Nest Material Research Articles

Cardboard nesting cavities may promote the development of Osmia cornuta and reduce infestation of kleptoparasitic mites

AbstractMason bees (Osmia spp.) are receiving increasing attention as they are very effective pollinators of multiple crops. However, different bee‐associated kleptoparasites are known which can be detrimental to the development of the bees’ offspring. To date, clear evidence‐based guidelines to control these kleptoparasites are lacking for growers. This study investigates whether different types of artificial nesting materials—cardboard tubes and wooden grooved boards—influence the development of the European orchard bee (Osmia cornuta) as well as the infestation rate of kleptoparasitic mites in the bees’ nest. This preliminary study provides insight that cardboard tubes reduce the infestation rate of mites by 81.8% and as such promote successful development of the European orchard bee by 15.5%. Using cardboard tubes over wooden grooved boards should be advised to growers as an effective management strategy to avoid infestation of kleptoparasitic mites and to enhance successful bee development.

Susceptibility of Red Mason Bee Larvae to Bacterial Threats Due to Microbiome Exchange with Imported Pollen Provisions.

Solitary bees are subject to a variety of pressures that cause severe population declines. Currently, habitat loss, temperature shifts, agrochemical exposure, and new parasites are identified as major threats. However, knowledge about detrimental bacteria is scarce, although they may disturb natural microbiomes, disturb nest environments, or harm the larvae directly. To address this gap, we investigated 12 Osmia bicornis nests with deceased larvae and 31 nests with healthy larvae from the same localities in a 16S ribosomal RNA (rRNA) gene metabarcoding study. We sampled larvae, pollen provisions, and nest material and then contrasted bacterial community composition and diversity in healthy and deceased nests. Microbiomes of pollen provisions and larvae showed similarities for healthy larvae, whilst this was not the case for deceased individuals. We identified three bacterial taxa assigned to Paenibacillus sp. (closely related to P. pabuli/amylolyticus/xylanexedens), Sporosarcina sp., and Bacillus sp. as indicative for bacterial communities of deceased larvae, as well as Lactobacillus for corresponding pollen provisions. Furthermore, we performed a provisioning experiment, where we fed larvae with untreated and sterilized pollens, as well as sterilized pollens inoculated with a Bacillus sp. isolate from a deceased larva. Untreated larval microbiomes were consistent with that of the pollen provided. Sterilized pollen alone did not lead to acute mortality, while no microbiome was recoverable from the larvae. In the inoculation treatment, we observed that larval microbiomes were dominated by the seeded bacterium, which resulted in enhanced mortality. These results support that larval microbiomes are strongly determined by the pollen provisions. Further, they underline the need for further investigation of the impact of detrimental bacterial acquired via pollens and potential buffering by a diverse pollen provision microbiome in solitary bees.

Results of national White Stork (Ciconia ciconia) census in Hungary in 2019

Abstract A national White Stork (Ciconia ciconia) census was organised in Hungary in 2019. The 14th country-wide nest count was coordinated by MME/BirdLife Hungary, also involving local branches and volunteers of the society and national park directorates. Altogether 5,018 nests and 2,358 White Stork nest holders without nest material were reported. 89.2% of occupied nests were built on electric poles. Although 80 years ago every third nests were found on trees, in 2019, only 6 were reported at that location. Successful pairs raised 2.62 nestlings on average, breeding success for all breeding pairs was 2.19, which is lower than typical, probably due to chilly and rainy weather during the breeding season. Based on 3,540 reported breeding pairs and former census data, the White Stork population of Hungary is estimated to be 3,860–4,020 pairs in 2019. The size of the population was ca. 15–16 thousand pairs in 1941, which halved by 1958 and decreased to 5 thousand pairs by the late 1960s. For four decades, the population fluctuated between 4,800 and 5,500 pairs but in the last twenty years, the number of breeding pairs slightly decreased in the country. The population decline is stronger in hilly areas of W Hungary, i.e. in Somogy, Vas and Zala counties is about 60%.

