SUPPORTING INFORMATION:
A Morphometric Sex Determination Model for Adult Greater Roadrunners
(Geococcyx californianus)
Rrf: Montalvo et al. • Field Sex Determination
ANDREA E. MONTALVO,1 Department of Wildlife and Fisheries Sciences, Texas
A&M University, College Station, TX 77843, USA
ROBERT A. POWELL, Department of Wildlife and Fisheries Sciences, Texas A&M
University, College Station, TX 77843, USA
MICHAEL D. MACDONALD, Department of Biological Sciences, San Jose State
University, San Jose, CA 95192, USA
DEAN RANSOM, JR.,2 Texas Agrilife Research and Extension Center, San Angelo, TX
76901, USA
ROEL R. LOPEZ, Department of Wildlife and Fisheries Sciences, Texas A&M
1
Table S1. Distribution of museum and live greater roadrunner samples from Fisher
County, Texas, USA, measured from 2003-2012 and their contributions to the sample
size.
Roadrunner skin locations
Contribution
Sam Houston State University Vertebrate Museum
5
Museum of Southwestern Biology at the University of New Mexico
60
New Mexico Museum of Natural History and Science
2
Sam Noble Oklahoma Museum of Natural History at the University
32
of Oklahoma
Biodiversity Research and Teaching Collections at Texas A&M
32
University
Angelo State Natural History Collections
10
Mayborn Museum at Baylor University
10
Road kill
3
Rob and Bessie Welder Wildlife Foundation Natural History
13
Collections
Natural Science Research Laboratory at the Museum of Texas Tech
16
University
Various natural history collections in California
25
Smithsonian Institution National Museum of Natural History
92
Field Museum of Natural History
39
Museum of Vertebrate Zoology at the University of California at
85
Berkeley
Live captured
9
2
Table S2. We rearranged the output logistic regression model results from museum and
live specimens from Fisher County, Texas, USA collected from 2003-2012 to focus on
the probability of the bill depth belonging to a female, P(female)  1/1  e
( 12.981.11 BD )
, so
that a probability >0.50 corresponds to the model predicting the sex as female. Solving
the model for the threshold between the sexes reveals bill depths ≥11.67 mm correspond
to a prediction of male, while bill depths of ≤11.66 correspond to a prediction of female.
BD (mm)
Model
Model sex
probability identification
Example 1
10.82
0.72
Female
Example 2
11.42
0.57
Female
Example 3
13.67
0.10
Male
Example 4
12.94
0.20
Male
3