Great Egg Research Articles

Discovery and Genomic Characterization of a Novel Hepadnavirus from Asymptomatic Anadromous Alewife (Alosa pseudoharengus).

The alewife (Alosa pseudoharengus) is an anadromous herring that inhabits waters of northeastern North America. This prey species is a critical forage for piscivorous birds, mammals, and fishes in estuarine and oceanic ecosystems. During a discovery project tailored to identify potentially emerging pathogens of this species, we obtained the full genome of a novel hepadnavirus (ApHBV) from clinically normal alewives collected from the Maurice River, Great Egg Harbor River, and Delaware River in New Jersey, USA during 2015-2018. This previously undescribed hepadnavirus contained a circular DNA genome of 3146 nucleotides. Phylogenetic analysis of the polymerase protein placed this virus in the clade of metahepadnaviruses (family: Hepadnaviridae; genus: Metahepadnavirus). There was no evidence of pathology in the internal organs of infected fish and virions were not observed in liver tissues by electron microscopy. We developed a Taqman-based quantitative (qPCR) assay and screened 182 individuals collected between 2015 and 2018 and detected additional qPCR positives (n = 6). An additional complete genome was obtained in 2018 and it has 99.4% genome nucleotide identity to the first virus. Single-nucleotide polymorphisms were observed between the two genomes, including 7/9 and 12/8 synonymous vs nonsynonymous mutations across the polymerase and surface proteins, respectively. While there was no evidence that this virus was associated with disease in this species, alewives are migratory interjurisdictional fishes of management concern. Identification of microbial agents using de novo sequencing and other advanced technologies is a critical aspect of understanding disease ecology for informed population management.

The Great Auk (Pinguinus impennis) had two brood patches, not one: confirmation and implications

Since the late 1600s it has been assumed that the Great AukPinguinus impenniswas similar to the Common GuillemotUria aalgeand Brünnich's GuillemotUria lomviain having a single, central brood patch. Through the examination of eight mounted museum specimens, we show that this is incorrect and that, like its closest relative the RazorbillAlca torda, the Great Auk had two lateral brood patches. We discuss how such misinformation persisted for so long. We also review the relationship between the number of brood patches and clutch size in the Alcidae. One implication of two brood patches is that the Great Auk would have incubated in a horizontal posture like the Razorbill, rather than in a semi‐upright posture like theUriaguillemots. Assuming that the Great Auk incubated like the Razorbill, it would probably have done so horizontally with its single egg pressed against one of the two lateral brood patches, positioned against the inside of one tarsus (and partially on the web of one foot), and with the wing on that side drooped to provide additional protection for the egg. Incubating in this way may have meant that the Great Auk's pyriform egg would have enabled it to use both level and sloping terrain, as in theUriaguillemots (but unlike the Razorbill). A horizontal incubation also has implications for estimates of their breeding density, which we estimate to have been around four pairs per square metre and, hence numbers on its largest known colony, Funk Island, Newfoundland (maximum 250 000 pairs).

Myxozoan parasites vary in river herring according to life history stage and habitat.

Anadromous river herring have declined in many parts of their range, leading to fisheries management efforts to help repopulate this species by improving connectivity of rivers and restoring populations by fish transfers. With data lacking on parasites in these species, this study sought to better understand myxozoans across various life stages and habitats in river herring populations in New Jersey, USA. We compared fish from riverine habitats during early-life growth and adults returning to spawn, marine-phase fish, and landlocked Alewife populations. Three myxozoan species were identified in young-of-the-year (YOY) anadromous river herring, including Kudoa clupeidae in the skeletal musculature, Myxobolus mauriensis in the rib cartilage, and an uncharacterized coelozoic myxozoan within the lumen of mesonephric tubules. In YOY river herring, Blueback Herring were 2 times more likely to be infected by K. clupeidae than Alewife (p = 0.019) and in the Maurice River, fish were 4 times more likely to be infected with M. mauriensis than fish from Great Egg Harbor River (p = 0.000) and 11 times more likely than the Delaware River (p = 0.001). Spawning adult river herring were infected with a previously undescribed myxozoan parasite infecting the kidney. Sequencing the 18S rDNA indicated this species is closely related to Ortholinea species. Myxobolus mauriensis and the Ortholinea-like species were absent from marine-phase river herring indicating that infections were linked to river environments occurring during early-life growth and spawning, respectively. No myxozoans were present in landlocked Alewife, showing that similar infections occurring in rivers were absent in lake environments in the region.

