Mercury and persistent organic pollutant concentrations in African fish eagles, marabou storks, and Nile tilapia in Uganda

The purpose of this research was to evaluate persistent organic pollutant (POP) and mercury concentrations in tissues of African fish eagles (Haliaeetus vocifer) and Nile tilapia (Oreochromis niloticus) from Lake Victoria near Entebbe and Lake Mburo, Uganda. Marabou stork (Leptoptilos crumeniferus) nestlings from urban Kampala (40 km from Entebbe) also were sampled for POPs and mercury. Total mercury was measured in the breast feathers of eight nestling and 10 adult African fish eagles from Lake Mburo, 10 nestling and five adult African fish eagles from Lake Victoria near Entebbe, and 20 nestling marabou storks from Kampala from June 2002 through January 2003. Mercury concentrations in all samples were below levels associated with adverse effects in similar species. Mercury concentrations were significantly higher in eagle adults and nestlings from Entebbe than in adults and nestlings from Lake Mburo (P< or =0.05). No significant differences (P> or =0.05) were found in mercury concentrations between sexes or between the entire fish eagle population sampled at Entebbe and marabou stork nestlings sampled at nearby Kampala. Plasma samples from the same birds were analyzed for 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane, aldrin, hexachlorocyclohexane (alpha-HCH), dieldrin, endrin, heptachlor and their metabolites, as well as total polychlorinated biphenyls (PCBs). Nile tilapia whole-body cross sections collected from Lake Mburo (n=3) and Lake Victoria near Entebbe (n=8) also were analyzed for these POPs and mercury. No samples contained POPs or PCBs at the limits of detection except for 4,4'-1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene in five adult eagle plasma samples (0.0026+/-0.0015 ppm wet weight) and five Nile tilapia samples (0.002+/-0.001 ppm wet weight) from Entebbe.     

Age-related environmental sensitivity and weather mediated nestling mortality in white storks Ciconia ciconia

We studied environmental sensitivity and mortality related to weather inclemency in white stork nestlings Ciconia ciconia in their southern European boundary (Doñana, SW Spain). The study of homeothermy acquisition and fault bars (i.e. a measure of stress on feathers) revealed that stork nestlings were specially sensitive to environmental conditions occurring before 20 d of age. Accordingly, most of nestling mortality concentrated during this sensitive period: 91% of deaths corresponded to nestlings younger than 20 d, 73% concentrating on nestlings up to 10 d-old. Nestling mortality and total breeding failure were highly variable among years, being especially high when rainy periods coincided with the early live of nestlings (between 1 April and 15 May). Maximum temperatures had a positive correlation with breeding success and nestling survival but this effect disappeared when controlling for rainfall. Our results are in agreement with previous studies conducted in other white stork populations in other latitudes. We suggest that this could be the result of a low homeothermy capacity of young nestlings jointly with an early breeding phenology that expose white storks to rain, but not to high temperatures. In the context of global climate change we suggest that the current decrease on spring rainfall could increase nestling survival while punctual rainy springs could have a negative effect on the reproduction of white storks.     

A role for corticosterone and food restriction in the fledging of nestling White storks

Fledging is a critical period in the life of a bird, notably because at this stage under-development and lack of experience in searching for food may impair survival. The behavioral changes that accompany nest departure are therefore expected to be finely tuned to body condition and growth by endocrine processes. This study examines the possible involvement of corticosterone (CORT) in the stimulation of fledging in White storks through measurement of the changes in its plasma levels in relation to growth, nutritional status and the hatching rank of nestlings. For the first time in nest-bound chicks, we show that fledging is preceded by a marked and progressive 4 fold increase in baseline plasma CORT levels concomitant with an increase in locomotor activity (wing flapping) at the nest. Data on changes in body size, body mass, plasma metabolites and feeding frequency support the view that the increase in plasma CORT was induced by food restriction rather than being endogenously programmed. The timing and intensity of plasma CORT increase was dependent on the hatching rank within a brood, this increase being blunted in the less developed chicks possibly to avoid the impairment of final wing growth. These results show that an increase in plasma CORT as a result of food restriction and through the stimulation of locomotor activity is involved in the control of fledging in White storks. Moreover the CORT increase is adjusted to the hatching rank-related growth status of nestlings.     

