above on south to below Provo.

Come to think of it, Ryan is in Idaho at his wife's family reunion so you won't be able to get in touch with him for a few days. There are a number of amateurs in the area that are quite savvy in finding the species up the canyon in those mts. but I do not have their names, phone numbers or email addresses.

You might make the same appeal in the '[bleep]' forum as there are likely to be some Utah herpers attending that forum.

Richard F. Hoyer (Corvallis, Oregon)

We I agree with him. I would liek to add I found mine in the forest "About 8 miles in" in a damp area between 8-10am under a biece of bark on a roted oak tree. That is the first and last one I have observed in my area "I kind of feel bad for colecting it" Be prepaird however if you do infact collect one these snakes can be verry verry picky eaters. I have read that it can take from 9 months to a year before they will take food. Mine in fact has yet to take food.
RR

Jason:
Have you reviewed Ryan Hoyer's web site? On the Rosy, Rubber, Sand Boa forum, I provided input to an individual that recently found a Rubber Boa in Idaho which may be of some help.

That being said, as a whole, the species is somewhat fickle with respect to feeding. During my field reacher effort this spring, I returned with more boas than I really wish to care for during the summer until I return to release them in the fall.
Of the 38 boas acquired this spring, there are still 7 specmens that have yet to take a meal.

Last year, a female from the Scodie Mts. in S. Calif. produced a litter of 5. Four of those juveniles have now take meals but there is one that still has yet to take a meal. In 11 months since birth, it has gone from 5.7g to 4.6g, a loss of 19.3% of its original weight yet is still in reasonable conditions. If it does not take prey by late Oct., I will try again beginning next mid March when I remove specimens from brumation.

On the flip side of the coin, a juvenile boa found this past 5/25 northwest of Bishop, Calif. in Mono County takes prey items just about every time offered.

If one is patient and maintains their Rubber Boa at relatively cool temperatures, eventually almost all boas with begin to take prey voluntarily. The major problem as I see it is that many herp keepers maintain their specimens at artifically high temperatures and if their snakes refused food for a considerable length of time, the snake rapidly uses up all body reserves and wastes away.

Richard F. Hoyer

Just curious about your research, Dr. Hoyer. What study are you conducting that requires a sample of 38 boas? Thanks in advance.

Erik:
I am an amateur much as are most individuals on these forums but simply have taken my hobby seriously enough to conduct basic
investigations into various aspects of C. bottae life history. My current emphasis deals with taxonomic issues and sample size can be very important in such an endeavor.

I made two trips to S. Calif. this spring. Weather conditions were mostly unsuitable for conducting searches during the first three week effort and I was able to record data on only 9 C. bottae. I returned later in May, released a number of those specimens, and continued searches in a variety of regions including southern Oregon. I only spent 6 days during that trip from Corvallis, Oregon to as far south as Alamo Mt. in Ventura County, about 900 or more miles distant. I was able to examine and release about 7-8 specimens during that time. But most of my time was spent driving between regions and making searches leaving little time to examine the specimens I found. It takes anywhere from about 20 to 30 minutes to examine and record data on each specimen. Hence my returning with more specimen this year. Now that they have been examined, most will released where found later in the year when I return to Calif. as has been the case since 1994.

And 38 specimens is not even a drip let alone a drop in the bucket when it comes to this species and sample size. Those specimens represent 7-8 different regions. To collect a reasonable sample from each area takes a number of years and in most regions, the sample size will remain small. To increase samples size, I also examine preserved specimens from a number of institutional collections.

This is only a partial explanation but hope it satisfies your inquiry.

Richard F. Hoyer

Hello again Dr. Hoyer. Thanks for the reply but perhaps I missed what specific goal your observations are leading toward. I, too, am an amateur herpetologist and have caught lots of boas over the years, as well. The one thing which has always struck me about this animal is how really undifferentiated it actually is no matter where you find it. Sure, some are lighter, some are darker, some are green, some are brown, some eat better than others, baby coastals are born dark instead of pink, but aside from that, I have never noticed any tangible difference between a boa from northern California, Southern California, or anywhere in between. Is there something specific you are trying to demonstrate through your field activities? Thanks once more.

