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1.
Biol Rev Camb Philos Soc ; 99(3): 1085-1099, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38303487

RESUMO

For a long time birds were assumed to be anosmic or at best microsmatic, with olfaction a poorly understood and seldom investigated part of avian physiology. The full viability of avian olfaction was first discovered through its functions in navigation and foraging. Subsequently, researchers have investigated the role of olfaction in different social and non-social contexts, including reproduction, kin recognition, predator avoidance, navigation and foraging. In parallel to the recognition of the importance of olfaction for avian social behaviour, there have been advances in the techniques and methods available for the sampling and analysis of trace volatiles and odourants, leading to insights into the chemistry underlying chemical communication in birds. This review provides (i) an overview of the current state of knowledge regarding the volatile chemical composition of preen oil and feathers, its phylogenetic coverage, chemical signatures and their potential functions, and (ii) a discussion of current methods used for the isolation and detection of volatiles. Finally, lines for future research are proposed.


Assuntos
Aves , Plumas , Compostos Orgânicos Voláteis , Animais , Plumas/química , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Aves/fisiologia
2.
Environ Pollut ; 324: 121398, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36878276

RESUMO

The goal of the present study was to investigate differences in biomarker responses related to metal(loid)s in white stork (Ciconia ciconia) nestling's blood from continental Croatia. To achieve this, a battery of biomarkers that can be affected by environmental pollutants, including metal(loid)s, was assessed (esterase activity, fluorescence-based oxidative stress biomarkers, metallothionein levels, glutathione-dependent enzyme activity). The research was conducted during the white stork breeding season in diverse areas (a landfill, industrial and agricultural sites, and an unpolluted area). White storks' nestlings near the landfill exhibited reduced carboxylesterase (CES) activity, elevated glutathione (GSH) concentration, as well as high Pb content in the blood. Increased As and Hg concentrations in blood were attributable to environmental contamination in agricultural area and an assumed unpolluted area, respectively. Furthermore, agricultural practices appeared to affect CES activity, as well as elevate Se levels. In addition to the successful implementation of biomarkers, present research showed that agricultural areas and a landfill are areas with increased metal(loid) levels possibly causing adverse effects on the white storks. This first-time heavy metal and metalloid analyses in the white stork nestlings from Croatia point to the necessary monitoring and future assessments of pollution impact to prevent irreversible adverse effects.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Poluentes Ambientais , Metais Pesados , Animais , Monitoramento Ambiental , Metais Pesados/toxicidade , Metais Pesados/análise , Poluentes Ambientais/análise , Aves/fisiologia , Glutationa , Biomarcadores
3.
Proc Biol Sci ; 290(1995): 20222401, 2023 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-36987641

RESUMO

In some species, sexual selection is stronger in females than males. In classically polyandrous birds, for instance, females compete for mating opportunities and males care for offspring. Sex steroids such as testosterone have been suggested to regulate the behaviours of 'role-reversed' females and males, but comparative studies did not find evidence for a role of testosterone in relation to sex roles. However, the large variability of hormone measurements across laboratories may prevent detecting subtle differences in hormone levels. To circumvent this caveat, I compared sex steroid concentrations of females and males of two closely related and cohabiting species with different mating systems: the classically polyandrous black coucal (Centropus grillii) and the monogamous white-browed coucal (C. superciliosus). Baseline and gonadotropin-releasing hormone (GnRH)-induced testosterone concentrations were twice as high in female black coucals than female white-browed coucals, and the low pre-breeding progesterone concentrations of female black coucals were consistent with progesterone's modulatory role during agonistic interactions in this species. Baseline and GnRH-induced testosterone and progesterone concentrations did not differ between males of both species. This study provides first evidence that elevated testosterone is associated with sex-role-reversed traits in females, whereas low levels of testosterone may not be necessary to facilitate sex-role reversal in males.


Assuntos
Androgênios , Testosterona , Animais , Feminino , Papel de Gênero , Progesterona , Comportamento Sexual Animal/fisiologia , Aves/fisiologia , Hormônio Liberador de Gonadotropina , Caracteres Sexuais
4.
J Exp Biol ; 226(5)2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36752123

