Silent Spring - the lost call

The "silence" in Rachel Carson's Silent Spring1 alludes to the demise of bird populations through reproductive problems and death resulting from exposure to the pesticides of that time, many of which are endocrine active. Endocrine disrupting chemicals (EDCs) are compounds which may interfere with the endocrine system, producing effects that may disrupt the physiologic function of hormones. Early research on EDC exposure in humans and wildlife has focused mainly on reproductive effects of estrogenic chemicals, however recent studies have revealed that effects of estrogenic as well as non-estrogen active chemicals are often more far reaching than the reproductive system, and even mild exposures experienced early in development may have detrimental effects that are maintained throughout adulthood. Here we show trenbolone acetate, an androgen active environmental contaminant used as a growth promoter for cattle, to cause a literal silence in Japanese quail (Coturnix japonica) chicks following a one time embryonic exposure. Vocalizations were not merely lessened; this is the first study to demonstrate an environmental contaminant to cause a complete abolishment of the ability to vocalize. Since many reasons for vocalization in birds are directly linked to survival of the individual and species, the potential for detrimental population effects is a grave possibility for many avian species that may encounter androgen active chemicals in the environment. Many androgen active EDCs are persistent and ubiquitous in distribution, thereforechances for exposure to these chemicals in birds may be high. We hope that powerful, yet subtle effects like the ones presented here will encourage further research with EDCs to expand beyond the traditional focus of reproductive effects of estrogenic chemicals

Toxicity Of Polybrominated Diphenyl Ethers (De-71) In Chicken (\u3ci\u3eGallus Gallus\u3c/i\u3e), Mallard (\u3ci\u3eAnas Platyrhynchos\u3c/i\u3e), And American Kestrel (\u3ci\u3eFalco Sparverius\u3c/i\u3e) Embryos And Hatchlings

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01–20 µg/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3’,4,4’,5-pentachlorobiphenyl; 0.002 µg/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 µg/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological changes in the bursa, but these responses were not observed in other species. Polychlorinated biphenyl congener 126 (positive control) reduced survival endpoints in chicken and kestrel embryos and caused sublethal effects (EROD induction, reduced bursal mass and follicle size) in chickens. Mallards were clearly less sensitive than the other species to administered penta-BDE and PCB 126. In a second experiment, the absorption of penta-BDE (11.1 µg/g egg, air cell administered during early development) into the contents of chicken and kestrel eggs was determined at various intervals (24 h postinjection, midincubation, and pipping). By pipping, 29% of the penta-BDE administered dose was present in the egg contents in chickens, and 18% of the administered dose was present in kestrel egg contents. Based on uptake in kestrels, the lowest-observed-effect level on pipping and hatching success may be as low as 1.8 µg total penta-BDE/g egg, which approaches concentrations detected in eggs of free-ranging birds. Because some penta-BDE congeners are still increasing in the environment, the toxic effects observed in the present study are cause for concern in wildlife

Toxicity Of Polybrominated Diphenyl Ethers (De-71) In Chicken (\u3ci\u3eGallus Gallus\u3c/i\u3e), Mallard (\u3ci\u3eAnas Platyrhynchos\u3c/i\u3e), And American Kestrel (\u3ci\u3eFalco Sparverius\u3c/i\u3e) Embryos And Hatchlings

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01–20 µg/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3’,4,4’,5-pentachlorobiphenyl; 0.002 µg/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 µg/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological changes in the bursa, but these responses were not observed in other species. Polychlorinated biphenyl congener 126 (positive control) reduced survival endpoints in chicken and kestrel embryos and caused sublethal effects (EROD induction, reduced bursal mass and follicle size) in chickens. Mallards were clearly less sensitive than the other species to administered penta-BDE and PCB 126. In a second experiment, the absorption of penta-BDE (11.1 µg/g egg, air cell administered during early development) into the contents of chicken and kestrel eggs was determined at various intervals (24 h postinjection, midincubation, and pipping). By pipping, 29% of the penta-BDE administered dose was present in the egg contents in chickens, and 18% of the administered dose was present in kestrel egg contents. Based on uptake in kestrels, the lowest-observed-effect level on pipping and hatching success may be as low as 1.8 µg total penta-BDE/g egg, which approaches concentrations detected in eggs of free-ranging birds. Because some penta-BDE congeners are still increasing in the environment, the toxic effects observed in the present study are cause for concern in wildlife