Eric:
My specific and current goals were mentioned in the first two sentences. I have been trying to discover all I possibly can about the life history aspects of the species.

The current focus or goal deals with trying to shed more light
on the relationships between various boa populations--in other words, a study dealing with taxonomic issues.

Existing literature on the Rubber Boa was pretty skimpy when I began my involvement with the species in the early 1960's. You could go to a univerity library and become and expert in a few days. Most of the literature at that time dealt with taxonomic issues and what eventually became known about the biology of the species was contained in scientific notes or short articles. The situation is only slightly change at the present time.

In 1974 I published a description of the boa population here in W. Oregon from a sample of somewhat over 300 specimens. I documented sex ratios amongst three age classes, described dimorphic differences between the sexes, and touch on taxonomic issues by indicating that the then recognized subspecies of C. b. bottae and C. b. utahensis was unworkable within Oregon.
Most of the information was new.

As a science teacher and helping raise a family, although I continued to go afield and gather information, time was not available to organize data and prepare drafts for publication. In late 1990 I was asked to present a paper at a symposium in the Seattle area and the following year, the proceedings were published. My topic dealt with reproduction in the species detailing data acquired on hundreds of litters. The paper was poorly written but the data was solid!

The Southern Rubber Boa (C. b. umbratica) had been desribed by Klauber in 1943 based on only two specimens, one each from the San Jacinto and San Bernardino Mts. in S. Calif. Some authors discounted that designation while one author suggested that umbratica be elevated to the species level. Upon retirement, I proposed a study of the SRB in conjuction with Dr. Glenn Stewart of Cal. Poly, Pomona. Virtually nothing was known about that race of boa which in 1971 had been designated as "RARE" by the Calif. Dept. of F & G later changed to "Threatened" in 1984.

I undertook that specific field study to try and shed some light on the basic biology of that regional population of C. bottae. Two papers developed from that study which were published in 2000. Essentially all of the information in those papers was new including information on diet, reproduction, size,
predation, etc. For instance, the conventional published thought
on the function of the blunt tail of C. bottae was for use against predators. This view was held despite the fact that no study had ever been conducted or data presented toward support of that position. Information on the basic function of the blunt tail acquired since the late 1960's, and alluded to in the two papers published in 1974, was again shown in the SRB study that the major function of the blunt tail is involved in feeding behavior.

At the time our study began, there was only about 28 - 30 preserved specimens of the SRB in all collections, not really large enough to make many determinations with confidence. Hence, one of our goals was to increase the size of SRB sample. We did that and as a result, were able to establish beyond any reasonable doubt that the SRB population in the San Bernardino Mts. was a dwarf form of C. bottae.

Because the issue of subspeciation was unsettled, the second project for was to address that issue. This meant acquiring larger samples of the species from various regions in which there was little or no representation. That is the thrust of my present efforts.

In a sense, you are correct in that superficially, all rubber boas look pretty much alike. However, the species probably has the most variation in major scalation features of any native snake. The scalation is so variable that in the late 1800's and early 1900's, there were about 6-7 species of boa described in 3-4 different genera. It wasn't until about the 1920's that all species were then placed into a single species we now identify as C. bottae. I use this variation in scalation as a natural tagging method. Boas are unique in this regard so that this natural type of fingerprinting allows me to identify individual specimens one from another.

You have alot of company in not being able to describe differences as despite it large distribution, its secretive habits do not readily lend to finding large samples and thus the species has been largely ignored as a subject for research.
When Dr. Stewart sent me data on 19 preserved SRB specimens in 1973, I noticed that the lengths he provided of those 19 SRB specimens were all pretty small. In my reply, I remarked on this point wondering if the SRB was a dwarf race of rubber boa. As mentioned above, they are and since 1997, I have confirmed that this dwarf form of C. bottae occurs in most if not all of the isolated mt. ranges and peaks in S. Calif. From the current evidence, C. bottae in the rest of the species distribution in N. Am. is what I call the large morph. Beside this size difference, there are scalation difference between different populations in different regions, some of which I believe may turn out to be statiscally significant.

