I discover 105 productive nests, mostly while riding much slower along side landscape

During for every reproduction seasons we sought after nests intensively everywhere the research site. I used the latest fate each and every nest before the egg hatched and/or nest failed. Nests was basically decided to go to anywhere between 0900 and you can 1700 circumstances and check outs endured two hundred meters from the colony, ranging from 1000 and 1700 instances. Amount of the focal observations ranged out of 31 min in order to seven h, plus the full duration of observation are 30.5 h. Once the all of our observations varied long so there were circumstances inside the which the men was at the newest dette nettstedet nest day long, to estimate new part of colony appeal i pooled the brand new focal findings out of nests which were at the same stage regarding incubation.

Once the guys may desert the colony whenever disturbed in the an initial phase of the nesting duration ( Fernandez and you can Reboreda 2000), i tracked a lot of the nests (9 of your 11 instances totaling 34 nest-days) during middle- 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.

We including measured adaptation in eggs heat inside the about three experimental nests (nests rather than male desire). I utilized nests that had been before deserted while the experimental nests. In per colony (clutch systems of sixteen, 21, and you will 23 eggs) we fixed one egg which have a thermistor in to the, to your cardiovascular system of your nest in a similar way one to we did to the effective nests (find above).