Egg Loss Research Articles

Kato-Katz slide preservation technique: Extension of viability and the benefits for schistosomiasis control programs

The World Health Organization recommends the use of the Kato-Katz method in the procedures of schistosomiasis control programs. Studies show the importance of a fast reading of the slides due to the decline of their viability, with the appearance of fungi or desiccation of the sample, which hinders diagnosis. It is necessary to establish a procedure to improve the long-term preservation of these Kato-Katz slides in order to accomplish the following: (1) preserve the slides for future quality control procedures and readings; (2) allow for the production of durable materials for training; and (3) train health professionals involved in diagnosing schistosomiasis. Therefore, this study aims to test a slide preservation methodology for these purposes. The results showed that the modifications made to the experimental slides demonstrated that egg loss was within the expected range and the limit accepted by quality control standards, as well as improved the diagnostic durability of the slides during the preservation times tested. We concluded that the application of the preservation technique to the slides promoted stabilization and permanence for long-term storage.

Understanding the effects of egg loss from fisher handling to improve conservation of a threatened freshwater crayfish (Euastacus armatus)

Context Handling of wild animals can have adverse effects on individuals that scale up to affect populations and ultimately species. Limited mobility and high harvest pressure expose the threatened Australian freshwater crayfish (Euastacus armatus) to multiple handling events by fishers that cause egg loss. Aim Our aim was to assess the effects from harvest pressure on the reproductive output of an E. armatus population. Methods A stochastic model based on empirical data and estimated harvest pressures was used to predict the effect of repetitive handling of individuals on a population of E. armatus subject to harvest and consequent egg loss. Key results Egg loss resulted in substantial predicted population-level declines, most pronounced in populations subject to high and extreme harvest pressures. Conclusions We advocate educating fishers to visually determine the reproductive condition of female crayfish by inspecting gonopore setation, eliminating the need for unfurling the tail. Implications Maximising species reproductive output through limiting handling loss supports the management and conservation of E. armatus populations.

First Documented Report of Complete Shell Pigment Loss in the Blue-Green Eggs of the Pied Flycatcher

First Documented Report of Complete Shell Pigment Loss in the Blue-Green Eggs of the Pied Flycatcher

The Effect of Eggshell Dipping with Various Types of Oils and Storage Duration on The Weight Loss and Shell Thickness of Table Eggs

Preserving eggs is very important to retain egg quality and increase shelf life, egg preservation is crucial. Eggs may be preserved by immersing them in several kinds of vegetable oil. The purpose of this research is to investigate the effects of dipping eggs in various types of oil and the duration of preservation on the shell thickness and weight loss of table eggs. The research material includes 45 chicken eggs, pure coconut oil, palm oil, maize (corn) oil, a screw micrometer, and a scale. The method utilized was experimental, employing factorials with a completely randomized design in a 3x5 factorial pattern and three (3) replications. Treatment A consists of oil types (A1 is pure coconut oil, A2 is palm oil, and A3 is maize (corn) oil), and treatment B: the storage duration of eggs at room temperature (including: 25 days for B1, 30 days for B2, 35 days for B3, 40 days for B4, and 45 days for B5). The variables that were noticed were the egg weight loss and shell thickness. Data were analyzed using analysis of variance and further analyzed using the Duncan Multiple Range Test (DMRT), utilizing SPSS version 16.0. The results suggest that the interaction between the kind of oil and storage length didn’t have significant consequences (P>0.05) egg weight loss and shell thickness. The type of oil significantly affects (P<0.05) shell thickness. The storage duration at room temperature significantly affects (P<0.05) on the egg weight loss and shell thickness. In conclusion, the best treatment for dipping eggs is using pure coconut oil and storing them at room temperature for up to 40 days.

Depredation of eggs of threatened freshwater turtles by the short-beaked echidna (Tachyglossus aculeatus (Shaw, 1792))

The echidna (Tachyglossus aculeatus) is documented as a new native predator of freshwater turtle eggs, particularly those of the vulnerable Fitzroy River turtle (Rheodytes leukops), and the critically endangered white-throated snapping turtle (Elseya albagula). This depredation has been identified in the Fitzroy, Burnett and Mary Catchments with echidnas recorded at traditional turtle nesting banks using direct observation of depredation of eggs, remote camera footage and identification of tracks. Echidnas were observed at traditional nesting banks for E. albagula and R. leukops nesting across eight months of the year. The presence of echidnas was more frequent during the R. leukops nesting season in spring. R. leukops is endemic to the Fitzroy Catchment and the depredation rate of eggs was significantly higher than for other species and catchments. The mean top egg depth of R. leukops nests was found to be the same depth as the echidna’s beak length. There was a significant increase in depredation during the five-year study period, with 47.4% of R. leukops clutches depredated by echidna in the 2022 season. This substantial loss of eggs and recruitment of hatchling turtles poses a significant threat to the populations of this threatened species.

