2017 ZEBRA-TAILED 

LIZARD MONITORING

HUALAPAI DEPARTMENT OF CULTURAL RESOURCES (HDCR)

DR. KERRY CHRISTENSEN (HDCR)

DR. LARRY STEVENS (MNA, AZ WILDLANDS COUNCIL) 

MS. MARIANNE CRAWFORD (BOR) 
Photograph of a male zebra-tailed lizard on the sand dunes at 

Diamond Creek, Hualapai Reservation
2017 Hualapai Zebra-tailed Lizard 

Monitoring – Diamond Creek

 This Project is funded by Reclamation under “Restoration of Extirpated 

Species to the CRE” as recommended by the “Species of Concern” Group. I 

think.

 The project started in the spring of 2012, and the current contract extends to 

2020.

 Funded by Reclamation’s Triennial Work Plan

 The results of this project will be used to verify that the zebra-tail population 

is or isn’t stable in the CRE at Diamond Creek and whether zebra-tails are 

affected by future HFE’s or natural flooding. 

 Future translocation should be considered if the population declines or 

additional genetic diversity is desired/needed.
BACKGROUND

Zebra-tailed lizards are a common Mohave and Sonoran Desert reptile species.

Prior to the 100,000 cfs floods in the Colorado River in Grand Canyon in 1983 and 

1984, zebra-tails were a common species on and around the sand dunes at 

Diamond Creek.

Because of the flooding, raft put-ins and take-out vehicles had to drive over the 

dunes to launch and take-out.

In the years after the flooding subsided, zebra-tailed lizards could not be found 

anywhere at Diamond Creek (Larry Stevens, personal communication).

In 2012, BOR funded an effort to translocate zebra-tailed lizards from upper 

Peach Springs Canyon to Diamond Creek. This effort was led by Dr. Larry 

Stevens. A total of 12 zebra-tailed lizards (6 males, 6 females) were captured in 

the spring of 2012 and released at Diamond Creek.

HDCR staff have been funded by BOR since then to annually monitor the zebratail lizard population at Diamond Creek and report back to BOR and the GCDAMP.
DIAMOND CREEK, HUALAPAI RESERVATION

An aerial photograph of the Diamond Creek Area at River Mile 226L where 

zebra-tailed lizards have been monitored from 2012 to 2017.
MALE ZEBRA-TAILED LIZARD
FEMALE ZEBRA-TAILED LIZARD
JUVENILE ZEBRA-TAILED LIZARD
BABY ZEBRA-TAILED LIZARD
METHODS

In 2017, monthly surveys were performed from April through September.

Surveys consist of one or two people walking the entire Diamond Creek area 

(Dunes, campground, roads and adjacent areas) and all lizards observed are 

identified by sight, and the location is plotted on an aerial photograph. Each 

survey takes about one hour.

If it is a zebra-tailed lizard that is sighted, it is recorded by sex and age if 

possible. The behavior is recorded and the distance to vegetation and vegetation 

species is recorded.

Back at the office, the data from the field data sheet are typed on a blank data 

sheet and the lizard locations are typed onto a blank aerial photograph.

After each survey, the typed data sheet and aerial photograph are shared with 

Marianne Crawford and Larry Stevens.

An annual report is prepared in September/October and provided to BOR and Dr. 

Stevens.

A presentation is usually given to the TWG, AMWG or at the ARM.
Zebra-tailed Lizard Monitoring Form

Monitor(s):_________________________________Date_____

Start:_____________________Finish____________________

Temperature:_______________ RH__________

Wind:_______________________

1st encounter: 

Behavior:______________________________________________

Distance to vegetation:_________Vegetation Type_________________

2nd encounter:

Behavior:______________________________________________

Distance to vegetation:__________Vegetation Type________________
DIAMOND CREEK AERIAL PHOTOGRAPH
Diamond Creek Dunes
Diamond Creek Campground
Figure 9. A photograph of the Diamond Creek Wash on the east side of the dune area at Diamond Creek where many 

zebra-tailed lizards had been found in the past. The August, 2016 monsoon flood eroded a large channel in the middle of 

the wash. no zebra-tailed lizards were found here in the post-flood surveys in 2016.
2016 ZTL SURVEY RESULTS

Date # of ztl 

located/ 

survey

# juveniles # Babies Mean dist. 

To veg. 

