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

Behavior

Introduction

Chilean Mockingbird is found mostly alone or in pairs. It is conspicuous in behavior much as in other mockingbirds (29). This species is notably curious and exhibits a high tolerance to human presence.

Locomotion

Walking, Running, Hopping, Climbing, etc.

On the ground, it hops and runs well, often standing with its tail cocked (28). It perches on trees and bushes, as well as human-made structures such as poles from where it vocalizes and searches for food (38, 62).

Flight

Flights are usually short and described as heavy high flights mixed with short glides (38, 31).

Self-Maintenance

Information needed.

Agonistic Behavior

Physical and Communicative Interactions

Wing-flashing Behavior

Wing-flashing behavior has been described in many species of the Mimus genus (63), yet no studies have reported this behavior in Chilean Mockingbird. A record in eBird presumably shows an individual displaying this behavior in central Chile while on the ground (Cabrera, eBird S42358122). Further studies and observations are recommended to confirm this behavior.

Alarm Calls and Agonistic Behavior

Alarm calls can be heard in presence of a predator or in aggressive interactions with other birds in which Chilean Mockingbird gives hoarse raspy notes Keeck-Keeck (62). If the threat persists they can harass it by flying close to it in order to drive it away. This behavior has been reported to occur in presence of Austral Pygmy-Owl (Glaucidium nana) (62) and Burrowing Owl (Athene cunicularia), among others. Agonistic behavior has been observed by an adult Chilean Mockingbird performing displays and alarm vocalizations to distract a domestic cat from preying on its chick (Barraza, eBird S119065184).

Territorial Behavior

Chilean mockingbird shows territorial behavior, but it is not clear if it is more noticeable in the breeding season (62).

Sexual Behavior

Mating System and Operational Sex Ratio

No information, but presumably socially monogamous.

Courtship, Copulation, and Pair Bond

Not much is known about courtship and pair-bonding in this species, but adults have been reported to show sexual displays in the breeding season. Birds perch in trees, bushes, or human-made structures such as public poles and light cables and sing loud and harmonically while repeatedly flapping their wings and their tail up and down. This display is more common in the early months of the breeding season (August and September) (Barros, eBird S19889425).

Social and Interspecific Behavior

Degree of Sociality

Chilean Mockingbird is rarely seen in large groups, however, in specific events where food is abundant large flocks of 40–80 birds can gather in one place. In central Chile, Marin (6) reported some of these events: In October 2004, a large number of individuals (more than 40) were observed consuming Lepidoptera larvae. On June 2009, between 30–40 birds were observed in a large litre tree (Lithraea caustica) consuming its fruits. On May 2012, more than 80 birds were observed around two peppers trees (Schinus molle) with ripe fruits, all trying to get a space to consume their fruits (6). This behavior was also reported in Coquimbo region, Chile in 2012, when 80 Chilean Mockingbirds were seen feeding on thrown avocados, pears and figs (Barros, eBird S10917261)

Nonpredatory Interspecific Interactions

Interactions with other species have been briefly reported or studied, however, it can be seen regularly feeding alongside many other species in both urban and natural areas. One of the most common interspecific interactions reported is with Austral Thrush (Turdus falcklandii) in which both species feed together on many fruits and berries such as Arrayan fruits (Rhaphithamnus spinosus) (25). Both species can also nest in the same tree with no agonistic behavior reported so far (Martínez, eBird S78194892).

Other observed feeding interactions occur with Rufous-collared Sparrow (Zonotrichia capensis), Great Shrike-Tyrant (Agriornis lividus), Diuca Finch (Diuca diuca), Moustached Turca (Pteroptochos megapodius), Long-tailed Meadowlark (Leistes loyca), Eared Dove (Zenaida auriculata), Rock Pigeon (Columba livia), Mourning Sierra Finch (Rhopospina fruticeti), Chilean Flicker (Colaptes pitius), Chalk-browed Mockingbird (Mimus saturninus), and Patagonian Mockingbird (Mimus patagonicus)(33).

Predation

Scarce information on this subject. Agonistic behavior with Austral Pygmy-Owl (Glaucidium nana) has been reported several times, including confirmed predation in central Chile (64). Chimango Caracara (Daptrius chimango) were seen attacking and injuring a bird in flight (Espinoza, eBird S49472804). An attack from a Plumbeous Rail (Pardirallus sanguinolentus) was reported on a juvenile bird (Almonacid, eBird S78143682). Considering its habitat, Peregrine Falcon (Falco peregrinus)might be a potential predator of this species, especially when predation on a similar species such as Patagonian Mockingbird (Mimus patagonicus) has been described in southern Chile and Argentina (65). Another potential predator is Harris's Hawk (Parabuteo unicinctus), although a diet study in central Chile found no evidence of this interaction (66).

Chilean green racers (Colubridae: Philodryas chamissonis) are potential predators in central Chile; one juvenile snake was observed being attacked and pecked by an adult Chilean Mockingbird (Felix Panes, eBird S127322731).

Domestic cats (Felis catus) are potential exotic predators in cities and urban parks. A predation attempt was reported on a Chilean Mockingbird chick in Chile (Barraza, eBird S119065184). Predation by domestic cats might be underestimated due to nocturnal habits and lack of studies.

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