Individual Escape Flight Performance Is Repeatable and Differs Between Long-Tailed Finch (Poephila acuticauda)...

Area of Science:

• Evolutionary biology
• Animal behavior
• Genetics

Background:

• Mitochondrial variation's role in fitness-related traits is an emerging evolutionary question.
• Asymmetric introgression in long-tailed finches (Poephila acuticauda) suggests selection, but direct fitness evidence is lacking.
• The eastern subspecies (P. a. hecki) mito-type introgressed into P. a. acuticauda may confer an energetic advantage, like superior escape flight.

Purpose of the Study:

• To investigate if mitochondrial variation influences escape flight performance in long-tailed finches.
• To test predictions of selective advantage for the P. a. hecki mito-type.
• To examine flight performance in hybrids and assess potential mitonuclear gene incompatibilities.

Main Methods:

• Spatial tracking software (Argus) quantified take-off flight performance in 158 wild-derived, captive long-tailed finches.
• Nine flight metrics were recorded, including average force and maximum vertical distance.
• Performance was compared between subspecies (P. a. hecki vs. P. a. acuticauda) and hybrid individuals.

Main Results:

• Average force and maximum vertical distance were lower in P. a. hecki males compared to P. a. acuticauda males.
• Contrary to predictions, P. a. hecki did not show superior escape flight performance.
• No impaired flight take-off performance was observed in female hybrids compared to matched individuals, nor between sexes in hybrids.

Conclusions:

• Take-off flight performance in long-tailed finches is not linked to the observed asymmetry in mito-type introgression.
• Mitochondrial variation does not appear to drive differences in escape flight performance in this species.
• Future research should consider flight path direction as a key factor in performance analysis.