I found 105 effective nests, mostly if you are riding slow over the surroundings

During each reproduction seasons i searched for nests intensively all over the study site. We adopted brand new fate of every colony up until the egg hatched and/or colony hit a brick wall. Nests was decided to go to ranging from 0900 and you may 1700 era plus the check outs lasted two hundred meters off the nest, between 1000 and you may 1700 period. Duration of the fresh focal observations Visittsted varied out of 30 min to eight h, while the overall time of observance try 31.5 h. While the our very own observations ranged in length and there were circumstances within the that male was at brand new nest all day, in order to guess this new part of nest appeal we pooled new focal observations from nests that have been in one stage from incubation.

Because men are more likely to desert this new nest when disrupted during the an early stage of your own nesting cycle ( Fernandez and you may Reboreda 2000), i monitored a lot of nests (nine of the eleven cases totaling 34 nest-days) during the mid- otherwise later incubation

The thermistor of the temperature logger was introduced in a fresh natural orphan egg (unattended eggs laid far from active nests; Navarro et al. 1998) through a small hole in the equatorial plane and fixed to the eggshell with epoxy adhesive. The egg was attached to the center of the nest and the data logger was hidden under the nest. The data logger automatically recorded the temperature at 3.8 or 6 min intervals during four or six days, respectively. We monitored egg temperatures in those 11 nests totaling 40 nest-days. In the other two cases we started the monitoring of the nest three and five days after the laying of the first egg. None of the nests used for monitoring male activity was deserted. We used the decrease in egg temperature to determine when the male left the nest ( Hainsworth et al. 1998, Flint and Grand 1999). We previously estimated egg cooling-rate of Greater Rhea eggs by heating six fresh eggs up to 33°C and then placing them in an environment at a temperature of 25°C, similar to temperatures registered in our study area between 1100 and 1300 hours (the warmest time of the day). We estimated egg cooling-rate by dividing the initial difference in temperature between eggs and the environment by the time elapsed until eggs reached a thermal equilibrium with the environment. The estimated egg cooling-rate for a temperature gradient of 8°C was 0.063 ± 0.01°C min ?1 . We assumed that the male left the nest when the difference in egg temperature was |T_(t) ? T_(t?1)| > 1°C, where T_(t) and T_(t?1) are egg temperatures at a time interval of 15 min when data loggers were set at 3.8 min intervals or 18 min when they were set at 6 min intervals. We considered that the male was outside the nest since the time at which the difference between T_(t) and T_(t?1) was negative until the time it was positive (i.e. the male resumed incubation). Although the sun can heat eggs when the male is absent (particularly at midday), unattended eggs never reached temperatures >30°C (see below). Therefore, it was possible for us to discriminate between an increase in temperature produced by the Sun and one produced by males when they resume incubation.

I together with counted type when you look at the eggs temperatures inside the three fresh nests (nests instead male attention). I used nests that were before discontinued since the fresh nests. When you look at the for each nest (clutch items of 16, 21, and you may 23 eggs) i repaired one egg which have a thermistor into the, towards center of your colony in a similar way you to i did on energetic nests (see a lot more than).