Widespread cultural change in declining populations of Amazon parrots.

Species worldwide are experiencing anthropogenic environmental change, and the long-term impacts on animal cultural traditions such as vocal dialects are often unknown. Our prior studies of the yellow-naped amazon (Amazona auropalliata) revealed stable vocal dialects over an 11-year period (1994-2005), with modest shifts in geographic boundaries and acoustic structure of contact calls. Here, we examined whether yellow-naped amazons maintained stable dialects over the subsequent 11-year time span from 2005 to 2016, culminating in 22 years of study. Over this same period, this species suffered a dramatic decrease in population size that prompted two successive uplists in IUCN status, from vulnerable to critically endangered. In this most recent 11-year time span, we found evidence of geographic shifts in call types, manifesting in more bilingual sites and introgression across the formerly distinct North-South acoustic boundary. We also found greater evidence of acoustic drift, in the form of new emerging call types and greater acoustic variation overall. These results suggest cultural traditions such as dialects may change in response to demographic and environmental conditions, with broad implications for threatened species.

Pre-Columbian transregional captive rearing of Amazonian parrots in the Atacama Desert.

The feathers of tropical birds were one of the most significant symbols of economic, social, and sacred status in the pre-Columbian Americas. In the Andes, finely produced clothing and textiles containing multicolored feathers of tropical parrots materialized power, prestige, and distinction and were particularly prized by political and religious elites. Here we report 27 complete or partial remains of macaws and amazon parrots from five archaeological sites in the Atacama Desert of northern Chile to improve our understanding of their taxonomic identity, chronology, cultural context, and mechanisms of acquisition. We conducted a multiproxy archaeometric study that included zooarchaeological analysis, isotopic dietary reconstruction, accelerated mass spectrometry radiocarbon dating, and paleogenomic analysis. The results reveal that during the Late Intermediate Period (1100 to 1450 CE), Atacama oasis communities acquired scarlet macaws (Ara macao) and at least five additional translocated parrot species through vast exchange networks that extended more than 500 km toward the eastern Amazonian tropics. Carbon and nitrogen stable isotopes indicate that Atacama aviculturalists sustained these birds on diets rich in marine bird guano-fertilized maize-based foods. The captive rearing of these colorful, exotic, and charismatic birds served to unambiguously signal relational wealth in a context of emergent intercommunity competition.

Semen analysis and successful artificial insemination in the St. Vincent amazon (Amazona guildingii).

The St. Vincent amazon (Amazona guildingii) is an endemic parrot on the Carribean island St Vincent. Due to poaching, trade, natural events such as hurricanes and habitat loss the species declined severely throughout the 20th century to a total number of 487 adult individuals and is currently regarded as vulnerable by IUCN. Captive breeding is attempted in terms of species conservation, but reproduction rates have been low due to reproductive problems such as mate aggression, asynchronous reproductive activity and infertile eggs. The aims of the present study were; firstly, to evaluate whether semen analysis might help to assess the fertility of males and to detect potential reasons for infertile eggs; secondly, to increase the number of offspring using artificial insemination, and as a future effect, to increase the presence of genetically valuable males in the ex-situ breeding population. For semen collection electric stimulation was used in 15 mature and healthy St. Vincent amazons with a success rate of 89% (202/227 attempts) in 14/15 males. Quality assessment of the semen included the evaluation of volume, pH, color, consistency and contaminations of the ejaculate, as well as estimation of motility, viability, morphology, concentration and total count of spermatozoa. Semen pH ranged from 6.7 to 7.5. Median sperm motility was 50% and median progressively forward motility 40%. Mean sperm concentration (x¯ ± SD) was 21,313.5 ± 22,408.8 spermatozoa/µl and mean sperm viability 66 ± 16%. Semen samples contained on average 20.5% morphologically normal spermatozoa and sperm malformations were detected mainly in the head (x¯ = 47.6%) and the tail regions (x¯ = 27.7%). Interestingly round bodies were detected in the ejaculates with a mean ratio of 0.6 round bodies per sperm. Semen analysis proved to be very useful to identify males with poor semen quality. Artificial insemination was performed 46 times in 9 females with either individual or pooled semen samples and 13 eggs from 7 females were laid afterwards. In 3 eggs, embryonic development was detected and 1 chick hatched successfully. Paternity testing confirmed the fatherhood of a one-winged semen donor male, a bird which was not able to copulate naturally. The results are very promising and underline that assisted reproduction techniques are a suitable tool for species conservation in captive breeding programs for psittacines.