RESUMO

Body temperature regulation under changes in ambient temperature involves adjustments in heat production and heat exchange rates between the animal and the environment. One mechanism involves the modulation of the surface temperature of specific areas of the body through vasomotor adjustment. In homeotherms, this thermoregulatory adjustment is essential for the maintenance of body temperature over a moderate temperature range, known as the thermal neutral zone (TNZ). The bill of the toco toucan (Ramphastos toco) has been described as a highly efficient thermal window and hypothesized to assist in the thermal homeostasis of this bird. Herein, we directly evaluated the contribution of heat exchange through the bill of the toco toucan and role of the bill in the delimitation of the TNZ. To do this, we measured metabolic rate (MR), via oxygen consumption, over a range of ambient temperatures from 0 to 35°C. MR measurements were made in birds with the bill intact and with the bill insulated. The limits of the TNZ did not differ between treatments, ranging from 10.8 to 25.0°C. The MR differed among treatments only at elevated temperatures (30 and 35°C), reaching 0.92±0.11 ml O2 g-1 h-1 (mean±s.d.) for the intact group and 1.13±0.13 ml O2 g-1 h-1 for the insulated group. These results indicate that although heat dissipation through the bill does not contribute significantly to widening of the TNZ, it may well be critically important in assisting body temperature regulation at higher temperatures extending above the upper limit of the TNZ.


Assuntos
Regulação da Temperatura Corporal , Temperatura Alta , Animais , Temperatura , Regulação da Temperatura Corporal/fisiologia , Termogênese , Aves/fisiologia
5.
Science ; 373(6551): 226-231, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244416

RESUMO

Early events in the evolutionary history of a clade can shape the sensory systems of descendant lineages. Although the avian ancestor may not have had a sweet receptor, the widespread incidence of nectar-feeding birds suggests multiple acquisitions of sugar detection. In this study, we identify a single early sensory shift of the umami receptor (the T1R1-T1R3 heterodimer) that conferred sweet-sensing abilities in songbirds, a large evolutionary radiation containing nearly half of all living birds. We demonstrate sugar responses across species with diverse diets, uncover critical sites underlying carbohydrate detection, and identify the molecular basis of sensory convergence between songbirds and nectar-specialist hummingbirds. This early shift shaped the sensory biology of an entire radiation, emphasizing the role of contingency and providing an example of the genetic basis of convergence in avian evolution.


Assuntos
Evolução Biológica , Néctar de Plantas , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Aves Canoras/fisiologia , Percepção Gustatória , Aminoácidos , Animais , Proteínas Aviárias/química , Proteínas Aviárias/metabolismo , Aves/fisiologia , Carboidratos , Dieta , Comportamento Alimentar , Multimerização Proteica , Sacarose
6.
Zoology (Jena) ; 147: 125941, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34126327

RESUMO

Flamingos inhabit specialized habitats and breed in large colonies, building their nests on islands that limit the access of terrestrial predators. Many aspects of their uropygial gland are still unknown. The uropygial gland, a sebaceous organ exclusive to birds, shares some histological features among species such as the presence of a capsule, adenomers with stratified epithelium and secondary and primary chambers. We found that the uropygial gland of the Chilean Flamingo (Phoenicopterus chilensis) displays most of these characteristics but lacks a primary storage chamber. This absence may be an adaptation to their aquatic environment. The uropygial secretion of this species has a variety of glycoconjugates while its lipid moiety is largely dominated by waxes and minor amounts of triacylglycerols and fatty acids. Mass spectrometry analysis of the preen wax showed branched fatty acids of varied chain length and unbranched fatty alcohols, resulting in a complex mixture of wax esters and no differences between sexes were observed. The glycoconjugates present in the preen secretion could play a role as antimicrobial molecules, as suggested for other bird species, while the absence of diester waxes in flamingos might be related with their nesting habits and limited exposure to predation. Our results were evaluated according to physiological and ecological aspects of the flamingo's biology.


Assuntos
Estruturas Animais/fisiologia , Aves/fisiologia , Secreções Corporais/química , Estruturas Animais/anatomia & histologia , Animais , Secreções Corporais/fisiologia , Feminino , Masculino , Tamanho do Órgão , Especificidade da Espécie
7.
Horm Behav ; 127: 104874, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33191199