Loss of sea turtle eggs drives the collapse of an insular reptile community

Marine subsidies are vital for terrestrial ecosystems, especially low-productivity islands. However, the impact of losing these subsidies on the terrestrial food web can be difficult to predict. We analyzed 23 years of survey data from Orchid Island to assess the consequences of the abrupt loss of an important marine subsidy. After climate-driven beach erosion and predator exclusion efforts resulted in the abrupt loss of sea turtle eggs from the terrestrial food web, predatory snakes altered their foraging habitats. This increased predation on other reptile species in inland areas, resulting in population declines in most terrestrial reptile species. Comparisons with sea turtle-free locations where lizard populations remained stable supported these findings. Our study emphasizes the cascading effects of generalist predators and the unintended consequences of single-species conservation, highlighting the importance of understanding species interconnectedness and considering potential ripple effects in marine-dependent insular ecosystems.

Field tests of egg and larval release methods of biological control agents (Archanara neurica, Lenisa geminipuncta) for introduced Phragmites australis australis (Cav.) trin. Ex Steud

Field releases of the stem-boring moths Archanara neurica and Lenisa geminipuncta (Lepidoptera: Noctuidae) as classical biological control agents for introduced Phragmites australis australis (Cav.) Trin. ex Steud. began in Canada during 2019. Since then, we have developed and tested release methods for eggs and larvae of both agents. Experiments here include comparisons of: (1) egg survival from exposed “egg card” and protected “egg cup” release methods to assess the risk of agent predation and test mitigation strategies; (2) performance of egg cups overwintered at the release site and those placed shortly before emergence in spring to test for any potential phenological asynchrony between biological control agents and the target weed; and (3) effectiveness of egg cup and larval-inoculated stem releases at a large geographic scale across 15 field sites in southern Ontario. Egg card releases experienced high egg loss likely due to predation (∼90 % of eggs), but egg cups were successful at reducing these losses to near zero. Releasing eggs in cups during the spring made it easier to place releases near phenologically synchronized microsites, minimized the risk of damage to the egg cups, and avoided a 16 % reduction in egg hatch likely associated with desiccation. Both larval-inoculated stems and egg cups produced highly encouraging feeding damage in the first season of release, with 7.7-fold higher damage from stem larvae compared to egg cups. Overall, we recommend a combination of larval-inoculated stems and spring egg cups for the primary release strategies of A. neurica and L. geminipuncta as biological control agents of introduced Phragmites. Both methods offer protection from predation and varying degrees of control over phenological mismatches. The release of larval-inoculated stems is a more labour-intensive but highly effective method in terms of initial feeding damage whereas egg cups are a more efficient mass-release method than stems with a lower amount of initial feeding damage per agent released.

In vitro post-ovulatory oocyte ageing in grass carp Ctenopharyngodon idella affects H4K12 acetylation pattern and histone acetyltransferase activity.

Delayed fertilization leads to the ageing of post-ovulatory oocytes and reduces the developmental competence of arising embryos. Little information is available about the molecular processes during fish oocyte ageing. The current study investigated the functional consequences of oocyte ageing in grass carp Ctenopharyngodon idella embryos. In addition, the dynamics of selected post-transcriptionally modified histones (acetylation of H3K9, H3K14, H4K5, H4K8, H4K12, and H4K16) were analyzed during oocyte ageing. Ovulated oocytes were aged in vitro for 4 h in the laboratory incubator at 20 °C and studied for selected post-translational modification of histones. In addition, histone acetyltransferase activity was investigated as an important regulator of histone acetylation modification. The results indicated a significant decrease in oocyte fertilizing ability through 1 h of post-ovulatory ageing, and a complete loss of egg fertilizing abilities was detected at 4-h aged oocytes. Furthermore, post-ovulatory oocyte ageing for 1 and 4 h led to decreased levels of H4K12 acetylation. The activity of histone acetyltransferases increased significantly after ageing of the oocytes for 30 h in vitro. This modification may partly contribute to explaining the failures of egg viability and embryo development in the offspring from the aged oocytes. The results are the first to report histone modifications as a crucial epigenetic regulator during oocyte ageing in fish and might also benefit other vertebrates.

