DESERT TORTOISE SIGN
RECOGNITION
INITIAL REQUIREMENTS
DESERT TORTOISE SIGN
RECOGNITION
 
Know and Understand USFWS Requirements for
Desert Tortoise Surveys
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Download, Read, Understand New USFWS Survey Requirements
100% Coverage
Appropriate Time of Year
Appropriate Temperatures
When Appropriate, Walk Transects in the Zone of Influence
Must Find the Project Site
–  Client Must Provide Good Maps and UTM Coordinates
–  Know How to Use Your Equipment (GPS Unit, Thermometer, Maps)
Find Sign in the Open
INITIAL REQUIREMENTS
 
Concentrate on the Task
–  Minimize Distractions
–  E.g. Talking, Phone Calls, etc.
–  More Difficult Keeping Concentration in Areas of Low Density but it is
vital to find some of the few sign that may be available
 
Data From Line Distance Transects
–  Shown that Live Adult Tortoises are Missed When Fieldworkers are Three
Meters from Each Other
–  Burrows and Scat are Much More Difficult to Find
 
Must be Able to Recognize Desert Tortoise Sign
LINE DISTANCE TRANSECTS - LIVE
TORTOISE ENCOUNTERS
And Under Cover
100
Follow
Lead
90
 
Top - Tortoises > 180 mm
MCL
Lower - All Tortoises
80
70
FREQUENCY
 
60
50
40
30
20
 
 
Adult Tortoises were Missed
at < 1.5 m
Live Tortoises more visible
than Scats and Burrows
At 8 meter intervals about
70% of adult tortoises are
located
10
0
0-1.4
1.5-2.9
3-4.4
4.5-5.9
6-7.4
7.5-8.9
9-10.4
10.5-11.9
12-13.4
13.5-14.9
15-16.4
16.5-18
PERPENDICULAR DISTANCE
Follow
Lead
140
120
100
FREQUENCY
 
80
60
40
20
0
0-1.4
1.5-2.9
3-4.4
4.5-5.9
6-7.4
7.5-8.9
9-10.4
10.5-11.9
12-13.4
13.5-14.9
15-16.4
16.5-18
PERPENDICULAR DISTANCE
DESERT TORTOISE SIGN
RECOGNITION
1
DESERT TORTOISE SIGN
RECOGNITION
Relative Frequency of Tortoises
Found in Burrows and in Open
BURROW
SHRUB
NOT ALL SIGN ARE VISIBLY
EQUAL
OPEN
100%
90%
 
Easy - Tortoise and
burrow
 
Not so Easy - Trail to
burrow, dark scat on
cobble
 
Cryptic - Old gray scat
on light cobble or dark
scat on dark cobble
RELATIVE FREQUENCY
80%
70%
60%
50%
40%
30%
20%
10%
2005
2007
TRAN
2005
TRAN
2004
FOCAL
2004
TRAN
2003
FOCAL
2003
TRAN
2002
FOCAL
2002
TRAN
TRAN
FOCAL
2001
FOCAL
TRAN
2001
FOCAL
FOCAL
0%
2007
2008
2008
YEAR AND OBSERVATION TYPE
SEARCH HABITAT
THOROUGHLY
 
 
 
 
 
 
SEARCH HABITAT
THOROUGHLY
Spend 75-80% of search
time within 2.5 meters
Tighten interval between
searchers as needed
Search in front and behind
you
Search under and thru shrubs
Keep search image of
tortoise, scat, and burrow
shapes in mind
CONCENTRATE!
SEARCH BURROWS
THOROUGHLY
 
 
 
DESERT TORTOISE SIGN
RECOGNITION
BE CAREFUL!
Do what is necessary to
search burrows
thoroughly
Use bright flashlight or
mirror
Use probe if needed (if
you have your Permit!)
2
DESERT TORTOISE SIGN
RECOGNITION
LOW DENSITY AREAS
 
Never assume tortoises
are not present!
TYPES OF SIGN
  IN
Always be diligent
Fewer rewards but of no
less importance
  Your confidence will be
deflated now and then
 