RESUMO

Current food supply is a major driver of timing of breeding in income-breeding animals, likely because increased net energy balance directly increases reproductive hormones and advances breeding. In capital breeders, increased net energy balance increases energy reserves, which eventually leads to improved reproductive readiness and earlier breeding. To test the hypothesis that phenology of income-breeding birds is independent of energy reserves, we conducted an experiment on food-supplemented ("fed") and control female black-legged kittiwakes (Rissa tridactyla). We temporarily increased energy costs (via weight handicap) in a 2 × 2 design (fed/unfed; handicapped/unhandicapped) during the pre-laying period and observed movement via GPS-accelerometry. We measured body mass, baseline hormones (corticosterone; luteinising hormone) before and after handicap manipulation, and conducted a gonadotropin-releasing hormone challenge. Females from all treatment groups foraged in similar areas, implying that individuals could adjust time spent foraging, but had low flexibility to adjust foraging distance. Consistent with the idea that income breeders do not accumulate reserves in response to increased food supply, fed birds remained within an energy ceiling by reducing time foraging instead of increasing energy reserves. Moreover, body mass remained constant until the onset of follicle development 20 days prior to laying regardless of feeding or handicap, implying that females were using a 'lean and fit' approach to body mass rather than accumulating lipid reserves for breeding. Increased food supply advanced endocrine and laying phenology and altered interactions between the hypothalamic-pituitary-adrenal axis and the hypothalamic-pituitary-gonadal axis, but higher energy costs (handicap) had little effect. Consistent with our hypothesis, increased food supply (but not net energy balance) advanced endocrine and laying phenology in income-breeding birds without any impact on energy reserves.


Assuntos
Charadriiformes/fisiologia , Abastecimento de Alimentos , Hormônios Gonadais/metabolismo , Comportamento Sexual Animal/fisiologia , Animais , Aves/fisiologia , Composição Corporal , Corticosterona/metabolismo , Metabolismo Energético/fisiologia , Comportamento Exploratório/fisiologia , Comportamento Alimentar/fisiologia , Feminino , Alimentos , Hormônio Liberador de Gonadotropina/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Hormônio Luteinizante/metabolismo , Masculino , Sistema Hipófise-Suprarrenal/metabolismo , Reprodução/fisiologia , Fatores de Tempo
8.
J Avian Med Surg ; 34(4): 338-342, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33355410

RESUMO

The purpose of this study was to determine reference interval intraocular pressure (IOP) values in 8 different species of companion birds. One hundred and nineteen companion birds (238 eyes) from a captive colony were examined: 21 pigeons (Columba livia; 18%), 17 African grey parrots (Psittacus erithacus; 14%), 22 common mynahs (Acridotheres tristis; 18%), 24 cockatiels (Nymphicus hollandicus; 20%), 12 zebra finches (Taeniopygia guttata; 10%), 9 budgerigars (Melopsittacus undulatus; 8%), 6 domestic canaries (Serinus canaria domestica; 5%), and 8 ring-necked parakeets (Psittacula krameri; 7%). Intraocular pressure was measured by rebound tonometry (TonoVet) avoiding induced, undesired pressure on the head, neck, or eyes. Mean IOP values varied by species. Mean (± SD) IOP values determined for each species were pigeon (5.42 ± 2.06 mm Hg), African grey parrot (4.93 ± 1.91 mm Hg), common mynah (6.22 ± 2.04 mm Hg), cockatiel (5.08 ± 1.76 mm Hg), zebra finch (5.90 ± 2.11 mm Hg), budgerigar (5.88 ± 2.31mm Hg), canary (5.83 ± 1.60 mm Hg), and ring-necked parakeet (6.25 ± 1.75 mm Hg). No statistically significant differences were found in IOP values between right and left eyes for the species studied (P > .22), with the exception of the ring-necked parakeet (P = .001). The results of this study provide representative IOP values measured using rebound tonometry in 8 different species of companion birds.


Assuntos
Aves/fisiologia , Pressão Intraocular , Animais , Animais de Estimação , Valores de Referência , Especificidade da Espécie , Tonometria Ocular/veterinária
9.
Int J Mol Sci ; 21(16)2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32784638

RESUMO

This review provides an updated overview of the seminal plasma composition, and the role of metabolic and protein components on the sperm function of avian species. In addition, the implication of seminal plasma on assisted reproductive techniques of birds was discussed. The semen of birds usually has exceptionally high sperm concentration with relatively little seminal plasma, but this contributes to very fast changes in sperm metabolism and function. The biochemical characteristics and physiological roles of the various seminal plasma components in birds (carbohydrates, lipids, amino acids, hormones, and proteins) are poorly understood. Seminal plasma content of proteins has an action on most cellular functions: metabolism, immunity, oxido-reduction regulation, proteolysis, apoptosis, ion homeostasis, and antimicrobial defenses. The variable amount of many proteins is related to a different fertility capacity of poultry sperm. The role of seminal plasma on semen conservation (chilling and freezing) remains largely a matter of speculation, as both inhibitory and stimulating effects have been found. Whereas the presence of seminal plasma did not seem to affect the sperm survival after freezing-thawing, DNA fragmentation is lower in the absence of seminal plasma. The molecular basis of the influence of seminal plasma on sperm cryo-resistance was also discussed in the present review.