Absorption and biotransformation of polybrominated diphenyl ethers DE-71 and DE-79 in chicken (\u3ci\u3eGallus gallus\u3c/i\u3e), mallard (\u3ci\u3eAnas platyrhynchos\u3c/i\u3e), American kestrel (\u3ci\u3eFalco sparverius\u3c/i\u3e) and black-crowned night-heron (\u3ci\u3eNycticorax nycticorax\u3c/i\u3e) eggs

We recently reported that air cell administration of penta-brominated diphenyl ether (penta-BDE; DE-71) evokes biochemical and immunologic effects in chicken (Gallus gallus) embryos at very low doses, and impairs pipping (i.e., stage immediately prior to hatching) and hatching success at 1.8 µg g-1 egg (actual dose absorbed) in American kestrels (Falco sparverius). In the present study, absorption of polybrominated diphenyl ether (PBDE) congeners was measured following air cell administration of a penta-BDE mixture (11.1 lg DE-71 g-1 egg) or an octa-brominated diphenyl ether mixture (octa BDE; DE-79; 15.4 lg DE-79 g-1 egg). Uptake of PBDE congeners was measured at 24 h post-injection, midway through incubation, and at pipping in chicken, mallard (Anas platyrhynchos), and American kestrel egg contents, and at the end of incubation in black-crowned night-heron (Nycticorax nycticorax) egg contents. Absorption of penta-BDE and octa-BDE from the air cell into egg contents occurred throughout incubation; at pipping, up to 29.6% of penta-BDE was absorbed, but only 1.40–6.48% of octa-BDE was absorbed. Higher brominated congeners appeared to be absorbed more slowly than lower brominated congeners, and uptake rate was inversely proportional to the log Kow of predominant BDE congeners. Six congeners or co-eluting pairs of congeners were detected in penta-BDE-treated eggs that were not found in the dosing solution suggesting debromination in the developing embryo, extraembryonic membranes, and possibly even in the air cell membrane. This study demonstrates the importance of determining the fraction of xenobiotic absorbed into the egg following air cell administration for estimation of the lowest-observed-effect level

Chesapeake Bay Fish–Osprey (\u3ci\u3ePandion Haliaetus\u3c/i\u3e) Food Chain: Evaluation Of Contaminant Exposure And Genetic Damage

From 2011 to 2013, a large-scale ecotoxicological study was conducted in several Chesapeake Bay (USA) tributaries (Susquehanna River and flats, the Back, Baltimore Harbor/Patapsco Rivers, Anacostia/ middle Potomac, Elizabeth and James Rivers) and Poplar Island as a mid-Bay reference site. Osprey (Pandion haliaetus) diet and the transfer of contaminants from fish to osprey eggs were evaluated. The most bioaccumulative compounds (biomagnification factor\u3e5) included p,p’-dichlorodiphenyldichloroethylene (DDE), total polychlorinated biphenyls (PCBs), total polybrominated diphenyl ethers (PBDEs), and bromodiphenyl ether (BDE) congeners 47, 99, 100, and 154. This analysis suggested that alternative brominated flame retardants and other compounds (methoxytriclosan) are not appreciably biomagnifying. A multivariate analysis of similarity indicated that major differences in patterns among study sites were driven by PCB congeners 105, 128, 156, 170/190, and 189, and PBDE congeners 99 and 209. An integrative redundancy analysis showed that osprey eggs from Baltimore Harbor/Patapsco River and the Elizabeth River had high residues of PCBs and p,p’-DDE, with PBDEs making a substantial contribution to overall halogenated contamination on the Susquehanna and Anacostia/middle Potomac Rivers. The redundancy analysis also suggested a potential relation between PBDE residues in osprey eggs and oxidative DNA damage in nestling blood samples. The results also indicate that there is no longer a discernible relation between halogenated contaminants in osprey eggs and their reproductive success in Chesapeake Bay. Osprey populations are thriving in much of the Chesapeake, with productivity rates exceeding those required to sustain a stable population