(Mr.) Richard F. Hoyer

I just wanted to toss in here that I am verry sad to report my rubber boas disapearence. I got home last night form work and went to feed him and he was gone. I completly disasembled his cage with no luck. Hopfully he will turn up but sence my wife has to cats I doubt it.
RR

Hello Mr. Hoyer,
Thanks for all the information you have to offer others here. I have long been a fan of Rubber Boas but my experience has been limited to one WC specimen and one CB specimen. The WC was caught by my brother about 21 years ago when we lived in Monterey, CA. We had a favorite Gopher Snake haunt and one day my brother found the little Rubber Boa. Unfortunately he did not stay but a day before he escaped. About 20 years later my brother happened to purchase a trio of Rubber Boas, one of which he gave me. I ended up returning this to him when I was getting rid of some snakes, but this was one of my favorites. Over the course of the few months I had him, he was one of the most aggressive feeders. He would eat up to 7 pinkies at a feeding, and was out prowling each night looking for more. By the time I returned him to my brother, he was considerably larger than his littermates. My question is what is their maximum size (length and girth)? As adults, can they eat adult mice or moles? It is often difficult to judge the size they get from pictures posted as there is usually nothing for scale purpose in the photos. Thanks! Milt

Milt:
Concerning your question about size, I have only kept records on weights along with total and tail lengths. The weight of a boa is only some measure of the condition they are in relative to their length at any point in time. It can vary from year to year depending on prey availability and in the case of some females, whether they are in reproductive condition or have recently produced a litter. Thus, I have never taken grith measurements.

Concerning maximum lengths, there are a number of considerations involved. First, there is a sizable difference between mean and maximum length attained by males and females of any boa population with males being considerable smaller than females on the average. Secondly, there are now two rather distinct size morphs in C. bottae, a dwarf form that is found mostly on the isolated mt. peaks and mt. ranges in S. Calif. and a larger morph which occurs from at least southern Tulare County on north and east through the rest of the species distribution.

I have not been able to acquire a large enough sample of every dwarf population to make any precise statement as to how uniform or how much variation may exist in those populations with respect to mean and maximum male and female lengths. But as a group, the largest females approach or slightly exceed 22 inches and the largest males are in the neighborhood of 19 1/2".

A considerable mount of variation is known to exist between populations of the large morph with respect to mean and maximum lengths. Populations at high elevations tend to be smaller. Whether there is a genetic basis and/or this situation is due to shorter seasons along with reduced prey species and availability is unknown. However, all populations I have examined have females that reach at least 25' and males that reach about 21".

I have examined live specimens from Oregon and Calif. in which females have reached 30" or a bit more. Considerable shrinkage occurs when specimens are preserved yet a female boa in the Cal. Poly, Pomona collection from the Lee Vining area on the east slopes of the Sierra Nevada Mts. was 29". It would be my estimate that when alive, that specimen probably exceeded 31".

Regarding the size of prey that can be handled by this species, obviously the larger the snake, the larger the prey that they can consume. That being the case, large adult females can consume moderate size voles, smaller size moles, gophers, chipmonks, and the like. Adult males struggle but can consume adult deer mice as about the largest prey they can handle. But the species by and large is a nest robber specializing on the nestlings of small mammals. Depending on the region, they also consume lizards, lizard and snake eggs, and birds. There are some other species consumed such as bats, snakes, etc. but they are way down the list in the percentage of prey taken.