Parrot Genomes and the Evolution of Heightened Longevity and Cognition.

Parrots are one of the most distinct and intriguing groups of birds, with highly expanded brains [1], highly developed cognitive [2] and vocal communication [3] skills, and a long lifespan compared to other similar-sized birds [4]. Yet the genetic basis of these traits remains largely unidentified. To address this question, we have generated a high-coverage, annotated assembly of the genome of the blue-fronted Amazon (Amazona aestiva) and carried out extensive comparative analyses with 30 other avian species, including 4 additional parrots. We identified several genomic features unique to parrots, including parrot-specific novel genes and parrot-specific modifications to coding and regulatory sequences of existing genes. We also discovered genomic features under strong selection in parrots and other long-lived birds, including genes previously associated with lifespan determination as well as several hundred new candidate genes. These genes support a range of cellular functions, including telomerase activity; DNA damage repair; control of cell proliferation, cancer, and immunity; and anti-oxidative mechanisms. We also identified brain-expressed, parrot-specific paralogs with known functions in neural development or vocal-learning brain circuits. Intriguingly, parrot-specific changes in conserved regulatory sequences were overwhelmingly associated with genes that are linked to cognitive abilities and have undergone similar selection in the human lineage, suggesting convergent evolution. These findings bring novel insights into the genetics and evolution of longevity and cognition, as well as provide novel targets for exploring the mechanistic basis of these traits.

Communal roosts of the Blue-fronted Amazons (Amazona aestiva) in a large tropical wetland: Are they of different types?

Psittacidae species are among the most threatened birds in the world. Approximately one-half of the 390 parrot species are experiencing population declines. The Blue-fronted Amazon (Amazona aestiva) is the most traded parrot worldwide and suffers from poaching and habitat loss. Many species of parrots, including the Blue-fronted Amazon, form communal roosts where they spend the night. Under certain circumstances, roost surveys can be a rapid and cost-effective way to obtain information about the demography of parrots or the consequences of threats. We surveyed an area of 2,700 km2 in a large wetland in mid-western of Brazil and located five Blue-fronted Amazon roosts. We conducted monthly counts of the birds arriving at these roosts for 28-61 months and stratified the counts into flock sizes. We used this information to estimate the number of parrots using these roosts to determine whether the roosts follow seasonal patterns and whether they have different flock-size structures and different dynamics throughout the year, as well as to determine the trends of the roosting parrots, which are stratified by flock size. The roosts were different, as they followed different seasonal patterns and had different flock-size structures, which could be interpreted in relation to the parrot breeding cycle. The trends of singletons, which index the number of reproductive couples each year, and the number of pairs parrots increased or fluctuated around a baseline, but the number of fledged young in the year declined throughout the study. This is of concern, as it indicates problems in population recruitment, which could have been unnoticed by the management authorities, as the total numbers were not decreasing. Although every monitored roost had birds of each age or reproductive condition strata, the fact that the roosts were different could be important in terms of management, as it will be more effective for the conservation of the Blue-fronted Amazon to protect a carefully chosen set of complementary roosts.

EFFECT OF ROUTINE HANDLING AND TRANSPORTATION ON BLOOD LEUKOCYTE CONCENTRATIONS AND PLASMA CORTICOSTERONE IN CAPTIVE HISPANIOLAN AMAZON PARROTS ( AMAZONA VENTRALIS).

Increased glucocorticoids cause a characteristic stress leukogram in mammalian taxa. It is assumed that avians exhibit a similar response, but to date, there have been no controlled studies to correlate serial endogenous corticosterone levels to hematologic values. An established flock of 18 Hispaniolan Amazon parrots ( Amazona ventralis) was used as a model in a crossover study. The treatment group was subjected to the stress of transport, restraint, and common clinical procedures with serial blood samples collected at 20-min intervals for hematology and corticosterone levels; the control group was sampled at the same intervals. Longitudinal data analysis was performed with linear mixed modeling. For all hematologic analytes, the baseline value had a significant positive effect on subsequent values (all P < 0.001). The white blood cell, heterophil, and eosinophil counts and heterophil to lymphocyte ratio increased over time in the treatment group, whereas it remained stable in the control group ( P = 0.016, P < 0.001, P < 0.001, P = 0.02, respectively, for the time*treatment effect). Lymphocyte absolute counts decreased over time, although not significantly; the decrease was significant for the relative lymphocyte count in the treatment group. Monocytes and basophils were not significantly altered. The treatment group had a higher mean corticosterone level overall than the control group by approximately 60% ( P = 0.008). The mean corticosterone level also increased over time in both groups by three- to fourfold ( P < 0.001) by 20 min then plateaued. These results demonstrate that some significant hematologic changes may arise with routine handling and transportation of birds and should be accounted for in hematologic interpretation of cell counts.

