Orange-winged Amazon Parrots Research Articles

Pharmacokinetics of single-dose oral atorvastatin and its metabolites support therapeutic use in orange-winged Amazon parrots (Amazona amazonica).

To evaluate the plasma concentrations and determine pharmacokinetic parameters of atorvastatin and its primary active metabolites (para- and ortho-hydroxyatorvastatin) after administration of a single oral dose in orange-winged Amazon parrots (Amazona amazonica). 8 adult orange-winged Amazon parrots (4 male, 4 female) of varying ages. A compounded oral suspension of atorvastatin 10 mg/mL was administered via oral gavage at 20 mg/kg to each bird. Blood samples were collected at 10 different time points from 0 to 30 hours postadministration to evaluate plasma levels of atorvastatin, para-hydroxyatorvastatin, and ortho-hydroxyatorvastatin. Pharmacokinetic analysis was performed using noncompartmental analysis and commercially available software. Mean ± SD atorvastatin half-life, tmax, and Cmax were 5.96 ± 11.50 hours, 1.60 ± 0.80 hours, and 82.60 ± 58.30 ng/mL, respectively. For para-hydroxyatorvastatin, the half-life, tmax, and Cmax were 6.46 ± 54.20 hours, 5.00 ± 2.51 hours, and 34.10 ± 16.00 ng/mL, respectively, and 5.58 ± 9.92 hours, 3.38 ± 2.10 hours, and 7.35 ± 3.96 ng/mL for ortho-hydroxyatorvastatin. The plasma concentrations and pharmacokinetic profile shown support the therapeutic use of atorvastatin at the dose evaluated in this species based on human pharmacokinetic data. While 20 mg/kg PO q24 hours could be used as a starting dosage until further studies evaluating multiple dose administration and efficacy in this species become available, the high interindividual variability results warrant monitoring of the treatment response to make dosing adjustments if needed.

Personality Characteristics Predictive of Social Pairing Outcome in Orange-Winged Amazon Parrots (Amazona amazonica)

ABSTRACT Most wild parrot species live in flocks, enriched by the environment and conspecific interactions. Captive parrots often live individually and are prone to behavioral maladaptation. If captive parrots and their behavior become intolerable, they are commonly relinquished to rescue organizations. This study aims to create parrot personality assessments for use by rescuers adding newly acquired parrots to shared environments. The study involved 20 orange-winged Amazon parrots (10 M, 10 F). Observers familiar with each bird scored its personality and analyses determined three sets of personalities: Social, Guarded, and Nervous Each parrot was paired with its 10 heterosexual counterparts and its interactions monitored remotely and captured on video. Pairing trials occurred over 72 hours in a specially designed pairing structure. Parrot personality could predict pairing success. Social-Guarded and Social-Nervous were more successfully paired, with individuals maintaining a close distance to one another and displaying increased rest-stretch behavior. Time of day influenced success with Social-Nervous pairs successful at all times of day, Social-Social pairs in the AM, and Guarded-Guarded pairs in the PM period. The study results suggest that rescues can use personality assessment and specific behaviors during cohabitation to predict OWA novel pairing outcomes.

Twice-daily oral administration of a cannabidiol and cannabidiolic acid-rich hemp extract was well tolerated in orange-winged Amazon parrots (Amazona amazonica) and has a favorable pharmacokinetic profile.

To determine the pharmacokinetics of 8 cannabinoids and 5 metabolites after oral administration of single and multiple doses of a cannabidiol (CBD)-cannabidiolic acid (CBDA)-rich hemp extract to orange-winged Amazon parrots (Amazona amazonica) as well as to evaluate the extract's adverse effects. 12 birds. Based on pilot studies, a single-dose study based on 30/32.5 mg/kg of cannabidiol/cannabidiolic acid of a hemp extract was administered orally to 8 fasted parrots, and 10 blood samples were collected over 24 hours after administration. After a 4-week washout period, the hemp extract was administered orally to 7 birds at the previous dose every 12 hours for 7 days, and blood samples were collected at the previous time points. Cannabidiol, Δ9-tetrahydrocannabinol, cannabinol, cannabichromene, cannabigerol, cannabidiolic acid, cannabigerolic acid, Δ9-tetrahydrocannabinolic acid, and 5 specific metabolites were measured by liquid chromatography-tandem/mass-spectrometry, and pharmacokinetic parameters were calculated. Adverse effects and changes in the plasma biochemistry and lipid panels were evaluated. Pharmacokinetic parameters for cannabidiol, cannabidiolic acid, Δ9-tetrahydrocannabinol, Δ9-tetrahydrocannabinolic acid, and the metabolite 11-hydroxy-9-tetrahydrocannabinol were established. For the multiple-dose study, cannabidiol/cannabidiolic acid mean Cmax was 337.4/602.1 ng/mL with a tmax of 30 minutes and a terminal half-life of 8.6/6.29 hours, respectively. No adverse effects were detected during the multidose study. The predominant metabolite was 11-hydroxy-9-tetrahydrocannabinol. Twice daily oral administration of the hemp extract based on 30 mg/kg/32.5 mg/kg of cannabidiol/cannabidiolic acid was well tolerated and maintained plasma concentrations considered to be therapeutic in dogs with osteoarthritis. Findings suggest different cannabinoid metabolism from mammals.

