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Homing trajectories and initial orientation in a Neotropical territorial frog, Allobates femoralis (Dendrobatidae).

Pašukonis A, Loretto MC, Landler L, Ringler M, Hödl W - Front. Zool. (2014)

Bottom Line: Recent data showed that Allobates femoralis, a frog with paternal tadpole transport, successfully returns to the home territories after experimental translocations of up to 400 m.In the arena assay, the frogs showed significant homeward orientation for translocation distances of 35 m to 70 m but not for longer and shorter distances.Our results describe a very accurate homing behavior in male A. femoralis.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. andrius.pasukonis@univie.ac.at.

ABSTRACT

Introduction: The ability to relocate home or breeding sites after experimental removal has been observed in several amphibians and the sensory basis of this behavior has been studied in some temperate-region species. However, the actual return trajectories have rarely been quantified in these studies and it remains unknown how different cues guide the homing behavior. Dendrobatidae (dart-poison frogs) exhibit some of the most complex spatial behaviors among amphibians, such as territoriality and tadpole transport. Recent data showed that Allobates femoralis, a frog with paternal tadpole transport, successfully returns to the home territories after experimental translocations of up to 400 m. In the present study, we used harmonic direction finding to obtain homing trajectories. Additionally, we quantified the initial orientation of individuals, translocated 10 m to 105 m, in an arena assay.

Results: Tracking experiments revealed that homing trajectories are characterized by long periods of immobility (up to several days) and short periods (several hours) of rapid movement, closely fitting a straight line towards the home territory. In the arena assay, the frogs showed significant homeward orientation for translocation distances of 35 m to 70 m but not for longer and shorter distances.

Conclusions: Our results describe a very accurate homing behavior in male A. femoralis. The straightness of trajectories and initial homeward orientation suggest integration of learned landmarks providing a map position for translocated individuals. Future research should focus on the role of learning in homing behavior and the exact nature of cues being used.

No MeSH data available.


Related in: MedlinePlus

Arena trajectory. Example of a single coded trajectory from the arena experiment, using a graphical arena representation as an interface. Solid outer circle represents the arena wall, small filled gray circle represents the release device, black dots connected by an interpolation line represent each hop of the frog in the arena. The orientation bearing was measured at the outer dashed circle (100 cm) and the straightness coefficient (SC) was calculated for the path between inner (30 cm) and outer (100 cm) dashed circles.
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Figure 4: Arena trajectory. Example of a single coded trajectory from the arena experiment, using a graphical arena representation as an interface. Solid outer circle represents the arena wall, small filled gray circle represents the release device, black dots connected by an interpolation line represent each hop of the frog in the arena. The orientation bearing was measured at the outer dashed circle (100 cm) and the straightness coefficient (SC) was calculated for the path between inner (30 cm) and outer (100 cm) dashed circles.

Mentions: In total, we analyzed 38 valid arena trials. We used a custom script written by the first author for MATLAB 7.11.0.584 (The MathWorks Inc., Natick, MA, USA) to code and extract the trajectory of each frog in the arena. A graphical representation of the arena with the reference grid was simultaneously displayed with the video recording of each trial and each hop position of the frog was coded with a mouse click at the corresponding location in the graphical representation. Each position was exported as the corresponding X- and Y-coordinates with the origin at the center of the arena. Arena trajectories were analyzed between an inner circle with 30 cm radius and an outer circle with 100 cm radius, in order to avoid the wall influenced movements close to the release device and close to the arena wall (Figure 4).


Homing trajectories and initial orientation in a Neotropical territorial frog, Allobates femoralis (Dendrobatidae).

Pašukonis A, Loretto MC, Landler L, Ringler M, Hödl W - Front. Zool. (2014)

Arena trajectory. Example of a single coded trajectory from the arena experiment, using a graphical arena representation as an interface. Solid outer circle represents the arena wall, small filled gray circle represents the release device, black dots connected by an interpolation line represent each hop of the frog in the arena. The orientation bearing was measured at the outer dashed circle (100 cm) and the straightness coefficient (SC) was calculated for the path between inner (30 cm) and outer (100 cm) dashed circles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3974440&req=5

Figure 4: Arena trajectory. Example of a single coded trajectory from the arena experiment, using a graphical arena representation as an interface. Solid outer circle represents the arena wall, small filled gray circle represents the release device, black dots connected by an interpolation line represent each hop of the frog in the arena. The orientation bearing was measured at the outer dashed circle (100 cm) and the straightness coefficient (SC) was calculated for the path between inner (30 cm) and outer (100 cm) dashed circles.
Mentions: In total, we analyzed 38 valid arena trials. We used a custom script written by the first author for MATLAB 7.11.0.584 (The MathWorks Inc., Natick, MA, USA) to code and extract the trajectory of each frog in the arena. A graphical representation of the arena with the reference grid was simultaneously displayed with the video recording of each trial and each hop position of the frog was coded with a mouse click at the corresponding location in the graphical representation. Each position was exported as the corresponding X- and Y-coordinates with the origin at the center of the arena. Arena trajectories were analyzed between an inner circle with 30 cm radius and an outer circle with 100 cm radius, in order to avoid the wall influenced movements close to the release device and close to the arena wall (Figure 4).

Bottom Line: Recent data showed that Allobates femoralis, a frog with paternal tadpole transport, successfully returns to the home territories after experimental translocations of up to 400 m.In the arena assay, the frogs showed significant homeward orientation for translocation distances of 35 m to 70 m but not for longer and shorter distances.Our results describe a very accurate homing behavior in male A. femoralis.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Cognitive Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. andrius.pasukonis@univie.ac.at.

ABSTRACT

Introduction: The ability to relocate home or breeding sites after experimental removal has been observed in several amphibians and the sensory basis of this behavior has been studied in some temperate-region species. However, the actual return trajectories have rarely been quantified in these studies and it remains unknown how different cues guide the homing behavior. Dendrobatidae (dart-poison frogs) exhibit some of the most complex spatial behaviors among amphibians, such as territoriality and tadpole transport. Recent data showed that Allobates femoralis, a frog with paternal tadpole transport, successfully returns to the home territories after experimental translocations of up to 400 m. In the present study, we used harmonic direction finding to obtain homing trajectories. Additionally, we quantified the initial orientation of individuals, translocated 10 m to 105 m, in an arena assay.

Results: Tracking experiments revealed that homing trajectories are characterized by long periods of immobility (up to several days) and short periods (several hours) of rapid movement, closely fitting a straight line towards the home territory. In the arena assay, the frogs showed significant homeward orientation for translocation distances of 35 m to 70 m but not for longer and shorter distances.

Conclusions: Our results describe a very accurate homing behavior in male A. femoralis. The straightness of trajectories and initial homeward orientation suggest integration of learned landmarks providing a map position for translocated individuals. Future research should focus on the role of learning in homing behavior and the exact nature of cues being used.

No MeSH data available.


Related in: MedlinePlus