Urofecal steroid profiles of captive Blue-fronted parrots (Amazona aestiva) with different reproductive outcomes.

Despite Psitaciformes (parrots) being the third largest nonpasserine order (398 species), it currently ranks second in number of threatened species (28%) according to the Internatinal Union for Conservation of Nature (IUCN) criteria. Since most of the literature concerning reproductive endocrinology in avian species derives from domestic and song birds, it is puzzling that advances in reproductive science for the Psitaciformes order lags far behind, in spite of the growing threats against them. In order to expand our knowledge of Neotropical parrots (Psittacidae), we examined annual changes in urofecal sex steroid metabolites of Blue-fronted amazon pairs (Amazona aestiva) exhibiting successful (nestlings) and unsuccessful breeding (infertile or no eggs). Urofecal samples were collected over a year from eight breeding pairs housed under the same environmental and management conditions. Fecal androgen and progestagen concentrations were determined in males and females, respectively, by enzyme immunoassays previously validated for this species. All eggs were registered between late winter and mid-spring, and egg-laying intervals varied between females (range: 1-8 days; average 3.60 ±â€¯0.51 days). Similar profiles of urofecal progestagens were observed in reproductively successful females and females producing infertile eggs, with progestagen peaks preceding egg laying events (1.77 ±â€¯0.50 days). In contrast, non-laying females had no rises in progestagens during the year. Successful and unsuccessful males did not displayed distinct annual patterns of androgen production, and apart from the peaks during the breeding season, more than half of the individuals intriguingly presented significant increases from late summer to early autumn, a period without reproductive activity. Finally, we noticed that samples with progestagen levels exceeding 40 ng/g had very high probability (>97.5%) to be from females in pre-laying or laying phases, suggesting a feasible application of this characteristic to noninvasively discriminate the reproductive status in amazon females with an accuracy and sensitivity of 94.55% and 58.13%, respectively. Our findings confirmed that urofecal progestagens and androgens are good indicators of the gonadal condition in Blue-fronted amazons, but there is still much to be done for their extensive use in artificial insemination or selection of the most suitable breeding birds for the season.

Sedative Effects of Intranasal Midazolam Administration in Wild Caught Blue-fronted Amazon (Amazona aestiva) and Orange-winged Amazon (Amazona amazonica) Parrots.

Safe and effective sedation protocols are important for chemical restraint of birds in clinical and diagnostic procedures, such as clinical evaluations, radiographic positioning, and blood collection. These protocols may reduce stress and ease the management of wild-caught birds, which are susceptible to injury or death when exposed to stressful situations. We compare the sedative effect of intranasal midazolam in wild-caught blue-fronted (Amazona aestiva) and orange-winged (Amazona amazonica) Amazon parrots. Ten adult parrots of each species (n = 20), of unknown sex, weighing 0.337 ± 0.04 (blue-fronted) and 0.390 ± 0.03 kg (orange-winged), kg were used. Midazolam (2 mg/kg) was administered intranasally and the total volume of the drug was divided equally between the 2 nostrils. Onset time and total sedation time were assessed. Satisfactory sedation for clinical evaluation was induced in all birds. Onset time and total sedation times were similar in both species: 5.36 ± 1.16 and 25.40 ± 5.72 minutes, respectively, for blue-fronted Amazons and 5.09 ± 0.89 and 27.10 ± 3.73 minutes, respectively, for orange-winged Amazons. A total of 15 animals showed absence of vocalization, with moderate muscle relaxation and wing movement upon handling, and 2 animals presented with lateral recumbence, with intense muscle relaxation and no wing movement, requiring no restraint. Three blue-fronted Amazons had no effective sedation. Intranasally administered midazolam at a dose of 2 mg/kg effectively promoted sedative effects with a short latency time and fast recovery in wild-caught parrots.