A new breeding colony of the Wedge-rumped Storm-Petrel (Hydrobates tethys kelsalli, Lowe 1925) on Foca Island, extreme Northwestern Peru

Breeding colonies of Storm-petrels (family Hydrobatidae) are poorly known and can be difficult to find because they typically nest on islands in crevices and burrows inside caves. In the past decade, some breeding locations of the Wedge-rumped Storm-petrel (Hydrobates tethys kelsalli) have been reported on islands off central Peru and northern Chile. Here we report the northernmost breeding colony of this subspecies from Isla Foca, northern of Peru. In April 2006 we found 28 nests, of which 46% had chicks and 54% had eggs. Nests consisted of small holes in the rock with no nest material used for construction. Nesting season coincided with that of other reproductive zones found on the Peruvian coast. These results contribute to the knowledge of the distribution of reproductive colonies of this subspecies on the Peruvian coast.

Using photographs to record plastic in seabird nests

The incidence of plastic in seabird nests can be used to track changes in the amounts of marine debris, but large sample sizes are needed for accurate estimates. Surveys of active nests cause disturbance to breeding birds, so we need an efficient way to sample nest plastics. Photographs of brown noddy Anous stolidus nests at Ducie Atoll, southeast Pacific Ocean, allowed rapid characterisation of plastic use with limited disturbance, and showed selection for blue-green items. Plastic was more prevalent in noddy nests at Ducie Atoll (97%) than at Inaccessible Island, South Atlantic Ocean (41%), despite lower debris densities at Ducie. Differences in nesting habitat and the resultant availability of natural nesting material drive this difference in plastic loads. Using photographs to record plastic in seabird nests reduces disturbance to breeding birds and might decrease the risk of missing cryptic debris items. Photographs also provide a permanent record of pollution levels.

Diptera communities of raptor (Aves) nests in Nova Scotia, Canada

AbstractThe identity, richness, and abundance of true flies (Diptera) from the nests of three cavity-nesting raptors (Aves) were investigated in northern Nova Scotia, Canada. After fledging, flies were extracted from the nest material using Berlese funnels within an emergence chamber. Thirty-one species/morphospecies from 14 families were collected, including eight new records for Nova Scotia and two new records for eastern North America.

Characterization of astrocytes throughout life in wildtype and APP/PS1 mice after early-life stress exposure

BackgroundEarly-life stress (ES) is an emerging risk factor for later life development of Alzheimer’s disease (AD). We have previously shown that ES modulates amyloid-beta pathology and the microglial response to it in the APPswe/PS1dE9 mouse model. Because astrocytes are key players in the pathogenesis of AD, we studied here if and how ES affects astrocytes in wildtype (WT) and APP/PS1 mice and how these relate to the previously reported amyloid pathology and microglial profile.MethodsWe induced ES by limiting nesting and bedding material from postnatal days (P) 2–9. We studied in WT mice (at P9, P30, and 6 months) and in APP/PS1 mice (at 4 and 10 months) (i) GFAP coverage, cell density, and complexity in hippocampus (HPC) and entorhinal cortex (EC); (ii) hippocampal gene expression of astrocyte markers; and (iii) the relationship between astrocyte, microglia, and amyloid markers.ResultsIn WT mice, ES increased GFAP coverage in HPC subregions at P9 and decreased it at 10 months. APP/PS1 mice at 10 months exhibited both individual cell as well as clustered GFAP signals. APP/PS1 mice when compared to WT exhibited reduced total GFAP coverage in HPC, which is increased in the EC, while coverage of the clustered GFAP signal in the HPC was increased and accompanied by increased expression of several astrocytic genes. While measured astrocytic parameters in APP/PS1 mice appear not be further modulated by ES, analyzing these in the context of ES-induced alterations to amyloid pathology and microglial shows alterations at both 4 and 10 months of age.ConclusionsOur data suggest that ES leads to alterations to the astrocytic response to amyloid-β pathology.

Detection of prey odours underpins dietary specialization in a Neotropical top-predator: How army ants find their ant prey.

