High frequency of extra-pair paternity in Swedish pied flycatchers revealed by allozyme electrophoresis and DNA fingerprinting

Summary We used two genetic techniques to study multiple parentage in the pied flycatcher (Ficedula hypoleuca). Allozyme electrophoresis of 131 nestlings from 22 clutches sampled in 1982 and 1987 showed that one nestling had a mismatched allele compared with its putative parents. In one additional nest the devitation from Mendelian inheritance of parental genotypes suggested extra-pair paternity. The calculated probability of detecting multiple paternity from the genetic variation at four loci was 0.115. The estimated population frequency of extra-pair fertilization (EPF) was 13%, based on two mismatches and the probability of detecting multiple paternity. The seven families (n = 38 nestlings) in the 1987 sample were also analyzed by DNA fingerprinting using the M13 and Jeffrey's 33.15 probes. Overall, 24% (n = 9) of the nestlings analyzed were genetically inconsistent with their putative father, with EPF occurring in three (43%) of the seven clutches. One nestling originated by intraspecific brood parasitism. Comparison of the two techniques using the same samples showed that allozyme electrophoresis has a resolution only 11% of that of DNA fingerprinting, close to the calculated probability of detecting multiple paternity (0.115). Both techniques suggest that extra-pair fertilization is relatively common in the Swedish populations investigated compared to the low frequency reported from a Norwegian population. Correspondence to: H.P. Gelter at the present address     

Analysis of lipid components for determining the condition of anchovy larvae,Engraulis mordax

It has been presumed that intertidal spawning by Limulus polyphemus minimizes the loss of egges to subtidal predators; however, this strategy involves considerable risks. Massive beach strandings of adults accompany seasonal spawning migrations of crabs along Cape May in Delaware Bay, (USA). At least 190000 horseshoe crabs, approximating 10% of the adult population, died from beach stranding along the New Jersey shore of Delaware Bay during the 1986 (May to June) spawning season. Abnormalities of the telson (which is used in righting behavior) were significantly more common among stranded crabs than among individuals actively spawning on the intertidal beach. The number of stranded crabs per day was not correlated with tidal height or environmental variables (wind speed, wave height) which characterized the conditions at spawning. A complex suite of factors, including the size of the available spawning population, tidal and weather conditions, and beach slope, influence the number stranded during the breeding season. Horseshoe crab stranding results in a large loss of gravid females from the population, and may represent a major input of organic matter to intertidal sandy beaches in certain regions of Delaware Bay.     

Female benefit,male risk: Polyandry in the true armyworm Pseudaletia unipuncta

In Lepidoptera polyandry is common and females may increase their lifetime reproductive output through repeated matings if they acquire essential resources from male ejaculates. However, the paternity of males mating with previously-mated females is far from assured unless sperm precedence is absolute. In this study on the polyandrous armyworm, Pseudaletia unipuncta, we used two strains of male (the black-eyed wild type and a red-eyed homozygous, recessive mutant), mated with red-eyed females, to determine (i) whether male investment has any impact on female reproductive output, and (ii) if females do benefit from multiple matings, to what extent males fertilize the eggs to which they contributed. Multiple mating resulted in a significant increase in both the fecundity and longevity of females. However, the degree of sperm precedence (those eggs fertilized by the second male) varied from 0–100%, but was not affected by either male size or age, or by the duration of copulation. In cases where sperm precedence was <50% (x = 12%) females produced significantly more eggs (1384 versus 940) prior to the second mating than females where sperm precedence was >50% (x = 89%), indicating that the quality of the first mating influenced the fertilization success of the female's second mate.     

