Effects of a fiber-rich diet on physiology and survival of farm-reared red-legged partridges (Alectoris rufa)

The sudden shift from a commercial energy-rich, fiber-poor diet to natural food is assumed as one of the causes of the low success of gamebird restocking. We fed farmed red-legged partridge (Alectoris rufa) chicks with a diet rich in fiber from their first month of life to the time of their release to assess the possible effects on morphometric characteristics and plasma biochemistry and whether those effects enhance survival after release into the wild. At the time of release, treated partridges showed heavier gizzards and bursas of Fabricius and longer small intestines than control birds fed commercial feed. Treated birds had also smaller pectoral muscles, lighter spleens and lower plasma levels of proteins, glucose, cholesterol and triglycerides. After release and radiotracking in a hunting area, we found no differences in the survival between both groups. Survival at the end of the study (day 39) was 58.3+/-14.2% for the control group and 24.2+/-13.8% for the treated group. The fiber-rich diet seems to have important effects on the physiology of the red-legged partridge, not always taken into account in previous studies.     

Variation in plasma biochemical parameters in captive adult red-legged partridges (Alectoris rufa) during daylight hours

Blood biochemical parameters may provide useful information about the physical condition of the individual, making them a useful tool in ecological studies. However, to avoid biases, factors affecting circulating levels of plasma metabolites must be investigated. In this paper, we analyse the effect of daytime sampling hour on seven plasma metabolites in adult red-legged partridges (Alectoris rufa) with free access to food during the breeding season. We found that sampling hour affected circulating levels of glucose and triglycerides but not those of cholesterol, total protein, uric acid, urea or albumin. A sex effect was found only for glucose, uric acid, urea and triglycerides. Repeated sampling affected all the parameters studied. These results suggest that the effect of sex, sampling hour and repeated sampling should be carefully controlled for (methodologically or by statistical procedures) to avoid undesirable sources of error at least in some blood parameters.     

Systemic candidiasis in farm-reared red-legged partridges (Alectoris rufa) caused by Leucosporidium spp

Background

Canine noroviruses (NoVs) have been recently described in south European countries and associated with outbreaks of diarrhea in kennels. Unlike human NoV which are known as an important cause of acute gastroenteritis, little is known about the role of canine NoV as pathogens in dogs as well as its epidemiological features.

Results

From 2007?C2011, 256 stool samples were collected from dogs across Portugal and tested by RT-PCR for canine NoV. Viral fecal shedding was found to be 23% (60/256). All sequences contained the GLPSG amino acid motif characteristic of the RNA-dependent RNA-polymerase gene of NoVs and had a high nucleotide identity (range 98%?C100%) to the canine NoV first described in Portugal. The highest shedding rate was detected during the winter months.

Conclusions

This study shows that canine NoV infection is endemic in the dog population of Portugal. Peak shedding was detected in the winter months, a well-known epidemiologic feature of human NoV infections.     

Recruitment of grey and red-legged partridges (Perdix perdix and Alectoris rufa) in relation to population density and habitat

The recruitment of first-year grey and red-legged partridges into subsequent breeding populations was investigated on 17 study areas in Britain.
The density of birds recruited per unit area increased with the density of birds available in their first autumn for potential recruitment in the following spring but decreased with adult density. The relationship between recruitment and adult density, while always negative, differed significantly between areas. These differences were correlated with variation in the amount of nesting habitat available to both species of partridge and with variation in nesting habitat quality. Recruitment of grey partridges was related to length of available nesting habitat, the amount of residual dead grass in the nesting cover, and earth bank height at the base of the nesting cover. Recruitment of red-legged partridges was also related to length of nesting habitat, together with the amount of nettle in the nesting cover.
It is suggested that the attractiveness of different areas to settling recruits is determined by the amount and quality of nesting habitat available.     

A quantitative assessment of the release of farm-reared red-legged partridges (Alectoris rufa) for shooting in central Spain

The release of farm-reared game is considered a conflictive management tool because of its potential harmful ecological effects on wildlife and associated habitats. Estimates of the number of animals released and the area where this game management takes place could give an idea of the magnitude of their potential impacts. We aimed to quantitatively assess the release of farm-reared red-legged partridges (Alectoris rufa) in the province of Ciudad Real, central Spain, one of the main hunting areas in this country. We analysed the official permits that the regional government granted to the hunting estates to release farm-reared partridges between 2006 and 2012. Our results show that an average of 800,000 partridges were released annually in the study area. A decrease in the number of hunting estates that used this game management practice, as well as in the number of red-legged partridges officially released, was observed during the last years within the study period. This might be a consequence of the current economic crisis, rather than a change in management styles. Release intensity was spatially heterogeneous, being higher in the southeast of the study area, where historically red-legged partridge was more abundant. Most of the red-legged partridges released came from only four farms placed in northern Spain. Our results suggest that this management activity should be better monitored and that spatial regulations should also be considered.     

