Source Paper
The role of flower consumption in Howler Monkey Females’ diet: adjustment across reproductive states
Gisbrecht A, Aristizabal JF, Rodríguez-Landa JF, Hernández-Salazar LT
PeerJ • 2026
Food Intake Behavioral Assessment
Objective: To assess food intake behavioral patterns and tannin consumption in mantled howler monkeys across different reproductive and lactation states
Protocol Steps
Subject identification and categorization
Identify 20 adult females using pelage coloration and physiological features, categorize into lactation states
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“females were identified by means of pelage coloration and certain physiological features”
Behavioral observation schedule
Collect data monthly for 10-20 days from sunrise for 5 hours in random order
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“Female behavior was collected every month for 10–20 days throughout the month, from sunrise and the following 5 h”
Food intake recording
Record time invested and food intake in grams for different food categories
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“We recorded the time invested (seconds) and food intake (grams) of the items consumed”
Feeding rate calculation
Record discrete food units consumed per minute during feeding sessions
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“recorded information on the number of discrete food units consumed during a feeding session”
Food sample collection
Collect consumed and dropped fruits or similar condition items from feeding trees
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“collected all consumed and dropped fruits or fruits in the same condition as consumed from that tree”
Sample drying
Dry leaves using light bulb heat, dry fruits and flowers at 35°C
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“leaves were dried in a cardboard box using the heat of a 60 W light bulb, and fruits and flowers were dried in a food dehydrator set at 35 °C”
Sample preparation for analysis
Process dried samples with methanol at 1:3 ratio, vortex and filter
View evidence from paper
“dried and pulverized samples were processed into solvents with methanol HPLC grade at a ratio of 1:3”
HPLC analysis
Use HPLC-VWD method with specific mobile phase composition and flow rate
View evidence from paper
“mobile phase A (acetonitrile), B (methanol), and C (water) were applied (15% A; 15% B; 70% C) at a 0.5 mL/min flow rate”