Non-Invasive Measurement of Adrenocortical Activity in Blue-Fronted Parrots (Amazona aestiva, Linnaeus, 1758).

Parrots kept in zoos and private households often develop psychological and behavioural disorders. Despite knowing that such disorders have a multifactorial aetiology and that chronic stress is involved, little is known about their development mainly due to a poor understanding of the parrots' physiology and the lack of validated methods to measure stress in these species. In birds, blood corticosterone concentrations provide information about adrenocortical activity. However, blood sampling techniques are difficult, highly invasive and inappropriate to investigate stressful situations and welfare conditions. Thus, a non-invasive method to measure steroid hormones is critically needed. Aiming to perform a physiological validation of a cortisone enzyme immunoassay (EIA) to measure glucocorticoid metabolites (GCM) in droppings of 24 Blue-fronted parrots (Amazona aestiva), two experiments were designed. During the experiments all droppings were collected at 3-h intervals. Initially, birds were sampled for 24 h (experiment 1) and one week later assigned to four different treatments (experiment 2): Control (undisturbed), Saline (0.2 mL of 0.9% NaCl IM), Dexamethasone (1 mg/kg IM) and Adrenocorticotropic hormone (ACTH; 25 IU IM). Treatments (always one week apart) were applied to all animals in a cross-over study design. A daily rhythm pattern in GCM excretion was detected but there were no sex differences (first experiment). Saline and dexamethasone treatments had no effect on GCM (not different from control concentrations). Following ACTH injection, GCM concentration increased about 13.1-fold (median) at the peak (after 3-9 h), and then dropped to pre-treatment concentrations. By a successful physiological validation, we demonstrated the suitability of the cortisone EIA to non-invasively monitor increased adrenocortical activity, and thus, stress in the Blue-fronted parrot. This method opens up new perspectives for investigating the connection between behavioural disorders and stress in this bird species, and could also help in their captive management.

Analogical reasoning in amazons.

Two juvenile orange-winged amazons (Amazona amazonica) were initially trained to match visual stimuli by color, shape, and number of items, but not by size. After learning these three identity matching-to-sample tasks, the parrots transferred discriminative responding to new stimuli from the same categories that had been used in training (other colors, shapes, and numbers of items) as well as to stimuli from a different category (stimuli varying in size). In the critical testing phase, both parrots exhibited reliable relational matching-to-sample (RMTS) behavior, suggesting that they perceived and compared the relationship between objects in the sample stimulus pair to the relationship between objects in the comparison stimulus pairs, even though no physical matches were possible between items in the sample and comparison pairs. The parrots spontaneously exhibited this higher-order relational responding without having ever before been trained on RMTS tasks, therefore joining apes and crows in displaying this abstract cognitive behavior.

Health and Reproductive Assessment of Selected Puerto Rican Parrots ( Amazona vittata ) in Captivity.

The Puerto Rican parrot ( Amazona vittata ) has become an iconic and high-profile conservation species. The cornerstone of the recovery plan for this critically endangered species is an active captive breeding program, management of the wild population, and a long-term reintroduction program. In 2002, 40 adult Puerto Rican parrots that had not produced viable offspring were selected for reproductive assessment at 2 aviary populations in Puerto Rico (Iguaca and Río Abajo), which are the only sources of parrots for release. The goal was to enhance reproductive potential and produce productive pairings in an attempt to augment the population growth and provide ample individuals for reintroduction. Seven Hispanolian Amazon parrots ( Amazona ventralis ) that were used as surrogate parents for the Puerto Rican parrots were also included in the study. This assessment included physical examination, endoscopic evaluation, hematologic and plasma biochemical profiles, viral screening, and hormonal assays. Results of general physical examination and hematologic and plasma biochemical testing revealed overall good health and condition of this subset of the population of Puerto Rican parrots; no major infectious diseases were found. Endoscopic examination also revealed overall good health and condition, especially of females. The apparent low fertility of male birds warrants further investigation. The findings helped to define causes of reproductive failure in the selected pairs and individual birds. New pairings resulting from the assessment helped to augment reproduction of this critically endangered species.

Gestural communication in a new world parrot.