Effects of a mixture of glycerol monolaurate and cinnamaldehyde supplementation on laying performance, egg quality, and antioxidant status in laying hens.

This study aimed to determine the effects of a mixture of glycerol monolaurate and cinnamaldehyde (GCM) supplementation on the laying performance, egg quality, antioxidant capacity, and serum parameters of laying hens. A total of 1120 14-week-old Jingfen-1 strain laying hens with similar performance were randomly allocated to four dietary treatments: control, and GCM groups supplemented with 250, 500, or 1000 mg kg-1 for 12 weeks. Compared with the control group, GCM-supplemented groups significantly reduced (P < 0.05) the rate of unqualified eggs of laying hens aged 17-24 weeks. Supplementation of GCM significantly increased (P < 0.05) yolk color and serum glutathione peroxidase (GSH-Px) activity but decreased (P < 0.05) the hydrogen peroxide (H2 O2 ) content in the serum of laying hens at the age of 20 weeks. Furthermore, groups supplemented with GCM showed a significant increase (P < 0.05) in Haugh unit, yolk color, activities of total superoxide dismutase and GSH-Px, and the glucose content in serum, and a decrease (P < 0.05) in the content of urea nitrogen and H2 O2 and malondialdehyde in serum of laying hens at the age of 24 weeks. 500 mg kg-1 GCM supplementation significantly increased (P < 0.05) the number of large white follicles and 1000 mg kg-1 GCM supplementation decreased the number of large yellow follicles in 28-week-old laying hens. These results indicated that GCM supplementation has positive effects on reducing egg loss and improving egg quality in the early laying period of laying hens. © 2023 Society of Chemical Industry.

Assessment of ecological damage from illegal fishing and judicial practice for damage compensation

In the context of China's comprehensive trial of an ecological damage compensation system, the lack of a widely accepted assessment model for assessing ecological damage caused by illegal fishing will inevitably affect the fairness of judicial rulings and the success of ecological restoration. In this study, we examined a typical illegal fishing case with a significant impact in China to illustrate the multi-dimensional damage caused by bottom trawls to the offshore ecosystem during a fishing moratorium as the first step in establishing a unified enforcement standard. Based on existing research, damage is divided into two types: quantifiable and unquantifiable. The former mainly refers to the ecological damage corresponding to illegal catches, while the latter includes habitat damage, mortality after escape, disturbance of spawning behaviour, and potential egg losses related to illegal catches. Quantifiable damage is the main basis for judging ecological environmental damage compensation cases, but it has not been fully utilized due to the lack of guiding documents. For unquantifiable damages, the “judicial discretion” of judges may be an effective measure to deal with this challenge. In addition, a preliminary amount correlation among two damage types was established based on a weight-based expert scoring method. This study provides a reference for China to establish a compensation mechanism for the ecological damage caused by illegal fishing in the future and can be applied to other regions plagued by illegal fishing around the world.

The Effect of Organic Trace Mineral Supplementation in the Form of Proteinates on Performance and Sustainability Parameters in Laying Hens: A Meta-Analysis.

