. The Canadian field-naturalist. 2000 Holmes and Ndcon: Nesting of the Tennessee Warbler 37 brood size = 6 nestlings, range 4 to 7). Hatching suc- cess was positively correlated with clutch size (87% for 5 egg clutches, 93% for 6 egg clutches and 100% for 7 egg clutches), but this trend was only marginally significant (Spearman rank correlation, r^ = , N= 11, P = ). Hatching occurred over a <24 h period at 4 nests, and over a <48 h period at 6 other nests. In these 10 nests, 46 (81%) of the young hatched in the first 24 h, and 11 (19%) in 24-48 h. There were enough observatio
. The Canadian field-naturalist. 2000 Holmes and Ndcon: Nesting of the Tennessee Warbler 37 brood size = 6 nestlings, range 4 to 7). Hatching suc- cess was positively correlated with clutch size (87% for 5 egg clutches, 93% for 6 egg clutches and 100% for 7 egg clutches), but this trend was only marginally significant (Spearman rank correlation, r^ = , N= 11, P = ). Hatching occurred over a <24 h period at 4 nests, and over a <48 h period at 6 other nests. In these 10 nests, 46 (81%) of the young hatched in the first 24 h, and 11 (19%) in 24-48 h. There were enough observations on two nests to estimate the period from the laying of the final egg until the hatching of the first nestling. This was 7 days at one nest (last egg laid on 21 June and nestlings hatched on 28 June) and 8 days at the other (last egg laid on 20 June and nestlings hatched on 28 June). At a third nest, this period was at least 8 days (the date the last egg was laid was not known). Reproductive success As stated previously, nesthngs were very sensitive to nest disturbance starting at about age 6 days. The young in two nests fledged prematurely when we attempted to measure them at age 7 days. In three other nests, 6-day-old young may have fledged pre- maturely as a result of activities associated with videotaping. In one case, a nesding was taped as it left the nest, although its three siblings remained. In the other two nests, all of the nestlings were still pre- sent at the end of taping, but the nests were empty by the next day. Because a number of young fledged prematurely in this study, it was not possible to estimate nesting success as the proportion of nesting pairs that suc- cessfully fledged at least one offspring. The follow- ing data do give some indication of nest mortality/survival rates, however. No nests were depredated/abandoned while they contained eggs (n = 11). One nest containing five young was aban- doned by the parents when the nestlings were <1 day old;
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Keywords: ., bookauthorottawafi, bookcentury1900, bookdecade1910, bookyear1919