Male birds can use visual signals to provide information about their sexual status, via bright coloration, sophisticated sexual displays and elaborate tail and head crests. The majority of forest bird species use vocal communication as their main strategy to show their physiological status during breeding season. It is also used to keep contact between individuals in the same group, in agonistic contexts, and by chicks begging for food. We registered, for the very first time, gestural communication acting in the context of biparental care for the Orange-winged Amazon, Amazona amazonica. This parrot presents at least nine different sounds uttered in contexts of alarm, agonistic, foraging, contact flight and others. This finding suggests that despite being a vocal species, this parrot can perform gestural communication related to parental care. The gestures exhibited by this species represent a strategy for survival, a clever way to protect the nest, reducing the risk of attracting the attention of predators.

Pharmacokinetics of long-acting nalbuphine decanoate after intramuscular administration to Hispaniolan Amazon parrots (Amazona ventralis).

OBJECTIVE: To evaluate the pharmacokinetics of nalbuphine decanoate after IM administration to Hispaniolan Amazon parrots (Amazona ventralis). ANIMALS: 9 healthy adult Hispaniolan Amazon parrots of unknown sex. PROCEDURES: Nalbuphine decanoate (37.5 mg/kg) was administered IM to all birds. Plasma samples were obtained from blood collected before (time 0) and 0.25, 1, 2, 3, 6, 12, 24, 48, and 96 hours after drug administration. Plasma samples were used for measurement of nalbuphine concentrations via liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were estimated with computer software. RESULTS: Plasma concentrations of nalbuphine increased rapidly after IM administration, with a mean concentration of 46.1 ng/mL at 0.25 hours after administration. Plasma concentrations of nalbuphine remained > 20 ng/mL for at least 24 hours in all birds. The maximum plasma concentration was 109.4 ng/mL at 2.15 hours. The mean terminal half-life was 20.4 hours. CONCLUSIONS AND CLINICAL RELEVANCE: In Hispaniolan Amazon parrots, plasma concentrations of nalbuphine were prolonged after IM administration of nalbuphine decanoate, compared with previously reported results after administration of nalbuphine hydrochloride. Plasma concentrations that could be associated with antinociception were maintained for 24 hours after IM administration of 37.5 mg of nalbuphine decanoate/kg. Safety and analgesic efficacy of nalbuphine treatments in this species require further investigation to determine the potential for clinical use in pain management in psittacine species.

Antinociceptive effects of long-acting nalbuphine decanoate after intramuscular administration to Hispaniolan Amazon parrots (Amazona ventralis).

OBJECTIVE: To evaluate the thermal antinociceptive effects and duration of action of nalbuphine decanoate after IM administration to Hispaniolan Amazon parrots (Amazona ventralis). ANIMALS: 10 healthy adult Hispaniolan Amazon parrots of unknown sex. PROCEDURES: Nalbuphine decanoate (33.7 mg/kg) or saline (0.9% NaCl) solution was administered IM in a randomized complete crossover experimental design (periods 1 and 2). Foot withdrawal threshold to a noxious thermal stimulus was used to evaluate responses. Baseline thermal withdrawal threshold was recorded 1 hour before drug or saline solution administration, and thermal foot withdrawal threshold measurements were repeated 1, 2, 3, 6, 12, 24, 48, and 72 hours after drug administration. RESULTS: Nalbuphine decanoate administered IM at a dose of 33.7 mg/kg significantly increased thermal foot withdrawal threshold, compared with results after administration of saline solution during period 2, and also caused a significant change in withdrawal threshold for up to 12 hours, compared with baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: Nalbuphine decanoate increased the foot withdrawal threshold to a noxious thermal stimulus in Hispaniolan Amazon parrots for up to 12 hours and provided a longer duration of action than has been reported for other nalbuphine formulations. Further studies with other types of nociceptive stimulation, dosages, and dosing intervals as well as clinical trials are needed to fully evaluate the analgesic effects of nalbuphine decanoate in psittacine birds.

Antinociceptive effects of tramadol hydrochloride after intravenous administration to Hispaniolan Amazon parrots (Amazona ventralis).

