The effects of partial mortality on the fecundity of three common Caribbean corals

The recent intensification of human disturbances in the Caribbean has increased the prevalence of partial mortality on coral colonies. Partial mortality can change colony size by directly shrinking colonies or by splitting colonies into fragments. A reduction in colony size can also adversely affect fecundity and fitness as internal resources shift away from reproduction toward colony maintenance. This study aimed to determine whether three Caribbean coral species, Siderastrea siderea, Montastraea faveolata, and Diploria strigosa, along the reef tract in Puerto Morelos, Mexico (20^o52′N, 86^o51′W), continued to dedicate resources to reproduction when colonies were fragmented to pre-maturation size. Contrary to expectations, eggs were found in colonies that were smaller than the maturation size and had been subjected to partial mortality. The continued dedication of resources toward reproduction, even in the smallest colonies, suggests that resource trade-offs away from reproduction are not as rigid as previously suggested in stressed corals.     

Regression-type estimators for adaptive two-stage sequential sampling

Adaptive two-stage sequential sampling (ATSSS) design was developed to observe more rare units and gain higher efficiency, in the sense of having a smaller variance estimator, than conventional sampling designs with equal effort for rare and spatially cluster populations. For certain rare populations, incorporating auxiliary variables into a sampling design can further improve the observation of rare units and increase efficiency. In this article, we develop regression-type estimators for ATSSS so that auxiliary variables can be incorporated into the ATSSS design when warranted. Simulation studies on two populations show that the regression-type estimators can significantly increase the efficiency of ATSSS and the detection of more rare units as compared to conventional sampling counterparts. Simulation of sampling of desert shrubs in Inner Mongolia (one of the two populations studied) showed that by incorporating a GIS auxiliary variable into ATSSS with the regression estimators resulted in a gain in efficiency over ATSSS without the auxiliary variable. Further, we found that the use of the GIS auxiliary variable in a conventional two-stage design with a regression estimator did not show a gain in efficiency.     

Higher soybean production using honeybee and wild pollinators, a sustainable alternative to pesticides and autopollination

This is the first report showing that using honeybee (Apis mellifera) and wild pollinators complementary pollination can enhance soybean productivity (Glycine max). Current industrial production of soybean involves autopollination and high loads of pesticides. Therefore, growers have neglected possible biotic pollination despite suggestions that soybean benefit from insect pollinators. Reports advocating possible biotic pollination are based on experiments where bees are caged with flowering plants and the absence of pesticides, thus not in field conditions. Therefore, here we compared in field conditions soybean yield produced (1) independently of biotic pollinators, (2) with wild pollinators and (3) with honeybee colonies. Results showed an increase of +6.34 % of soybean yield in areas where wild pollinators had free access to flowers. The introduction of honeybee colonies further raised the yield of +18.09 %. Our findings therefore show that, though soybean is autogamous, allowing pollination by wild pollinators leads to higher yields. Moreover, adding honeybee mitigates pollination deficits and improves yield compared to current practices.     

How safe is the playground? An environmental health risk assessment of As and Pb levels in school playing fields in NE England

The risk from potentially toxic elements in playground soils is of concern to children’s health as a result of the potential for intentional or unintentional consumption. Current approaches, based on total potentially toxic element concentration, may overestimate the risk. This has resulted in the development and use of in vitro gastrointestinal extraction protocols. The concentration of arsenic (As) and lead (Pb) in soils collected from 12 schools in north-east England has been compared with Soil Guideline Values from seven countries as well as reported literature concentrations for playgrounds and recreational parks. It was found that the mean As concentration of 14.1 ± 5.4 mg/kg does not exceed the England residential Soil Guideline Value in any location, while the mean Pb concentration of 298 ± 380 mg/kg is high but not excessive. Both concentrations have been assessed using the maximum potential daily intake from soil that a child could ingest. Based on this protocol Pb does not exceed the tolerable daily intake in any playground location, while As is generally 10 times lower than the oral index dose in the majority of playgrounds. The oral bioaccessibility of As and Pb was investigated. It was concluded that the highest concentrations were determined in the gastric phase with maximum bioaccessibilities of 54 and 46 % for As and Pb, respectively. Here we have demonstrated that minimal risk arises from the investigated playgrounds provided that good personal hygiene is adhered to.     