Pharmacokinetics of butorphanol tartrate in a poloxamer P407 gel formulation administered to orange-winged Amazon parrots (Amazona amazonica).

To determine the pharmacokinetics of butorphanol tartrate incorporated into poloxamer 407 (P407) after subcutaneous administration to orange-winged Amazon parrots (Amazona amazonica). Six orange-winged Amazon parrots, ages 28 to 45 years. A sterile formulation of butorphanol in P407 (But-P407) as a 25% gel was created to produce a concentration of 8.3 mg/mL. The formulation was administered SC at a dose of 12.5 mg/kg to all birds. Blood samples were collected at baseline prior to injection (time 0) and then at 0.08, 0.5, 1, 1.5, 4, 8, and 12 hours after drug administration. Butorphanol concentrations were quantitated via liquid chromatography-tandem mass spectrometry. Pharmacokinetic analysis was performed using noncompartmental analysis and a commercially available software program. Plasma concentrations of butorphanol remained > 100 ng/mL for > 4 hours for some birds (3/5) but were < 100 ng/mL for all birds by the 8-hour mark. Cmax and tmax were 346.9 ± 233.7 ng/mL and 1.3 ± 0.274 hours, respectively. Half-life was 1.56 ± 0.445 hours. No adverse effects were detected. Butorphanol was absorbed from the But-P407 25% by the majority of the orange-winged Amazon parrots in this study (3/5), although to a lesser extent compared to Hispaniolan Amazon parrots. Absorption followed a pharmacokinetic profile compatible with a sustained-release drug. A dose of 12.5 mg/kg, SC, would be expected to provide antinociception for 4 to 8 hours, although pharmacodynamic studies in this species using this formulation have not demonstrated this.

Pharmacokinetics of hydromorphone hydrochloride after intramuscular and intravenous administration of a single dose to orange-winged Amazon parrots (Amazona amazonica).

To evaluate the pharmacokinetics of hydromorphone hydrochloride after IM and IV administration to orange-winged Amazon parrots (Amazona amazonica). 8 orange-winged Amazon parrots (4 males and 4 females). Hydromorphone (1 mg/kg) was administered once IM. Blood samples were collected 5 minutes and 0.5, 1.5, 2, 3, 6, and 9 hours after drug administration. Plasma hydromorphone concentrations were determined with liquid chromatography-tandem mass spectrometry, and pharmacokinetic parameters were calculated with a compartmental model. The experiment was repeated 1 month later with the same dose of hydromorphone administered IV. Plasma hydromorphone concentrations were > 1 ng/mL for 6 hours in 8 of 8 and 6 of 7 parrots after IM and IV injection, respectively. After IM administration, mean bioavailability was 97.6%, and mean maximum plasma concentration was 179.1 ng/mL 17 minutes after injection. Mean volume of distribution and plasma drug clearance were 4.24 L/kg and 64.2 mL/min/kg, respectively, after IV administration. Mean elimination half-lives were 1.74 and 1.45 hours after IM and IV administration, respectively. Hydromorphone hydrochloride had high bioavailability and rapid elimination after IM administration, with rapid plasma clearance and a large volume of distribution after IV administration in orange-winged Amazon parrots. Drug elimination half-lives were short. Further pharmacokinetic studies of hydromorphone and its metabolites, including investigation of multiple doses, different routes of administration, and sustained-release formulations, are recommended.

Evaluation of the thermal antinociceptive effects of hydromorphone hydrochloride after intramuscular administration to orange-winged Amazon parrots (Amazona amazonica).

