Laying order, hatching asynchrony and nestling body mass in Tree Swallows Tachycineta bicolor (original) (raw)
Related papers
Effects of nest-box density on the behavior of Tree Swallows during nest building
Journal of Field Ornithology, 2006
In territorial species, increased density is often linked to an increase in aggressive interactions, which may result in trade-offs between competitive behavior and nest construction. We examined the impact of nesting in areas of high-density versus low-density nest boxes on conspecific interactions and nest-building effort in a population of Tree Swallows (Tachycineta bicolor). We also examined whether expected differences in behavior related to variation in nest quality and reproductive success in high-density and low-density areas. No differences in either nest-building behavior or reproductive success were observed between areas of high-density and low-density boxes, but there was a tendency of more frequent behavioral interactions at high density. Similarly, there was a significant difference between pairs defending single nest boxes and those defending multiple nest boxes in the number of interactions with conspecifics. These results suggest that although there may be more competition with conspecifics for Tree Swallows nesting at high density, this does not appear to affect either nest quality or reproductive success.
Size, condition, and territoriality in male tree swallows (Tachycineta bicolor)
1994
Male tree swallow (Tachycineta bicolor) territory owners and floaters were compared in terms of size and nutritional condition to test the resource holding potential hypothesis. Owners were larger than floaters when compared using six morphological measurements. There were no differences in dry mass, ash, or fat content, but territory owners were heavier and had larger protein reserves than floaters. Territory owners may be those individuals who win intrasexual conflicts for the possession of nest boxes, or those who, because of their better nutritional condition, can arrive at the breeding grounds earlier to secure a territory.
Journal of Avian Biology, 2007
It is well established that extra-pair young are present to varying degrees in nests of most avian species. However, the timing of extra-pair copulations during a female's fertile cycle is not well known, nor is how these copulations translate into the distribution of extra-pair young within the laying sequence. We determined the rates of successful within-pair copulations where at least one cloacal contact was achieved, and the number of extra-pair copulations/attempts in 17 pairs of tree swallows Tachycineta bicolor during the mornings encompassing the female's fertile period. We also examined nestling paternity with respect to laying order in eighteen mixed-paternity tree swallow broods. The rate of successful within-pair copulations peaked three days prior to a female laying her first egg, and decreased steadily throughout the laying period. We therefore predicted that extra-pair young would be more likely to hatch out of later-laid than earlier-laid eggs within a female's brood. We found no evidence of an increased frequency of extra-pair young with laying order. Instead, extra-pair young appear to be randomly distributed within the laying sequence of tree swallows.
The Auk, 2005
AяѠѡџюѐѡ.-Food abundance, weather, and female body condition are believed to infl uence the timing of breeding and reproductive performance of birds. We simultaneously studied the eff ects of weather and food abundance on reproduction in Tree Swallows (Tachycineta bicolor) while experimentally reducing female condition and foraging effi ciency by clipping some fl ight feathers prior to egg laying. Control females laid larger clutches earlier in the season, had longer incubation periods, and raised heavier nestlings than experimental females. Fledging success did not diff er aĞ er controlling for laying date and brood size. Greater insect abundance was associated with laying earlier in the season, heavier eggs, and shorter incubation periods. Most likely, feather-clipping aff ected clutch size through reduced foraging effi ciency, which delayed the date of laying, rather than through loss of body condition. This outcome is consistent with the idea that Tree Swallows are "income" breeders that base their timing of reproduction on short-term rates of food intake near the time of breeding. Contrary to studies of other species, Tree Swallows do not appear to time their laying so that hatching will coincide with seasonal peaks in food supply. Rather, they appear to breed when temperature and food abundance are suffi cient to allow females of a given body condition to initiate egg laying.