Assuntos
Aves/fisiologia , Reprodução/fisiologia , Sêmen/metabolismo , Animais , Exossomos/metabolismo , Peptídeos/metabolismo , Técnicas de Reprodução Assistida
10.
J Avian Med Surg ; 34(2): 123-131, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32702951

RESUMO

Ocular examinations were completed on a group of 10 Atlantic puffins (Fratercula arctica), 5 males and 5 females that ranged in age from 8 months to older than 30 years. The exams consisted of intraocular pressure/rebound tonometry, tear production/phenol red thread test, central corneal thickness/ultrasound pachymetry, and corneal sensitivity/esthesiometry. On ocular examination, there were no corneal abnormalities observed. Bilateral cataracts were diagnosed in 8 puffins, 6 of which were considered incipient, focal subcapsular opacities. One bird had hypermature cataracts and was removed from the study and excluded from data analysis; the other birds had no evidence of ophthalmic pathology that would interfere with diagnostic results (n = 9). All results for 9 birds were included in the study, with the exception of 1 puffin's tear production, which was too low for accurate assessment and was excluded from data analysis. There were no significant differences between right and left eye measurements for intraocular pressure, corneal thickness, and corneal sensitivity. The median intraocular pressure for both eyes (OU) was 13 mm Hg with an interquartile range [IQR] of 12-15 mm Hg. The median corneal thickness OU was 241 µm, IQR 233-248 µm. The median corneal sensitivity OU was 1.13 cm, IQR 0.81-1.50 cm. There was a significant difference between right and left eye measurements for tear production (right eye median, 7.5 mm/15 s, IQR 6.5-9.3 mm/15 s; and left eye median, 5.0 mm/15 s, IQR 4.0-7.3 mm/15 s) (P= .03), with the right eye producing more tears than the left. However, 1 puffin was determined to be an outlier, and when removed, there was no longer a significant difference (OU median, 7.0 mm/15 s, IQR 4.6-8.0 mm/15 s) (P = .38). There was no significant difference between sex and intraocular pressure, tear production, and corneal sensitivity. However, there was a significant difference between sex and corneal thickness (P = .02), with males (left eye median, 249 µm, IQR 241-249 µm) having thicker corneas than females (left eye median, 236 µm, 234-238 µm). Although sample size precluded statistical testing, there appeared to be an association between opacities and increasing age. There were no associations between age and intraocular pressure, tear production, or corneal thickness. There was a moderate correlation between age and corneal sensitivity, with older birds showing decreased corneal sensitivity (r = -0.57). Although the sample size of 9 birds was small, these findings provide preliminary ranges for ocular parameters of Atlantic puffins.


Assuntos
Aves/fisiologia , Córnea/fisiologia , Lágrimas/fisiologia , Tato/fisiologia , Animais , Feminino , Pressão Intraocular , Masculino , Valores de Referência , Tonometria Ocular/veterinária
11.
Vet Clin North Am Exot Anim Pract ; 23(3): 639-649, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32690449

RESUMO

A great deal of attention has been directed toward developing better options for palliative care and hospice, and improving euthanasia techniques in all species. Euthanasia of exotic pets is technically more difficult because of anatomic differences and small patient size. Traditional intravenous euthanasia techniques in conscious patients are stressful and should generally be avoided in exotic pets; simple intramuscular administration of high dosages of anesthetics followed by delivery of euthanasia solutions is preferred. Options for mammals, birds, and reptiles are presented.


Assuntos
Envelhecimento , Doenças das Aves/terapia , Aves/fisiologia , Mamíferos/fisiologia , Répteis/fisiologia , Assistência Terminal , Anestésicos/administração & dosagem , Animais , Animais Exóticos , Aves/anatomia & histologia , Tomada de Decisões , Eutanásia Animal , Cuidados Paliativos na Terminalidade da Vida , Hospitais para Doentes Terminais , Mamíferos/anatomia & histologia , Cuidados Paliativos , Répteis/anatomia & histologia
12.
J Avian Med Surg ; 34(1): 17-25, 2020 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-32237678