Interspecies comparisons of brominated flame retardants in relation to foraging ecology and behaviour of gulls frequenting a UK landfill

This study quantifies and compares concentrations and profiles of legacy and alternative (alt-) brominated flame retardants (BFRs) in the eggs of three gull (Laridae) species of international/UK conservation concern – great black-backed gulls (Larus marinus; n = 7), European herring gulls (L. argentatus; n = 16) and lesser black-backed gulls (L. fuscus; n = 11) in relation to their foraging ecology and behaviour in order to investigate potential exposure pathways at a remote landfill in western Scotland, UK. Egg concentrations of sum (∑) polybrominated diphenyl ethers (∑8PBDEs) in all three species exceeded those for most reported avian species using landfill, except for those in North America. Despite relatively high detection frequencies of ∑hexabromocyclododecanes (∑3HBCDDs) (94–100%), concentrations of ∑8PBDEs exceeded ∑3HBCDDs and ∑5alt-BFRs, with ∑8PBDE levels similar in all three species. Egg carbon isotopic (δ13C) values highlighted a greater marine dietary input in great black-backed gulls that was consistent with their higher BDE-47 levels; otherwise, dietary tracers were minimally correlated with measured BFRs. ∑3HBCDD egg concentrations of herring gulls markedly exceeded those reported elsewhere in Europe. Decabromodiphenylethane (DBDPE) was the only alt-BFR detected (6–14% detection rate), in a single egg of each species. The great black-backed gull egg contained the highest concentration of DBDPE measured in biota to date globally and provides strong evidence for its emerging environmental presence as a BDE-209 replacement in UK wildlife. Correlations between δ13C (dietary source) and some measured BFRs in eggs suggest multiple routes of BFR exposure for gulls frequenting landfill through their diet, behaviour, preening, dermal exposure and likely inhalation. The frequent use of landfill by herring gulls and their increased egg BFR burdens suggest that this species may be an important bioindicator of BFR emissions from such sites.

Interspecific aggression declines seasonally in breeding great tits Parus major

AbstractDuring the breeding season, great tits show aggression to protect their nest from intra‐ and interspecific intruders. Aggression is a labile trait that can be plastically expressed as a result of individual differences (e.g., personality), seasonal gradients in the costs and benefits of aggression, or other environmental components (e.g., number of competitors). Competitors may try to take over great tit nests, because the number of suitable nesting sites is limited, and great tits may guard high quality territories. Taking over a great tit nest may be especially fruitful in early phenological stages (egg laying) when great tits frequent their nests less often. However, great tits may compensate for this vulnerability by being more aggressive toward intruders during early nesting stages, a pattern that has already been established in an intraspecific context. Previous studies have shown that interspecific intruders were most likely to die from great tit aggression during great tit egg laying, suggesting great tits may also be more aggressive during this phase in an interspecific context. Here, I tested this hypothesis with simulated territorial intrusions in great tit territories using taxidermized blue tits Cyanistes caeruleus (hereafter called blue tit models). Great tit aggression (number of calls and approach distance toward blue tit model) was assayed during egg laying, incubation, and chick rearing in the breeding season of 2014. Although sample size was low due to a high fraction of non‐responders (n = 44 out of 89 assays across 26 out of 35 individuals), I found that great tits showed a seasonal decline in aggressiveness, which is congruent with intraspecific results on this study species. I discuss my findings in the context of differential adjustment to climate change between interspecific competitors.

All Our Eggs In One Basket: Challenges of High Resolution X-Ray Micro-Computed Tomography of Great Auk Pinguinus impennis Eggshell

