We discover 105 effective nests, primarily if you are riding reduced across the landscaping

Through the for each and every reproduction season i sought after nests intensively around the research web site. We followed the brand new fate of each colony until the eggs hatched and/or nest unsuccessful. Nests was went along to anywhere between 0900 and you can 1700 period as well as the visits endured 200 m off the colony, anywhere between 1000 and 1700 instances. Duration of the latest focal findings varied out-of 29 minute to 7 h, additionally the full lifetime of observance try 30.5 h. As the the findings ranged in total so there were circumstances in which the male is at brand new nest day long, so you can imagine this new portion of nest focus we pooled new focal findings regarding nests which were at the same stage away from incubation.

While the guys will desert the fresh colony whenever disrupted in the an early stage of your own nesting cycle ( Fernandez and you may Reboreda 2000), we monitored a good many nests (nine of eleven cases totaling 34 nest-days) throughout middle- or 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 site 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.

We together with measured type inside the eggs temperatures in around three experimental nests (nests instead of men desire). We made use of nests that had been in past times left behind since fresh nests. When you look at the for every single nest (clutch systems out of sixteen, 21, and 23 egg) we fixed one-egg that have a great thermistor into the, with the cardio of your colony similarly one i performed towards the productive nests (pick significantly more than).