The effect of supplementing organic trace minerals (OTM), in the form of mineral proteinates (Bioplex® Cu, Fe, Mn, and Zn, Alltech Inc., Nicholasville, KY, USA), in the diets of laying hens was examined using Comprehensive Meta-Analysis (CMA) statistical software. The impact on production performance, egg quality traits, and sustainability parameters related to the carbon footprint of egg production was assessed. Data were obtained from 32 global studies, comprising 107 dietary assessments of 30,992 laying hens. Overall pooled effect size (raw mean difference) of production performance when dietary organic trace minerals were supplemented either in basal diets, partial replacement of inorganic trace minerals (ITM), or total replacement of ITM, indicated that use of Bioplex minerals resulted in 2.07% higher hen-day production (HDP), whilst feed conversion ratio (FCR) was lower by 51.28 g feed/kg egg and 22.82 g feed/dozen eggs, respectively. For egg quality traits, daily egg mass was 0.50 g/hen/day higher and egg weight was 0.48 g per egg greater when Bioplex minerals were incorporated in the diet. The mean difference in egg loss was -0.62%. Eggshell thickness was greater by 0.01 mm, and a higher eggshell strength of 0.14 kgf was observed. Eggshell weight was heavier by 0.20 g, eggshell percentage was higher by 0.15%, and Haugh unit was 1 point higher (0.89). We also carried out a meta-regression of the effects of the study factors (location, year of study, hen breed/strain, age of hens, number of hens, and study duration) on the overall pooled effect size of the production performance and egg quality traits in response to supplementary OTM inclusion, and it indicated that certain factors had a significant (p < 0.05) impact on the results. Finally, a life cycle assessment (LCA) model was selected to evaluate the impact of feeding organic trace mineral proteinates on the carbon footprint (feed and total emission intensities) of the egg production using the data generated from the meta-analysis. Results showed that the inclusion of OTM proteinates resulted in an average drop in feed and total emission intensities per kg eggs of 2.40% and 2.50%, respectively, for a low-global-warming-potential (GWP) diet and a drop of 2.40% and 2.48% for feed and total emissions, respectively, based on high-GWP diet. Based on the overall results, the inclusion of organic trace mineral proteinates in layer diets can benefit production performance and egg quality traits while contributing to a lower carbon footprint.

Spatial and temporal distribution of fish egg communities in the adjacent waters of Daya Bay nuclear power plant and their relationship with environmental factors

The thermal discharge of Daya Bay Nuclear Power Plant has a certain impact on the ecological environment of the adjacent waters. In order to understand and evaluate changes in the fish egg community structure in the adjacent waters of Daya Bay Nuclear Power Plant and their relationship with environmental factors, four surveys were conducted to investigate fish eggs in January (winter), March (spring), August (summer) and November (autumn) of 2020. A total of 100,985 fish eggs were collected and 17 taxa were identified, belonging to five orders, 14 families and 17 genera. Among them, Perciformes and Clupeiformes were the main contributing taxa to fish egg species and abundance in the waters adjacent to Daya Bay Nuclear Power Plant. The number of fish egg species ranged from high to low was summer, spring, autumn and winter; the average abundance ranged from high to low was spring, summer, winter and autumn. The results showed that except in winter, the average abundance of fish eggs was greater in northeast area than in southwest area. The Shannon-Weiner species diversity index (H’), Pielou evenness index (J’) and Margalef richness index (d) were significantly different between seasons, but none were significantly different between areas. The results of NMDS analysis showed that there were significant differences in fish egg communities between seasons. Surface seawater temperature the average abundance of fish eggs was positively correlated in the results of all four seasons. Although the entrainment effect of nuclear power plant water intake and thermal pollution of partial waters owing to thermal discharge can cause some loss of fish eggs, fish resources can still be effectively maintained.

Effect of sprayed different concentrations of Moringa oleifera leaves extract on broiler breeder hatching eggs

This research aimed to study the impact of spraying different Concentrations of Moringa oleifera leaves Extract on Broiler Breeder Hatching Eggs. The results cleared that, at 18th day the egg weight ranged from 60.50 in the group treated with 5 % M. Water extract to 62.16 gm in control group. While, the egg losses observed in group 4 that, treated with 2 % M. water extract that was 20.56 % at 21st day. The higher hatchability % of total eggs showed in control group that was 69.70 %. While, the hatchability % of fertile eggs showed a higher percentage in group 5 that treated with 5 % M. Water extract that was 99.02 %. The higher percentage of dead embryo observed in control group that was 9.10 % and the lower level observed in the group 2 that treated with 2 % M. Alchole exteract that was 5.46 %. The total aerobic bacteria counts at 18th day of incubation showed a lower level in group 5 that treated with 5 % M. water extract that was 7.88. while, the activity of chicks and in abnormal chicks increased in group that treated with 5% M. Water extract that was 8.96 % and 2 % respectively. Overall, the higher concentration of Alchole extract of M. olifera , increased the weight of hatching eggs with a reduction in total egg losses,% of the eggs. While, the higher concentration of the water extract of M. olifera improved the hatchability % a reduction in total aerobic counts on the egg shell and improved chick quality and activity.

Food waste: causes and economic losses estimation at household level in Pakistan.