High resolution X-ray micro-computed tomography gives the ability to research objects in unprecedented detail in 3D without damaging them but applying these new techniques to specimens can be complex. In 2017 the Natural History Museum (NHM), London embarked on a ground-breaking project with University of Sheffield to compare extinct Great Auk Pinguinus impennis eggshell microstructure to that of their extant relatives to gain new insight into their breeding ecology. NHM has a ZEISS Xradia 520 Versa X-ray microscope capable of submicron X-ray imaging in 3D but using it required supporting and moving complete eggshells within the confined, potentially harsh, mechanised environment of the microscope without risk. Ensuring the correct position and orientation of each egg to image nine distinct areas on the eggshell was also a challenge. Collaboration with colleagues in the NHM Conservation and Imaging & Analysis Centres developed a bespoke solution to hold and protect the eggs during scanning. All six NHM Great Auk eggshells and the inside of the microscope were surface scanned using a handheld structured light scanner. Scan data produced 3D models from which accurate 3D printed plastic replicas were made of the three Great Auk eggs prioritised for research. Each replica was used to mould a two-part, custom-built, case for each egg constructed from conservation grade epoxy putty and lined with polyethylene foam. This provided close-fitting, durable cases which could be used for the 6-month duration of the project. Each case enclosed its matching Great Auk egg entirely and had the advantage of being rock-hard, electrically insulating and water, heat and chemical resistant. A system of three, interchangeable, tailor-made mounting brackets were designed that married with the cases and held them safely and precisely inside the microscope at the correct angles and positions for imaging. The structured light scan of the inside of the microscope was used to model the necessary rotational movements of the cases and brackets inside the scanner, ensuring that all movements had sufficient clearance to avoid risk of impact. This system successfully protected the fragile c. 200 year old eggs throughout 70 scanning sessions. This provides a methodology for high resolution X-ray micro-computed tomography imaging of any similarly sized, fragile, object.

A Study of Butterfly Diversity and Distribution at Kolkar Science College Campus Indore, India

The photoautotroph’s and the heterotroph’s are associated with each other. The relationship may be either beneficial or determinant to each other. Such one beautiful beneficial relationship exists in nature between plants and butterflies. Flying insect are the most common and colorful component of an ecosystem in general and butterflies in particular. They play a very important in herbivorous food chain/web. The present study was carried out at Holkar Science College Campus Indore District, Madhya Pradesh, India, during 2014 to 2015. A total of 41 butterfly species were recorded. Family Nymphalidae (19) dominates in the study area, followed by Pieridae (08), with minimum members of Hesperiidae (02). Total larval food plants recorded from the campus are 44 belonging to 23 different families. Hygrophylla aericulata ware found most importance larval food plants as they supports the five pansies found here. The ratio of food plants and butterflies is near about 1:1. Plants of the Asteraceae family were more used by butterflies as nectar food plants. These findings are important with respect to butterfly diversity in planning conservation strategies in the area. The very common butterflies are Common jezebel, Common gull, Common emigrant, Mottled emigrant, Common grass yellow, Lime blue, Pale grass blue, Small grass jewel, and common are Lemon pansy, Great egg fly, Danaid egg fly, Plain tiger and among very rare includes Common baron, Common sailor, Chocolate pansy, Grey pansy Spot swordtail, Royal peacock, Commander, and Common wanderer.

Myxobolus mauriensis n. sp. Infecting Rib Cartilage of Young-of-the-Year River Herring in New Jersey: Notes on Pathology, Prevalence, and Genetics.

: River herring populations, including Alosa pseudoharengus and Alosa aestivalis , have significantly declined as a result of anthropogenic factors throughout their range in eastern North America. To better understand the health of the species, parasite surveys were conducted in several New Jersey rivers. A novel myxozoan parasite, Myxobolus mauriensis n. sp., is described infecting the cartilage of pleural ribs in young-of-the-year fish. The parasite forms large polysporic plasmodia forming pseudocysts within the ribs, which extend into the musculature. Pathology associated with infection includes costochondritis, breaks in the rib bones, and deformed bone growth. Rupture of large pseudocysts and release of mature spores are associated with myositis, dermatitis, and peritonitis. Phylogenetic analysis reveals that M. mauriensis n. sp. occurs in a long-branching clade basal to other myxobolids, grouping with several Myxobolus species from marine fish (Myxobolus groenlandicus, Myxobolus aeglefini, and Myxobolus albi). The closest identity is to M. groenlandicus, with 83% identity based on a 1,762-bp sequence of the SSU 18S rDNA. Similarly, spore morphology, tropism for cartilage, and association with marine/brackish environments are shared in these 4 species. Mature spores of M. mauriensis n. sp. are similar to other reported myxobolids, though spores are slightly wider (12.1 ± 0.44 μm) than long (11.4 ± 0.44 μm), with a length:width relationship of 0.94 (±0.04), a feature not commonly described for other species of Myxobolus. Prevalence was studied by histology and fresh observation. In both Blueback Herring and Alewife, the highest infection prevalence occurred in the Maurice River at around 20%, and lower prevalence was found in the Great Egg Harbor River at around 5%. In the Delaware River, prevalence was about 2% in Blueback Herring, while the parasite was not detected in Alewife samples.