Richard F. Hoyer

Yes I have read the website many time over in the last few months. It is done well and has a lot of good information on it. Unfortunately I have tried braining and all of the above and the snake still refuses to take prey. I feel like setting it free were I collected it but I keep seeing reference to these snakes going up to a year without eating. What would you recommend I do. I currently keep a breeding pair of S. Alligator Lizards as well as a baby Garter Snake and California King Snake out of all my reptiles my Rubber Boa is the only one that wont readily take food.
RR

Jason:
It would help if I knew more details. When did you capture the specimen and what is its length and present weight? How are you maintaining your specimen--, what type and size container are you using to house the specimen, what is the substrate, is it by itself, do you have multiple hides for it, does it wander around in its enclosure during the day, at what temperature is it being maintained, do you allow the temperature to fluctuate during 24 hours, that is, do you allow it to cool off at night and early morning or are you maintaining its enclosure in an area with a relatively constant 24 hour temperature, is it exposed to the normal 24 hour dark/light cycle or is it exposed to constant light? Look at its tail and if it is partly collapsed (not filled out), it may be dehydrated and/or being kept at too high of temperatures and thus using up body reserves rapidly.

Even if I knew the above and recommended adjustments, there is no guaranty that the boa would take prey. After all, as I indicated in a prior post, there is one neonate from last year that has yet to take its first meal and it was born on 8/19/02 so is over 11 months old.

The first thing you might do is to take a quart or gallon jar and place the boa in about 1/8" of water in the jar with holes in the lid and leave it undisturbed for 15 -20 minutes. If it immediately begins to drink when you gently place it in the bottom of the jar with water, then there is some chance it was slightly dehydrated. If it continues to drink for a prolonged period of time - 30 seconds or longer, then it was definately dehyrated.

If that is the case, then I suggest you use a shallow, plastic lid from a half gallon or gallon container as a source of water and place it beneath a curved piece of bark or other such cover object so at night when the boa comes out to wander around, it can access the water source beneath the hide.

After killing the pinky mouse, have you washed it with detergent then thoroughly rinsed it? After doing so, poke only a small hole in the brain case with a pin or needle and squeeze only a small portion of fluid from the hole and spread over the forehead and nose of the pinky. Place the pinky under a hide with space for the boa to crawl beneath. Make sure the ends of the hide are covered so it is dark beneath the hide (as is the case when wild boas invade the nests of native small mammals),
then enter the boa at the entrance of the hide and leave it for 2-3 hours. At this time of year, this process is probably best done at night as the species is pretty much noctural during warm weather and thus actively hunting during the night.

Even if you do all of the above, some specimens simply do not readily take prey under captive conditions. I had one adult female given to me by herpetologists Dr. Robert Storm of Ore. St. U. back in the early 1970's that went for 14 months before taking her first meal. That was a great lesson in learning to be patient and for maintaining specimens of this species at relatively cool temperatures.

Richard F. Hoyer

The snake looks to be a pretty good health. I am keeping it in a 10G eclosure with full hood. The hood has air hols and 2 15W lights. I keep the cage from 70-80 during the day and let it drop off at night simpy by turning the light off. The snake has several hids wich include but arenot limited to rocks and fake plants. There is a fake tree in there that is holowed out for the snake to crawl, hide or sleep in its manny cavities. The snake hides all day and comes out at night. I have tryed brainign a pinky but to no avale. The resone I coleced it? Not sure realy. There was no specific resone I turned over a piece of bark and here it was. After studying it for a half hour or so I decided to take it home. The size looks fairly perportionate to the length I would have to say it was not undser or over wieght. It is roughly off the top of my head about 8-10" long. I must say these snakes do teach you patients. Unfortunatly they hit the check book hard as I do not yet have a full breeding population of mice I must go down every week and buy 2 frozen babbys. Thats ok though its worth it.
RR

Richard,

thank you very much for your reply. I will both visit the web site and email your son. It is marvelous that someone would take the time to answer a strangers request.

Have a great weekend !

I found 11 in one night last year, it was around 55-60 degrees, fur tree moist areas are best.
Chuck

Hi Chuck,

thank you for the response. Did you have such luck here in dry and hot Utah?

Yes, they're everywhere here. Try east cyn, lambs, cyn, big & small cottonwood cyns, Logan cyn, and anywhere there are conifers and creeks near and you should have good luck, go after a cold rain. I found mine last year when it was 55-60 degrees. I's also try American fork loop and provo cyn. the top of the loop looks real good near the ferns.
Chuck

ps, I'd say that they are as common as the gopher and yellow bellies if you look in the right places.