Diet explains interpopulation variation of plasma carotenoids and skin pigmentation in nestling white storks

Carotenoids have a dietary origin in birds, but mechanisms by which they are absorbed in the gut, transported in the blood, metabolized at various sites, and deposited in the integument remain poorly understood. Variation in both plasma carotenoid levels and external color may reflect different access to dietary carotenoids or individual physiological differences in the uptake and deposition of carotenoids. We compared total plasma carotenoid concentration in nestling white storks (Ciconia ciconia) from 11 Spanish colonies in two consecutive years. The main food item in one of the colonies was the red swamp crayfish (Procambarus clarkii), a recently introduced species. Storks in the remaining colonies ate a variety of foods but no crayfish. Total plasma carotenoid levels in the colony where crayfish were consumed were about five times higher than in any other colony. These differences were maintained after controlling for the significant interyear variability, as well as for sex, age, and body mass of birds. Skin pigmentation also differed, being intensely orange in storks that consumed crayfish but white (unpigmented) in the remaining individuals. With thin-layer chromatography (TLC) and electronic absorption spectroscopy, astaxanthin was confirmed as the major carotenoid in crayfish as well as in the plasma, skin, and body fat of crayfish-eating storks, whereas lutein was the main carotenoid in plasma samples from the other colonies. These results indicate that a newly available carotenoid in the environment, astaxanthin, can be absorbed in large quantities from the gut and be transported in the blood before deposition in different tissues.     

Clinical pathology and morphometrics of African fish eagles in Uganda

Packed cell volumes (PCVs) and plasma chemistry parameters were measured in 15 adult and 18 nestling African fish eagles (Haliaeetus vocifer) sampled from June 2002 through January 2003 in Uganda. Morphologic measurements were obtained from 15 adult eagles. All eagles were examined for blood parasites and sexed by examination of DNA from red blood cells. Ten adults and eight nestlings were sampled from Lake Mburo and five adults and 10 nestlings were sampled from Lake Victoria near Entebbe, Uganda. Analysis of variance was conducted to assess the association between site, age, sex, and plasma chemistry parameters and the association between sex and morphologic characteristics. Plasma chemistry values for nestling and adult African fish eagles were similar to those reported for other captive and free-ranging eagle species. Packed cell volumes for nestling African fish eagles were markedly lower than values reported for nestlings of other eagle species, although the mean estimated age of nestlings sampled also was lower. A significant association (P < or =0.05) was found between PCV of nestling eagles and study site (lower at Lake Mburo) but no association was found between PCV and nestling body weight (P> or =0.05). An unidentified Plasmodium sp. was present in erythrocytes of three nestlings from Lake Mburo. No other blood parasites were seen. There was significant variation (P< or =0.05) in PCV, calcium, phosphorous, potassium, cholesterol concentrations, and creatine kinase activity between adults and nestlings; all were lower in adults. Aspartate transaminase activity was higher in adults. Like other Haliaeetus sp., body weight, bill depth, culmen length, footpad length, and hallux length as well as bill depth measurements were significantly (P < or = 0.05) greater for females than males. The objective of the study was to provide baseline biologic and physiologic information that may prove useful in the management and study of captive and wild populations of African fish eagles.     