Radar and optical mapping of surge persistence and marsh dieback along the New Jersey Mid-Atlantic coast after Hurricane Sandy

ABSTRACTThis study combined a radar-based time series of Hurricane Sandy surge and estimated persistence with optical sensor-based marsh condition change to assess potential causal linkages of surge persistence and marsh condition change along the New Jersey Atlantic Ocean coast. Results based on processed TerraSAR-X and COSMO-SkyMed synthetic aperture radar (SAR) images indicated that surge flooding persisted for 12 h past landfall in marshes from Great Bay to Great Egg Harbor Bay and up to 59 h after landfall in many back-barrier lagoon marshes. Marsh condition change (i.e. loss of green marsh vegetation) was assessed from optical satellite images (Satellite Pour l’Observation de la Terre and Moderate Resolution Imaging Spectroradiometer) collected before and after Hurricane Sandy. High change in condition often showed spatial correspondence, with high surge persistence in marsh surrounding the lagoon portion of Great Bay, while in contrast, low change and high persistence spatial correspondence dominated the interior marshes of the Great Bay and Great Egg Harbor Bay estuaries. Salinity measurements suggest that these areas were influenced by freshwater discharges after landfall possibly mitigating damage. Back-barrier marshes outside these regions exhibited mixed correspondences. In some cases, topographic features supporting longer surge persistence suggested that non-correspondence between radar and optical data-based results may be due to differential resilience; however, in many cases, reference information was lacking to determine a reason for non-correspondence.

A Beaked and Feathered God

A Beaked and Feathered God

Danbala/Ayida as Cosmic Prism

This essay decenters notions of centrality and periphery as we aim to delineate the metaphysical elements of Haitian Vodou, a Diasporic religion in the Americas, and the manner in which its metaphysics becomes a national ethos of sorts, rooted in time, both past and present. We aim to use Danbala and Ayida as motif to explore Vodou hierophanies and irruptions of the sacred; as motif of negotiated relationships with divine energies, of ritual lineage and human ancestry, of complex gender notions; and as meditations on the natural world. These themes reveal important notions of oneness of being, of equilibrium and balance, as well as konesans, the all-encompassing wisdom that merges with knowledge—all represented by the great cosmic egg of the rainbow-serpent entities Danbala and Ayida.

The evolution of the New Jersey Pine Plains

Fire in the New Jersey Pine Plains has selectively maintained a dwarf growth form of pitch pine (Pinus rigida), which is distinct from the surrounding tall forest of the Pine Barrens and has several other inherited adaptations that enable it to survive in an environment dominated by fire. Pitch pine progeny from two Pine Plains sites, the West and East Pine Plains, were grown in common garden environments with progeny from two Pine Barrens stands, Batsto and Great Egg Harbor River. The tests were replicated in five locations: in New Jersey, Connecticut, two sites in Massachusetts, and Korea. One of the tests was monitored for up to 36 yr. Progeny of Pine Plains origin were, in general, shorter, more crooked, precocious, bore more cones, had a higher frequency of serotinous cones, and had a higher frequency of stem cones than did Pine Barrens progeny, wherever they were grown. The Pine Plains is an ecotype that has evolved in response to disturbance. The several characters that distinguish it from the surrounding tall forest of the Pine Barrens are inherited. The dwarf stature and crooked form not only enable the ecotype to persist in an environment of frequent fires but also increase its flammability.

The Island of the Great Egg

The Island of the Great Egg

Variable Contributions of Mercury from Groundwater to a First-Order Urban Coastal Plain Stream in New Jersey, USA