Defense of extra nest-sites by a cavity nesting bird, the Tree Swallow (Tachycineta bicolor)
1994
We use data from field experiments and observations of Tree Swallows Tachycineta hicolor defending single and extra nest-sites at nestbox and cavity populations to determine the function of extra nest-site defense behaviour. About 50% of pairs travelled up to 56 m to defend neighbouring nest-sites for a month or longer. Both sexes defended extra nestsites. Males spent more time than females at extra nest-sites, especially during later stages of the breeding cycle. In Experiment 1, 60% of extra nest-sites erected beside occupied nestboxes were defended by a neighbouring settled pair. In Experiment 2, males, and perhaps females, preferred to settle on territories with two nest-sites versus those with one. There were no age differences for either sex when comparing birds which defended extra nest-sites with those that did not. Physical characteristics of males were not different between defense types, but females that defended extra nest-sites had longer wings than those that defended one nest-site. Although they may be beneficial in cases where a nest-site is destroyed by a predator, extra nest-sites were usually not essential for renesting. Residents were evicted from territories with extra nest-sites as often as those with only one nest-site. Polygyny was not observed in the natural populations, but one quarter of males with extra nest-sites in the nestbox populations attracted a second female. Our data suggest that male Tree Swallows exhibit resource defense polygyny, and females probably defend extra nest-sites to prevent or delay settlement by other females.
The Auk, 2004
Oћђ ќѓ ѡѕђ most fundamental discoveries in behavioral ecology has been the importance of variation in individual quality. From sexual selection (Andersson 1994) to foraging (Grant and Grant 2002) and life histories (Kruuk et al. 2002), phenotypic variation can have important eff ects on fi tness of individuals and those with which they interact. For example, in lifehistory studies, ecologists have oĞ en observed that individuals that produce more off spring also survive at a higher rate (Smith 1981, Verhulst and Tinbergen 1991). Instead of questioning the existence of fundamental trade-off s in life-history allocation, most researchers have aĴ ributed those positive correlations to nonheritable phenotypic quality variations that overwhelm underlying genetic trade-off s (Partridge and Harvey 1985). If those individual quality diff erences are AяѠѡџюѐѡ.-In many avian species, including Tree Swallows (Tachycineta bicolor), females that lay eggs earlier in the season have higher fi tness. It has been hypothesized that nonheritable variation in individual quality could explain how variation in laying date persists in the face of this apparently directional selection. Previous experimental work on Tree Swallows has suggested that natural variation in fl ight ability enables early-laying females to aĴ ain feeding rates high enough to support egg production on earlier, sparser food than later-laying females. We tested that hypothesis with standardized fl ights through a 9.75-m fl ight-performance test tunnel. One group of female swallows was tested at the height of the breeding season on 28 May regardless of their nesting phenology; another group was tested on the 11th day of incubation. Average acceleration in the tunnel was negatively correlated with clutch initiation date for the females tested on 28 May. Daily variation in ambient environmental conditions had strong eff ects on swallow fl ight performance in the tunnel, and no relationship was observed in the day-11 birds. Because natural variation in foraging performance is correlated with variation in female Tree Swallows' clutch initiation dates, fl ight ability appears to be a key element of individual quality in this species.
The Condor, 1989
We examined 10 characteristics of natural cavities and their influence on reproductive success of Tree Swallows (Tachycineta bicolor) nesting in dead trees in beaver ponds. Large ranges were found for entrance height and area, cavity volume, and nearness to shore of nest sites. Other characteristics were less variable: 46% of cavities were less than 2 m above the pond surface, and 48% had entrance widths of 4-5 cm. Tree Swallow nest sites were uniformly dispersed in the ponds.
Canadian Journal of Zoology, 2019
Natal environment and parental quality can influence offspring phenotype, including physiological and morphological traits. We investigated how offspring morphology and feather corticosterone (CORTf; a physiological index of allostatic load) may be related to nest environment and parental characteristics by cross-fostering 3-day-old nestling Tree Swallows (Tachycineta bicolor (Vieillot, 1808)) between quaking aspen (Populus tremuloides Michx.) and plywood nest boxes that differed in microclimate. We evaluated the relative importance of natal influences, common rearing environment, and nest-box environment on nestling quality. Nestlings raised in quaking aspen boxes tended to have lower CORTf, although this result only approached significance. Nestling body mass was best predicted by the biological mother’s mass and random effects of natal and rearing nest identity, wing length was best predicted by random effects of rearing nest, and head–bill length was best predicted by random eff...