Food waste is one of the major sustainability issues that need to be addressed due to its negative impacts on the economy, environment, and food security. To develop food waste reduction policies on regional and global level, it is mandatory to have a clear understanding of the various factors prompting food waste at household level and the extent of the economic losses incurred by food waste. Reducing food waste can decrease household expenditure on food, freeing resources for health, education, and well-being. The current study was aimed to (1) examine the food waste behavior of the respondents and to (2) determine the level of monetary losses from food waste. To address these objectives, a questionnaire survey and sample of food waste generated during 24 h were collected from 51 households in Tehsil Kahror Pakka, District Lodhran, Punjab, Pakistan. The survey focus was on levels of food waste and respondents' knowledge and behaviors about food waste. Economic estimation of food waste was also done. In the survey, respondents from both high- and low-income households revealed that their fruit and vegetables (31%; 32%) and peel and scrap (53%; 48%) losses were higher while egg losses (4%; 4%) were lower among various food waste categories. Wanting to eat fresh food and having no time to save food were the reasons for food waste. Monetary losses from food waste (US$ 12.8/Rs. 3677.01 per capita per annum) were higher in high-income households compared to low-income households.

Au loaded mesoporous SiO2/gelatin hydrogel: Detecting low humidity and NH3

In this paper, a composite hydrogel film (Au/Me-SiO2/G) based on Au nanoparticles, mesoporous silica and gelatin was prepared, which can be used for low relative humidity (RH) detection. Au-1%/Me-SiO2/G exhibits a response of 423% in the range of 0.4–30% RH, a short response time of 28 s, a linearity of R2 = 0.997, and good long-term stability. With the outstanding ability to adsorb water molecules, the sensor can detect NH3 at room temperature and low humidity environment. The response of the sensor to NH3 significantly increases with the humidity. At 30% RH, the initial impedance value of the sensor is as low as ∼6.6 MΩ, and the response to 50 ppm NH3 is 78%. In addition, an egg storage scenario was simulated, and the water loss in eggs was monitored simultaneously by the prepared humidity sensor and a commercial sensor. The results demonstrate the practical application detection ability of the prepared humidity sensor.

Spawning ecology of the Saint Paul's Gregory Stegastes sanctipauli, a damselfish endemic to the remote St. Peter and St. Paul's Archipelago.

We studied the spawning ecology of Stegastes sanctipauli, a damselfish endemic to the small and remote St. Peter and St. Paul's Archipelago (Brazil), aiming to determine the main correlates of reproductive success, as inferred from rates of egg losses along a spawning season. New clutches appeared mostly in the last quarter moon, when egg predation intensified. Predation by heterospecifics, particularly Halichoeres radiatus (Linnaeus, 1758), accounted for most egg losses, while filial cannibalism showed negligible influence. Predation pressure was highest for larger nests with higher initial density of eggs. Hatching of eggs occurred close to the new moon (i.e. ~5 days after spawning). Most nests occur in shallow reefs (<16 m depth), where main food resources for adults (turf algae) are concentrated, but abundance of egg predators, particularly H. radiatus, is also highest. This later result suggests that the spawning activity of S. sanctipauli is influenced by the trade-offs between food accessibility by adults and egg predation risk. The patterns recorded here are similar to those known for other tropical damselfish species and may reflect strategies for attenuating predation pressure over new fry and eggs.

Is UV-C light compatible with biological control of twospotted spider mite?

Biological control agents such as predatory mites, Neoseiulus cucumeris Oudemans, Amblyseius swirskii Athias-Henriot, and Phytoseiulus persimilis Athias-Henriot are effective in the management of a cosmopolitan crop pest, Tetranychus urticae Koch. Studies have shown that physical control by ultraviolet B (UV-B, 280–315 nm) light applications can control T. urticae by reducing egg hatch. However, to have a successful biological control program, the compatibility with other crop management strategies such as use of UV light needs to be determined. Therefore, the objectives of this study were to, 1) assess the impact of UV-C (200–280 nm) application on egg hatchability of biological control agents, A. swirskii, N. cucumeris, P. persimilis, and the pest T. urticae; 2) assess the impact of UV-C application on feeding efficiency of P. persimilis on T. urticae eggs; and 3) determine the LD50 and LD90 of adult female T. urticae to UV-C exposure. Results indicate that more eggs of A. swirskii survived when 200 J/m2 UV-C was used to control T. urticae, which suffered higher egg loss from the same UV-C dose. Also, UV-C treatments of 200 and 350 J/m2 did not have a significant impact on predation by P. persimilis adult females on T. urticae eggs. Therefore, UV-C can be compatibly utilized along with biological control of T. urticae by timing the application before release of predators. After 24 h of application, the UV-C LD50 for T. urticae adults was 8,839.35 J/m2 and the LD90 was 12,352.91 J/m2. After 48 h of application, the LD50 was 7,449.81 J/m2 and the LD90 was 9,621.83 J/m2. These UV-C doses are not feasible for T. urticae adult suppression, but biological control agents can play a crucial role with effective predation on T. urticae adults.