RESUMO

The aim of this study was to describe the anesthetic effects of an injectable anesthetic protocol, based on ketamine, midazolam, and medetomidine, followed by inhalational sevoflurane, in 8 elegant-crested tinamous (Eudromia elegans) undergoing experimental surgery. Initial doses for both injectable agents were tested in 1 bird and then refined with an algorithm based on the effects observed in the pilot procedure. Heart and respiratory rates, as well as nociceptive reflexes, were evaluated before anesthesia (baseline) and intraoperatively, at 10 minute intervals. The time from injection to anesthetic induction and surgical anesthesia, as well as the time from atipamezole injection to recovery, was recorded for each bird. The median doses of medetomidine and ketamine were 0.075 mg/kg and 33 mg/kg, respectively. Anesthetic induction was achieved within 10 (range, 4-45) minutes from intramuscular injection, whereas time to surgical anesthesia was 22 ±16 minutes. The baseline heart rate values were significantly higher than those measured intraoperatively at any time point (P = .001). Intraoperatively, 5 of 8 tinamous (63%) developed cardiac arrhythmias. Other encountered complications were regurgitation in 2 birds (25%), cardiac arrest in 1 bird (13%) soon after injection of the anesthetic agents, and prolonged recovery in another bird (13%), which was euthanized. Necropsy of the 2 fatal outcomes (25%) showed evidence of hepatic lipidosis in both (100%) and intramyocardial fat accumulation in 1 bird (50%). This report highlights the challenges of tinamou anesthesia. Cardiac complications are common in this species, and close monitoring of intraoperative cardiovascular variables is recommended for prompt recognition and treatment.


Assuntos
Anestesia/veterinária , Anestésicos/administração & dosagem , Aves/fisiologia , Anestésicos/efeitos adversos , Anestésicos Inalatórios/administração & dosagem , Animais , Feminino , Injeções Intramusculares/veterinária , Complicações Intraoperatórias/induzido quimicamente , Complicações Intraoperatórias/veterinária , Ketamina/administração & dosagem , Masculino , Medetomidina/administração & dosagem , Midazolam/administração & dosagem , Sevoflurano/administração & dosagem
13.
J Avian Med Surg ; 34(1): 41-51, 2020 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-32237681

RESUMO

An inability of the body to appropriately respond to extreme temperatures will result in pathological changes to vital organs and adverse hematological changes. Mild heat exposure of a bird to a temperature above the zone of thermoneutrality can induce subclinical heat stress, which may be a precursor to illness. The ability to identify subtle changes that may be associated with subclinical heat stress can be important in early diagnosis and treatment of heat stress in birds. Pathological changes to internal body organs, post-heat exposure, were microscopically examined in 13 budgerigars (Melopsittacus undulatus), 15 zebra finches (Taeniopygia guttata), and 8 diamond doves (Geopelia cuneata) as model species for the bird orders Psittaciformes, Passeriformes, and Columbiformes, respectively. There was mild to moderate congestion of the lungs of 28/36 birds examined, including all of the budgerigars and diamond doves. In 8/15 zebra finches no significant lung congestion was noted. Interstitial and pulmonary hemorrhage was in observed in one diamond dove. The most common hepatic pathologic change identified was micro- and macro-vesicular hepatocellular vacuolation (4/15 zebra finches, 5/13 budgerigars, and 8/8 diamond doves). There was mild to moderate congestion in the kidneys of 1/15 zebra finch, 2/ 13 budgerigars, and 4/8 diamond doves, as well as in the gastrointestinal tract of 1/15 zebra finch and 7/8 budgerigars. Budgerigars showed a decrease in hematocrit and a significant change in the numbers of heterophils and lymphocytes following heat exposure. The basophil population of cells remained relatively stable in both budgerigars and diamond doves. These findings indicate avian species differences in body organ and hematological changes following exposure to similar elevations in environmental temperatures.


Assuntos
Aves/fisiologia , Clima Desértico , Temperatura Alta , Estresse Fisiológico , Animais , Austrália , Aves/sangue , Rim/patologia
14.
Exp Gerontol ; 132: 110833, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31923625