To evaluate the thermal antinociceptive effects of hydromorphone hydrochloride after IM administration to orange-winged Amazon parrots (Amazona amazonica). 8 healthy adult parrots (4 males and 4 females). In a randomized crossover study, each bird received hydromorphone (0.1, 1, and 2 mg/kg) and saline (0.9% NaCl) solution (1 mL/kg; control) IM, with a 7-day interval between treatments. Each bird was assigned an agitation-sedation score, and the thermal foot withdrawal threshold (TFWT) was measured at predetermined times before and after treatment administration. Adverse effects were also monitored. The TFWT, agitation-sedation score, and proportion of birds that developed adverse effects were compared among treatments over time. Compared with the mean TFWT for the control treatment, the mean TFWT was significantly increased at 0.5, 1.5, and 3 hours and 1.5, 3, and 6 hours after administration of the 1- and 2-mg/kg hydromorphone doses, respectively. Significant agitation was observed at 0.5, 1.5, and 3 hours after administration of the 1 - and 2-mg/kg hydromorphone doses. Other adverse effects observed after administration of the 1- and 2-mg/kg doses included miosis, ataxia, and nausea-like behavior (opening the beak and moving the tongue back and forth). Although the 1- and 2-mg/kg hydromorphone doses appeared to have antinociceptive effects, they also caused agitation, signs of nausea, and ataxia. Further research is necessary to evaluate administration of lower doses of hydromorphone and other types of stimulation to better elucidate the analgesic and adverse effects of the drug in psittacine species.

Evaluation of the thermal antinociceptive effects of subcutaneous administration of butorphanol tartrate or butorphanol tartrate in a sustained-release poloxamer 407 gel formulation to orange-winged Amazon parrots (Amazona amazonica).

To determine the thermal antinociceptive effects of butorphanol tartrate and butorphanol tartrate in a sustained-release 25% poloxamer 407 (P407) gel formulation (But-P407) in parrots. 13 orange-winged Amazon parrots (Amazona amazonica). First, butorphanol tartrate (5 mg/kg) or saline (0.9% NaCl) solution was administered IM to birds in a randomized complete crossover design. The temperature prompting a foot withdrawal response to a thermal stimulus (ie, the thermal threshold) was determined 30 minutes before (baseline) and at various points after treatment administration. Second, But-P407 (12.5 mg/kg) or P407 was administered SC in a similar crossover design. Thermal threshold was determined before and at various points after treatment administration. Third, But-P407 (12.5 mg/kg) or saline solution was administered SC and evaluated as in the second trial. Sedation was scored immediately before each time point in all 3 trials. In the first trial, a significant increase in thermal threshold was noted 30 minutes after butorphanol tartrate (vs saline solution) administration. No sedation was noted. In the second and third trials, no significant difference was identified between results for But-P407 and those for either control treatment (saline solution or P407). Mild sedation was noted in the second trial following But-P407 administration. Results suggested a small but significant thermal antinociceptive effect of butorphanol tartrate lasting between 30 minutes and 1.5 hours in orange-winged Amazon parrots. No antinociceptive effect of butorphanol tartrate was demonstrated when delivered in P407. Further research is needed to evaluate the potential analgesic effects of But-P407.

Thermal antinociceptive and agitation-sedation effects after intramuscular administration of hydromorphone hydrochloride in orange-winged Amazon parrots (Amazona amazonica)

Thermal antinociceptive and agitation-sedation effects after intramuscular administration of hydromorphone hydrochloride in orange-winged Amazon parrots (Amazona amazonica)

Hematologic, Plasma Biochemical, and Lipid Panel Reference Intervals in Orange-winged Amazon Parrots ( Amazona amazonica ).

To establish reference intervals in orange-winged Amazon parrots ( Amazona amazonica ) for the complete blood count, plasma biochemical values, and lipid panel and to evaluate age- and sex-related variations, blood samples were obtained from 29 healthy juvenile and adult parrots. Concentrations of total protein, bile acids, phosphorus, total cholesterol, low-density-lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol were significantly higher in adult compared with juvenile birds, while uric acid concentration was significantly higher in juveniles. The white blood cell count, lymphocyte count, and phosphorus and potassium concentrations were significantly higher in females, while chloride concentration was significantly higher in males. In this species, direct measurement of LDL-C resulted in lower concentrations than LDL-C calculated with the Friedewald formula. Assessment of the agreement between the calculated and measured LDL-C concentrations indicated a systematic bias of 19.1 mg/dL and a proportional bias of 1.07. A correction factor of -19 mg/L could be applied to the Friedewald formula, to obtain a result closer to the measured LDL-C, providing clinically acceptable (<20% difference) agreement in 66% of the samples. Triglyceride concentrations within the range measured in healthy birds of the present study did not significantly affect the bias between calculated and directly measured LDL-C. Further studies are needed to investigate the impact of nutritional factors, genetics, and exercise on biochemistry and lipoprotein panel analytes in orange-winged Amazon parrots.