Skeletal pathology in Pan troglodytes schweinfurthii in Kibale National Park, Uganda

The ecological pressures shaping chimpanzee anatomy and behavior are the subject of much discussion in primatology and paleoanthropology, yet empirical data on fundamental parameters including body size, morbidity, and mortality are rare for wild chimpanzees. Here, we present skeletal pathology and body size data for 20 (19 crania, 12 postcrania) chimpanzees (Pan troglodytes schweinfurthii) from Kibale National Park, Uganda. We compare these data with other East African populations, especially Gombe National Park. Estimated body size for Kibale chimpanzees was similar to other East African populations and significantly larger than Gombe chimpanzees. The high rates of trauma and other skeletal pathology evident in the Kibale chimpanzee skeletons were similar to those in the Gombe skeletal sample. Much of the major skeletal trauma in the Kibale skeletons was attributable to falls, although other pathologies were noted as well, including apparent injuries from snares, degenerative arthritis, and minor congenital abnormalities.     

The feather lipids of the marabou stork (Leptoptilos crumeniferus)

• 1.1. Marabou feather lipids differ significantly from those of the uropygial gland secretion by the presence of sterols, sterol esters, di- and monoglycerides and free fatty acids.
• 2.2. Triglycerides are converted into di- and monoglycerides in the plumage.
• 3.3. The feather “bloom” during the nesting period consists of keratinous material, not lipid.

     

Chaunocephalosis in a wild population of Asian open-billed storks in Thailand.

The most common trematode collected from Asian open-billed storks (Anastomus oscitans) was Chaunocephalus ferox (80% prevalence). The trematode was paired in granulomas in the intestinal wall. Based on histological examination of these capsules, there was degeneration and necrosis of muscle cells in the tunica muscularis. Granulation tissue with hetrophil and lymphocyte infiltration appeared in the granulomas. Intestinal villi were shorter and wider in infected areas than in non-infected areas. Some intestinal glands were dilated. Storks with high intensity of C. ferox appeared ill. The death of storks infected with C. ferox may result from malnutrition due to the loss of absorptive function of the intestine and from the effect of granuloma formation which might interfere with the intestinal peristalsis.     

Influence of weather conditions on the flight of migrating black storks

This study tested the potential influence of meteorological parameters (temperature, humidity, wind direction, thermal convection) on different migration characteristics (namely flight speed, altitude and direction and daily distance) in 16 black storks (Ciconia nigra). The birds were tracked by satellite during their entire autumnal and spring migration, from 1998 to 2006. Our data reveal that during their 27-day-long migration between Europe and Africa (mean distance of 4100 km), the periods of maximum flight activity corresponded to periods of maximum thermal energy, underlining the importance of atmospheric thermal convection in the migratory flight of the black stork. In some cases, tailwind was recorded at the same altitude and position as the birds, and was associated with a significant rise in flight speed, but wind often produced a side azimuth along the birds'' migratory route. Whatever the season, the distance travelled daily was on average shorter in Europe than in Africa, with values of 200 and 270 km d⁻¹, respectively. The fastest instantaneous flight speeds of up to 112 km h⁻¹ were also observed above Africa. This observation confirms the hypothesis of thermal-dependant flight behaviour, and also reveals differences in flight costs between Europe and Africa. Furthermore, differences in food availability, a crucial factor for black storks during their flight between Europe and Africa, may also contribute to the above-mentioned shift in daily flight speeds.     

Growth and sex of nestling Merlins in Orkney

Seventeen Merlin nestlings in six broods on Mainland Orkney in 1981 were weighed and measured regularly until they fledged. Nine chicks grew more rapidly and attained greater weights than the remaining eight irrespective of when they hatched in relation to their siblings. They also had longer beaks, hind claws, middle toes and tarsi, and thicker tarsi, and were therefore assumed to be females. It is suggested from measurements of these birds that weight in relation to wing and/or tenth (outer) primary length are sufficient to judge the sex of the young from about 13 days old. It is also suggested that the results may be generally applicable in northern Britain.     

Clinical and X-ray aspects in childhood arthrogryposis pathology

This paper gives a retrospective analysis of clinical and X-ray changes in arthritic influenza deformity in relation to age, starting from neonatality. All the data presented are of interest since this disease occurs extremely rarely, has a multiple lesion pattern, and leads to disability and lowered social adaptation.