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I need some help sexing my hernandezi as I have never done it before. I have an inkling by comparing the two, but am not positive. Attached is a picture of the cloaca of the one I beleive to be male. I will get a shot of the 'female' when they wake up tomorrow. Thanks for any help.

Yes, this is a male.

Lester G. Milroy III

...would I also be correct in sexing this one as a female?

~Aaron

BadBoid, we'd sure like to see a full close up pic of the two if you are willing?
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2 Kings 6:15-17

Heres one I just took. The smaller one with all the orange and white is the one Lester confirmed as being a male. The larger one with all the deep reds is the one I think (and hope!) to be female. I notice the male doing a lot more of the head bobbing and 'push ups', and they get along far too well to both be males.

This is a male also.

Lester G.Milroy III

That is somewhat disappointing. Can anyone suggest where I might find some females for these guys? I do not see them offered as much as DHLs and such. I think this would be a neat one to foster in captivity. They do seem a degree heartier than some other species.

It is a little difficult to tell from a photo but both look to be females to me. Males have enlarged post anal scales. Do they have these? Healthy females will have fat build up in the lower tail which can be mistaken for hemipenial buldges. This method is reliable for all species except for p. cornutum.

Neither of them have noticeably enlarged post-anal scales. I also would have thought there would have been some sort of territorial aggression if they were both males. I watched them very closely and observed none. Are HLs just not very terrotorial?

None of the HL species show any form of territoriality or aggressive behaviors toward each other or toward other species.

Lester G. Milroy III

Aggression has been reported in ditmarsi(Montanucci), mcalli(Baur), and cornutum (Whitford and Whitford). I have personally observed aggresion in female to female taurus and full on combat in wild male to male mcalli.

Aggression is a rare occurance. Richard and I had a discussion on this years ago concerning P. ditmarsi. Other reports have also cited aggession as a rare occurance. With all of the species I have worked with, in communal groupings, I have never seen aggression (captive or in wild populations). There are also reports of P. cornutum charging human captors. Aggression? How about a defensive posturing?

Aggression is not a typical behavior.

Lester G. Milroy III

Just out of curiosity, from what species did your opinion generate? You have told me you only work with one species (coronatum) "captive or in wild populations)". I thought the other two (modestum and platyrhinos) didn't do well for you?

I primarily work with P. coronatum, but I have worked with all others except P. asio and P. ditmarsi. I have had some good discussions with Richard Montanucci on P. ditmarsi and their ecology and biology and have had some good discussions with Wendy Hodges about P. asio.

All have done well for me in the past, and present, in gathering baseline data on ecological and biological data. It is not opinion, it is direct observation.

Lester G. Milroy III

I'd be very interested to know your experience with bracconieri, taurus, and obiculare. Did you keep them or conduct field work in Mexico? Your statement "None of the HL species show any form of territoriality or aggressive behaviors toward each other or toward other species. " is completely false (but most all of your other statements are as well so it is no surprise). When describing observations based on a few individuals it is grossly inaccurate to apply it to all individuals for all species is it not?

Well Jeff, here you go again. You just never cease to amaze me.

You have no idea what work I have done with horned lizards. You have no idea the data I have on horned lizards. I share the information I have as I see fit, to answer questions people have on horned lizards. My answers are based on observations in the field and in captive study. If you do not like it, that is your problem.

I maintain photographic records and video tape records of my observations. I have hundreds, if not thousands, of hours in the field and in captive study of horned lizards. If you have a problem with that, to bad.

When was the last time you did a PVA on any species of horned lizard? When was the last time you radio tracked horned lizards to determine their home ranges? When was the last time you took blood samples to do hormone cycle analysis or DNA analysis? When was the last time you did a Lincoln-Peterson index population survey. When was the last time you did a plant density analysis in horned lizard habitat for spacial analysis and habitat utilization?

When was the last time you had permits to legally capture and study any species of horned lizard? When was the last time you worked with any state F&G LE unit to curb illegal collections of horned lizards? When was the last time you read the notice on this forum header about the status of horned lizards in many states?

My experiences with any species of horned lizard is none of you concern. What ever I share on this forum, you turn into some sort of argument that is in no way constructive.

Do you have any idea what the differences are in aggressive behavior and defensive behavior? Probably not. I stand on my observations that aggressive behavior is extremely rare and that horned lizards do not show any form of territoriality displays. If you do not like that observation, prove it wrong! Give me a sample size that makes it a false observation. Give me the details of the confrontations: weather conditions, time of the year, temperatures, resources available, etc.

I am a biologist, Jeff. If you do not like it, that is just too bad. I talk with other biologists all of the time. I work with ecologists, botonists and entomologists all of the time. I also work with F&G and F&W and their LE agencies. If that troubles you, oh well.

When I publish my research and studies of horned lizards, you will probably argue with it also. You will argue the mean, the mode, the standard deviation, the mDNA mapping, the hormone cycles, the PCR methodology. But you know what, you will have to understand all of the above first to even have a clue what the research is presenting.

So, Jeff, if you want to discuss, and I stress discuss, horned lizards, keep it at that and if you disagree, show me the observational data. Not anecdotal information. The data!

Lester G. Milroy III

Without getting involved in this feud you and Jeff seem to have going, I would like to ask you about some of your research if you dont mind. I am specifically interested in your radio tracking research involving home ranges.

