An assemblage of wintering waders in coastal Kenya: activity budget and habitat use

To contribute to the poorly known ecology of Palearctic immigrant waders in East Africa, we studied the foraging system (roosting and foraging behaviours, 24‐h activity rhythm, time‐activity budget and habitat use) of eleven wader species overwintering on the Kenyan coast. The waders congregated in communal roosts and completely overlapped in their foraging rhythms, which in this tidal environment were completely determined by tides, and which were independent of the dark/light cycle. All species, both tactile and visual foragers, fed both by day and by night. This study, along with similar findings for other areas of the Palaeotropics, shows that wader activity throughout the 24‐h day is essentially uniform, and is only slightly influenced by the dark/light cycle, but is modified by tidal levels. The total time devoted to feeding by each wader species was related to their body mass. Each species used a specific micro‐habitat for foraging.     

Low tide distribution of wintering waders and shelduck on the Severn Estuary in relation to the proposed tidal barrage

Waders and shelduck were counted at low tide on 162 sectors comprising 85% of the intertidal area (21 467 ha) of the Severn Estuary on 12 occasions during winter 1987/88. On average, 50% of birds present at low tide utilized just 13 sectors (12% of the area); 90% of birds occurred on only 56 sectors, leaving large expanses of intertidal sand virtually devoid of birdlife. Dunlin, the numerically dominant species, occurred widely on the middle and outer estuary, whereas shelduck predominantly occurred on the outer estuary and redshank around many tributary river mouths. Curlew, the most ubiquitous species, was the only one concentrated on the inner estuary. Severe gales in both late December and mid-January concentrated all main species within fewer sectors, probably by the short-term removal of surface sediment from substantial areas. It is estimated that the proposed tidal barrage would eliminate intertidal areas accounting for between c. 40% (for shelduck and curlew) and 80% (for redshank) of current total low tide usage by the internationally important populations present.     

Testing the effects of recreational disturbance on two upland breeding waders

Previous work has shown that Golden Plovers Pluvialis apricaria guarding chicks utilize heavily disturbed habitat at a lower rate than surrounding areas, but that such rates of avoidance are reduced when the movement of people is restricted to a surfaced footpath. However, there remained some unanswered questions, which are addressed in this paper. First, we examine to what extent habitat avoidance is dependent upon visitor numbers, and find no evidence that Golden Plovers avoided disturbed areas at a site where visitor pressure was half that previously studied. Secondly, we examine whether these relationships between habitat occupancy and disturbance apply to other upland waders and find that Dunlin Calidris alpina habitat utilization in disturbed areas showed a non-significant increase of approximately 50% following the provision of a surfaced footpath, in a manner similar to that observed for Golden Plover. Thirdly, we examine whether the large numbers of visitors (120 per weekend day) using the surfaced footpath impact on Golden Plover breeding success, despite the lack of habitat avoidance. There was no evidence that nest location, clutch survival or chick growth rates were reduced close to the footpath. Together, these results suggest that high levels of disturbance can impact upon habitat usage by upland waders, but only in limited circumstances where visitor pressure is very high (greater than at least 30 visitors per weekend day). However, access to such areas can be permitted for large numbers of visitors without impacting upon wader reproductive performance through the provision of a well-surfaced route.     

Hunting impact on waders in Spain: effects of species protection measures

The hunting impact on waders in Spain was studied to test the efficiency of species protection measures. Using information on ringed bird recoveries in Spain of 28 species a hunting impact index was calculated. The results show a high hunting pressure similar to that of other groups of birds. The hunting impact on quarry species was higher than on protected species. The change of protection level in a group of species from quarry to protected species resulted in a decrease in hunting impact. A negative trend in the hunting impact was found during a 15-year period. This result could be due to under-reporting or falsification of death causes in the recovery report. However, recoveries of shot and dead birds showed a positive relationship in contrast with expected if found dead reports increased by falsification, suggesting that there has not been a falsification of the ring recovery reports. Nevertheless, in spite of the decrease in the hunting pressure when protection measures were applied, hunting impact remains very high on protected species for a long time and studies evaluating the impact of hunting on the population dynamics of waders needs further study.     