(m)

Vegetation 

type(s)

April 26, 

2016

10 4 0 0.72 Creosote, 

baccharis

May 26, 

2016

8 3 0 1.39 Brittle bush, 

creosote

June 30, 

2016

10 1 0 0.79 Creosote, brittle 

bush

July 20, 

2016

9

9.25*

0 3 0.51 Mesquite, 

creosote, brittle 

bush

August 26, 

2016

5 0 1 1.02 creosote

September 

16, 2016

6

5.5**

0 2 0.78 Creosote, 

mesquite

October 27, 

2016

0 0 0 0 NA

Average*** 7.8 1.33 1.0 0.87

Table 1. Summary of 2016 Diamond Creek zebra tailed lizard monitoring results.

*average number of zebra-tailed lizards found in pre-flood surveys.

**average number of zebra-tailed lizards found in post-flood surveys.

***The October 27 survey results were not included in calculating the averages.
RESULTS * = LOTS OF FOOT TRAFFIC ** = SECOND MOST EVER OBSERVED

Date # of ztl 

located/ 

survey

# juveniles # Babies Mean 

dist. To 

veg. (m)

Vegetation 

type(s)

April 27, 

2017

9 1 1 0.61 Creosote, seep 

willow, 

mesquite, brittle 

bush

May 24, 

2017

9 1 0 2.45 Creosote, 

mesquite, brittle 

bush

June 23, 

2017

8 2 0 1.34 Creosote, brittle 

bush

July 26, 

2017

11 0 0 1.95 Creosote, 

mesquite

August 18, 

2017*

7* 1 1 1.57 Creosote, brittle 

bush

September 

15, 2017

14** 0 5 1.61 Creosote, brittle 

bush, mesquite

Average 9.7 0.83 1.2 1.59
YEARLY AVERAGES

Year Mean # of 

ZTL 

located*/

survey

0.81-2.62/acre

Mean # 

Juveniles

Mean # Babies Mean distance to 

vegetation

2012 4.0

0.93/acre*

0.6 0.0 1.2

2013 3.5

0.81/acre*

1.0 0.0 1.3

2014 5.6

1.3/acre*

2.4 0.13 (3 total) 2.0

2015 11.3

2.62/acre*

2.7 1.70 (10 total) 0.9

2016 7.8

1.81/acre*

1.33 1.0 (6 total) 0.87

2017 9.7

2.24/acre*

0.83 1.2 (7 total) 1.59

Table 2. A summary of the results of zebra-tailed lizard surveys from 2012 to 2017.

* Average density of ztl’s in creosote scrub habitats is 4.8-6.0 lizards per acre.
The results of the September zebra-tail survey

Bztl 2 Ztl 1

Bztl 3

Ztl 4

Ztl 5

Ztl 6

Bztl 7, Ztl8

Ztl9 Ztl 10 Ztl 11

Bztl 12

Bztl 13

Ztl 14

T

T

T

T

T
DISCUSSION

After the flood of August, 2016, it appears that the zebra-tailed lizard population 

rebounded to a population size similar to pre-flood numbers

We will continue to work with Reclamation, Dr. Stevens and others to monitor the 

Diamond Creek population and undertake future translocations if necessary.

There is great potential for additional ecological and genetic studies of the 

lizards at Diamond Creek and in Peach Springs Canyon.

 What are the factors affecting survival and reproduction?

 Does habitat quality limit the zebra-tail population at Diamond Creek?

 Do these lizards utilize the riparian habitats at Diamond Creek?

 Are these zebra-tails affected by human visitors? How so?

 What is the survival rate of baby and juvenile zebra-tails?
QUESTIONS?