Fecundity of the narrow-clawed crayfish Pontastacus leptodactylus in the water bodies of Belarus

Pre-larvae hatching fecundity and ovarian fecundity of narrow-clawed crayfish populations were estimated in the lakes and reservoirs of Belarus. Statistically significant differences in the fecundity of females from various water bodies were noted only for Lake Kichino. For all other water bodies, the fecundity dependence on the length of females did not differ statistically and was described by one equation. The greatest loss of eggs was noted during the spawning period (oviposition), insemination and attachment to pleopods of the female. During this short period (2–3 hours), egg mortality of females 120 mm TL is 30 %, it decreases for small females and increases for large ones. During the gestation period, egg mortality averages 8 %.

The eggshell defect as a factor affecting the egg quality after storage

The aim of the study was to assess the influence of shell defects on the quality of eggs after storage. The study material consisted of 1,800 brown-shelled eggs from cage rearing system which were candled on the day of laying to determine the shell quality. Eggs with the 6 most common shell defects (external crack, severe stripe marks, points, wrinkled, pimples, sandy) and eggs without defects (control group) were then stored for 35 days at 14°C and 70% humidity. The weight loss of eggs was monitored every 7 days, and the quality characteristics of whole eggs (weight, specific gravity, shape), shell (defects, strength, color, weight, thickness, density), albumen (weight, height, pH) and yolk (weight, color, pH) of 30 eggs from each group were analysed at the beginning (0 days) and after 28 and 35 days of storage. The changes resulting from water loss (air cell depth, weight loss, shell permeability) were also evaluated. The study showed that all investigated shell defects significantly influenced the characteristics of the whole egg during the storage, modifying traits such as specific gravity, water loss, shell permeability, albumen height and pH, as well as proportion, index and pH of the yolk. Furthermore, an interaction between time and the shell defects presence was found.

A simple trail camera modification reveals red-bellied woodpeckers as important egg predators of box-nesting wood ducks

Artificial nesting structures have been used to aid the recovery and maintenance of certain avian populations such as the wood duck (Aix sponsa). The success of nest boxes for wood ducks relies on excluding common nest predators such as raccoons (Procyon lotor) and rat snakes (Pantherophis spp.) via the use of predator guards; however, woodpeckers cannot be excluded. Red-bellied woodpeckers (Melanerpes carolinus) are foraging generalists and have been anecdotally observed preying on wood duck eggs where documenting predation events is difficult to accomplish through traditional nest box monitoring. Here, we used custom-modified trail cameras to document egg depredations and foraging events by red-bellied woodpeckers and the removal of damaged eggs by wood ducks during the laying and incubation periods. We captured 35,686 videos and documented 1173 different events consisting of 608 (51.8%) videos of red-bellied woodpeckers and 565 (48.2%) of wood ducks. We determined 38 (30.6%) eggs were depredated during the laying period and 14 (11.3%) during incubation. Wood ducks removed 23 (60.5%) eggs depredated during the laying period and 13 (92.9%) depredated during incubation. We found no difference in the daily number of times red-bellied woodpeckers visited boxes with nests in the laying or incubation period (t = −0.967, df = 14.699, P = 0.349). Red-bellied woodpeckers depredated 1.0 ± 0.2 eggs during each event and returned to forage on previously depredated eggs 5.3 ± 4.4 times each day spending 2.1 ± 1.1 min during each return. Our results suggest that red-bellied woodpeckers forage on eggs when nests are unguarded, and they have previously been under-recognized in the literature as predators of wood duck eggs. Future nest box programs should consider the impact red-bellied woodpeckers have on wood duck egg loss and nest survival.