SPECIES

Chilean Mockingbird Mimus thenca Scientific name definitions

Natacha González, Vicente Pantoja, Maria Jesus S. Mallea, Matías Garrido, Antoine Touret, Angélica Almónacid, Heraldo V. Norambuena, and Fernando Medrano
Version: 2.0 — Published March 3, 2023

Diet and Foraging

Feeding

Food Capture and Consumption

Forages mainly on the ground, but also in vegetation to 3 m or more. In dense matorral 2 m tall, foraging times spent in three height categories (ground, ground to 1 m, and 1–2 m) were 55%, 28%, and 17%, respectively; corresponding figures for 2 m tall open Acacia bushland 92%, 7%, and 1%, and for 1 m tall low coastal scrub 85%, 15% and 0% (52). Time on the ground includes periods spent turning leaf litter and digging around plant stems and under fallen branches; time spent above ground includes searching vegetation for insects. Also perches on telephone poles and utility wires.

Foraging Behavior

Chilean Mockingbird is omnivorous and feeds on different terrains. They can be seen hopping and walking on the ground in grassland environments feeding on insects and even small lizards (Liolaemus) (6, 25, Andino Zabaleta, eBird S127323358).

In most of their range, the species inhabits areas close to urban areas and gardens which has resulted in many individuals with extreme tolerance to human presence. They can regularly be seen feeding on food thrown by people. This behavior also occurs in Argentinian populations (33).

Diet

Major Food Items

Omnivorous, feeding on both insects and fruit. Fruits include those of Cestrum parqui (53), Muehlenbeckia chilensis (52), Aristotelia chilensis (53), Lithraea caustica (53), Peumus boldus (52), Schinus latifolius (ML85504641), Schinus molle (52), Tristerix corymbosus (53), Tristerix aphyllus (53), Trichocereus chilensis (53, ) and Eulychnia acida (54), as well as a variety of cultivated fruits (e.g Rubus ulmifolius; Prunus domestica).

From August–September it feeds on nectar and insects from Puya chilensis (6). It is also recorded taking nectar and insects from Puya alpestris zoellnerii.

A remarkable coevolutionary association between the Chilean Mockingbird and endoparasitic mistletoes (Tristerix aphyllus) (55, 56). The bird swallows the whole fruits and defecates the mucilaginous seeds intact (55). Host cacti grow longer spines in order to prevent the mockingbirds from dispersing the mistletoes seeds on them while perched (57).

Catches Insects, including Orthoptera, Lepidoptera, Coleoptera (Tenebridae), and their larvae. Also takes small lizards such as wreath tree iguana (Liolaemus lemniscatus; 52).

Quantitative Analysis

Information needed.

Food Selection and Storage

Prefers to consume nectar with a high content of fructose and glucose, e.g. Puya alpestris (Bromeliaceae), as well as fruits, avoiding foods rich in sucrose due to its low capacity to produce sucrase-isomaltase (58; 59).

Nutrition and Energetics

Information needed.

Metabolism and Temperature Regulation

Chilean Mockingbird has a basal metabolic rate (BMR) estimated at 128.80 ± 20.09 mL O2 h−1 (15).

Drinking, Pellet-Casting, and Defecation

It drinks water. Defecation while perched in cactus is made in all the directions, and is not the driver of the directionality of growth of mistletoes (60).

Recommended Citation

González, N., V. Pantoja, M. J. S. Mallea, M. Garrido, A. Touret, A. Almónacid, H. V. Norambuena, and F. Medrano (2023). Chilean Mockingbird (Mimus thenca), version 2.0. In Birds of the World (N. D. Sly, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.chimoc1.02