Territory configuration moderates the frequency of extra-group mating in superb fairy-wrens Glen C. Bain, Michelle L. Hall, and Raoul A. Mulder Presentation by: Nick O’Hanley, Sara Mackellar, and Allison Bowes

The Issue/Hypothesis Extra-Pair mating is influenced by territory composition. Hypothesis: There will be higher rates of extra pair mating in clustered territories compared to linearly arranged territories.

Introduction Territory Configuration Hypothesis Good Genes Hypothesis Genetic Compatibility Hypothesis Focused heavily on male behaviours and dominance when the focus was territories.

Materials & Methods What is a territory? Linear sites that were supposedly fragmented had connectivity between sites although they were separated by a large distance. What consists of ‘fragmentation’ in a linear habitat? What were the type of landscape that occurred within these territories, i.e. geomorphology, vegetation coverage, etc.

Materials and Methods Sampling areas were composed of different environmental conditions which could have affected mating behaviour. One was near a city and the other was a bird sanctuary. Clustered habitat was protected - Birds were in safer conditions than the linear habitat Could have taken another linear sample in Lara region.

Field Methods What defines territories linear or clustered or their shape? Dependent on nest location? Bird density? Competition? Total number of birds heard or observed with playback audio within a territory to determine densities How do you determine if it was the same bird? Very short time period - Only 3 times for 20 seconds. Inaccurate estimation of extra mating pairs if nest location is unknown Measuring a lot of variables - looked at one variable on its own

https://www.youtube.com/watch?v=pO1LGBtNHcU

Field Methods One hour may not be sufficient to determine social composition within nests. Could have missed sampling birds within the territory.

Paternity Analysis Assumed the dominant males in the territory was the father, then went on to ‘the next best option.’ Perhaps false identification of parentage due to locus accounting. 1 locus = mutation, 2 locus = extra-pair young Somewhat guessing or ‘playing the odds between siblings - picking the best ‘match or supposed father’ as opposed to complete definitive evidence Linear territories had a much smaller sample size than the clustered territories (72 nestlings from 32 broods vs. 44 nestlings from 17 broods)

Jerry Springer Episode Who’s the father?!

Results Table 1 - Wilcoxon’s rank-sum analysis of differences between linear and clustered territories Perhaps too many variables (relevance of body mass?) Level of male care? Breeding density? What makes up a “neighbourhood”? Neighbouring nest distance questionable

Results Lumped together their data with that of other studies Differences in experimental design/analyses? Statistical analysis? Figure 2 - The effect of territory configuration on the percentage of extra-group offspring

Results Only assigned paternity to 76% of young in clustered and 67% in linear; focused heavily on mating behaviour Consideration of patch/resource quality? Effect of female choice

Discussion Should a brood be composed of more male offspring, they may become helper males, prompting extra-pair mating to increase genetic diversity No reasoning/explanation for some of their results (e.g. why did they find no effect of brood size?) Which males are more likely to be chosen to become extra-pair father? How is this decided? Idea of comparing two different species is good, however comparison to possum is a stretch

Discussion Differences between observers? Time of year changes rate of EGP (i.e. mating season vs. non-mating season)

Suggestions for Improvement Instead of tape playback, the point count method or transects could be used. Stand in one spot and count all birds within a certain radius Larger sample size for the linear sites Another continuous for the Boho site (only 1 was taken) Look at effect of female dominance Take other factors into consideration (ie. patch quality)

Overall Conclusions Poor Density measurements More linear samples are needed Need more sense of what defines a territory within the study and species Guessing game of parentage Too many variables, some irrelevant Simplification of results, sampling and relationships between variables

Questions?