RESUMO

Age is an important parameter for a variety of ecological applications, including population viability analyses, contaminants monitoring and targeting of individuals for conservation. While many organisms can be aged by annual rings, dentition and other techniques (i.e., fish otoliths, clam growth rings, mammal tooth wear), there are no minimally invasive biomarkers for accurately aging birds in the wild. For the past century, banding has been the only way to identify a bird of known age, which requires continuous effort on a large scale with possibly low return rates. Recent studies have identified pentosidine as a potential biomarker of chronological aging in several bird species. To test this idea in four species of long-lived seabirds, we collected skin biopsies from the foot webs of previously banded, known-age seabirds: black-legged kittiwakes (Rissa tridactyla; 0-19 y old), Atlantic puffins (Fratercula arctica; 5-26 y old), razorbills (Alca torda; 0-15 d old) and thick-billed murres (Uria lomvia; 0-35 y old). Foot web samples were specifically chosen because this was the least invasive site for substantial skin biopsy. Samples were analysed with high performance liquid chromatography to quantify pentosidine levels. Collagen levels were estimated through hydroxyproline assays to normalize pentosidine content across individuals. Kittiwakes displayed a weak correlation (r2 = 0.20) between age and pentosidine/collagen. Puffins (adults only, r2 = 0.02), razorbills (chicks only, r2 = 0.08), and murres (adults, r2 = 0.04) did not show any associations with age. We concluded that pentosidine content in the foot web does not appear to be a reliable method for aging seabirds in the wild. An absence of change in pentosidine in the foot web with age is further evidence that long-lived seabirds may maintain physiological performance into old age.


Assuntos
Envelhecimento/fisiologia , Arginina/análogos & derivados , Charadriiformes/fisiologia , Lisina/análogos & derivados , Animais , Arginina/análise , Arginina/metabolismo , Biomarcadores , Aves/fisiologia , Lisina/análise , Lisina/metabolismo
15.
Proc Biol Sci ; 287(1918): 20191917, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31937223

RESUMO

Telomere length (TL) and shortening is increasingly shown to predict variation in survival and lifespan, raising the question of what causes variation in these traits. Oxidative stress is well known to accelerate telomere attrition in vitro, but its importance in vivo is largely hypothetical. We tested this hypothesis experimentally by supplementing white stork (Ciconia ciconia) chicks with antioxidants. Individuals received either a control treatment, or a supply of tocopherol (vitamin E) and selenium, which both have antioxidant properties. The antioxidant treatment increased the concentration of tocopherol for up to two weeks after treatment but did not affect growth. Using the telomere restriction fragment technique, we evaluated erythrocyte TL and its dynamics. Telomeres shortened significantly over the 21 days between the baseline and final sample, independent of sex, mass, size and hatching order. The antioxidant treatment significantly mitigated shortening rate of average TL (-31% in shorter telomeres; percentiles 10th, 20th and 30th). Thus, our results support the hypothesis that oxidative stress shortens telomeres in vivo.


Assuntos
Antioxidantes/metabolismo , Aves/fisiologia , Suplementos Nutricionais , Encurtamento do Telômero/fisiologia , Animais
16.
Horm Behav ; 123: 104574, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31442427

RESUMO

The authors of the original challenge hypothesis proposed influential hypotheses concerning the relationship between testosterone concentrations in the blood and aggressive social behaviors. Many of the key observations were made in avian species studied in the wild and in captivity. In this review we evaluate some remaining questions about the ideas discussed in the challenge hypothesis from a neuroendocrine perspective. For example, a rise in testosterone in response to a social aggressive stimulus might involve complex social information being processed by the brain and an appropriate signal sent to the gonadotrophin-releasing hormone (GnRH) neuronal system. Alternatively, social stimuli could more directly stimulate the testis and testosterone release via sympathetic innervation of the testis though such pathways have not been linked to a response to social behaviors. The social behavior decision network in the brain seems to play a key role in the regulation of aggressive behavior but how sensory information concerning aggressive behaviors is interpreted appropriately, processed by the social decision network and sent to the GnRH system is still not well understood. There are continuing questions about the extensive species variation in whether an increase in testosterone occurs in response to a territorial challenge, what its function might be and whether increases in testosterone are necessary to activate morphological changes, or the expression of sexual and aggressive behaviors associated with successful reproduction.


Assuntos
Sistemas Neurossecretores/fisiologia , Reprodução/fisiologia , Comportamento Sexual Animal/fisiologia , Meio Social , Testosterona/fisiologia , Agressão/fisiologia , Animais , Aves/metabolismo , Aves/fisiologia , Encéfalo/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Masculino , Neurônios/metabolismo , Sistemas Neurossecretores/metabolismo , Territorialidade , Testosterona/sangue
17.
Environ Geochem Health ; 42(3): 781-793, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30864071