Carotenoids in fish. XIX. Carotenoids in the eggs of Oncorhynchus keta (Walbaum)

The author investigated the presence of various carotenoids in the eggs of Oncorhynchus keta by means of columnar and thin-layer chromatography. The investigations revealed the presence of the following carotenoids: canthaxanthin, lutein-epoxide, 4-hydroxy-4-keto-ß-carotene, tunaxanthin, astaxanthin ester and asterin acid. Astaxanthin ester comprised the greatest part, 67.8% of, all carotenoids.     

Variation in reproductive output of marine turtles

Most marine turtle species are non-annual breeders and show variation in both the number of eggs laid per clutch and the number of clutches laid in a season. Large levels of inter-annual variation in the number of nesting females have been well documented in green turtle nesting populations and may be linked to environmental conditions. Other species of marine turtle exhibit less variation in nesting numbers. This inter-specific difference is thought to be linked to trophic status. To examine whether individual reproductive output is more variable in the herbivorous green turtle (Chelonia mydas Linneaeus 1758) than the carnivorous loggerhead (Caretta caretta Linneaeus 1758), we examined the nesting of both species in Cyprus over nine seasons. Green turtles showed slower annual growth rates (0.11 cm year⁻¹ curved carapace length (CCL) and 0.27 cm year⁻¹ curved carapace width (CCW)) than loggerhead turtles (0.36 cm year⁻¹ CCL, 0.51 cm year⁻¹ CCW). CCL was highly correlated to mean clutch size in both green (R²=0.51) and loggerhead turtles (R²=0.61) and maximal clutch size of green turtles (R²=0.58). Larger females did not lay a greater number of clutches or have a shorter remigration interval than smaller females of either species. On average, the size of green turtle clutches increased and that of loggerhead turtles decreased as the season progressed. Individual green turtles, however, produced more eggs per clutch through the season to a maximum in the third or fourth clutch. In loggerhead turtles, clutches 1-4 were very similar in size but the fifth clutch was 38% smaller than the first. No individuals of either species were recorded laying more than five clutches. Green turtles may not be able to achieve their maximum reproductive output with respect to clutch size throughout the season, whereas only loggerhead turtles laying five clutches (n=5) appear to become resource depleted. Green turtles nesting in years when large numbers of nests were recorded laid a greater number of clutches than females nesting in years with lower levels of nesting.     

Pair formation and reproductive output in domestic pigeons

Mate selection is a conceivable mechanism whereby an animal could increase its reproductive success. The present study investigates the relationship between mate selection and reproductive output in domestic pigeons. Pairs allowed to form spontaneously, in a situation permitting a certain degree of choice, were compared with pairs randomly assigned to each other. The prediction was that spontaneously formed pairs should on average achieve a better reproductive output than pairs randomly formed. In a reproduction test the spontaneously formed pairs began egglaying earlier, laid a greater number of eggs and had a larger number of fertilized eggs. It is suggested that the difference between the groups affected such important reproductive variables that it could have a substantial effect on the birds reproductive success.     

The rally call recognition in males of two hybridizing partridge species, red-legged (Alectoris rufa) and rock (A. graeca) partridges

The red-legged (Alectoris rufa) and rock (A. graeca) partridges hybridize and produce fertile offspring along a contact zone in French Southern Alps. The rally call emitted during pair formation, could play an important role in species recognition, acting as a behavioral reproductive isolating mechanism between males and females. In the present study, the coding system of the rally call was investigated from captive males of the two species and from F1 hybrids. By playing-back natural signals, we found that the two species as well as hybrid males responded to Alectoris signals but not to another species belonging to the Phasianidae family (Colinus virginianus). Results also indicate that red-legged and rock partridges responded stronger to conspecific calls than to heterospecific ones. However, they reacted similarly to conspecific and hybrid calls. F1 hybrids responded stronger to hybrids calls than to the two species ones. They did not distinguish the two parental species signals from each other. Although the two species showed the ability to discriminate the conspecific from the heterospecific signal, they clearly responded to the other species. This behaviour may play a role in the hybridization phenomenon.     

