Puerto Rican Tody is a flycatching insectivore. The average metabolism was estimated at 1.9 kcal/bird day (Faaborg 1977), and experiments demonstrate the basal metabolic rate for nonbreeding adults is 3.24 ± 0.59 mL O2/g/hour (Merola-Zwartjes and Ligon 2000). In studies with captive todies, they can consume about 40% of their body weight in insects per day (Raffaele et al 1998).
There are several techniques todies use to capture prey items. Most commonly, they leaf feed. The tody perches, points its bill upward, and scans the undersurfaces of leaves and bark above it for insects by rapidly jerking its head from side to side (Raffaele 1989). Perches used do not have dense leaves so the bird has a clear view above and below (Kepler 1972). When an insect is spotted, the bird flies out, sweeps the insect off the leaf surface using a sideways motion of their flat beak, and flies to a new perch in a single short, curved flight (Raffaele 1989, Harris 2009). The tody nearly exclusively uses this method to obtain food (Kepler 1972, Raffaele 1989, Rodriguez Camacho 2006). Todies sometimes feed off the tops of leaves as well.
Another foraging method is air-feeding, where the tody perches with bill pointed upward and then flies from the perch and snatches an insect in air like a flycatcher, and returns to a different perch (Kepler 1972). Aerial feeding is used less than 10% of the time; aerial feeding is used twice as often in dry scrub, where insect abundances are higher, than the rain forest (Kepler 1972). Other feeding methods included hovering with upward-tilted beaks, feeding off tree-trunks, or hopping along branches to glean from tops of leaves (Kepler 1972). The surfaces todies most frequently forage from are, in order of preference: leaves; trunks, branches and twigs; air; inflorescences, fruits and seedpods; and the ground or small sloping banks either bare or covered in moss (Kepler 1972).
Throughout all habitats, 30% of foraging flights resulted in a captured insect (Kepler 1972). Todies perched for an average of 9.0 seconds between foraging flights, and averaged 1.0 successful captures per minute in the rain forest and 1.7 successful captures per minute in xeric scrub (Kepler 1972). Efficiency and feeding techniques varied throughout the year and for different habitats, depending on availability of different insects (Kepler 1972).
Several studies have examined the height at which todies forage in the canopy, generally concurring that they forage near the ground. Rodriguez Camacho (2006) found todies forage in the lower ¼ of the height of the canopy, which is approximately between ground level and a height of 3 meters. Waide (1996) observed todies foraging as high as 22 m above ground, at the top of the canopy, but stated most foraging occurs at or below 10 m. Kepler (1972) found the average foraging height was 4.7 m (n = 2187 observations), with 50% of foraging occurring below half the height of the rain forest canopy. Foraging heights differ in different habitats, possibly from canopy cover height differences, with the average foraging height being 2.1 m for xeric shrub and 4.7 m for the rain forest (Kepler 1972). After Hurricane Georges of 1998, todies foraged lower in the canopy, and foraged in sites with more foliage cover than random sites, but did not change foraging techniques (Hernandez 1999).
Based on foraging observations and stomach analysis, the tody diet consists of insects (85.9%), spiders (8.2%), lizards (3.5%), seeds (2.4%), and rarely fruit or frogs (Waide 1996). Although todies are almost completely insectivorous, they consume a minimum of fourteen insect orders and forty-nine families, making their diet broad (Kepler 1972, Waide 1996). The orders Hemiptera, Coleoptera, Orthoptera, Dermaptera, Homoptera, and Diptera make up over 10% of their diet each (Waide 1996). They have been documented feeding on the orders Odonata, Mantodea (Gonatista grisea), Neuroptera, Hymenoptera (Family Formicidae, among others), Diplopoda, Nematoda, Collembola, Blattodea, Phasmatodea, Lepidoptera (larvae and adults), and Ephemeroptera (Waide 1996). They likely also feed on Isoptera (Waide 1996). Todies have been observed to feed on fruit, and some research indicates that seeds compose more than 10% of the diet (Waide 1996). The most abundant insects in the Susúa Forest are Diptera (31% of adult diet) and Coleoptera (23% of adult diet), and those are also the most frequently consumed orders by adults (Waide 1996, Rodriguez Camacho 2006).
Diets change slightly with age. Nestlings feed primarily on Homoptera (30% of diet), Coleoptera (25%), and Lepidoptera (16%) (Kepler 1972, Waide 1996). Most food items brought to nestlings are lacewings (Neuroptera) or moths (Lepidoptera), and adults show discrimination in which items they consume or bring to the nest (Kepler 1972, Merola 1995). Adults sometimes feed on small Anolis lizards, but feed more frogs than lizards to nestlings (Waide 1996). Although the Puerto Rican Tody is considered an insectivore, it has been observed to supplement the diet of nestlings with fruit from the Clusia krugiana tree up to 18.4% of the times food was brought to the burrow (Merola 1995).