OBJECTIVE: To determine the antinociceptive and sedative effects of tramadol in Hispaniolan Amazon parrots (Amazona ventralis) following IV administration. ANIMALS: 11 healthy Hispaniolan Amazon parrots of unknown sex. PROCEDURES: Tramadol hydrochloride (5 mg/kg, IV) and an equivalent volume (≤ 0.34 mL) of saline (0.9% NaCl) solution were administered to parrots in a complete crossover study design. Foot withdrawal response to a thermal stimulus was determined 30 to 60 minutes before (baseline) and 15, 30, 60, 120, and 240 minutes after treatment administration; agitation-sedation scores were determined for parrots at each of those times. RESULTS: The estimated mean changes in temperature from the baseline value that elicited a foot withdrawal response were 1.65° and -1.08°C after administration of tramadol and saline solution, respectively. Temperatures at which a foot withdrawal response was elicited were significantly higher than baseline values at all 5 evaluation times after administration of tramadol and were significantly lower than baseline values at 30, 120, and 240 minutes after administration of saline solution. No sedation, agitation, or other adverse effects were observed in any of the parrots after administration of tramadol. CONCLUSIONS AND CLINICAL RELEVANCE: Tramadol hydrochloride (5 mg/kg, IV) significantly increased the thermal nociception threshold for Hispaniolan Amazon parrots in the present study. Sedation and adverse effects were not observed. These results are consistent with results of other studies in which the antinociceptive effects of tramadol after oral administration to parrots were determined.

Comparison of osmolality and refractometric readings of Hispaniolan Amazon parrot (Amazona ventralis) urine.

To evaluate the relationship between osmolality and specific gravity of urine samples from clinically normal adult parrots and to determine a formula to convert urine specific gravity (USG) measured on a reference scale to a more accurate USG value for an avian species, urine samples were collected opportunistically from a colony of Hispaniolan Amazon parrots (Amazona ventralis). Samples were analyzed by using a veterinary refractometer, and specific gravity was measured on both canine and feline scales. Osmolality was measured by vapor pressure osmometry. Specific gravity and osmolality measurements were highly correlated (r = 0.96). The linear relationship between refractivity measurements on a reference scale and osmolality was determined. An equation was calculated to allow specific gravity results from a medical refractometer to be converted to specific gravity values of Hispaniolan Amazon parrots: USGHAp = 0.201 +0.798(USGref). Use of the reference-canine scale to approximate the osmolality of parrot urine leads to an overestimation of the true osmolality of the sample. In addition, this error increases as the concentration of urine increases. Compared with the human-canine scale, the feline scale provides a closer approximation to urine osmolality of Hispaniolan Amazon parrots but still results in overestimation of osmolality.

Evidence for vocal learning and limited dispersal as dual mechanisms for dialect maintenance in a parrot.

Studies of avian vocal dialects commonly find evidence of geographic and acoustic stability in the face of substantial gene flow between dialects. The vocal imitation and reduced dispersal hypotheses are alternatives to explain this mismatch between vocal and genetic variation. We experimentally simulated dispersal in the yellow-naped amazon (Amazona auropalliata) by moving individuals within and across dialect boundaries in Costa Rica. One juvenile translocated across dialect boundaries altered its contact call to imitate the acoustic form of the local call six weeks post-release. In contrast, four adults translocated across dialect boundaries returned to their original capture site within 120 days, while five cross-dialect translocated adults who remained at the release site did not alter their contact calls. Translocated individuals were observed to show some segregation from resident flocks. The observation of vocal imitation by the juvenile bird supports the vocal imitation, whereas the behavior of adults is more consistent with the reduced dispersal hypotheses. Taken together, our results suggest that both post-dispersal learning by juveniles and high philopatry in adults could explain the stability of vocal dialects in the face of immigration and gene flow.

Nutritional levels of diets fed to captive Amazon parrots: does mixing seed, produce, and pellets provide a healthy diet?

Poor nutrition is a serious problem in captive psittacine birds. Seed-based diets are known to contain excess fat, low calcium:phosphorus ratios, and other nutrient deficiencies, whereas many consider nutritionally superior, formulated diets to be monotonous. As a result, many bird owners feed a mixture of seed, produce, and formulated diet. However, the nutritional contents of such mixed diets have rarely been evaluated. In this study, we describe the nutrient contents of diets consumed by 7 adult (>6 years old), captive Amazon parrots offered produce (50% fresh weight), formulated diet (25%), and seed (25%). Diets consumed were deficient in calcium, sodium, and iron and contained more than the recommended amount of fat. In addition, the birds chose foods that exacerbated these imbalances. Birds offered low-seed diets (60% pellet, 22% produce, 18% seed, wet weight) consumed diets with more fat than recommended but acceptable levels of calcium and all other nutrients measured, as well as acceptable calcium:phosphorus ratios. This suggests that small quantities of seeds may not result in nutritionally imbalanced diets. Birds fed 75% formulated diet and 25% produce consumed diets within the recommendations for nearly all measured nutrients, demonstrating that owners of psittacine birds should be encouraged to supplement manufactured diets with low energy-density, fresh produce items to provide stimulation and foraging opportunities without fear of causing major nutritional imbalances.