Filtered total mercury (FTHg) concentrations in a rapidly urbanizing area ranged from 50 to 250 ng/L in surface waters of the Squankum Branch, a tributary to a major river (Great Egg Harbor River (GEHR)) traversing both urban and forested/wetland areas in the Coastal Plain of New Jersey. An unsewered residential area with Hg-contaminated well water (one of many in the region) is adjacent to the stream’s left bank. Although the region’s groundwater contains total Hg (THg) at background levels of 5,000 ng/L (left bank) and nearly 2,000 ng/L (right bank). The Hg content of bankside soils and sediments was high (up to 12 mg/kg) and mostly acid leachable where groundwater with high Hg concentrations discharged, indicating contributions of Hg by both runoff and shallow groundwater. Elevated concentrations of nutrients and chloride in some groundwater plumelets likely indicated inputs from septic-system effluent and (or) fertilizer applications. The Hg probably derives mainly from mercurial pesticide applications to the former agricultural land being urbanized. The study results show that soil disturbance and introduction of anthropogenic substances can mobilize Hg from soils to shallow groundwater and the Hg contamination travels in narrow plumelets to discharge points such as stream tributaries. In the entire GEHR watershed, THg concentrations in groundwater discharging to streams in urban areas tended to be higher than concentrations in water discharging to streams of forested areas, consistent with the results from this small watershed. Other areas with similar quartzose coastal aquifers, land-use history, and hydrogeology may be similarly vulnerable to Hg contamination of shallow groundwater and associated surface water.

Insecticidal activity against Aedes aegypti of m‐pentadecadienyl‐phenol isolated from Myracrodruon urundeuva seeds

Myracrodruon urundeuva Fr. Allemao is a common tree in the Caatinga that has been widely used for various medical purposes. Previous studies showed that the ethanol seed extract of M. urundeuva has potent activity against the larval stage of the dengue vector Aedes aegypti. Given this potential insecticidal activity, bioguided separation steps were performed in order to isolate the active compound(s). The isolation process resulted in only one active chemical compound, identified by infrared spectroscopy and mass spectrometry as m-pentadecadienyl-phenol. This compound presented potent larvicidal and pupicidal activity (LC50 10.16 and 99.06 µg mL(-1) respectively) and great egg hatching inhibitory activity (IC50 49.79 µg mL(-1)). The mode of action was investigated through observations of behavioural and morphological changes performed in third-instar larvae treated with m-pentadecadienyl-phenol solution after 1, 6, 12, 16 and 20 h of exposure. Some changes were observed as flooding of the tracheal system, alterations in siphonal valves and anal gills and lethargy, probably caused by the strong anticholinesterasic activity reported previously. The compound isolated from M. urundeuva seeds, m-pentadecadienyl-phenol, showed potent activity against immature stages of dengue vector, Ae. aegypti, being considered the main larvicidal principle.

"A pleasant Land to see" Part Two

This is the concluding portion of an article, the first half of which appeared in the Journal for June, 1962, and consisting of a collection of passages by various authors describing New Jersey scenery. In this part there are passages about The Raritan River Valley, The Highlands of Navesink, Sandy Hook, Manasquan, Barnegat, The Pine Barrens, Timber Creek, Great Egg Harbor, and Cape May County.

Images of Birds in Mordvinian Mythology

The article focuses on various functions of birds appearing as an indispensable element of the mythological system. First of all, their role is underlined in the cosmogonic and anthropogonic act. The most archaic is the image of the Great Bird, the creator of the world and man (among Mordvinians- Erzians). Mention is made about the role of prophetic birds and their use in the capacity of sacrifice and rituals. Gods and deities presented themselves in im- ages of different birds (duck, eagle, pigeon, swan, swallows etc.). Some compari- sons with other Finno-Ugric ethnoses (Mari, Komi etc.) are given. Images of birds occupy a particular place in the mythology of Mordvinians, and among other peoples. However, the subject matter presented in the article has so far not received the due attention of researchers. Birds appear as an indis- pensable element of the mythological system and perform different functions. First of all, it is essential to describe their cosmogonic and anthropo- gonic functions. The image of the Great Bird (mdM Ine Narmon', mdE Ine Narmun') is the most archaic in Mordvinian mythology where she acts as the creator of the world. Thus, she lays the Great World Egg (mdE Ine Al, mdM Otsiu Al), from which the world appears. The Earth comes from the egg-yolk, while the sky and the underground solidity emerge from the eggshell. A similar motif, the creation of the world from an egg laid by a bird, is typical in the cosmogony of other Finno-Ugric peoples: Finns, Estonians, Saami, Komi (Myths 1994: 564). Likewise, in Mordvinian mythology, the Great Bird is the original mother of some ethnoses and deities. According to a Mordvinian myth, the forefathers of Erzians-Mordvinians, Russians and Chuvashs were born from the three eggs of the Great Bird. Similarly, deities-patronesses of fertility - Norovava (mdE), wind - Varmava (mdM, mdE), woods - Vir'ava (mdM, mdE) were hatched out of three eggs laid by Ine Narmun' (mdE) in the nest on