Revisando el papel de los buitres en al interfaz de enfermedades que afectan a humanos, animales salvajes y ganado : una perspectiva africana

Vultures are a key component of an effective scavenger guild and have evolved a number of adaptations that allow them to locate and dispose of carcasses quickly and efficiently. The continuing decline of African vultures is threatening the stability of the African scavenger guild, which may result in increased carcass decomposition times and thus, more rapid development of pathogenic bacteria. The absence of competitive regulation by these apex scavengers may also result in changes in the composition of the vertebrate scavenger guild, with an increase in mammalian scavengers giving rise to increased contact rates at carcasses, which may increase the risk of viral disease transmission to humans, livestock, and other wildlife. Although the economic value of vultures in terms of the sanitation services they provide has been evaluated, their contribution to the economics of human health and veterinary care remains to be quantified. Efforts to do so are hampered by lack of data, as well as a number of confounding factors that may mask causality, such as improved disease prevention and surveillance systems. However, the circumstantial nature of the link between vultures and disease prevention should not deter efforts to conserve them, as their regulation of mammalian scavengers and the sanitation services they provide place them firmly within the sphere of One Health, thereby warranting their urgent protection. The restoration of vulture populations and the ecosystem services they provide will benefit the welfare of all humans, but particularly those who are most vulnerable to economic instability and the spillover of disease at the human-wildlife-livestock interface.This review article is a product of an investigation entitled ‘‘There is still time to save Africa’s vultures,’’ hosted and funded by the National Socio-Environmental Synthesis Center (SESYNC) in Annapolis, MD USA.https://bioone.org/journals/journal-of-raptor-researcham2022Zoology and Entomolog

Chesapeake Bay Fish–Osprey (\u3ci\u3ePandion Haliaetus\u3c/i\u3e) Food Chain: Evaluation Of Contaminant Exposure And Genetic Damage

From 2011 to 2013, a large-scale ecotoxicological study was conducted in several Chesapeake Bay (USA) tributaries (Susquehanna River and flats, the Back, Baltimore Harbor/Patapsco Rivers, Anacostia/ middle Potomac, Elizabeth and James Rivers) and Poplar Island as a mid-Bay reference site. Osprey (Pandion haliaetus) diet and the transfer of contaminants from fish to osprey eggs were evaluated. The most bioaccumulative compounds (biomagnification factor\u3e5) included p,p’-dichlorodiphenyldichloroethylene (DDE), total polychlorinated biphenyls (PCBs), total polybrominated diphenyl ethers (PBDEs), and bromodiphenyl ether (BDE) congeners 47, 99, 100, and 154. This analysis suggested that alternative brominated flame retardants and other compounds (methoxytriclosan) are not appreciably biomagnifying. A multivariate analysis of similarity indicated that major differences in patterns among study sites were driven by PCB congeners 105, 128, 156, 170/190, and 189, and PBDE congeners 99 and 209. An integrative redundancy analysis showed that osprey eggs from Baltimore Harbor/Patapsco River and the Elizabeth River had high residues of PCBs and p,p’-DDE, with PBDEs making a substantial contribution to overall halogenated contamination on the Susquehanna and Anacostia/middle Potomac Rivers. The redundancy analysis also suggested a potential relation between PBDE residues in osprey eggs and oxidative DNA damage in nestling blood samples. The results also indicate that there is no longer a discernible relation between halogenated contaminants in osprey eggs and their reproductive success in Chesapeake Bay. Osprey populations are thriving in much of the Chesapeake, with productivity rates exceeding those required to sustain a stable population

