Reward Tracking and Memory Decay in the Monarch Butterfly, Danaus plexippus L. (Lepidoptera: Nymphalidae)

Abstract

Due to their long‐distance migration routes and high longevity, monarch butterflies (Danaus plexippus) are likely to benefit from learning how to discriminate and remember suitable feeding resources. In this study, we assessed monarchs’ abilities to track changing nectar sources over time and to retain learned information presented in two conditioning schedules. Non‐preferred (blue and red) and preferred (yellow) artificial flowers were concomitantly offered to monarchs in a three‐phase experiment. In each phase, flowers of only one color contained sucrose solution, while the others contained water. The rewarding color was changed in each phase. Instantaneous observations were made to assess butterfly visits to each color during each phase; continuous observations over the first 90 min of a new phase allowed us to look in more detail at the transition process. Overall, monarchs tracked sucrose availability, visiting the rewarding flowers more often than the unrewarding ones, regardless of innate preferences. However, butterflies reverted to innate color preferences when the newly rewarding color was different from the initial trained color. In a second experiment, memory decay was compared for butterflies trained according to two schedules: ‘single training’ (sucrose solution in red vs. water in blue artificial flowers in one 15‐min session per day) or ‘intermittent training’ (as above, but in two 7.5‐min sessions per day). Afterwards, butterflies were tested on alternate days for a week in arrays containing unrewarding models of both colors. Following either training schedule, memory persisted for at least 3 d after reinforcement ceased. Our findings reveal that monarchs are able to change their feeding responses according to the flowers’ reward status despite innate preferences, as well as to retain flower information for about half a week regardless of the conditioning dynamics.

Predicting monarch butterfly (Danaus plexippus) movement and egg-laying with a spatially-explicit agent-based model: The role of monarch perceptual range and spatial memory

“…2). Agents have a perceptual range assumed to represent the distance that they can detect milkweed plants through olfactory or visual cues (Bergstrom et al, 1994;Garlick, 2007;Rodrigues and Weiss, 2012). Wild monarchs likely use olfaction for long-range detection of milkweed, and visual cues at short distances (Garlick, 2007).…”

“…If more than one patch is detected within the perceptual range, the agent must choose which patch to move toward (i.e., decisional flight). Monarch agents are assumed to have a higher probability of moving toward patches with higher milkweed density, based on laboratory and greenhouse studies suggesting that increased number of milkweed plants result in an increased intensity of olfactory and/or visual cues (Bergstrom et al, 1994;Rodrigues and Weiss, 2012;Garlick, 2007). Monarch agent attractiveness to a patch is based on the milkweed density parameter, after adjustments.…”

“…Memory capabilities are well known in some insects such as honey bees (Hammer and Menzel, 1995) and learning behavior in butterflies (Lewis, 1986) and moths (Cunningham et al, 1999) has been documented. Monarch butterflies learn associations between color and nectar sources (Blackiston et al, 2011) and can remember these associations for up to three days (Rodrigues and Weiss, 2012).…”

Flower use of the butterfly Maniola jurtina in nectar‐rich and nectar‐poor grasslands: a nectar generalist with a strong preference?

“…But in this study, yellow flowers ( Ranunculus acris especially) were frequently visited by other butterfly species. This is confirmed by other studies; examples include Thymelicus flavus (Goulson et al ., ), Battus philenor (Weiss, ), Danaus plexipus (Rodrigues & Weiss, ) and Lysandra bellargus (Rusterholz & Erhardt, ). Our results are in line with sex‐specific flower colour preferences.…”

Southern Monarchs do not Develop Learned Preferences for Flowers With Pyrrolizidine Alkaloids

“…The southern monarch is closely related to the temperate monarch butterfly Danaus plexippus, as both species belong to the subgenus Danaus (Brower et al 2010;Hay-Roe et al 2007;Smith et al 2005). Associative color learning (Blackiston et al 2011;Rodrigues et al 2010a), aversive learning and risk aversion (Rodrigues et al 2010a), as well as memory capacity (Rodrigues and Weiss 2012), have been shown for D. plexippus in the context of feeding. Taken together, these studies indicate that these sister species may have similar cognitive abilities.…”