Natal and Breeding Dispersal in House Wrens (Troglodytes aedon)

The Auk ◽  
1988 ◽  
Vol 105 (3) ◽  
pp. 480-491 ◽  
Author(s):  
Nancy E. Drilling ◽  
Charles F. Thompson

Abstract We studied the natal and breeding dispersal of yearling and adult House Wrens (Troglodytes aedon) for 7 yr in central Illinois. The forested study areas contained 910 identical nest boxes placed in a grid pattern. On average 38.1% (n = 643) of the adult males and 23.3% (n = 1,468) of the adult females present in one year returned the next; 2.8% (n = 6,299) of the nestlings that survived to leave the nest returned each year. Adult male (median distance = 67 m) and adult female (median = 134 m) breeding dispersal was less than yearling male (median = 607.5 m) and yearling female (median = 674 m) natal dispersal. Females that returned had produced more offspring the previous season than had nonreturning females, and females that successfully produced at least one chick in their last nesting attempt of the previous season moved shorter distances than did unsuccessful females. There were, however, no consistent differences between returning and nonreturning females in two other measures of reproductive success. Females that were unsuccessful in their last breeding attempt of the previous year were more likely to be successful in their next attempt if they moved two or more territories than if they did not move. Reproductive success did not affect the likelihood that a male would return nor the distance that he moved. The success of subsequent nesting attempts by males was also not related to the distance moved. Inbreeding avoidance may explain differences between breeding and natal dispersal, but it does not explain the lack of difference in dispersal of yearling females and males. Differences between adult and yearling dispersal are best explained by advantages accruing to adults that remain near former breeding sites and by the necessity for yearlings to move farther because of their late return from the wintering grounds. The advantages for adults to reoccupy previous breeding sites are counterbalanced, especially in females, by advantages associated with moving after breeding failure.

The Auk ◽  
2002 ◽  
Vol 119 (3) ◽  
pp. 800-807 ◽  
Author(s):  
John D. Styrsky ◽  
Robert C. Dobbs ◽  
Charles F. Thompson

Abstract Evolutionary theory predicts that heritability of fitness-related traits should be low. Egg size in birds is a fitness-related trait, but exhibits high heritability. One possible explanation for the apparent failure of natural selection to exhaust variability is that variation in egg size is mediated by female condition. In this study, we estimated repeatability of egg size within and between successive clutches in a wild, double-brooded population of House Wrens (Troglodytes aedon) in central Illinois, and examined the relationship of egg size with female size and condition. Repeatability of egg volume and mass in individual birds was high within years and between successive years (>0.77), suggesting a substantial heritable component to variation in egg size. However, egg mass was also significantly correlated with female condition. We suggest that the high repeatability values largely reflect permanent but nongenetic (ontogenetic) variation in egg size among females, which is reflected in the positive correlation of egg size with female condition. If variation in egg size is attributable to a combination of nonheritable, ontogenetic variation and variation due to current environmental conditions among females, then selection may not produce an evolutionary response in egg size.


Behaviour ◽  
1996 ◽  
Vol 133 (5-6) ◽  
pp. 357-366 ◽  
Author(s):  
William A. Searcy ◽  
L. Scott Johnson

AbstractThis study tested the hypothesis that the song of male birds can function to attract mates. At 11 different locations on our Wyoming study area, we broadcast the song of male house wrens (Troglodytes aedon) from a loudspeaker mounted next to an empty nest box in an unoccupied wren territory. The number of female wrens attracted to the 'speaker box' was compared to the number visiting a silent, control box on another, unoccupied territory nearby. Females visited speaker boxes at a significantly higher rate than they visited control boxes. Ten females visited speaker boxes in six different trials during periods when no male was associated with either the speaker or control box (total time = 45.5 h; visit rate = 0.22/h). In contrast, only one female visited a control box during these same periods (= 0.02 visits/h), and she did so after first visiting the speaker box. Two females visited the speaker box simultaneously in some trials and chasing or fighting always ensued. Many females showed signs of settling permanently at speaker boxes, remaining at speaker boxes from their arrival to the end of the trial (> 5 h in two cases), and most began constructing nests in boxes, despite the absence of a male. In summary, this study provides strong experimental evidence that the song of male house wrens can function to attract mates for breeding.