 
SCAT
 
 
 
 
 
 
 
ORDER OF FREQUENCY
–  Scat
–  Burrows
–  Carcasses
–  Live Tortoises
–  Drinking Depressions
–  Tracks
–  Eggs or Eggshell Fragments
Variety of colors
Age from dark to light
Aging: Current year/Not Current Year
Shaped like a short cigar
May be straight, a
crescent, tapered ends or
not, but not serrated or
twisted
Material generally largenot chewed
Material generally
oriented linearly
GEOPHAGUS SCAT
DESERT TORTOISE SIGN
RECOGNITION
IS IT TORTOISE?
 
Top - Chuckwalla
 
Bottom - Desert Iguana
 
Check: Odor, Shape,
Particle Alignment,
Location
3
DESERT TORTOISE SIGN
RECOGNITION
SHEEP
OR IS IT NOT TORTOISE?
 
 
 
 
Top - Sheep
 
Bottom - Burro
 
Check: Particle size and
alignment, shape
Typically in Flocks
Large Areas of Impact
Bedding Areas and Many Scat
BURROW
 
 
 
 
Shaped like a half-moon
Flat bottom
Sides angle directly from the floor
Well-rounded, clean (no rocks) mound
BURROW CLASSES
 
Class 1 - Active:
tortoise or tracks
present
BURROW CLASSES
 
 
DESERT TORTOISE SIGN
RECOGNITION
Class 1 - Active:
tortoise or tracks
present
Class 2 - Good: No
structural degradation,
a tortoise could just
walk in
4
DESERT TORTOISE SIGN
RECOGNITION
BURROW CLASSES
POTENTIAL TORTOISE
BURROW CLASSES
 
Class 3- Poor:
Substantial structural
degradation, much
effort needed to use the
burrow
Class 4 - Good
condition
  Class 5 - Poor
condition
 
IS IT A TORTOISE BURROW?
 
Yes! - Look back in the
tunnel for the actual
shape - or for a tortoise
IS IT A TORTOISE BURROW?
 
Fox Burrow
–  Trail on mound and
into burrow
–  Vertical rise at base
–  Tracks
IS IT A TORTOISE BURROW?
 
Badger Burrow
–  Claw marks on burrow
walls
–  Vertical rise at base
DESERT TORTOISE SIGN
RECOGNITION
IS IT A TORTOISE BURROW?
 
Kangaroo Rat burrow in sandy soils the sides
collapse
5
DESERT TORTOISE SIGN
RECOGNITION
JUVENILE TORTOISE BURROW
TORTOISE TRACKS
May use rodent burrows
when very small
  Will dig their own
burrows when very
young
  Check for tracks in
tunnel
  Search surrounding area
for more burrows and
tortoise
Seen only in soft soil
Two rows of footprints
  Use toenail marks to
determine direction of
travel
 
 
 
GEOPHAGUS SITES
GEOPHAGY SITES
 
 
 
 
Often under surface of
desert pavement
Or along washbanks
Often under surface of desert pavement
Soil on beak will be dry and not embedded in scales
DRINKING DEPRESSIONS
 
 
 
 
DESERT TORTOISE SIGN
RECOGNITION
Always in areas with
fine soils
Commonly at base of a
rock
Tortoise will eat mud or
suck up water thru nares
Not in typical sandy or
loam soils
6
DESERT TORTOISE SIGN
RECOGNITION
TORTOISE EGGS
 
 
Size of ping pong balls
Are oval, round, or
elongate
TORTOISE NESTS
 
 
May be in the open
Generally associated
with a burrow
CARCASSES
  Two
Main Objectives
–  Estimate Time Since Death
–  Determine Cause of Death
  Amount
of Disarticulation of Scutes or Bones
has Nothing to do with Time Since Death
 
