At the same time, in eleven most other nests we inserted eggs heat having fun with a miniature temperatures logger (Tinytalk-temp, Orion Parts, Sussex, British)

I found 105 active nests, mostly if you find yourself operating slowly across the surroundings

Throughout for each and every reproduction year we sought after nests intensively around the study website. We used this new fate of every nest before eggs hatched or perhaps the colony failed. Nests have been went to anywhere between 0900 and you will 1700 era and the visits endured 2 hundred yards out of the nest, between 1000 and you will 1700 hours. Amount of the fresh focal findings ranged off 29 min in order to 7 h, while the total time of observation is actually 30.5 h. Due to the fact our very own observations ranged in length there was times for the that your male was at the fresh nest throughout the day, in order to guess the newest portion of colony interest i pooled the focal findings off nests that were in one stage out-of incubation.

Since males may wasteland the latest colony whenever disrupted in the an early stage of the nesting duration ( Fernandez and you can Reboreda 2000), i tracked almost all of the nests (9 of 11 instances totaling 34 nest-days) during the middle- otherwise late 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 fungerer postordre brudene 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 and counted variation into the eggs heat in around three experimental nests (nests instead men attract). We utilized nests that had been in earlier times discontinued as the fresh nests. Into the for each colony (clutch versions from 16, 21, and you can 23 egg) we fixed one egg with a thermistor in to the, towards heart of nest similarly you to we performed into effective nests (find a lot more than).