2019 ◽  
Vol 97 (1) ◽  
pp. 50-56
Author(s):  
C.L. Gable ◽  
T.J. Underwood ◽  
G.P. Setliff

House Wrens (Troglodytes aedon Vieillot, 1809) regularly add spider egg cases (Arachnida: Araneae) to their nests, which may be an example of heterospecific cleaning. This behavior involves one animal employing another to remove parasites from their nests. In House Wren nests, juvenile spiders hatching from egg cases may facilitate the reduction of mites that feed on nestlings. We tested this ectoparasite reduction hypothesis by monitoring House Wren nests for spider egg cases and by collecting completed nests to compare the number of spider egg cases and Dermanyssus hirundinis (Hermann, 1804) mites. No significant relationship was found between the number of spider egg cases and number of D. hirundinis mites in nests. We also found no significant relationship between the number of D. hirundinis mites in nests and the body condition of nestlings. Finally, no significant difference was found between the number of D. hirundinis mites in early versus late season nests, but significantly more spider egg cases were added to late season nests. Of a subsample of spider egg cases dissected, we found that 28% contained spider eggs or embryos. We also identified three species of juvenile spiders from House Wren nests using DNA barcoding. Overall, we found no evidence that spider egg cases reduce the number of D. hirundinis mites or engender better quality offspring in House Wren nests.


Author(s):  
Leidy Alejandra Barragan Contreras ◽  
Rafael Antelo ◽  
Adolfo Amezquita

Testosterone is a steroid hormone involved in the expression of many morphological, physiological, and behavioral traits that arguably affect reproductive success. The evidence for that link is, however, incomplete or absent in the research on crocodylian species. Testosterone levels are also known to change throughout the breeding season, often on an hourly basis, which may further complicate studying their relationship with breeding success. We tested here whether baseline testosterone levels, measured out of the breeding season, are correlated with morphometry and reproductive success in Caiman crocodilus (LINNAEUS, 1758). Paternity tests, based on the amplification and genotyping of eight fluorochrome labeled microsatellites, failed to support a continuous relationship between these variables. Although adult males of all sizes contribute to reproduction, paternity was overrepresented in a few males with high values of maleness index (bigger males), supporting a despotic or pyramidal hierarchy among males. Maternity assignments supported the existence of multiple paternity, a phenomenon previously attributed in this species to the lack of large males caused by human hunting. The idea of larger males having more offspring is widespread in crocodylians, but to our knowledge, this is the first investigation that prove this dogma.


Behaviour ◽  
2004 ◽  
Vol 141 (4) ◽  
pp. 391-405 ◽  
Author(s):  
◽  
◽  

AbstractDuring courtship in the beaugregory (Stegastes leucostictus), a coral reef fish, males turn the dorsal half of their bodies from dull brown to bright yellow, and perform a series of rapid dipping movements in front of females. To look for evidence that females select males on the basis of these characteristics, we provided males with artificial breeding sites in the field, measured their reproductive success, and videotaped courtship. Reproductive success was measured by monitoring both the number and size of egg clutches present in the breeding site that was defended by the male. Both unmanipulated and experimentally induced courtship events were videotaped in separate groups of 88 (of which 32 were videotaped courting females) and 30 males, respectively. Experimental induction of courtship was done by placing a female in a clear plastic cylinder 0.5 m away from the breeding site of a territorial male; each of the 30 males received 8 different female presentations, but never more than one a day, and with a different female every time. We compared (i) the cumulative amount of eggs and number of clutches with the amount of yellow colouration and dipping rate for individual males in both the observational and experimental groups, (ii) individual variation in percentage yellow and dipping rate (for the experimental group only) with reproductive success on the same day when courtship was videotaped, and (iii) egg survivorship (ratio of final to early stage eggs) with yellow colouration and dipping rate, to see if these characteristics indicate male parental ability. Individual variation in courtship characteristics was not correlated with reproductive success on that day. In contrast, however, mean values of percentage yellow and dip rate were correlated with both the number of clutches and amount of eggs, for both the observational and experimental group of males, indicating that females preferentially spawn with males that have the brightest yellow colouration and the highest dip rate. Percentage yellow colouration was correlated with egg survival in the unmanipulated males, but not in the experimental group, while dipping rate was not correlated with egg survival in either group. We argue here that female assessment of male courtship is part of a complex process of female choice, in which females either simultaneously or sequentially examine territorial, breeding site, and male characteristics, and thereby attempt to enhance the survivorship of their offspring.


1983 ◽  
Vol 61 (3) ◽  
pp. 570-573 ◽  
Author(s):  
Ian G. Jamieson ◽  
Fred C. Zwickel

Ten years of banding and censusing data from Blue Grouse (Dendragapus obscurus) were analyzed with respect to dispersal of juveniles and site fidelity of yearlings and adults. Juvenile females dispersed farther than juvenile males. In sibling pairs of the same sex, brothers settled closer to one another than sisters. In sibling pairs with birds of opposite sex, females dispersed farther than males. Adult males first established territories close to where they had been sighted as yearlings, or nonterritorial adults, and most females returned in spring to the same general area where they had previously nested. Two-year-old females showed less fidelity to breeding sites they had used as yearlings than older females to sites they had used in previous years.


Sign in / Sign up

Export Citation Format

Share Document