Improving the re-introduction of rescued Magellanic penguins through extended health evaluation with minimal sampling volume and material

Improving the re-introduction of rescued Magellanic penguins through extended health evaluation with minimal sampling volume and material

The Relationship between Personality Dimensions and Resiliency to Environmental Stress in Orange-Winged Amazon Parrots (Amazona amazonica), as Indicated by the Development of Abnormal Behaviors.

Parrots are popular companion animals, but are frequently relinquished because of behavioral problems, including abnormal repetitive behaviors like feather damaging behavior and stereotypy. In addition to contributing to pet relinquishment, these behaviors are important as potential indicators of diminished psychological well-being. While abnormal behaviors are common in captive animals, their presence and/or severity varies between animals of the same species that are experiencing the same environmental conditions. Personality differences could contribute to this observed individual variation, as they are known risk factors for stress sensitivity and affective disorders in humans. The goal of this study was to assess the relationship between personality and the development and severity of abnormal behaviors in captive-bred orange-winged Amazon parrots (Amazona amazonica). We monitored between-individual behavioral differences in enrichment-reared parrots of known personality types before, during, and after enrichment deprivation. We predicted that parrots with higher scores for neurotic-like personality traits would be more susceptible to enrichment deprivation and develop more abnormal behaviors. Our results partially supported this hypothesis, but also showed that distinct personality dimensions were related to different forms of abnormal behavior. While neuroticism-like traits were linked to feather damaging behavior, extraversion-like traits were negatively related to stereotypic behavior. More extraverted birds showed resiliency to environmental stress, developing fewer stereotypies during enrichment deprivation and showing lower levels of these behaviors following re-enrichment. Our data, together with the results of the few studies conducted on other species, suggest that, as in humans, certain personality types render individual animals more susceptible or resilient to environmental stress. Further, this susceptibility/resiliency can have a long-term effect on behavior, as evidenced by behavioral changes that persisted despite re-enrichment. Ours is the first study evaluating the relationship between personality dimensions, environment, and abnormal behaviors in an avian species.

Performance on the Hamilton search task, and the influence of lateralization, in captive orange-winged Amazon parrots (Amazona amazonica)

Psittacines are generally considered to possess cognitive abilities comparable to those of primates. Most psittacine research has evaluated performance on standardized complex cognition tasks, but studies of basic cognitive processes are limited. We tested orange-winged Amazon parrots (Amazona amazonica) on a spatial foraging assessment, the Hamilton search task. This task is a standardized test used in human and non-human primate studies. It has multiple phases, which require trial and error learning, learning set breaking, and spatial memory. We investigated search strategies used to complete the task, cognitive flexibility, and long-term memory for the task. We also assessed the effects of individual strength of motor lateralization (foot preference) and sex on task performance. Almost all (92%) of the parrots acquired the task. All had significant foot preferences, with 69% preferring their left foot, and showed side preferences contralateral to their preferred limb during location selection. The parrots were able to alter their search strategies when reward contingencies changed, demonstrating cognitive flexibility. They were also able to remember the task over a 6-month period. Lateralization had a significant influence on learning set acquisition but no effect on cognitive flexibility. There were no sex differences. To our knowledge, this is the first cognitive study using this particular species and one of the few studies of cognitive abilities in any Neotropical parrot species.

Bathing behavior of captive Orange-winged Amazon parrots ( Amazona amazonica)

Feather maintenance behaviors, particularly preening and bathing, are nearly universal in birds, though their expression and function vary across species. Based on the rain-bathing style of wild Amazon parrots, parrots were sprayed with water to simulate rainfall, and subsequent bathing behavioral parameters were recorded as well as behavioral states accounting for activity budgets 1 h pre- and post-spray. When parrots were sprayed on Day 0 and next sprayed 2, 4 or 6 d later, it took more than 4 d for bathing bout length, bathing latency and number of birds bathing to return to values comparable to Day 0. Across three different times of the day (morning, midday, afternoon) all but one parrot bathed in the morning while fewer parrots bathed in the midday and afternoon time periods. Bathing duration in the morning was 10.8 ± 1.7 min and decreased significantly in later time periods while latency-to-bathe time in the morning was 1.4 ± 0.3 min and increased thereafter. Further, there were no significant effects of bathing on resting and feeding across the day but significant effects on preening were evident, with preening dropping to negligible levels after bathing; this is consistent with a motivational relationship between bathing and preening. Captive parrots displayed several postures and a general sequence of postures that resembled those of wild rain-bathing parrots. When other parrots in the same room were sprayed, non-sprayed parrots performed sham-bathing, possibly reflecting social facilitation of bathing. Results show that captive Orange-winged Amazon parrots have a bathing bout length of ∼10 min, with a refractory period of >4 d and a tendency to bathe in the morning.