RESUMO

Differences in bird eggshell thicknesses occur due to numerous factors, including thinning due to persistent organic pollutants. Not only does thinning weaken the shell; weaker shells combined with elevated ambient temperature and changes in humidities may result in changes in water loss rates from the egg contents. Therefore, thinner eggshells raise concern of water being lost faster than normal at lower relative humidities, which may affect hatching. To investigate the combined effects, we developed and tested an effective method that measures water loss through different thickness eggshells at controlled temperatures and relative humidities to assist in ascertaining the combined effects of climate change (temperature and humidity) and changes in eggshell thickness on bird reproduction. The fastest rate of loss was at 40% RH at 40 °C (0.1 mL/cm2/day), and the slowest was at 22 °C at 80% RH (0.02 mL/cm2/day). Eggshell thickness had a significant effect on water loss at all humidity treatments, except at the highest temperature and humidity treatment (80% RH and 40 °C). Temperature explained 40% of the variance, RH explained 20%, and interactions between temperature and humidity explained 15% of the variance (repeated-measures, two-way ANOVA). Generalized linear analyses revealed that both factors temperature and humidity contributed significantly in any two-way combinations. We have laid the ground for a system to test the combined effects of temperature and humidity changes associated with climate change and eggshell thinning associated with pollutants, on water loss across eggshells.


Assuntos
Mudança Climática , Casca de Ovo/química , Água/química , Animais , Aves/fisiologia , Galinhas , Ovos , Umidade , Temperatura
18.
SAR QSAR Environ Res ; 31(1): 1-18, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31724447

RESUMO

Ecological risk assessment is challenged by the need to assess hazard to the diverse communities of organisms inhabiting aquatic and terrestrial systems. Computational approaches, such as Quantitative Structure Activity Relationships (QSAR) and Interspecies Correlation Estimation (ICE) models, are useful tools that provide estimates of acute toxicity where data are lacking or limited for ecological risk assessments (ERA). This review describes the technical basis of ICE models for use in pesticide ERA that may be used in conjunction with QSAR model estimates or surrogate species toxicity data and demonstrates the potential for improving hazard assessment. Validation and uncertainty analysis of ICE model predictions are summarized and used as guidance for selecting ICE models and evaluating toxicity predictions. A user-friendly web-based ICE modelling platform (Web-ICE) is described and demonstrated through case studies. Case studies include the development of Species Sensitivity Distributions generated from QSAR and ICE estimates, comparative sensitivity for a pesticide and its degradate, and application of ICE-estimated toxicity values for listed species assessments.


Assuntos
Praguicidas/efeitos adversos , Relação Quantitativa Estrutura-Atividade , Poluentes Químicos da Água/efeitos adversos , Animais , Aves/fisiologia , Crustáceos/efeitos dos fármacos , Peixes/fisiologia , Mamíferos/fisiologia , Microalgas/efeitos dos fármacos , Modelos Teóricos , Medição de Risco , Especificidade da Espécie , Incerteza
19.
Zoo Biol ; 38(6): 498-507, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31517405

RESUMO

The use of radio frequency identification (RFID) technology is common in animal-monitoring applications in the wild and in zoological and agricultural settings. RFID is used to track animals and to collect information about movements and other behaviors, as well as to automate or improve husbandry. Disney's Animal Kingdom® uses passive RFID technology to monitor nest usage by a breeding colony of northern carmine bee-eaters. We implemented RFID technologies in various equipment configurations, initially deploying low-frequency (LF) 125 kHz RFID and later changing to high-frequency (HF) 13.56 MHz RFID technology, to monitor breeding behavior in the flock. We installed antennas connected to RFID readers at the entrances of nest tunnels to detect RFID transponders attached to leg bands as birds entered and exited tunnels. Both LF-RFID and HF-RFID systems allowed the characterization of nest visitation, including the timing of nest activity, breeding pair formation, identification of egg-laying females, participation by nonresidents, and detection of nest disruptions. However, we collected a substantially larger volume of data using the increased bandwidth and polling speed inherent with HF-RFID, which permitted tag capture of multiple birds simultaneously and resulted in fewer missed nest visits in comparison to LF-RFID. Herein, we describe the evolution of the RFID setups used to monitor nest usage for more than 7 years, the types of data that can be gained using RFID at nests, and how we used these data to gain insights into carmine bee-eater breeding behavior and improve husbandry.


