anogenital distance measurement (Sciuridae)

Knowledge graph centered on anogenital distance measurement (Sciuridae) with 30 nodes and 114 connections. Top connected: Rocky Mountain Biological Laboratory, Gothic, Marmota, Yellow-bellied Marmot, Colorado East River Valley.

Method synopsis

Measurement of anogenital distance using dial or digital callipers to 1mm accuracy as a proxy for prenatal testosterone exposure and masculinization. Distance measured from centre of genital opening to centre of anus.

Synthesized from method descriptions across 2 papers using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Masculinized female yellow-bellied marmots initiate more social interactions (2012), Biology Letters. Implementations in other papers (listed below) may differ.

1. Individual capture and marking
   Marmots were individually trapped and marked with unique symbols on their back using hair dye to facilitate behavioral observations. Each individual was weighed and the anogenital (AG) distance was measured (distance from center of genital papilla to anus).
   Quantities: 202 female marmots total: 110 juveniles and 92 yearlings from 89 different littersDuration: Conducted regularly from 2002 to 2009Conditions: During active season from natal emergence to hibernation
   Equipment: traps, hair dye, measuring tools
2. AG distance index calculation
   AG distance measurements were standardized by extracting residuals from a linear regression of AG distance against body mass to create an AG distance index independent of body size effects.
   Quantities: Calculated for all 202 individualsDuration: Post-processing analysisConditions: Statistical analysis phase
   Equipment: statistical software

Typical Equipment

• dial callipers
• digital callipers

Output Measurements

• anogenital distance
• anogenital distance index

Papers Using This Protocol (2)

Species Studied With This Protocol

Places Where Used