Ari E. Martínez

 

 

Traits that Influence dependence on Heterospecific Information about Predators

Predators can strongly influence community ecology and honest behavioral signals that identify potential predatory threats are often used not only by conspecifics but also by nearby heterospecifics to great effect. I seek to understand the nature of dependence on heterospecific information about predators, because it is hypothesized to be the underlying factor behind the formation of permanent members of mixed–species flocks of forest birds. An understanding of traits that determine dependence on heterospecific information provides predictive power to understand species most likely to assemble in flocks. 

 

 

 

 

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Heterospecific alarm calls, Predation Risk and Habitat Use

Does predation risk influence the spatial distribution of species and to what extent does presence/absence of keystone informants influence the distribution of those species? Mixed-species flocks exert great influence on the behavior of many species as they move daily throughout their territory. My current work focuses on the consequences of reliance on heterospecific information for habitat use and how flock species richness is influenced by the presence of keystone informants.

 

 

 

 

 

Dynamics of heterospecific eavesdropping of antwswarm following birds

Heterospecific eavesdropping can be an important source of information for animals making daily decisions, which ultimately have fitness consequences. Studies evaluating eavesdropping have mostly focused on predator detection signals, but, eavesdropping for information about food resources has received less attention. In conjunction with collaborators from the Smithsonian Tropical Research Institute, I am currently investigating whether birds searching for insects flushed by antswarms may eavesdrop on heterospecifics to assess the presence and size of an antswarm.  We are conducting playback experiments in Neotropical forest in both Soberanía National Park and Barro Colorado Island with antswarm following birds to test different hypotheses about cues used to find and evaluate antswarms.  We manipulate different vocal cues such as 1) a species’ degree of specialization on antswarms, 2) flock size, and 3) flock species richness to understand which components are used by easvesdropping birds to evaluate and assess antswarms.

 

 

 

 

The ecology of avian defense against predators
In conjunction with my collaborator Gustavo Londoño of ICESI University, we are currently interested in understanding the ecological and evolutionary determinants of nest defense. How do different species traits influence responses to nest predators?  Do species have different responses for different predators? Are their commonalities to the vocal responses to different types of predators?  How do level of reproductive investment and predation risk influence nest defense?  We are currently testing the responses of different nesting specis to predator decoys of different predator types along elevational gradients in Peru and Colombia to address these questions.