Assuntos
Aves/fisiologia , Monitorização Fisiológica/veterinária , Comportamento de Nidação/fisiologia , Dispositivo de Identificação por Radiofrequência , Telemetria , Animais , Animais de Zoológico , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos
20.
Pesqui. vet. bras ; 39(8): 655-662, Aug. 2019. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1040731

RESUMO

This study aimed to determine and evaluate whether there are differences in values of MAC in wildlife captured guan (Penelope obscura) under different conditions of social stress. This study used 27 bird species guan (P. obscura), divided into two groups: animals kept in the same enclosure (Collective Group) and animals kept in individual cages (Individual Group). The research was conducted at the Advanced Research Base of IBAMA, Painel/SC, and at the Clinical Veterinary Hospital of the "Universidade do Estado de Santa Catarina", Lages/SC. The birds were captured using network trap with manual disarmament and transported to the Veterinary Hospital in cages. The animals were fasted for 2 to 6 hours before the procedure; anesthetic induction was performed with isoflurane for instrumentation. The isoflurane CAM was placed in the target value 1.3v% in the first animal of each group, and waited 15 minutes for the nociceptive (electric) stimulus, in the value of 50 hertz and 50mA, held in faradic form (3 consecutive simple stimuli, followed by 2 continuous stimuli). The stimulus was performed on the lateral side of the left pelvic limb in the tibiotarsal region, and the electrodes were fixed with a 22G needle at a distance of 5cm between them. The bird's responses to the stimulus were considered positive (wing movements, head or vocalization) or negative (not presented movements of wings, head or vocalization) and the MAC value of the animal was recorded. Negative responses reduced next birds' MAC value by about 10%, and MAC positive responses increased by about 10%. Statistical analysis was done by methods up and down and analyze quantal for MAC and paired t-test for equivalent or t-test for variances not equal variances for the physiological variables. At the end of the experiment, the birds were reintroduced in the same capture area. The MAC value of isoflurane in the Collective Group was 1.4v% and the Individual Group 1.9v% to 0.903atm. It is observed that guan (P. obscura) in the Collective Group showed lesser anesthetic resistance to isoflurane than the birds in the Individual Group, showing that some levels of social stress can influence the MAC values of the isoflurane.(AU)


Este estudo teve como objetivo determinar e avaliar se há diferença nos valores de CAM em jacus (Penelope obscura) capturados em vida livre e submetidos a diferentes condições de estresse social. Foram utilizadas 27 aves da espécie jacu (P. obscura) de vida livre, que depois de capturados foram alocados em dois grupos: 10 animais que permaneceram em grupo no mesmo recinto (Grupo Coletivo) e 17 animais que permaneceram em gaiolas individuais (Grupo Individual). A pesquisa foi realizada na Base de Pesquisa Avançada do IBAMA, Painel/SC, e no Hospital de Clínica Veterinária da Universidade do Estado de Santa Catarina, Lages/SC. A captura foi realizada utilizando armadilha de rede com desarmamento manual e as aves foram transportadas para o Hospital Veterinário em gaiolas. Os animais foram submetidos a um jejum alimentar de 2 a 6 horas antes do procedimento, a indução anestésica foi realizada com isoflurano para instrumentação. A CAM de isoflurano foi colocada no valor alvo 1,3v% no primeiro animal de cada grupo, e esperado 15 minutos para realização do estímulo nociceptivo (elétrico), no valor de 50 hertz e 50mA, realizado de forma farádica (3 estímulos simples consecutivos, seguidos de 2 estímulos contínuos). O estímulo foi realizado na face lateral do membro pélvico esquerdo na região tibiotársica, e os eletrodos fixados com agulha 22G a uma distância de 5cm entre elas. A resposta da ave ao estímulo foi considerada positiva (movimentos de asas, cabeça ou vocalização) ou negativa (não apresentou movimentos de asas, cabeça ou vocalização) e o valor de CAM do animal foi registrado. Para resultados negativos, a CAM da próxima ave foi reduzida em torno de 10%, para positivos a CAM foi aumentada em torno de 10%. A análise estatística foi feita pelos métodos up and down e análise quantal para a CAM e teste t de pareado para variâncias equivalentes ou teste t para variâncias não equivalentes para as variáveis fisiológicas. Ao final do experimento as aves utilizadas foram reintroduzidas na mesma área de captura. O valor da CAM de isoflurano no Grupo Coletivo foi de 1,4v% e no Grupo Individual a CAM de 1,9v% a 0,903atm, sendo o valor do Grupo Coletivo significativamente menor que o Grupo Individual. Observa-se assim que os jacus (P. obscura) que permaneceram em recinto coletivo apresentaram uma menor resistência anestésica ao isoflurano que as aves que permaneceram em recintos individuais, mostrando que alguns níveis de estresse social como os observados aqui podem influenciar sobre os valores da CAM do isoflurano.(AU)


Assuntos
Animais , Estresse Psicológico , Aves/fisiologia , Galliformes/fisiologia , Isoflurano/administração & dosagem , Animais Selvagens
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