The two reindeer parasites,Hypoderma tarandi andCephenemyia trompe (Oestridae), have evolved similar olfactory receptor abilities to volatiles from their common host

Summary Using the linked gas chromatographical/electroantennogram (GC/EAG) technique it was revealed that the reindeer warble fly (H. tarandi) was specifically able to sense the same components from reindeer interdigital pheromone gland as the reindeer nose bot fly (C. trompe) another reindeer endoparasite. These two species belong to the same family (Oestridae), but different subfamilies, and the evolution towards an endoparasitic life cycle is thought to have been independent. The development of olfactory abilities to find reindeer from long distances is hypothesized to have taken place through convergent evolution or exists because of their common ancestry.     

Environmental conditions influence egg color of reed warblers <Emphasis Type="Italic">Acrocephalus scirpaceus</Emphasis> and their parasite,the common cuckoo <Emphasis Type="Italic">Cuculus canorus</Emphasis>

The outer layer of the eggshell in birds is in many cases covered by pigments that are assumed to be genetically determined traits with a negligible environmental component. To test the hypothesis that spring environmental conditions (i.e., temperature and rainfall) may affect bird egg pigmentation, we measured by spectrophotometry and photography egg coloration and spottiness on reed warbler (Acrocephalus scirpaceus L.) clutches parasitized by the common cuckoo (Cuculus canorus L.) collected over a period of 24 years and preserved in the Zoological Museum, Copenhagen, Denmark. In addition, we investigated whether spring environmental conditions may influence the coevolutionary relationship between the cuckoo and its host via changes in cuckoo–host egg matching. Generalized mixed models revealed that reed warbler eggs were more brilliant in those springs with a higher rainfall and tended to be bluer and greener in springs with a lower relative temperature. On the other hand, cuckoo eggs were bluer and greener in springs with a higher rainfall. Cuckoo–host egg matching in blue-greenness and spottiness was better in springs with a higher rainfall. These results provide support for the existence of an environmental component on bird egg coloration and suggest that environmental factors may potentially affect the outcome of important features of the arms race between cuckoos and reed warblers.     

MHC and fertilization success in the Arctic charr (Salvelinus alpinus)

Genes of the major histocompatibility complex (MHC) are remarkably polymorphic. Several selection mechanisms have been invoked to account for this diversity, including disassortative mating preferences. In addition, eggs may discriminate between sperm based on MHC. To investigate the effects of MHC-genotype on fertilization success, we obtained mature gametes from ripe Arctic charr (Salvelinus alpinus) males and females captured on spawning grounds. The eggs of each female were divided into two batches, and by letting each of 2 males fertilize 1 of the batches, we obtained a total of 36 half-sibling batch-pairs. The semen was diluted to ensure that the two males in each half-sibling batch-pair contributed with the same number of sperm cells. We found that MHC-heterozygous males had significantly higher fertilization success than MHC-homozygous males and neither initial spermatocrit, sperm motility nor swimming velocity co-varied with difference in fertilization success. There was no effect of female genotype or female-male MHC-similarity on fertilization success. However, one MHC-allele was associated with increased fertilization success. It seems plausible that the difference in fertilization success between homo- and heterozygous males may be due to MHC-dependent sperm selection by the ovum.Communicated by M. Abrahams     

Benefits of protected areas for nonbreeding waterbirds adjusting their distributions under climate warming

Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993–2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm-dwelling species or extirpation of cold-dwelling species by modeling change in standard deviation of the CTI (CTI_SD). Using linear mixed-effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTI_SD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTI_SD metrics to improve understanding of the colonization-extirpation patterns driven by climate warming.     

