CARLOS A. BOTERO				DEPARTMENT of NEUROBIOLOGY and BEHAVIOR & LABORATORY of ORNITHOLOGY, CORNELL UNIVERSITY
Last update July 2006
Home	CV		Publications		Mockingbirds	Last update July 2006
Contents Home Mockingbird research My other research Publications Curriculum Vitae		Other research Dynamics of mixed-species flocks of insectivorous birds Mixed-species flocks are social groups of several different species that travel together through their habitat. They range from temporary associations to long-term relationships with multi-species territoriality. One of the long standing questions in the study of this phenomenon is how different species manage to stay together while traveling through highly complex environments (e.g. the understory) and using the habitat in completely different ways. It has been suggested that certain species, known as “nuclear species” help maintain the cohesion of these groups by emitting acoustic or visual signals on a regular basis. In 1999 I experimentally tested this hypothesis in the gallery forests of Rio Vichada in Colombia, home of one of the most common “nuclear” species in the Amazonian mixed-species flocks of insectivorous birds: the white-flanked antwren (Myrmotherula axillaris). These antwrens flash their wing approximately every two seconds while moving (all through the day!!). In males this behavior is so conspicuous (because their body is black but their flanks are white) that it is thought to act as a visual signal of cohesion. However, my experiment showed that these antwrens indeed help other species join the flock but that they do not help others stay longer in it (probably because birds that find prey by gleaning cannot afford to be constantly watching where the antwrens are going). (Botero, C. A. 2002. JFO. 73(1): 74-81). Wing-flashing and prey-flushing? Wing-flashing occurs in both male and female white-flanked antwrens (despite their striking difference in coloration and contrast) and these wrens are commonly seen pursuing insects as they flush them from the substrate. Because of this, Santiago Ramírez and I tested the hypothesis that wing-flashing in this species could be related to foraging. The questions for this study were (1) is there a correlation between wing-flashing and foraging rates, (2) is the slope of this relationship influenced by gender or age and (3) does the conspicuous color contrast of males give them any advantages in prey flushing over females. After a few years in grad school I was finally ready to tackle the necessary statistical models required to analyze these complex data. Now it is all a matter of finding the time to write it up (but you know how that can go sometimes!!). Automated classification of sounds into types and During the course of my dissertation I have developed a series of software tools in Matlab. An important part of this development are the routines AUTOCLASSIFIER and REPVALIDATOR2 which are window based programs that allow users to easily classify sounds into types based on spectral cross correlation and to validate their results with a user friendly graphical interface. All of my Matlab routines are available for free public use (except those that rely on proprietary code by third parties). If you are interested in any of these routines send me an email and I’ll be glad to send you the code.