Egg Size Variation in Blue TitsCyanistes caeruleusand Great TitsParus majorin Relation to Habitat Differences in Snail Abundance

Wild passerines, especially tits, utilize snail shells as the main source of calcium necessary for laying females to construct egg shells. This research found that the two study areas, representing two habitat types — a mature decid- uous forest and a human-disturbed parkland — are inhabited by different snail assemblages: both species richness and density are much higher in the parkland than in the forest. This means that less calcium is available to female tits in the forest than in the parkland, which could result in calcium limitation in the former habitat. Egg size traits, i.e. volume, length and breadth, in the Blue Tit show a consistent long-term pattern of variation that reflects the pattern of calcium availability: egg trait values are higher in the parkland than in the woodland. No habitat-related variation in egg size traits was found in the Great Tits. We suggest that the lack of a relation between Great Tit egg characteristics and snail availability results from the higher ecological plasticity of this species in comparison with the Blue Tit, including its abil- ity to exploit alternative sources of calcium.

Mercury and Methylmercury Dynamics in a Coastal Plain Watershed, New Jersey, USA

The upper Great Egg Harbor River watershed in New Jersey’s Coastal Plain is urbanized but extensive freshwater wetlands are present downstream. In 2006–2007, studies to assess levels of total mercury (THg) found concentrations in unfiltered streamwater to range as high as 187 ng/L in urbanized areas. THg concentrations were <20 ng/L in streamwater in forested/wetlands areas where both THg and dissolved organic carbon concentrations tended to increase while pH and concentrations of dissolved oxygen and nitrate decreased with flushing of soils after rain. Most of the river’s flow comes from groundwater seepage; unfiltered groundwater samples contained up to 177 ng/L of THg in urban areas where there is a history of well water with THg that exceeds the drinking water standard (2,000 ng/L). THg concentrations were lower (<25 ng/L) in unfiltered groundwater from downstream wetland areas. In addition to higher THg concentrations (mostly particulate), concentrations of chloride were higher in streamwater and groundwater from urban areas than in those from downstream wetland areas. Methylmercury (MeHg) concentrations in unfiltered streamwater ranged from 0.17 ng/L at a forest/wetlands site to 2.94 ng/L at an urban site. The percentage of THg present as MeHg increased as the percentage of forest + wetlands increased, but also was high in some urban areas. MeHg was detected only in groundwater <1 m below the water/sediment interface. Atmospheric deposition is presumed to be the main source of Hg to the wetlands and also may be a source to groundwater, where wastewater inputs in urban areas are hypothesized to mobilize Hg deposited to soils.

Effects of laying order and experimentally increased egg production on organic pollutants in eggs of a terrestrial songbird species, the great tit ( Parus major)

In this study, concentrations and profiles of organic pollutants were investigated in a passerine species with a large clutch size, the great tit ( Parus major). In the first clutches, mean egg concentrations decreased significantly in relation to the laying order from 3025 ± 416 ng/g lw to 2267 ± 386 ng/g lw for sum PCBs and from 989 ± 339 ng/g lw to 695 ± 320 ng/g lw for sum DDTs. Sum PBDE concentrations also decreased in relation to the laying order from 68 ± 10 ng/g lw to 53 ± 11 ng/g lw, but not significantly. Although laying order effects were found, variation in concentrations within clutches was smaller than among clutches. To further investigate the impact of laying large numbers of eggs on levels and profiles of organic pollutants, initiation of replacement clutches was experimentally induced. Mean sum PCB and sum PBDE concentrations were significantly lower in eggs of replacement clutches compared to first clutches. In addition, first clutches had a higher contribution of the higher chlorinated and more persistent PCB congeners, CB 170, 180 and 183, and a lower contribution of CB 52, 95 and 149 compared to replacement clutches. Because of the differences in concentrations and profiles between the first and replacement clutches, the combined use of eggs from both the first and replacement clutches for monitoring purposes is not recommended. In conclusion, we suggest that, due to the larger variation among clutches compared to the variation within clutches, one randomly collected great tit egg from a first clutch is useful as a biomonitoring tool for organic pollutants. To our knowledge, this is the first study in which the impact of an experimentally increased clutch size on the levels and profiles of contaminants in eggs has been investigated.