Deciphering the mechanisms that underpin dietary specialization and niche partitioning is crucial to understanding the maintenance of biodiversity. New world army ants live in species-rich assemblages throughout the Neotropics and are voracious predators of other arthropods. They are therefore an important and potentially informative group for addressing how diverse predator assemblages partition available prey resources. New World army ants are largely specialist predators of other ants, with each species specializing on different ant genera. However, the mechanisms of prey choice are unknown. In this study, we addressed whether the army ant Eciton hamatum: (a) can detect potential prey odours, (b) can distinguish between odours of prey and non-prey and (c) can differentiate between different types of odours associated with its prey. Using field experiments, we tested the response of army ants to the following four odour treatments: alarm odours, dead ants, live ants and nest material. Each treatment had a unique combination of odour sources and included some movement in two of the treatments (alarm and live ants). Odour treatments were tested for both prey and non-prey ants. These data were used to determine the degree to which E. hamatum are using specific prey stimuli to detect potential prey and direct their foraging. Army ants responded strongly to odours derived from prey ants, which triggered both increased localized recruitment and slowed advancement of the raid as they targeted the odour source. Odours from non-prey ants were largely ignored. Additionally, the army ants had the strongest response to the nest material of their preferred prey, with progressively weaker responses across the live ant, dead ant and alarm odours treatments respectively. This study reveals that the detection of prey odours, and especially the most persistent odours related to the prey's nest, provides a mechanism for dietary specialization in army ants. If ubiquitous across the Neotropical army ants, then this olfaction-based ecological specialization may facilitate patterns of resource partitioning and coexistence in these diverse predator communities.

The roles of temperature, nest predators and information parasites for geographical variation in egg covering behaviour of tits (Paridae)

AbstractAimNest building is widespread among animals. Nests may provide receptacles for eggs, developing offspring and the parents, and protect them from adverse environmental conditions. Nests may also indicate the quality of the territory and its owner and can be considered as an extended phenotype of its builder(s). Nests may, thus, function as a sexual and social signal. Here, we examined ecological and abiotic factors—temperature, nest predation and interspecific information utilization—shaping geographical variation in a specific nest structure—hair and feather cover of eggs—and its function as an extended phenotype before incubation in great (Parus major) and blue tits (Cyanistes caeruleus) across Europe. We also tested whether egg covering is associated with reproductive success of great tits.LocationFourteen different study sites and 28 populations across Europe.TaxonParus major, Cyanistes caeruleus.MethodsWe recorded clutch coverage estimates and collected egg covering nest material from the tit nests. We also measured nest specific breeding parameters and phenotypic measurements on adults. We tested whether mean spring temperatures, nest predation rates and flycatcher (Ficedula spp) densities in the study areas explain the large‐scale geographical variation of clutch coverage and reproductive success of tits.ResultsThe degree of egg coverage of great tits increased with lower mean spring temperature, higher nest predation rate and higher flycatcher density. We did not find egg covering of blue tits to be associated with any of the ecological or abiotic factors. Moreover, egg covering of great tits was not associated with reproductive success in our cross‐sectional data, yet a rigorous assessment of fitness effects would require long‐term data.Main conclusionsOur findings suggest that, in great tits, egg covering may simultaneously provide thermal insulation against cold temperatures during egg‐laying in spring and also represent a counter‐adaptation to reduce information parasitism by flycatchers and nest predation. Hence, geographical variation in interspecific interactions, and consequently in co‐evolutionary processes, may affect the evolution of nest characteristics besides environmental conditions.

