Is clutch size individually optimized?

Brood size manipulations were carried out to test whether clutchsize variation in individual great tits (Parus major) controlledfor laying date was tuned to their phenotypic quality and/orlocal food abundance (individual optimization hypothesis; IOH).Broods with different original clutch sizes, but equal hatchingdates, were manipulated to a common brood size. A third broodwas kept as a control. Under the IOH, we expected a positiveassociation between reproductive success and original clutchsize. Fledgling production varied in an inconclusive way aftermanipulation, with data from 1 out of 3 years favoring the IOH.The effect of manipulation on the probability of a second clutchwas consistent with the IOH in another 1 out of the 3 years.When fitness accrued to second broods was also taken into considerationin terms of annual fledgling production, results from 2 outof 3 years tended to support the IOH. There was no effect ofthe manipulation on fitness (estimated as the number of recruitsplus parents breeding in the next season). Both the clutch component(local recruitment) and the parental component (survival tillnext breeding season) varied inconclusively with respect tothe IOH. On the basis of fitness measurements, the IOH couldnot be confirmed as an explanation for clutch size variationin this population. In 2 out of 3 years one of the three fitnesscomponents measured varied in accordance with the IOH. Overallthe evidence for the IOH in this data set is therefore weak.     

Exploring the drivers of variation in trophic mismatches: A systematic review of long‐term avian studies

1. Many organisms reproduce in seasonal environments, where selection on timing of reproduction is particularly strong as consumers need to synchronize reproduction with the peaked occurrence of their food. When a consumer species changes its phenology at a slower rate than its resources, this may induce a trophic mismatch, that is, offspring growing up after the peak in food availability, potentially leading to reductions in growth and survival. However, there is large variation in the degree of trophic mismatches as well as in its effects on reproductive output.
2. Here, we explore the potential causes for variation in the strength of trophic mismatches in published studies of birds. Specifically, we ask whether the changes in the degree of mismatch that have occurred over time can be explained by a bird''s (a) breeding latitude, (b) migration distance, and/or (c) life‐history traits.
3. We found that none of these three factors explain changes in the degree of mismatch over time. Nevertheless, food phenology did advance faster at more northerly latitudes, while shifts in bird phenology did not show a trend with latitude.
4. We argue that the lack of support in our results is attributable to the large variation in the metrics used to describe timing of food availability. We propose a pathway to improve the quantification of trophic mismatches, guided by a more rigorous understanding of links between consumers and their resources.

     

LONG-RANGE MOVEMENTS OF SOUTH ATLANTIC RIGHT WHALES EUBALAENA AUSTRALIS

Abstract: Movements of southern right whales between Gough Island and South Africa, and between Argentina and Tristan da Cunha, southern Brazil, and South Georgia are documented through matching of six photoidentified individuals. These include the resighting of a male in a mid-oceanic locality some 4,424 km away from (and 11 yr after) its last sighting in a coastal area where it had been seen in six of the preceding eight years, a female photographed in mid-Atlantic resighted with a calf in a coastal nursery area 2,769 km away, resightings of females with calves in different nursery areas 2,051 km apart in different years, and the first example of a link between a coastal nursery area and a feeding ground in high latitudes. The possible implications of these movements for estimates of calving interval and survival rate based on resightings in coastal waters are discussed. The potential for intermingling between populations on either side of the South Atlantic seems greater than was previously considered likely from a comparison of animals photographed in coastal waters.     

Descriptive and experimental evidence for timing-mediated polygyny risk in a pied flycatcher Ficedula hypoleuca population

In polygynous species with biparental care, mates are often acquired in succession. Most research has focussed on the cost of polygyny in secondary females, but primary females may also suffer from reduced paternal care. The likelihood of sharing a male may be higher for early laying females, which could counteract the fitness benefits of breeding early. In this study, we use 12 years of data on pied flycatchers Ficedula hypoleuca, to show that the likelihood of becoming a primary female of a polygynous male declines over the season. Moreover, we provide experimental evidence that early breeding elevates polygyny risk, through an experimental manipulation that introduced early breeding females to a population with later breeding phenology. We found that, independently of breeding date, primary females slightly more often experienced complete brood failures than monogamous females, but did not differ in number of fledged offspring among successful broods or number of locally returning recruits. However, apparent survival in subsequent years was substantially lower in primary females, indicating that they may compensate for reduced male care at the expense of future reproduction. Our study reveals that polygyny risk indeed increases with early breeding and entails a local survival cost for primary females. However, this cost is likely largely outweighed by fitness benefits of early breeding in most years. Hence it is unlikely that the increased polygyny risk of early breeding counteracts the fitness benefits, but it may reduce selection for breeding extremely early.     