Ostrich chick humoral immune responses and growth rate are predicted by parental immune responses and paternal colouration

One of the most important measures of offspring performance is growth rate, which is often traded off against another important survival trait, immune function. A particular feature of ostrich chicks maintained in farmed environments is that cohorts of chicks vary widely in size. As parents can have a profound effect on the phenotype and fitness of their offspring, we investigated whether chick growth and immune defence were related to variation in levels of immune defence in their genetic parents. As secondary sexual traits of sires could serve as indicators of male quality, and be used in female mating decisions, we also investigated whether chick growth rate and immune defence were related to male plumage and integumentary colouration. We found that offspring growth rates and humoral responses were related to the humoral responses of their parents, suggesting that at least some components of humoral immune capacity are heritable. The white colour of male ostrich feathers was correlated to the humoral response and growth rate of their offspring, suggesting that this visual cue involved in the male courtship display could serve as an important signal to females of male quality, thereby forming the basis of mate choice in this species.     

Temporal separation of two fin whale call types across the eastern North Pacific

Fin whales (Balaenoptera physalus) produce a variety of low-frequency, short-duration, frequency-modulated calls. The differences in temporal patterns between two fin whale call types are described from long-term passive acoustic data collected intermittently between 2005 and 2011 at three locations across the eastern North Pacific: the Bering Sea, off Southern California, and in Canal de Ballenas in the northern Gulf of California. Fin whale calls were detected at all sites year-round, during all periods with recordings. At all three locations, 40-Hz calls peaked in June, preceding a peak in 20-Hz calls by 3–5 months. Monitoring both call types may provide a more accurate insight into the seasonal presence of fin whales across the eastern North Pacific than can be obtained from a single call type. The 40-Hz call may be associated with a foraging function, and temporal separation between 40- and 20-Hz calls may indicate the separation between predominately feeding behavior and other social interactions.     

Dealing with urban noise: vermilion flycatchers sing longer songs in noisier territories

In noisy conditions, several avian species modulate their songs in amplitude and in the temporal or frequency domains, presumably to improve communication. Most studies on how passerine birds perform such adjustments have been carried out in oscines, a group well known for the importance of learning in the development of their songs. On the other hand, suboscines, in which learning appears to have little influence on the development of their songs, have been largely neglected. We evaluated song adjustment to noise in the vermilion flycatcher (Pyrocephalus rubinus), a suboscine bird. We conducted song recordings and noise measurements at several territories within Mexico City during the length of the dawn chorus. Males living in noisier places sang long songs, while those males inhabiting quieter places sang both short and long songs. We also found evidence of individual song plasticity, as males sang less versatile songs (i.e., songs with more introductory elements) later in the morning when noise levels were higher. This individual shift in song seems to be more associated to time of the day rather than to the observed rise in noise. However, we cannot discard an effect of noise, which should be evaluated with an experiment. We discuss our results in the context of other studies with oscine passerines and other taxa and consider implications for signaling in intra- and intersexual contexts.     

Feather coloration in museum specimens is related to feather corticosterone

Colorful ornaments in birds are often sexually selected signals of quality, and variation in ornament expression may be mediated by physiological stress through the secretion of corticosterone. However, testing for links between ornamentation and corticosterone often requires sampling live animals, and such physiological measures may not be matched in the time span in which they were sampled (e.g., very dynamic plasma corticosterone vs. plumage coloration, which is relatively static). Here, we use museum specimens to test for a link between the color of a sexual ornament and feather corticosterone at the time of ornament formation. In red-winged blackbirds, Agelaius phoeniceus, carotenoid-based epaulets appear to be important in male–male social interactions, territory maintenance, and female choice. We measured reflectance spectra of adult male epaulets and plucked adjacent feathers for corticosterone analysis via radioimmunoassay. We controlled for differences in the number of mates, specimen age, and geography by selecting only males with one mate and only birds collected in Florida during a 3-year period. Epaulet hue and red chroma did not vary with feather corticosterone, but males whose epaulets scored high for mean brightness and red brightness had significantly lower corticosterone than males with low brightness scores. This correlation with brightness but not hue or chroma is consistent with an effect of corticosterone (CORT) on feather microstructure, with elevated CORT leading to lower reflectance of white light from the keratin matrix surrounding the carotenoid pigments.     

Fast and efficient synthesis of N-substituted β-aminobutyric acids by grinding at room temperature

Green chemistry is gaining increasing interest due to the growing awareness of the chemical community for sustainable development. Green chemistry solutions include synthesis without solvent and catalyst because many solvents and catalysts are toxic and expensive. Herein, we report the solvent and catalyst free method for the synthesis of N-substituted derivatives of β-aminobutyric acid by direct aza-Michael addition of amines to crotonic acid. The protocol involves simple mixing or grinding the reactants at room temperature. The β-amino acid derivatives were obtained in 82–100 % yield with a short reaction time without any tedious workup procedures. Our findings thus reveal a promising alternative to previously used procedures.