Isolation and Characterization of Antibiotic Producing Actinomycetes from Mud Nest of Wasps

The recent increase in antibiotic resistance demands the discovery of novel antibiotics. Hence, this project was designed to explore novel antibiotic producing Actinomycetes from mud nest of wasps. For this, 9 types of active mud nests of wasp available in Rajshahi, Bangladesh were collected. For each nest, nest material was aseptically homogenized with a 1X saline solution and then diluted homogenate was plated in Actinomycetes Isolation Agar medium to isolate Actinomycetes. Total 27 purified cultures of bacteria were isolated from 9 collected mud nests of wasp. To collect the extract of mud nest, homogenate was filtered and centrifuged. Then, the extracts were assessed for their efficacy to inhibit bacterial growth with disc diffusion method. However, only extract of nest number 9 (N9) showed antimicrobial efficacy against tested bacteria, E. coli. Then antimicrobial efficacy of the 27 isolates was assessed using an agar cross-streak method and disc diffusion method. It was found that among the 27 isolates; only the isolate N9C2 was able to inhibit the growth of studied bacteria, E. coli. Then, 16S rDNA was isolated, amplified and sequenced from the isolate N9C2 for its identification. According to NCBI blast, the highest similarity of sequence (99%) of 16S rDNA of the isolate N9C2 was shown to that of Streptomyces coelescens strain AS 4.1594. Then, the isolate N9C2 was characterized. It was found that the isolate was a gram positive filamentous bacterium. It was found that the isolate N9C2 was resistant to Amoxicillin, Ampicillin and Cephalexin while it was sensitive to Tetracycline, Erythromycin and Ciprofloxacin. It was also found that the isolate N9C2 can grow optimally at pH 7 and at 37ºC. Finally, it can be concluded that mud nests of wasp is a vital source of antibiotic producing Actinomycetes such as Streptomyces coelescens strain AS 4.1594.

The Effects of Early Life Stress, Postnatal Diet Modulation, and Long-Term Western-Style Diet on Later-Life Metabolic and Cognitive Outcomes.

Early life stress (ES) increases the risk to develop metabolic and brain disorders in adulthood. Breastfeeding (exclusivity and duration) is associated with improved metabolic and neurocognitive health outcomes, and the physical properties of the dietary lipids may contribute to this. Here, we tested whether early life exposure to dietary lipids mimicking some physical characteristics of breastmilk (i.e., large, phospholipid-coated lipid droplets; Concept Nuturis® infant milk formula (N-IMF)), could protect against ES-induced metabolic and brain abnormalities under standard circumstances, and in response to prolonged Western-style diet (WSD) in adulthood. ES was induced by exposing mice to limited nesting material from postnatal day (P) 2 to P9. From P16 to P42, male offspring were fed a standard IMF (S-IMF) or N-IMF, followed by either standard rodent diet (SD) or WSD until P230. We then assessed body composition development, fat mass, metabolic hormones, hippocampus-dependent cognitive function, and neurogenesis (proliferation and survival). Prolonged WSD resulted in an obesogenic phenotype at P230, which was not modulated by previous ES or N-IMF exposure. Nevertheless, ES and N-IMF modulated the effect of WSD on neurogenesis at P230, without affecting cognitive function, highlighting programming effects of the early life environment on the hippocampal response to later life challenges at a structural level.

Effects of Different Farrowing Environments on the Behavior of Sows and Piglets.

Simple SummaryThe farrowing crate has long been a severe welfare problem of sows as its space restriction greatly impairs the behavioral expression of sows and induces long-term stress. We aimed to investigate the behavioral pattern of sows and piglets reared under different farrowing systems a farrowing crate and free farrowing pens with sloping walls with or without nest materials. Sows and piglets in free farrowing pens had a higher level of activity and lower level of performing abnormal behaviors. Providing nest material enhanced the beneficial effect of free farrowing system on the behavior of sows and piglets. These results encourage us to introduce the free farrowing systems to the pig industry and thus improve the welfare condition of farrowing sows. However, improved managements should be investigated as the piglet loss in the free farrowing systems tended to be higher than that in the farrowing crate system.We investigated the effect of different farrowing systems on the behavior of sows and piglets. In total, 22 hybrid sows (Yorkshire × Landrace) were randomly assigned into three farrowing systems, farrowing crate (FC), free farrowing pen with sloping walls (FFS), and free farrowing pen with sloping walls and nest materials (FFSN). The FFS and FFSN sows were more active, and exhibited less abnormal behaviors compared with the FC sows before and after parturition. FFS and FFSN piglets were more active compared with FC piglets. The increased activity of the FFS and FFSN sows might encourage the activity of their piglets, resulting in more proximity to sow behavior of their piglets. Providing nest materials improved the investigative behavior of sows and piglets. The total mortality of piglets in the free farrowing systems tended to be higher compared with the farrowing crate system. In conclusion, free farrowing system has beneficial effects on the behavior of sows and piglets but extra care in management needs to be taken to avoid piglet loss. Adding nest material in the farrowing pens is suggested to enrich the behavioral pattern of sows and piglets.

