Stephanie Godfrey, Andrew Sih, C. Michael Bull The response of a sleepy lizard social network to altered ecological conditions Stephanie Godfrey, Andrew Sih, C. Michael Bull Hannah Kienzle & Marissa Hackman

Questions Do changes in rainfall and climate over 3 years affect lizard body condition and behaviour (activity and home range use) Do these changes influence social structure? Hypotheses Overall, frequency of interactions would increase due to aggregation during dry periods Intersexual pairing associations in network have lower strength with drier conditions Non-pairing associations increase with drier conditions

Title “The response of a sleepy lizard social network to altered ecological conditions” What other conditions? They only really care about rainfall

Introduction Missing information: Types of interactions? Intrasexual interactions They measured and analyzed this, but never mention what these consist of More on sleepy lizard biology They only wrote 2 sentences Source: Haydyn Bromley

Introduction They are mainly focusing on the effect of environmental change on aspects of the social network However, these lizards are not in a controlled environment and there may be multiple changes at once, cannot directly test They mention guppies and population response to changes in predation risk What about the lizards? Did their predator populations fluctuate over the 3 years?

Introduction GPS loggers: “Allow deeper insight into cryptic aspects of their social system beyond pair associations” If they wanted insight into activity beyond pair associations, why study during breeding time? “Most of annual activity was confined to this period” Then maybe they aren’t very social (beyond mating)? Is this worth studying?

Methods - Study Area How did they section off area? Captured all lizards within area What if home range extended outside of this zone? Homogeneity of area Small ponds? Bushes? Refuge density Patch density and quality

Methods

Methods - Timing - Start pairing up around September - Mate end of October, early November, then separate -

Methods - Timing Breeding season (Sept-Nov) lies within study period (Aug to Dec) Did interactions change throughout study period as breeding starts/ends? Is 3 years enough to examine differences in climate? Pseudoreplication?

Methods Tested whether home range area or activity level varied between years for the 30 individuals that were observed in all three years How did they know these were the same 30 individuals? Tend to molt 4-5 times a year

Methods GPS and activity loggers Lizards interacting when 2m apart, but GPS precision is 6m So they used 14m as their interaction distance...

Methods - Social Network Based on frequency of two active lizards near each other What about one active lizard? What if they approach slowly? … etc. Can’t quantify length of interactions Used ideal gas model This implies that there are no physical barriers

Methods - Social Network To deal with varying number of lizards, they took subset of 40 from the central part of the enclosure Was this randomized? How did they choose? ? ? Source: Stephan Leu

Results - Climate and Body Condition Is 3 years long enough to compare climate? Longer dry periods may change amount of activity Temperature lowest in 2010 How important is temperature? Source: Mark Semeniuk

Results - Social Networks Table 3 with associations was difficult to interpret “Significantly correlated associations”

Results - Social Networks Degree strength, clustering coefficient, mean edge weight results Difficult to read and interpret, did not relate terms back to what they translate to biologically Why include useless figures? Clustering coefficient and network density were not significant, yet they included graphs/tables

Results - Overall Too much? rainfall, temperature, body condition, intersexual and intrasexual associations and strength, pair and extra pair strength, strength (overall), degree, clustering coefficient, mean edge weight

Discussion Explain that in previous studies, low rainfall = less food = less foraging time They never look at food availability “Although all changes we detected were apparent responses to the very dry year in 2008 our study was inadequately replicated to make rigorous conclusions” They made conclusions anyway, as it is the basis for the whole paper

Discussion “Our major aim was not to attribute changes in network structure to specific climatic conditions. Instead we asked whether networks retained their structure over ecologically variable conditions.” Although they looked at changes over time instead of spatial differences in climate, they only really looked at one specific condition (rainfall)

Discussion Intrasexual interactions (specifically male- male) year to year did not change in strength, but position in network relative to each other changed They said that they can’t explain without observations Extra pair increase in dry conditions They don’t know if mating is actually occurring

General thoughts They can’t really directly analyze the effects of rainfall on social network, even though this is the focus of their entire paper Need more than 3 years Could have been more focused

Questions?