Does nestbox type significantly alter the ectoparasitic load and breeding success in the nests of secondary-cavity-nesting passerines, at Nagshead, Forest of Dean?

This research aims to find if nestbox type causes a significant difference in the ectoparasite load and breeding success rate in the nests for four co-occurring secondary cavity nesting passerines, breeding in nestboxes at Nagshead Nature Reserve, Forest of Dean. The different nestbox types used in this study are old and new standard wooden nestboxes and deep nestboxes, which are designed to reduced predation. Nests were taken from nestboxes used by Blue Tit (Cyanistes caeruleus), Great Tit (Parus major), Nuthatch (Sitta Europaea) and Pied Flycatcher (Ficedula hypoleuca) by Nestbox Species Surveyors at the end of the 2019 breeding season, and later dissected to determine ectoparasite abundance and nest composition. Nest data collected by Nestbox Species Surveyors was used to calculate the breeding success rate. Population of woodland birds in 2018 was found to be overall 29% than in 1970. Deforestation and habitat management are causes in the reduction of nesting sites available for woodland bird species. Pine Martens (Martes martes), a known predator to secondary cavity nesting birds, were reintroduced into the Forest of Dean in September 2019. Individuals using nestboxes are at a potential increased risk of predation as nestboxes are accessible to Pine Martens. The abundance of adult Hen Fleas and Blowfly pupae in deep nestboxes was found to be significantly higher compared to the nestbox types. Nuthatch nests were found to have the highest mean abundance of adult Hen Fleas, while Pied Flycatcher nests had the highest mean abundance of Blowfly pupae, compared to the other species. Leaves as a nest material were found to have a significant influence and negative correlation with both ectoparasites mentioned. Breeding success rate in standard new boxes was significantly lower than the other nestbox types, with no significant difference occurring between deep and standard old nestboxes. Breeding success in Nuthatch nests were found to be significantly lower than the other avian study species potential linking the increased abundance of adult Hen Fleas previously found. Leaves were found to be significantly influencing and positively correlating with breeding success. These findings add to the data and knowledge about the difference in ectoparasite load and breeding success between nestbox types and the secondary cavity nest passerines, which use these nestboxes. This study also opens up potential for recommended future studies to be carried out at Nagshead.

Microclimate, CO2 and CH4 concentration on Blue tits (Cyanistes caeruleus) nests: effects of brood size, nestling age and on ectoparasites

ABSTRACTThe presence of nestlings and other nest dwelling living beings in nests built in cavities could alter the composition of gases inside the cavity. In addition, this different concentration of gases could be used by some parasites as a cue to localize their hosts. Here, we explored the temporal variation in the concentration and isotopic signature of carbon dioxide (CO2) and methane (CH4) inside nest boxes of blue tits Cyanistes caeruleus during the nestling period (days 3, 8, 13, 20 and 21 post-hatching). Concentration of gases and isotopic signature were significantly different inside of nests than outside (forest) during the nestling period. CO2 concentration was higher inside nest while CH4 was lower than in forest air. The differences in the concentration of CO2 between nest boxes and forest were higher on days 8th and 20th of nestling age than in other ages while the CH4 was lower on day 20th of nestling age than in other ages. Moreover, CO2 variation was positive and significantly related with brood size and negative and significantly with hatching date. The difference of CO2 between inside of nests and forest on 8th day of nestling age were negative and significantly related to flea larvae abundance as measured at the end of the nestling period. A significant positive relationship was found between the difference of CH4 between nests and forest and the final abundance of flea larvae for the same nestling age. In addition, flea larvae abundance was positive and significantly related with the relative humidity in nests at 8 days of nestling age. Moreover, blowfly pupae abundance was negative and significantly related with the difference of temperature in nests at 3 day of nestling age. The condition of blue tit females was negative and significantly related with the abundance of blowfly pupae.

Potential Use of Cuticular Hydrocarbons in Estimating the Age of Blowfly Pupae Chrysomya megacephala (Diptera: Calliphoridae)

Gas chromatography coupled with mass spectrometry (GC–MS) was used to determine the weathering time in cuticular hydrocarbon of pupae Chrysomya megacephala in sheltered condition. The results have shown that cuticular hydrocarbons (CHC) of the pupae were a mixture of n-alkanes, methyl-branched alkanes, and dimethyl-branched alkanes, with carbon chain length ranging from C19 to C39.The study presents the significant correlation between the changes pattern in relative abundance of several CHC and development phase in pupae. Further analysis with multiple linear regression indicated that several CHC compounds showed strong correlation to blowfly pupae age, which were then utilized to create a prediction equation for the age estimation. Finally, the application of the age-dependent model had revealed that estimated age correlated significantly with chronological age of samples C. megacephala., y = 0.97x + 0.092, R2 = 0.9698. The study concluded that, CHC have a potential to estimate age of immature C. megacephala, and possibly in other flies species, and might further be used to determine the PMI.