Wall Structure Affects Insulation of Nests Built by Thrushes

Incubation and rearing of nestlings are energetically demanding activities that can be affected by insulation conferred by the nest wall. Although thermal properties of nests are widely studied, no reports to date have dealt with the relative effects of the various structural parts of the nest wall. This experimental study investigated the effects of air movement, and for the first time, the effects of wall structure, on nest insulation for the Common Blackbird Turdus merula and Song Thrush Turdus philomelos of the Turdidae. Insulatory values, i.e. difference in cooling rate measured simultaneously inside and outside a nest, and internal cooling rates within the nest cup, were determined using temperature loggers under still-air and moving-air conditions. Moving-air increased insulatory values and internal cooling rates in both species. Insulatory values were positively correlated with the nest base thickness, but not nest side wall thickness. Removal of the outer nest wall and cup lining to reveal the internal mud cup of thrush nests reduced the insulatory value compared to the whole nest, the effect of which was exacerbated under moving-air conditions. These results may reflect that the nest wall confers huge insulatory advantages and especially so during periods of air movement. However, it is unclear whether this is related to the presence of particular nest materials that confer insulation, or to the amount of air trapped in the nest wall. Alternatively, the thermal conductivity of the materials lining the cup wall may be important.

Quantifying the relative predation pressure on bumblebee nests by the European badger (Meles meles) using artificial nests.

Bumblebee populations are declining. Factors that impact the size and success of colonies act by either limiting resource availability (bottom‐up regulation) or causing mortality, for example, pesticides, disease, and possibly predation (top‐down regulation). The impact of predation has not been quantified, and so, the current study used novel artificial nests as a proxy for wild bumblebee nests to quantify the relative predation pressure from badgers in two habitats: woodland and grassland, and at two nesting depths: surface and underground. Badgers occur across most parts of the UK and are known to predate on bumblebee nests. We found that significantly more artificial nests (pots containing bumblebee nest material) were dug up compared with control pots (pots without bumblebee nest material). This shows that artificial nests have the potential to be used as a method to study the predation of bumblebee nests by badgers. In a location of high badger density, predation pressure was greater in woodland than grassland, whereas no difference was observed in relation to nest depth. Woodland and grassland are shared habitats between bumblebees and badgers, and we suggest that higher predation may relate to activity and foraging behavior of badgers in woodland compared with grassland. We discuss how badger predation in different habitats could impact different bumblebee species according to their nesting behaviors. Understanding the relative impact of badger predation on bumblebee colonies provides key information on how such top‐down regulation affects bumblebee populations.

Tree cavity abundance and beyond: Nesting and food storing sites of the pygmy owl in managed boreal forests