Estrategia para conservar las poblaciones de buitres del viejo mundo utilizando el enfoque de una salud

One Health brings the powerful interrelationship between human and wildlife health together with ecosystem health. The initial concept of One Health was formulated decades ago and focused on disease transfer from wildlife to human populations. More recently, the concept has been used to associate resilience to disease with the health of the ecosystem and resilience to environmental stressors. The need for a One Health approach is particularly evident in the plight of Old World vultures, which are facing a conservation crisis due to drastic reductions in populations across their entire range. Moreover, vulture conservation exemplifies many contemporary tenets of One Health; vultures are critical to a sustainable and resilient ecosystem, which in turn is essential for the socio-ecological health of human communities. In this review, we examine the complex factors contributing to the demise of Old World vulture populations, using the lens of One Health to conceptualize the primary drivers impacting the health and sustainability of these populations. The One Health concept provides the basis for the development of a framework that incorporates a multidimensional approach and includes human health, wildlife health, environmental and disease-related stressors, disease incidences, societal pressures, and environmental contaminants. Integrating societal needs with management aimed at maintaining healthy vulture populations is key for successfully using a One Health framework to optimize the health of human and wildlife populations and ensure ecosystem health.El enfoque ‘‘Una Salud’’ promueve una poderosa interrelacio´n entre la salud de los humanos y de la fauna salvaje asociados a la salud de los ecosistemas. El concepto inicial de Una Salud fue formulado de´cadas atra´s y se enfocaba en la transferencia de enfermedades de la fauna salvaje a las poblaciones humanas. Ma´s recientemente, el concepto ha sido usado para asociar la resiliencia a las enfermedades con la salud de los ecosistemas y la resiliencia a factores de estre´s ambiental. La necesidad de utilizar el enfoque de Una Salud es particularmente evidente ante la dif´ıcil situacio´n de los buitres del Viejo Mundo, los cuales se enfrentan a una situacio´n de crisis de conservacio´n debido a la reduccio´n dra´stica en sus poblaciones a lo largo de toda su a´rea de distribucio´n. Adema´s, la conservacio´n de los buitres ejemplifica mucho de los principios contempora´neos de Una Salud; los buitres son cr´ıticos para un ecosistema sostenible y resiliente, lo que a su vez es esencial para la salud socio-ecolo´gica de las comunidades humanas. En esta revisio´n, examinamos los factores complejos que contribuyen al descenso de las poblaciones de buitres del Viejo Mundo, usando el enfoque de Una Salud para conceptualizar los factores principales que impactan en la salud y la sostenibilidad de estas poblaciones. El concepto de Una Salud proporciona las bases para el desarrollo de un marco de referencia que incorpora un enfoque multidimensional, incluyendo la salud humana y de la vida silvestre, factores estresantes ambientales y de enfermedades, incidencia de enfermedades, presiones sociales y qu´ımicos ambientales. Integrar las necesidades de la sociedad con la gestio´n destinada a mantener poblaciones saludables de buitres es clave para usar exitosamente el marco de referencia de Una Salud y as´ı optimizar la salud de las poblaciones humanas y de la fauna salvaje asegurando la salud del ecosistema.The National Science Foundationhttps://bioone.org/journals/journal-of-raptor-researcham2022Zoology and Entomolog

Endocrinology of the Avian Reproductive System

The purpose of this review is to provide an overview of the avian reproductive system. Attention is given to the neuroendocrine regulation of hypothalamic and pituitary gland hormones as well as the target tissues regulated by these hormones. Emphasis is placed on the dynamics of the system and the effects of alterations resulting from environmental and other influences on the function of the reproductive system. The ovulatory cycle, oviduct, and shell gland are discussed relative to egg formation and the hormonal regulation of this process. Testicular function and the cellular bases for spermatogenesis and steroid production are also discussed