The effects of improvement of upland, marginal grasslands on the breeding success of Lapwings Vanellus vanellus and other waders

Data on the breeding success of Lapwings Vanellus vanellus on unimproved and improved grassland, with comparative data for arable land, were obtained from a study on 760 Lapwing clutches. The study was undertaken in the Eden Valley, Cumbria, and Teesdale, Co. Durham, between 1985 and 1987. First clutches were larger on unimproved grassland with a mean of 3.73 eggs compared to 3.61 eggs on improved grassland. In contrast, replacement clutches were larger on improved areas (3.90 eggs) than on unimproved (3.47 eggs). On average, 40% of eggs laid on unimproved pastures hatched compared to only 17% on improved pastures. No significant difference in hatching success was found between unimproved and improved meadows with 32% and 22% of eggs hatching, respectively. Overall, 73% of unsuccessful first clutches were replaced on unimproved pastures, whereas on meadows and improved pastures combined, only 32% were replaced. Survival of small chicks was highest on unimproved areas. Production on unimproved areas was sufficient to replace adult losses and so maintain numbers, whereas on improved land production was too low to maintain existing breeding densities. Hatching success on unimproved areas was similar for the four species of wader considered. On improved areas, Redshank hatching success was relatively high, with 54% of pairs producing chicks, compared to 35% for Lapwing and 23% for Curlew.     

The effects of raptor predation on wintering wader populations at the Tyningharne estuary, southeast Scotland

Raptor predation on waders was studied by direct observation of raptors hunting a known wader population and subsequent recovery of dead waders. In each of three winters, raptor predation was shown to be the most significant cause of mortality in most small wader species, Sparrowhawks Accipiter nisus , Merlins Falco columbarius and Peregrines F. pere-grinus attacked waders with a success rate of 11.6%. 8.8% and 6.8%, respectively. Most waders attacked or found dead were Redshank Tringa totanus and Dunlin Calidris alpina; most were killed by Sparrowhawks. Kleptoparasitism of raptors carrying prey by Carrion Crows Corvus corone significantly increased the winter mortality of some waders. Redshank populations were most affected by raptor predation: over 50% of the total population (which was found to be closed during most of the winter) and over 90% of the juvenile population were taken in two winters: juvenites were more likely to be killed by raptors.     

Short-term tolerance to morphine: effects of diazepam, phenobarbital, and amphetamine

Short-term tolerance to morphine, which can be demonstrated in as little as 3 hours after a single administration of the opiate, was examined in animals chronically pretreated with diazepam, phenobarbital, or amphetamine. Tail-flick latency in mice and changes in plasma corticosterone in rats were the parameters tested in these experiments. Rats primed with either saline or morphine, 10 mg/kg, were injected 3 hours subsequently with morphine, 5 mg/kg. Those primed with saline showed the characteristic plasma corticosterone elevation following morphine, when serial blood samples were examined, whereas those previously treated with morphine did not. Mice were primed with saline or either of two doses of morphine, 30 or 100 mg/kg, 3.5 hours prior to estimation of tail-flick latency and ED50 determinations. Mice primed with either dose of morphine had significantly higher ED50's than those primed with saline. Chronic treatment with diazepam or amphetamine in either species did not significantly alter short-term tolerance development by either parameter. However, with phenobarbital pretreatment, the plasma corticosterone response was attenuated and short-term tolerance to morphine's analgesic effects did not occur. Further studies in morphine-pelleted mice showed that analgesic tolerance occurred similarly in all groups. This suggests that barbiturates may delay the process.     