Natural cavities are a critical resource for non-excavating hole-nesting birds, many of which are declining in northern Europe. In the heavily managed boreal forests in Finland, cavities may be a scarce resource, but their availability to different hole-nesters has been examined in only a few studies. We studied the abundance of suitable cavities in two managed forest landscapes 300 km apart for a forest-dwelling predator, the Eurasian Pygmy Owl Glaucidium passerinum, which requires tree cavities for both nesting and food hoarding. We further examined the preferences of the owls for different cavity characteristics in two experiments and several years of monitoring data with nest boxes resembling natural cavities. We found that natural cavities were scarce in the landscape (6.5/km2). However, natural cavity abundance per se does not seem to limit the breeding density of this predator, as suggested by a low occupancy rate in natural cavities and nest boxes. Owls cleaned the cavities that were filled with nest material of other birds, which provides a greater number of possible cavities to choose from. Cavities whose characteristics prevent the nest from being reached by predators were clearly preferred, as the owls select cavities with more than 5 cm width of the front wall and 15–30 cm of entrance-bottom distance within the cavity. The entrance hole orientation or the height of the cavity from the ground did not affect cavity occupancy by pygmy owls for nesting. In addition, none of the characteristics of the cavities that we surveyed affected their use for food hoarding. While the number of cavities per se may not limit the nesting of the owls, they may be limited by suitable habitat with abundant food supply around available cavities, or by lack of cavities in suitable habitats. They also need more cavities in the winter than in the summer, as each individual needs one to six cavities for hoarding food to survive over winter. Effective conservation strategies for this forest specialist should therefore include the maintenance of high-quality habitat that contains suitable cavities, supporting the need for protection of mature and old-growth forests as a whole, and not just of cavity bearing trees alone.

Material Type and Position Determines the Insulative Properties of Simulated Nest Walls

Incubation in birds takes place within a nest that is often assumed to confer a degree of thermal insulation. The range, amounts and organisation of materials used to construct nest walls hampers our understanding of the degree to which they provide insulation during incubation. This experimental study used temperature loggers in a model system to test the insulative properties of materials extracted from bird nests to determine: 1) whether differences existed in terms of insulation, and 2) if the position of a material mattered when two materials were tested in combination. Animal-derived materials offered better insulation than plant-derived materials, whether tested singly or in combination. Halving the mass of each material did not affect insulation conferred by the material proximal to the temperature logger. Differing thermal conductivities of the materials in contact with the temperature logger may explain these results. If a bird strategically places an animal-derived material only into a nest cup lining then it may be sufficient to provide good insulation for the whole nest. More research is needed to generate thermal conductivity data for commonly used nest materials to test this idea more rigorously in finite element heat transfer models.—Deeming, D.C., Griffiths, J.D. & Biddle, L.E. (2020). Material type and position determines the insulative properties of simulated nest walls. Ardeola, 67: 127-136.

Inferring Termite Colony Size Using Wood Consumption in Subterranean Termites (Blattodea: Rhinotermitidae) in Laboratory-Rearing Conditions.

Termite colony size can influence its foraging activity, reproductive maturity, and, for pest species, potential for structural damage. Estimating colony size of subterranean termite species in field conditions has been challenging owing to their extensive foraging territory and their cryptic nesting habit and has primarily relied on mark-recapture methods. With laboratory-reared colonies in individual containers, determining colony size can be achieved by processing all termites from the nest material, which can be labor intensive and partially destructive. However, with the recent rise in the need of large laboratory colonies for use in colony-wide experimental protocols, there was an imperative to develop a procedure to estimate initial colony sizes without imposing a major stress on colonies before an experiment. In this study, the average daily wood consumption of whole colonies was used to infer the colony size of two Coptotermes, Wasmann (Blattodea: Rhinotermitidae) species and their hybrids in laboratory-rearing conditions. Correlations between the daily wood consumption and several demographic variables within colonies were established. Linear models varied across all species mating types with R2 values greater than 0.8 for all demographic variables. For colonies from all mating combinations, Pearson's correlation coefficient values were greater than 0.94 between their daily wood consumption and both the number of workers and total number of termites, and greater than 0.91 between daily wood consumption and colony mass. Therefore, in colonies with fixed laboratory conditions, their average daily wood consumption determination, which is nondestructive on colonies, can be used to infer colony size of subterranean termites.