Lamsiekte (botulism): Solving the aetiology riddle

The reason or reasons why it took Sir Arnold Theiler so many years to unravel the riddle of the aetiology of lamsiekte in cattle and whether P.R. Viljoen’s lifelong grudge for receiving insufficient credit from Theiler for his research contribution was justified are analysed in this paper. By 1912, Theiler knew that Duncan Hutcheon had advocated the use of bonemeal as a prophylactic against the disease in the early 1880s. Hutcheon’s colleague, J.D. Borthwick, had shown conclusively in a field experiment in 1895 that lamsiekte did not occur in cattle fed a liberal allowance of bonemeal; and bone-craving had been identified by Hutcheon and several farmers as being associated with the occurrence of the disease (a ‘premonitory’ sign). Hutcheon regarded a phosphate deficiency of the pastures as the direct cause of lamsiekte. However, Theiler did not accept this, was convinced that intoxication was involved and developed a ‘grass toxin’ theory. Viljoen (1918) also latched onto the grass toxin theory. He did not believe that osteophagia existed, stating categorically that he had not observed it on the experimental farm Armoedsvlakte where > 100 cases of lamsiekte had occurred during the > 3 years that he spent there. Moreover, he did not believe in the prophylactic value of bonemeal. However, careful analysis of a subsequent publication, of which he was a co-author, revealed that in late 1918 and early 1919 he reproduced the disease by drenching cattle with blowfly pupae and larvae as well as with crushed bones from decomposing bovine carcasses. For this breakthrough he did not get proper credit from Theiler. Reappointed to study lamsiekte on Armoedsvlakte in the autumn of 1919, Theiler, probably already aware that the toxin he was seeking was in the decomposing bones or carcass material rather than the grass, deliberately ‘walked with the cattle’ on the farm to encounter a classic manifestation of bone-craving (osteophagia). The penny then immediately dropped. Theiler, actually rationalising an hypothesis that was about four decades old, did so with a vengeance. Within less than two years he had reproduced lamsiekte by exposing cattle with natural bone-craving to rotten carcass material, had chemical proof that the grazing was phosphorus-deficient, had developed a satisfactory bonemeal prophylactic dosage programme, and the bacterial toxin concerned – perhaps the trickiest contribution – had been produced in culture. Hence the table was set for the later development of an excellent lamsiekte vaccine.

Purification, molecular cloning and heterologous expression of a glutathione S-transferase from the Australian sheep blowfly (Lucilia cuprina)

Three glutathione S-transferases from Lucilia cuprina (Australian sheep blowfly) pupae were purified by affinity chromatography and anion-exchange chromatography. One isoenzyme was composed of M(r)-24,800 subunits, and two isoenzymes had subunits of M(r) 23,900. The M(r)-23,900 subunits showed immunological identity and were immunologically distinct from the M(r)-24,800 subunits. All three enzymes were active with the substrate 1-chloro-2,4-dinitrobenzene and had low activity with 1,2-dichloro-4-nitrobenzene. A cDNA clone encoding a M(r)-23,900 subunit (LuGST1) was isolated and sequenced. The sequence has close similarities (> 81%) to that of GSTs from the fruitfly Drosophila melanogaster and Musca domestica (housefly). The deduced amino acid sequence of the Lu GST1 subunit showed no significant similarity to that of the mammalian GSTs to the Alpha, Mu and Pi classes, but shows some similarity (33%) over the first 100 residues with the rat subunit 12 Theta-class GST. Southern blots of genomic DNA hybridized with the LuGST1 cDNA identified many hybridizing fragments. Taken together, these data indicated that the L. cuprina genome contains multiple glutathione S-transferase genes.

HOST SELECTION AND OVIPOSITION BEHAVIOR OF NASONIA VITRIPENNIS (HYMENOPTERA: PTEROMALIDAE) ON TWO HOST SPECIES

The oviposition behavior of the pteromalid parasitoid Nasonia vitripennis (Walker) was investigated in an attempt to explain the difference in population density maintained on two species of host, the housefly, Musca domestica L., and the blowfly, Phaenicia sericata (Meigen). The behavior of a female wasp was significantly affected by the species of host to which she was exposed. When presented with 10 pupae for 24 hours she averaged 14.2 eggs on 3.0 housefly hosts and 8.3 eggs on 7.2 blowfly hosts of the same size.The importance of the alteration in behavior to the population density of Nasonia became apparent when the suitability of the two host species was examined. At all densities of eggs more wasps matured on blowfly pupae than on housefly pupae of the same size. Survival on both hosts decreased as the density of Nasonia eggs increased. The difference in egg distribution, coupled with lower survival on housefly pupae and at increased density suggests a considerably lower production by this parasitoid on housefly hosts, compared with that on blowfly pupae.