The effects of sex and childlessness on the association between status and reproductive output in modern society

Examining the association between socioeconomic status and reproductive output in modern societies has led to conflicting results. In this study, we used a representative sample of contemporary Swedish men and women to analyze possible reasons for the contradictory results. We found that the relationship between socioeconomic status—described here by income and highest educational level attained—and reproductive output is dependent on sex and the inclusion or exclusion of childless individuals. In men, there is a strong positive association between income/education and average offspring count if childless individuals are included in the analysis; this association is absent when such individuals are excluded. We attribute this reversal mainly to the higher proportion of childless individuals among men of lower socioeconomic background. Among other factors, female choice appears to be a major cause of this association because the proportion of men who never married increased with decreasing income category and educational level. In women, however, including and excluding childless individuals both yielded a negative association between income and average offspring count as well as a null or negative relationship between education and average offspring count.     

Carotenoids in human blood plasma after ingesting paprika juice

We investigated the presence of different carotenoids in male human subject after the ingestion of paprika juice, and identified capsanthin, capsanthone, cucurbitaxanthin A, 11-cis-capsanthin, lutein and zeaxanthin in the human plasma. These results suggest that capsanthone and 11-cis-capsanthin might be as important as capsanthin for human health.     

Maternal investment and size-specific reproductive output in carcharhinid sharks

1.  Life-history theory predicts that organisms will provide an optimal level of parental investment for offspring survival balanced against the effects on their own survival and future reproductive potential.
2.  Optimal resource allocation models also predict an increase in reproductive output with age as expected future reproductive effort decreases. To date, maternal investment in sharks has received limited attention.
3.  We found that neonatal dusky sharks ( Carcharhinus obscurus ) are not independent from maternal resource allocation at the point of parturition but instead are provisioned with energy reserves in the form of an enlarged liver that constitutes approximately 20% of total body mass.
4.  Analysis of long-term archived data sets showed that a large proportion of this enlarged liver is utilized during the first weeks or months of life suggesting that the reported weight loss of newborn sharks signifies a natural orientation process and is not necessarily related to prey abundance and/or indicative of high mortality rates.
5.  Interrogation of near-term pup mass in two carcharhinids, the dusky and spinner shark ( Carcharhinus brevipinna ), further revealed an increase in reproductive output with maternal size, with evidence for a moderate decline in the largest mothers.
6.  For the dusky shark, there was a trade-off between increasing litter size and near-term pup mass in support of optimal offspring size theory.
7.  For both the dusky and spinner shark, there was a linear increase in near-term pup mass with month, which may indicate variable parturition strategies and/or that carcharhinids are able to adjust the length of the gestation period.
8.  The identification of optimal size-specific reproductive output has direct implications for improving the reproductive potential of exploited shark populations and for structuring future management strategies.     

Transgenerational effects of food availability on age at maturity and reproductive output in an asexual collembolan species

Transgenerational effects of environmental conditions can have several important ecological and evolutionary implications. We conducted a fully factorial experiment manipulating food availability across three generations in the collembolan Folsomia candida, a springtail species that inhabits soil and leaf litter environments which vary in resource availability. Maternal and grandmaternal food availability influenced age at maturity and reproductive output. These effects appear to be cumulative rather than adaptive transgenerational life-history adjustments. Such cumulative effects can profoundly influence eco-evolutionary dynamics in both stable and fluctuating environments.     

The effects of a coral disease on the reproductive output of Montastraea faveolata (Scleractinia: Faviidae)

The direct impacts of coral diseases on coral populations have been assessed by quantifying coral tissue loss and colony mortality, but the determination of the indirect effects of diseases, such as disruptions in life history functions (e.g. reproduction, growth and maintenance), are more difficult to ascertain and have been scant. This study involved a comparison of various measures of reproductive output from histological slides of healthy tissue samples of Montastraea faveolata and tissue samples from colonies with white plague (WP) infections in Dominica (West Indies). Although the variability in the reproductive data was high, WP had significant negative impacts on the percentage of reproductive polyps per cm2, the percentage of reproductive mesenteries within a polyp, oocyte quantity per polyp, mean oocyte volume (mm3), and fecundity (oocyte volume per cm2 of tissue). However, these effects were only observed in the tissue directly impacted by the WP disease "band" and were not observed in tissue samples taken 20 cm away from the lesion. Therefore, the effects of a coral disease (WP) on reproductive output are localized and not expressed colony-wide.