Patterns of sperm storage in relation to sperm competition in passerine birds
Article Abstract:
The number and length of sperm storage tubules (SST) in 20 species of passerine birds encompassing seven subfamilies were estimated using a method for observing SSTs in oviduct tissue preparations. A ninefold variation across species was found for the average number of SSTs per female which was positively correlated with body mass and egg size. Interspecific variation in SST number was attributed to allometry. Selection for greater sperm length in the presence of limited access to storage sites was suggested. Evidence was obtained for a history of coevolution between sperm and sperm storage sites in females which is independent of body size.
Publication Name: The Condor
Subject: Biological sciences
ISSN: 0010-5422
Year: 1993
User Contributions:
Comment about this article or add new information about this topic:
Male incubation in Barn Swallows: the influence of nest temperature and sexual selection
Article Abstract:
A study was conducted to ascertain the role of male Barn Swallows (Hirundo rustica) in the incubation process. Four colonies of barn Swallows were observed in southeastern Canada during the 1989 breeding season. The study showed that 9% to total incubation time during the day was contributed by the males. The maximum contribution was made during the early morning hours, when female swallows needed to replenish energy reserves lost during night incubation, and during the last stages of incubation. Factors such as extra-pair copulations and male attractiveness did not hinder the contribution of male Barn Swallows to incubation.
Publication Name: The Condor
Subject: Biological sciences
ISSN: 0010-5422
Year: 1992
User Contributions:
Comment about this article or add new information about this topic:
Lack of sperm storage by female migrants and the significance of copulations en route
Article Abstract:
Sperm from insemination during migration probably do not retain viability in migratory birds. Copulations occurring en route may be an epiphenomenon resulting from the need to be ready to breed on arrival at the breeding grounds. Females appear to have either a developed specialized sperm storing tubule (SST) or an undeveloped SST during migration. A study conducted on 11 female migrant birds indicates that the proportion of migrating females with a developed SST is probably low as they remain undetected with a relatively small sample.
Publication Name: The Condor
Subject: Biological sciences
ISSN: 0010-5422
Year: 1996
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Genetic markers substantiate long-term storage and utilization of sperm by female painted turtles
- Abstracts: Growth and maturation of Sereer adolescent girls (Senegal) in relation to seasonal migration for labor. High levels of habitual physical acitivity in West African adolescent girls and relationship to maturation, growth, and nutritional status: results from a 3-year prospective study
- Abstracts: Influence of temperature and substrate concentration on bacterial growth yield in Seine River water batch cultures
- Abstracts: Epigenetic spreading of the Drosophila dosage compensation complex from roX RNA genes into flanking chromatin
- Abstracts: Targeting chromatin disruption: transcription regulators that acetylate histones. A positive role for histone acetylation in transcription factor access to nucleosomal DNA