Awareness and Practices Relating to Zoonotic Diseases Among Smallholder Farmers in Nepal

Increasing livestock production to meet growing demands has resulted in greater interactions at the livestock–wildlife–human interface and more opportunities for zoonotic disease spread. Zoonoses impose enormous burdens on low-income countries like Nepal, where populations are largely dependent on livestock production and access to shared grazing lands, often near protected areas, due to population pressures. Several livestock-associated zoonoses have been reported in Nepal; however, little is known regarding Nepali farmers’ knowledge of zoonoses and opportunities for disease management. We conducted a cross-sectional study to investigate Nepali farmers’ awareness of zoonoses, assess current health challenges, and evaluate disease prevention and control practices. We found that awareness of zoonotic pathogens was limited, especially in informally educated and illiterate farmers; the majority of which were women. Further, farmers’ preventive herd health, food safety, and sanitation practices were not associated with their awareness. Several farmers reported high-risk practices despite being aware of zoonotic diseases, suggesting a disconnect between the farmers’ awareness and practice. Our study highlights the need for improving Nepali farmers’ knowledge of zoonoses and disease prevention measures. Closing these awareness-practice gaps will require an improved understanding of risk and effective drivers of behavior change, alongside engagement of farmers in development of zoonotic disease prevention programs that encourage participation of both male and female farmers across all levels of education.     

Phylogenetic and chemotaxonomic characterization of Acidaminococcus fermentans

The phylogenetic position of Acidaminococcus fermentans was determined by comparative sequence analysis of the 16S rRNA. This Gram-negative bacterium is a member of the Sporomusa cluster that is defined by other Gram-negative bacteria, i.e. Sporomusa, Megasphaera, Selenomonas, Butyrivibrio, Pectinatus, and Zymophilus. The branching point of this group within the radiation of Gram-positive bacteria of the Clostridium/Bacillus subphylum and adjacent to Peptococcus niger could be confirmed. Chemotaxonomic data were provided for a more detailed characterization of A. fermentans.     

Long‐distance dispersal in migratory pied flycatchers Ficedula hypoleuca is relatively common between the UK and the Netherlands

Long‐distance dispersal can potentially have important consequences for evolutionary change, but is difficult to quantify. We present quantitative estimates of natal dispersal between the UK and the Netherlands in a long‐distance migratory bird, the pied flycatcher. Due to over 90 000 individual ringed adults caught and 730 000 ringed nestlings we are able to estimate that dispersal of young born in the UK to breeding in the Netherlands occurs on average 43 times yr^?1, and probably even more recently. We estimated that between 2000 and 2009 about 0.70% of the Dutch adult population could be immigrants from the UK. No cases of dispersal from the Netherlands to the UK were observed. Dispersing individuals bring new genes to the Netherlands, as males in the UK have a darker plumage than Dutch males. We found a good qualitative match between the proportion of dark males breeding in two Dutch populations and the estimated immigration rate from the UK. This and potentially other genetic differences may allow for new evolutionary directions if these genes are beneficial in the new population. The causes of dispersal are unknown, but it is striking that especially birds from the northern range limit dispersed.     

Amino acid sequence determination of guanyl-specific ribonuclease Sa from Streptomyces aureofaciens

Using automated Edman degradation of two nonfractionated peptide mixtures of tryptic and staphylococcal protease digests of the protein, the complete amino acid sequence of the guanyl-specific ribonuclease Sa from Streptomyces aureofaciens was established. Ribonuclease Sa contains 96 amino acid residues (Mr 10,566). A 50% sequence homology of ribonuclease Sa to the guanyl-specific ribonuclease St from S. erythreus was found.