Environmental Impacts of a Secondary Lead Smelter in Landskrona, Southern Sweden

Scandinavia has one secondary lead smelter that recycles lead from approximately 85% of used car batteries in Scandinavia and which has been active since the 1940s. The smelter, situated in Landskrona, has undergone a comprehensive clean up programme during the last decade, during which time production has doubled, while at the same time discharges of dust and lead to the atmosphere have decreased.Top and depth soil samples were taken on a 0.5km×0.5Km grid throughout the city of Landskrona, which covers an area of approximately 15km². Samples were analysed by ICPAES for a number of elements including Pb, Zn, Cu, Cd, As, Sb and Hg. Road dust samples from selected sites were collected and similarly analysed. Blood samples were taken from 37 volunteer schoolchildren (aged 8–11) from two schools in Landskrona. House dust samples were taken from each child's home. Soil samples were taken from homes which had gardens, public and school play areas. Elevated heavy metal concentrations were found in close proximity to the secondary lead smelter, and this soil enrichment influences the whole of the town, modified to some extent by the prevailing wind. The smelter does not influence the soil lead concentration at distances greater than 3.5km, where the soil reflects the background value for the area.Road dust samples also show decreases in lead concentrations with distance from the smelter. The average level of lead in house dust was considerably lower than that found in Birmingham, UK. Blood lead levels in the child population ranged from 1.5–5.1gdl^–1, with a mean of 3.05gdl^–1, showing a distinct decrease from those measured in 1978–82. No significant difference in blood lead concentrations with distance of the home from the smelter, nor between attenders at the two schools was revealed in the limited number of children studied.     

Brominated flame retardants and other organobromines in Norwegian predatory bird eggs

A set of 62 unhatched eggs was collected from six different predatory bird species throughout Norway after incubation period was completed. They were analysed for PBDE, PBB, TBBP A and naturally occurring halogenated compounds. BDE 47, 99 and 153 were the dominating congeners, with species dependent PBDE patterns. BDE 153 was observed as the most abundant congener in eggs of peregrine falcon, golden eagle and merlin. The highest PBDE level (sum of nine congeners) was found in eggs of white-tailed sea eagle with up to 800ng/gww (median sumPBDE: 184ng/gww), followed by eggs of peregrine falcon and osprey (median sumPBDE: 155 and 105ng/gww, respectively). Golden eagle eggs showed the lowest concentration of all species (median sumPBDE: 3ng/gww). The levels in the peregrine falcon are similar to those found earlier in the Baltic region [Lindberg, P., Sellstrom, U., Haggberg, L., de Wit, C.A., 2004. Higher brominated diphenyl ethers and hexabromocyclododecane found in eggs of peregrine falcons (Falco peregrinus) breeding in Sweden. Environmental Science & Technology. 38 (1), 93-96]. The differences between species are not fully explainable, due to lack of data from the major food species. BB 101 and 153 were found in eggs of all investigated bird species. Especially in samples of white-tailed sea eagle, peregrine falcon and goshawk additional unknown penta- and hexabrominated biphenyls were detected. TBBP A was detected in all of eight eggs analysed sampled from four different bird of prey species. The naturally occurring halogenated compounds Q1, the dibromotrichloro monoterpene MHC-1, and 2,4,6-tribromoanisole (TBA) were detected in all of seven analysed samples except for one peregrine falcon egg.     

Chloride imbalances in soil lysimeters

The assumption that soil neither acts as a source or a sink of chloride is evaluated by incubating soil cores in lysimeters in a climate chamber under controlled conditions. Some of the lysimeters acted as a sink while others acted as a source of chloride. Considerable amounts of organic chlorine were lost by leaching. The loss by leaching of organic chlorine could only explain part of the discrepancy in the lysimeters where the soil acted as a sink and it could certainly not explain the cases where the soil acted as a source.The storage of organic chlorine was four times larger than the storage of chloride and comparably small changes in the organic chlorine storage will thus have a considerable influence on the chloride budget. However, the soil was too heterogeneous to determine whether a change in the storage had taken place or not. It is concluded that the observed chloride surplus and also, at least to some extent, the observed chloride deficit, most likely was caused by net-changes in the storage of organic chlorine in soil. An inverse correlation was found between the initial chloride content of the soil and the imbalance in the chloride budget.Dry deposition of chloride is generally assumed to equal the run-off minus the wet deposition. Extrapolation to the field situation suggests that the output of organic chlorine by soil leachate is at risk to cause an underestimation of the dry deposition by about 25%.