Thanks Chuck,

I live just west of the Cottonwoods and have not had any luck. Although the temps were near 80. I will wait until it cools down and a cold rain? Did you have to look under items or were they out and about?

thanks so much

I like Chuck have found high numbers of boas in the Wasach Mts. east of Salt Lake in one day or night. On two seperate occasions this year I have found 17 individuals and 13 on another day a month apart. They are very common but also very secretive and you have to be in the right places at the right time. Good luck boa hunting.

Thanks Saun,

perhaps I will improve my skills and actually find one. Did your luck also occur on days below 70 degrees? Any luck in the Cottonwoods..........

again yours and Chucks POSTs give me hope. Thanks

Yes the boas were found under 70 degrees. I'd have you e-mail me personally but I'm reluctant to post my address on a public forum. If you know another way to contact me I'd be willing to help you find one.
Shaun

Hey Shaun,

I sent an email via the email option. Being new to this forum I am not it will work or if I did it correctly. Thanks so very much for your emails and help. Please let me know if you received any mail.

Thanks

Dr. G.
Probably did not mention or emphasize that the best time to conduct searches for many species of snakes, including and in particular C. bottae, is in the spring and again in the fall. However, the window of opportunity is much longer in the spring.

In the late spring and early summer, once subsurface temperatures rise considerable, the snakes no longer need to come to the surface or under cover objects on the surface in order to thermoregulate as the can now find those temperatures below the surface. Also, in the spring, freezing or near freezing temperatures are the norm in the late night and early morning hours so the species is primarily diurnal at that time of year. But once subsurface temperatures are warm enough for the species to find its preferred temperature and it is generally too hot during the day for safe surface activity (and they have a wide range of preferred temperatures), they become crepuscular and noctural to a great extent. This can be viewed even in captive specimens at mid summer in which the boas remain hidden under cover objects in their enclosures only to be seen wandering around in the enclosure at night.

Knowing the above, I rarely go out during day light hours during mid summer, warm weather. Where I can sometimes find upwards of 30 - 40 boas during the day in the spring, I am lucky to find one during this time of year. And I have a huge advantage over most individuals in that I make use of artifical cover objects in order to find all of my specimens locally.

In my studies of the SRB in the San Bernardino Mts. of S. Calif., even during the spring when it was going to be warm on any particular day, I would purposely start early in the morning around 8:30 - 9 AM then quit around 1 PM or thereabouts as from that point on, making searches was essentially futile as the boas would invariably retreat underground when surface tempertures became too warm.

I have not gone to driving roads much at night but I know a number of individuals that have found a good number of specimens in this manner over the years. I picked up two last fall north of Bishop, Calif. driving roads. It seem to be particularly effective with cloud cover and/or after a rain.

Shaun V. showed my son Ryan where he had observed the 17 adult males but it must be emphasized that this was in the spring. Go back to the same spot now during mid day and I would very much be surprised if anyone could locate even one specimen.

But I am the first to acknowledge that others may have different experiences and techniques that work in their particular region so those in Utah will know far more than myself about their area.

Richard F. Hoyer

Richard is right that about the only time to see boas on the surface or while flipping is mostly in the spring and fall and right now is not very productive other than night driving. I have found several the last couple weeks driving at night and one about 2 hours before dark one warm evening that had just eaten quite alot.
Shaun

I am eternally grateful to you Richard for your time and expertise. I shall await cooler temps. Thank you

Just road cruised.

Dr., keep in mind that when you do find one it probably won't eat well. They like voles, moles and gophers. Sometimes lizards. Domestic mice aren't their favorite.
Chuck

Chuck thanks for the warning and rest assured if I find one and bring it home, I will be posting any problems. Why invent the wheel when other better informed folks like yourself are out there. So, thanks and email me if you feel generous enough to suggest roads or areas to look.

Again my thanks