| 1. |
- Balbontin, Javier, et al.
(author)
-
Age-related change in breeding performance in early life is associated with an increase in competence in the migratory barn swallow Hirundo rustica
- 2007
-
In: Journal of Animal Ecology. - : Wiley. - 1365-2656 .- 0021-8790. ; 76:5, s. 915-925
-
Journal article (peer-reviewed)abstract
- 1. We investigated age-related changes in two reproductive traits (laying date and annual fecundity) in barn swallows Hirundo rustica L. using a mixed model approach to di-stinguish among between- and within-individual changes in breeding performance with age. 2. We tested predictions of age-related improvements of competence (i.e. constraint hypothesis) and age-related progressive disappearance of poor-quality breeders (i.e. selection hypothesis) to explain age-related increase in breeding performance in early life. 3. Reproductive success increased in early life, reaching a plateau at middle age (e.g. at 3 years of age) and decreasing at older age (> 4 years). Age-related changes in breeding success were due mainly to an effect of female age. 4. Age of both female and male affected timing of reproduction. Final linear mixed effect models (LME) for laying date included main and quadratic terms for female and male age, suggesting a deterioration in reproductive performance at older age for both males and females. 5. We found evidence supporting the constraints hypothesis that increases in competence within individuals, with ageing being the most probable cause of the observed increase in breeding performance with age in early life. Two mechanisms were implicated: (1) advance in male arrival date with age provided middle-aged males with better access to mates. Yearling males arrived later to the breeding grounds and therefore had limited access to high-quality mates. (2) Breeding pairs maintaining bonds for 2 consecutive years (experienced pairs) had higher fecundity than newly formed inexperienced breeding pairs. 6. There was no support for the selection hypothesis because breeding performance was not correlated with life span. 7. We found a within-individual deterioration in breeding and migratory performance (arrival date) in the oldest age-classes consistent with senescence in these reproductive and migratory traits.
|
|
| 2. |
- Hermosell, Ignacio G., et al.
(author)
-
Sex determination in barn swallows Hirundo rustica by means of discriminant analysis in two European populations
- 2007
-
In: Ardeola. - 0570-7358. ; 54:1, s. 93-100
-
Journal article (peer-reviewed)abstract
- Aims: Differences in morphology in adult barn swallows were investigated using bone and feather measurements taken from birds from a northern (Danish) and a southern (Spanish) European population. Discriminant Function Analysis was used to help in discriminating the sex of individuals of both populations. Location: Badajoz (Spain) and Kraghede (Denmark). Methods: Two discriminant functions were obtained using biometric data from adult individuals, one for each European population. These functions were validated using external data from a sample of an Italian and Ukrainian barn swallow populations. Results: Three morphometric variables: the length of the outermost tail feathers, the length of the inner tail feathers and the length of the keel were retained in the discriminant function in the two populations studied. Overall, these functions allowed us to determine the sex of adult birds with 90.1 % and 91.9 % accuracy for the Spanish and the Danish populations, respectively External validation using a sample from the Italian population to validate Spanish discriminant function and from the Ukrainian population to validate the Danish discriminant function showed that 91 % of Italian and 86 % of Ukrainian swallows were correctly classified. Conclusions: The two discriminant functions obtained would be highly valuable in future work carried out on this species because it would allow researchers to determine the sex of individuals shortly after arrival to the breeding areas without having to wait for the beginning of courtship or incubation for reliable sexing.
|
|
| 3. |
- Marzal, Alfonso, et al.
(author)
-
Co-infections by malaria parasites decrease feather growth but not feather quality in house martin
- 2013
-
In: Journal of Avian Biology. - 0908-8857. ; 44:5, s. 437-444
-
Journal article (peer-reviewed)abstract
- During moult, stressors such as malaria and related haemosporidian parasites (e.g. Plasmodium and Haemoproteus) could affect the growth rate and quality of feathers, which in turn may compromise future reproduction and survival. Recent advances in molecular methods to study parasites have revealed that co-infections with multiple parasites are frequent in bird-malaria parasite systems. However, there is no study of the consequences of co-infections on the moult of birds. In house martins Delichon urbica captured and studied at a breeding site in Europe during 11 yr, we measured the quality and the growth rate of tail feathers moulted in the African winter quarters in parallel with the infection status of blood parasites that are also transmitted on the wintering ground. Here we tested if the infection with two haemosporidian parasite lineages has more negative effects than a single lineage infection. We found that birds with haemosporidian infection had lower body condition. We also found that birds co-infected with two haemosporidian lineages had the lowest inferred growth rate of their tail feathers as compared with uninfected and single infected individuals, but co-infections had no effect on feather quality. In addition, feather quality was negatively correlated with feather growth rate, suggesting that these two traits are traded-off against each other. We encourage the study of haemosporidian parasite infection as potential mechanism driving this trade-off in wild populations of birds.
|
|
| 4. |
- Marzal, Alfonso, et al.
(author)
-
Malaria infection and feather growth rate predict reproductive success in house martins
- 2013
-
In: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 171:4, s. 853-861
-
Journal article (peer-reviewed)abstract
- Carry-over effects take place when events occurring in one season influence individual performance in a subsequent season. Blood parasites (e.g. Plasmodium and Haemoproteus) have strong negative effects on the body condition of their hosts and could slow the rate of feather growth on the wintering grounds. In turn, these winter moult costs could reduce reproductive success in the following breeding season. In house martins Delichon urbica captured and studied at a breeding site in Europe, we used ptilochronology to measure growth rate of tail feathers moulted on the winter range in Africa, and assessed infection status of blood parasites transmitted on the wintering grounds. We found a negative association between haemosporidian parasite infection status and inferred growth rate of tail feathers. A low feather growth rate and blood parasite infections were related to a delay in laying date in their European breeding quarters. In addition, clutch size and the number of fledglings were negatively related to a delayed laying date and blood parasite infection. These results stress the importance of blood parasites and feather growth rate as potentially mechanisms driving carry-over effects to explain fitness differences in wild populations of migratory birds.
|
|