DESERT TORTOISE SIGN
RECOGNITION
Look Thru Coyote Scats
7
DESERT TORTOISE SIGN
RECOGNITION
TIME SINCE DEATH
  Based
on amount of weathering of scutes and bones
most weathered portions
  Categories
  Use
–  < 1 year (all parts have sheen and luster)
–  1 - 2 years (bones and scutes faded, no luster)
–  2 - 4 years (scutes faded, may be cracked and curling;
bones faded, may be pinholes or superficial cracks
–  > 4 years (scutes very weathered, bones deossifying,
layers of collagen cracked and peeling)
 
 
 
 
Juveniles age more rapidly than adults, in a separate
portion of the key
Note lack of ossification
Completely ossify at 7 to 10 years (90 to 110 mm)
Less than one year time since death
DESERT TORTOISE SIGN
RECOGNITION
 
Left - < 1 year (bones, scutes, and scales are glossy)
 
Right - 1-2 years (scutes, tightly adhered, are fading
8
DESERT TORTOISE SIGN
RECOGNITION
CAUSE OF DEATH
 
Look at situation
prior to intrusion
 
Search entire site,
parts may be
scattered
 
Most will be
unknown
DESERT TORTOISE SIGN
RECOGNITION
9
DESERT TORTOISE SIGN
RECOGNITION
 
Left - Entrance wound
 
Right - Exit wound, note concoidal fracture
DESERT TORTOISE SIGN
RECOGNITION
10
DESERT TORTOISE SIGN
RECOGNITION
LIVE DESERT TORTOISE
 
 
 
Size
Sex
Health Status
– 
– 
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– 
– 
Weight
Parasites
URTD Signs
Shell/bone Abnormalities
Injuries
  No
Permit - No Harrass!!!
CARAPACE
 
 
 
 
 
PLASTRON
Nuchal
Marginals (11 each side
[Peripherals])
Pygal
Costals (4 each side)
Vertebrals (5)
 
 
 
 
 
 
WEIGHT
LENGTH
 
Length = MCL
 
–  Maximum or Midline
Carapace Length
 
Straight-line distance
from nuchal to pygal
 
 
 
DESERT TORTOISE SIGN
RECOGNITION
Gulars
Humerals
Pectorals (Pleurals)
Abdominals
Femorals
Anals
Use medium-weight
string, dental floss,
plastic bag, etc.
Always keep hand under
the tortoise
Pesola scales are the
most consistent
Long throw for accuracy
11
DESERT TORTOISE SIGN
RECOGNITION
STERILIZE
 
Sterilize all equipment
that contacts tortoise
 
Use 20% solution
(bleach or chlorinebased solution)
 
Change solution weekly
FEMALE
 
 
 
 
 
Short Tail
Flat Plastron
Short Gular
Longer Rear Nails
Small Chin Glands
MALE
Long Tail
Concave Plastron
  Long Gular
  Usually Larger Chin
Glands
 
 
HATCHLING
 
Hatchling Plate or
Areola
 
Gray Material is
New Growth
JUVENILE
 
Few Growth Annuli
 
Note New Growth from
Previous Spring
 
Annuli deposition is
when a tortoise grows,
not annually
DESERT TORTOISE SIGN
RECOGNITION
12
DESERT TORTOISE SIGN
RECOGNITION
ANOMALOUS TORTOISE
DESERT TORTOISE SIGN
RECOGNITION
13
DESERT TORTOISE SIGN
RECOGNITION
EXTERNAL PARASITES
INJURIES
DOGS
 
 
 
 
DESERT TORTOISE SIGN
RECOGNITION
Have Nothing but
Time and Energy
Substantial Risk to
Desert Tortoises
Other Wildlife
And People
14
DESERT TORTOISE SIGN
RECOGNITION
Thank you
IN CONCLUSION
  Know
and Recognize Sign
- Sign is easy to miss
  Recognize Normality - Behaviors, Morphology,
Health Signs
  Document
  Photograph
  Ask Questions (USFWS, CDFG, BLM)
  Distribute Data and Information
  CONCENTRATE
DESERT TORTOISE SIGN
RECOGNITION
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