Breeding behaviour and diet of the Crowned Eagle Stephanoaetus coronatus in western Tanzania

The aim of the current study was to reveal the breeding ecology of Crowned Eagles in western Tanzania through constant daytime monitoring. The breeding circumstances of three resident pairs in the focal study area suggest that the breeding cycle of the species is seasonal, because they lay eggs in the dry season, so that fledging occurs in the rainy season. One pair brought a total of 88 prey items (a minimum of 80 prey individuals) during the breeding period from nest-making to the point at which the nestling was about to fledge at 106 days old. Prey animals comprised three vertebrate taxa (mammal, reptile and bird), of which mammals dominated, ranging over primates, rodents, carnivores, hyraxes and bovids. Diversity of prey taxa increased in the later stage of the nestling period. As well as breeding periodicity and prey selectivity, I describe details of some novel behaviours related to breeding ecology of the species, such as nest material delivery, copulation, feeding behaviour, unilateral eye closure, alert behaviour and defensive behaviour.

The microbiota of the Lasius fuliginosus – Pella laticollis myrmecophilous interaction

Myrmecophilous insects depend on their ant hosts during at least part of their life cycle. Lasius ants appear to be primarily involved as host in myrmecophilous interactions, especially with aphids and beetles, e.g. staphylinid. Pella laticollis is a rove beetle having a close ecological association with Lasius fuliginosus, which is correlated to its behavior adapted to avoid attack. Microorganisms can also play an important role in the maintenance of such relationships. We used 16S rRNA sequencing on the Illumina MiSeq platform to identify the bacterial communities associated with larvae and adults of both L. fuliginosus and P. laticollis. In addition, we determined the microbiota profiles of the nest-carton, an organic material lining the nest chambers. We obtained more than two million good quality reads. Taxonomic annotation showed that the profiles consisted of a total of 20 phyla, among which Proteobacteria was the most abundant. The samples were grouped according to the host’s developmental stage or the nest material, and the differences between those groups were significant. Only the microbiota of L. fuliginosus larvae and adults did not differ significantly. Analyses at the genus level indicated a heightened abundance of Pseudomonas in the insects’ profiles. The bacterial communities associated with the nest-carton included bacterial genera recorded from soil and dead wood. The profiles showed the presence of two well-known endosymbiotic bacteria, namely, Rickettsia and Wolbachia. According to our findings, the bacterial communities associated with larvae and adults of both L. fuliginosus and P. laticollis formed clusters according to the host’s identity and its developmental stage. The profiles determined for the nest-carton formed a separate group. Our study is in line with a new research trend that is focusing on microbiota associated not only with ants, but also with myrmecophiles and ant nests inhabited by those species.

Sub-lethal effects of permethrin exposure on a passerine: implications for managing ectoparasites in wild bird nests.

Permethrin is increasingly used for parasite control in bird nests, including nests of threatened passerines. We present the first formal evaluation of the effects of continued permethrin exposure on the reproductive success and liver function of a passerine, the zebra finch (Taeniopygia guttata), for two generations. We experimentally treated all nest material with a 1% permethrin solution or a water control and provided the material to breeding finches for nest building. The success of two consecutive clutches produced by the parental generation and one clutch produced by first-generation birds were tracked. Finches in the first generation were able to reproduce and fledge offspring after permethrin exposure, ruling out infertility. Permethrin treatment had no statistically significant effect on the number of eggs laid, number of days from clutch initiation to hatching, egg hatch rate, fledgling mass or nestling sex ratio in either generation. However, treating nest material with permethrin significantly increased the number of hatchlings in the first generation and decreased fledgling success in the second generation. Body mass for hatchlings exposed to permethrin was lower than for control hatchlings in both generations, but only statistically significant for the second generation. For both generations, an interaction between permethrin treatment and age significantly affected nestling growth. Permethrin treatment had no effect on liver function for any generation. Permethrin was detected inside 6 of 21 exposed, non-embryonated eggs (28.5% incidence; range: 693–4781 ng of permethrin per gram of dry egg mass). Overall, results from exposing adults, eggs and nestlings across generations to permethrin-treated nest material suggest negative effects on finch breeding success, but not on liver function. For threatened bird conservation, the judicious application of this insecticide to control parasites in nests can result in lower nestling mortality compared to when no treatment is applied. Thus, permethrin treatment benefits may outweigh its sub-lethal effects.