Antinociceptive effects after oral administration of tramadol hydrochloride in Hispaniolan Amazon parrots (Amazona ventralis).

OBJECTIVE: To evaluate antinociceptive effects on thermal thresholds after oral administration of tramadol hydrochloride to Hispaniolan Amazon parrots (Amazona ventralis). Animals-15 healthy adult Hispaniolan Amazon parrots. PROCEDURES: 2 crossover experiments were conducted. In the first experiment, 15 parrots received 3 treatments (tramadol at 2 doses [10 and 20 mg/kg] and a control suspension) administered orally. In the second experiment, 11 parrots received 2 treatments (tramadol hydrochloride [30 mg/kg] and a control suspension) administered orally. Baseline thermal foot withdrawal threshold was measured 1 hour before drug or control suspension administration; thermal foot withdrawal threshold was measured after administration at 0.5, 1.5, 3, and 6 hours (both experiments) and also at 9 hours (second experiment only). RESULTS: For the first experiment, there were no overall effects of treatment, hour, period, or any interactions. For the second experiment, there was an overall effect of treatment, with a significant difference between tramadol hydrochloride and control suspension (mean change from baseline, 2.00° and -0.09°C, respectively). There also was a significant change from baseline for tramadol hydrochloride at 0.5, 1.5, and 6 hours after administration but not at 3 or 9 hours after administration. CONCLUSIONS AND CLINICAL RELEVANCE: Tramadol at a dose of 30 mg/kg, PO, induced thermal antinociception in Hispaniolan Amazon parrots. This dose was necessary for induction of significant and sustained analgesic effects, with duration of action up to 6 hours. Further studies with other types of noxious stimulation, dosages, and intervals are needed to fully evaluate the analgesic effects of tramadol hydrochloride in psittacines.

Effects of dopamine and dobutamine on isoflurane-induced hypotension in Hispaniolan Amazon parrots (Amazona ventralis).

OBJECTIVE: To assess the effects of dopamine and dobutamine on the blood pressure of isoflurane-anesthetized Hispaniolan Amazon parrots (Amazona ventralis). ANIMALS: 8 Hispaniolan Amazon parrots. PROCEDURES: A randomized crossover study was conducted. Each bird was anesthetized (anesthesia maintained by administration of 2.5% isoflurane in oxygen) and received 3 doses of each drug during a treatment period of 20 min/dose. Treatments were constant rate infusions (CRIs) of dobutamine (5, 10, and 15 µg/kg/min) and dopamine (5, 7, and 10 µg/kg/min). Direct systolic, diastolic, and mean arterial pressure measurements, heart rate, esophageal temperature, and end-tidal partial pressure of CO(2) were recorded throughout the treatment periods. RESULTS: Mean ± SD of the systolic, mean, and diastolic arterial blood pressures at time 0 (initiation of a CRI) were 132.9 ± 22.1 mm Hg, 116.9 ± 20.5 mm Hg, and 101.9 ± 22.0 mm Hg, respectively. Dopamine resulted in significantly higher values than did dobutamine for the measured variables, except for end-tidal partial pressure of CO(2). Post hoc multiple comparisons revealed that the changes in arterial blood pressure were significantly different 4 to 7 minutes after initiation of a CRI. Overall, dopamine at rates of 7 and 10 µg/kg/min and dobutamine at a rate of 15 µg/kg/min caused the greatest increases in arterial blood pressure. CONCLUSIONS AND CLINICAL RELEVANCE: Dobutamine CRI at 5, 10, and 15 µg/kg/min and dopamine CRI at 5, 7, and 10 µg/kg/min may be useful in correcting severe hypotension in Hispaniolan Amazon parrots caused by anesthesia maintained with 2.5% isoflurane.