Haematological studies on the prewintering and wintering frog, Rana esculenta

1. A study of the haematology of the frog Rana esculenta including erythrocyte count (RBC), haemoglobin content (Hb), haematocrit (HCT), mean cell volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and erythrocyte size as a function of prewinter and winter was made. 2. The RBC count and Hb were significantly higher in contrast to MCV and MCH values during prewinter in both sexes. 3. The surface area to volume ratio was higher in prewinter whereas the length to width ratio (eccentricity) of the cytosome and nucleus was significantly higher during winter in both sexes. 4. Sexual differences in the erythrocyte count, Hb content and the surface area to volume ratio were also observed. 5. The physiological significance of these observations are reported for Rana esculenta.     

Short-term effects of meteorological factors on children hand,foot and mouth disease in Guangzhou,China

Hand, foot and mouth disease (HFMD) is a contagious viral illness that commonly affects infants and children. The underlying risk factors have not yet been systematically examined. This study analyzed the short-term effects of meteorological factors on children HFMD in Guangzhou, China. Daily count of HFMD among children younger than 15 years and meteorological variables from 2009 to 2011 were collected to construct the time series. A generalized additive model was applied to estimate the effects of meteorological factors on HFMD occurrence, after adjusting for long-term trend, seasonal trend, day of week, and public holidays. A negative association between temperature and children HFMD occurrence was observed at lag days 1–3, with the relative risk (RR) for a 1 °C increase on lag day 2 being 0.983 (95 % confidence intervals (CI) 0.977 to 0.989); positive effect was found for temperature at lag days 5–9, with the highest effect at lag day 6 (RR?=?1.014, 95 % CI 1.006 to 1.023). Higher humidity was associated with increased HFMD at lag days 3–10, with the highest effect at lag day 8 (RR?=?1.009 for 1 % increase in relative humidity, 95 % CI 1.007 to 1.010). And we also observed significant positive effect for rainfall at lag days 4 and 8 (RR?=?1.001, 95 % CI 1.000 to 1.002) for 1-mm increase. Subgroup analyses showed that the positive effects of temperature were more pronounced among younger children. This study suggests that meteorological factors might be important predictors of children HFMD occurrence in Guangzhou.     

Short-term and long-term effects of lay groups on weight reduction.

Three groups participated in a slimming programme run by lay people. The course lasted eight weeks, and the average weight loss was about 7 kg both in a small well-controlled study of 33 women and in a much larger one comprising over 10,000 people. Both studies were prospective. The long-term effect was studied in a random sample of about 1000 people. After four years 30-35% of the participants had kept the initial weight loss or were still reducing their weight, and only 15% had regained all the lost weight or more. That this result was better than usual may be because the programme operated through small groups of eight to 12 members run by the obese people themselves. The "slim-club hostesses'' had all been obese and had succeeded in losing weight in the same programme. Group pressure and competition may also be important. Finally, the programme tried to change life styles, encouraging more exercise and reduced consumption of alcohol. The combination of scientific methods (behaviour therapy) and lay work may provide a clue for solving obesity and other serious health problems.     

The diet of king eiders wintering in Nuuk,Southwest Greenland,with reference to sympatric wintering common eiders

Coastal and offshore waters of Southwest Greenland are internationally important wintering areas for king eiders (Somateria spectabilis) breeding in eastern Canadian Arctic and in northwestern Greenland. This paper presents the first assessment of their winter diet. Based on esophageal-proventricular samples from 26 females (13 juveniles and 13 older birds) and 15 males (11 juveniles and four older birds) collected in 2000–2002 (November–May) in coastal waters of Nuuk, we identified 28 prey species. The diet consisted of almost equal proportions (aggregate fresh mass) of polychaetes, echinoderms, crustaceans and molluscs. The dominant prey species were Pectinaria spp. (26.8%), Strongylocentrotus droebachiensis (18.4%), Mya eideri (11.2%) and Hyas araneus (9.7%). The polychaetes have previously been identified as important prey for eiders in Greenland, but apparently not outside Greenland. Compared with a diet study of common eiders Somateria mollissima from the same wintering area, the king eiders consumed significantly less bivalves and significantly more echinoderms. This difference corresponded with observations that common eiders were feeding in shallow waters, while king eiders were feeding in deeper waters farther from the shore. Benthic surveys are needed to confirm that diet corresponds with prey availability.