Did you observe an overlap in the ranges of whatever species you were dealing with? were these overlaps statistically the same between male-female homeranges and male-male homeranges?

Since your work is still unpublished, I hope that you will post as much of your data as you are willing. Otherwise you have to understand that, despite your position as a biologist, you are asking us to accept your argument on nothing more than your word.

Once again, I am not trying to be contentious, but only to understand how you were led to argue for a complete absence of territoriality for this genus.

Just to add a little insight check this article out [ Munger, J. 1984. Home Ranges of Horned Lizards (*Phrynosoma*) Circumscribed and Elusive?. Oecologica, 62: 351-360.] as well as the following link. When conducting homerange studies their are many variables including the time of year the study was conducted, long term amount of rainfall (was the study conducted during a drought period), locality (was the study site near any unnatural structures), as well as the species being tracked. It would be nearly impossible to population status. I'm sure every individual is different. I can tell you certain individuals of p. mcallii will defend a food source during drought periods by continually snout butting and biting (Baur and personal observation. I can also tell you p. ditmarsi will mutilate, decapitate, and if large enough cannibalize other members of it's species (Montanucci and Baur). Is that defensive posturing Lester?
Homerange Abstract

The link does not work. I am curious to what you are citing.

Lester G. Milroy III

Journal of Herpetology: Vol. 37, No. 4, pp. 679–686.

Movement, Home Range, and Activity Patterns of the Horned Lizard, Phrynosoma mcallii

Bernard Wone,and Beate Beauchamp

Sixty-nine telemetered Phrynosoma mcallii from the Colorado Desert in California were relocated for up to nine months to examine activity patterns, home-range sizes and overlap, distance traveled between relocations, and onset and duration of hibernation. Total area used by the lizards ranged from 651–59,237 m2. Males had significantly larger mean summer home ranges and traveled significantly further than females. The duration of winter dormancy for eight telemetered lizards was 85 ± 8 (mean ± SE) days. Nearly all telemetered lizards were underground by mid-November and emerged as early as late December. Telemetered P. mcallii were out in the open or underneath a shrub throughout the day during spring and fall. They retreated into burrows to escape the midday summer heat. When out in the open, males perched on an elevated surface 19.0% of the time, whereas females perched 4.3%. Telemetered lizards exhibited considerable overlap among their home ranges; males shared 11% of their home ranges with females, whereas females shared 42% of their home ranges with males.

Here is another

Journal of Herpetology: Vol. 33, No. 4, pp. 517–525.

Movements, Home Ranges, and Survival of Texas Horned Lizards (Phrynosoma cornutum)
Wm. Scott Fair,a and Scott E. Henkea

aCaesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville, Kingsville, Texas 78363, USA

ABSTRACT

Home ranges, movements, and survival rates of nine Texas horned lizards (Phrynosoma cornutum) were determined by radio-telemetry in Duval County, Texas, during March through October 1994. Lizards were tracked five days each month from time of initial capture until hibernation and were located every 1–2.5 h from sunrise to sunset during these days. Nine of 16 radio-transmittered lizards were followed for 1 month of telemetry. Total area of use for horned lizards ranged from 291 to 14,690 m2, and lizards exhibited considerable overlap between their respective areas. However, Texas horned lizards exhibited minimal overlap between their concurrent weekly home ranges, and their weekly home ranges appeared mobile. The average weekly home ranges of horned lizards in spring were small, peaked in June, and decreased in size each month until the lizards entered hibernation. Minimum daily movements averaged by month ranged from 58.9 m in June to 14.0 m in October. The minimum daily movements ranged from 0.0 to 246.7 m. Daily survival rate for Texas horned lizards was 99%. Assuming that survival of lizards was not altered by transmitters and that rates were constant over time, the annual survival rate ranged from 9% to 54%, based on a 245 d active period and calculated from lizards presumed dead (i.e., missing or dead) and confirmed dead, respectively.

Yes, I know. Talked with Bernie and Scott some time back and discussed data. I am well aware of the data sets. Thank you.

Lester G. Milroy III

I also have data from other researchers about P. modestum and P. hernandezi. It is not new to me at all.

Lester G. Milroy III

There are numerous overlaps between male-female home ranges and male-male home ranges in P. coronatum, P. platyrhinos, P. solare, and P. mcalli.

Sample size for P. coronatum = 718; P.platyrhinos = 321; P. solare = 73; P. mcalli = 132. No aggressive behaviors, no territoriality. Overlaps of 77% for P. coronatum; 63% for P. platyrhinos; 58% for P. solare; 69% for P. mcalli.

Term of tracking: P. coronatum - ongoing; P. platyrhinos - 3 years; P. solare - 2 years; p. mcalli - 2 years.

Lester G. Milroy III

Are these lizards you tracked yourself?

Sure are! Thank you.

Lester G. Milroy III

Also to note the enlarged femoral pores. These are quite obvious in males also.
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2 Kings 6:15-17

"During 2001, four adults (3 males and 1 female)[solare] were transported to an outdoor enclosure in southern Utah. Within two weeks of their arrival, an extremely aggressive behavior was noted by all males toward both sexes of Texas Horned Lizards (P. cornutum) that had already been brought-in the year before, and had successfully bred and them hibernated in the same enclosure. No such aggression was observed toward any of the 3 other species sharing the enclosure."

Here is the link:

What we know about solare