The role of stimulus complexity, age and experience in the expression of exploratory behaviour in the Chimango Caracara, Milvago chimango

Abstract

Exploration represents an important way by which organisms evaluate environment information. The decision of whether or not an animal should investigate environmental changes may influence the extent to which animals learn about their surroundings and cope with habitat modifications. We analysed exploration behaviour in a suburban population of a raptor species, the Chimango Caracara, Milvago chimango, by examining how age, previous experience and object complexity influence novel object exploration. Our findings showed that object complexity did not influence caracaras initial approach and contact with objects, but did influence the degree of engagement during exploratory activities, as measured by total exploration time and number of exploration events. These variables were higher for complex objects than for simple objects. Experience resulted in less exploration of simple objects. It is likely that, for caracaras, simple objects are easier to encode and recall than complex objects, so additional exploration of such objects would not provide further information. Results suggest that exploratory behaviour in this raptor was guided more by the benefits of a greater quantity of information obtained by exploring complex objects, than by the risks associated to this activity. We can conclude that caracaras cope with novel features in their surroundings with a novelty-seeking strategy, characteristic for generalist species in discovering early new resources opportunities, and which might be a determining factor for adaptive responses to environment modification.

Assessing Potential Predation Risk by Introduced Predators on Unattended Eggs in the Red-Tailed Tropicbird, Phaethon rubricauda, on Rapa Nui (Easter Island)

“…Within the total time of visits (less than 0.1% of the recorded time), Chimango Caracara tried insistently to break an experimental egg by kicking and pecking it without success. However, their innovative and learning abilities coupled with their capacity to transmit novel behaviors through social learning (Biondi, Guido, Bo, Muzio, & Vassallo, 2015) raise the question whether Chimango Caracara specimens at Rano Raraku can eventually find the way to effectively depredate on red-tailed tropicbird eggs. Nonetheless, the presence and behavior of this raptor bird is a significant threat for red-tailed tropicbird unattended nestlings that are probably easier for these predators to catch and handle compared with an egg.…”

Childhood as a solution to explore–exploit tensions

“…Beyond humans, primates and rodents, there are good theoretical reasons to predict that older individuals will be less exploratory and/or neophilic than younger individuals [78], and the empirical literature, for the most part, seems to agree with this prediction ( parrots and corvids: [79], geladas: [80], chimango caracara: [81][82][83]: great tits: [84,85], hyenas: [86]). In wild spotted hyenas, juveniles were less neophobic, more persistent and exhibited a greater diversity of initial exploratory behaviours, relative to adults, when they were presented with a puzzle box [86].…”

Spontaneous object recognition: a promising approach to the comparative study of memory

“…In birds, age has been repeatedly shown to affect the latency and duration of novel object exploration. In Milvago chimango , a neotropical raptor, juveniles (<1 year in age) approach a novel object more quickly and explore it for longer than adults (Biondi et al, 2010 , 2013 , 2015 ). Juvenile ravens, in contrast, explore objects more at 6 months of age than 3 months of age (Stöwe et al, 2006 ).…”

“…A few studies do validate the unsurprising conclusion that for a variety of species, the specific object does matter (Toms and Echevarria, 2014 ). For example, complex objects are explored more by birds than simple objects (Biondi et al, 2015 ), and steep objects are explored more by drosophila than shallower objects (Robie et al, 2010 ).…”

“…In raptors, habituation is apparent to simple objects with extended exploration of more complex objects. For example, Biondi et al ( 2015 ) found that raptors who are previously exposed to simple and complex objects spend less time than controls exploring simple objects in a test, but explore complex objects almost as long as controls.…”