Preference and motivation for different diet forms and their effect on motivation for a foraging enrichment in captive Orange-winged Amazon parrots ( Amazona amazonica)

Motivation tests were conducted to assess preference strength for diet form and a cage enrichment device by Orange-winged Amazon parrots ( Amazona amazonica) held in individual cages, N = 10. Each cage was equipped with two trough-type feeders, one of which had a hinged lid that required lifting to access feeder content; cost of lifting the lid could be increased by the addition of up to 480 g upon it, ∼1.5 times the mass of an Amazon parrot. Motivation tests were conducted using three different diet forms of pellets (regular-sized, 0.16 g/pellet (cylindrical-shaped); large-sized, 3.4 g/pellet (cylindrical); and over-sized, 3–5 g/pellet (cuboid-to-spheroid)) manufactured from the same diet formulation. When regular pellets were concomitantly freely available, birds were still highly motivated to gain access to either large-sized or over-sized pellets, with 7 of 10 birds lifting the maximum weight of 480 g. In motivation tests comparing over-sized vs. large-sized pellets, birds worked more for over-sized pellets (when large-sized pellets were freely available) than vice versa: motivation for over-sized pellets exceeded that for large-sized pellets by approximately 242.67 ± 64.4 g ( F = 14.2, P = 0.0055; Sign Test, P = 0.0078). Additional tests assessed motivation to access 2.5 cm/side wooden cube enrichment devices when regular or over-sized pellets were freely available. Birds removed more cubes when fed regular pellets (Sign Test, P = 0.0078) and lifted an average of 221.33 ± 64.62 g more to access them ( F = 11.73, P = 0.009; Sign Test, P = 0.0063), than when over-sized pellets were freely available, suggesting that enrichment devices may act as foraging substitutes. Likewise, both wooden cubes and over-sized pellets elicited comparable podomandibulation (handling with beak and foot) behavior, and podomandibulation was reduced when parrots were fed regular as opposed to over-sized pellets (58 ± 10 s [mean ± SE] vs. 4.27 min ± 31 s; P < 0.0001). Finally, there was no evidence of contrafreeloading: in control experiments, birds only removed pellets which were freely available, when the same pellets were concomitantly available in weighted-lid feeders ( F = 120.20, P < 0.0001). In summary, these results show that captive Orange-winged Amazon parrots strongly prefer pellet forms that are substantially larger than what is commercially recommended for them; preferred forms more closely resemble that of native wild foods, such as palm fruits.

Over-sized pellets naturalize foraging time of captive Orange-winged Amazon parrots ( Amazona amazonica)

Parrots held in captivity experience distinctly different environmental demands, as compared to their wild conspecifics, particularly in regard to feeding. Cages equipped with computer-monitored infra-red beams (placed across a primary perch, in front of the feeder, in front of the drinking fount, and at the peak of the cage; interruption of a beam indicated a parrot's location) were used to supplement direct observation in characterizing activity budgets of adult male and female captive Orange-winged Amazon parrots ( Amazona amazonica) fed pelleted diets. Parrots spent nearly all of their time perching, moving off the perch only a few times daily to drink and a few dozen times daily for pellet meals (each meal consisting of pellet retrieval and manipulation of the pellet(s) before swallowing). Such meals were temporally clumped, usually into 3–5 meal clusters per day, and clusters tended to be concentrated in morning and afternoon periods of a 12:12 LD light cycle, with a midday respite. Over-sized pellets formulated to be approximately 20–30 times larger than regular pellets (approximately 3–5 g each vs. 0.16 g each, respectively) exerted no detectable effect on the frequency distribution of off-perch bout lengths, but over-sized pellets dramatically increased post-pellet retrieval manipulation time approximately five-fold. In choice preference trials, parrots strongly preferred over-sized pellets to regular pellets, retrieving over-sized pellets approximately seven-times more often. Likewise, parrots offered only regular pellets removed 47.6 ± 6.4 g (mean ± SE) pellets from their feeder per day, but removed only 6.5 ± 2.0 of regular pellets, if over-sized pellets were offered concurrently. Finally, the option of manipulating/consuming over-sized pellets strongly affected use of wooden cube enrichment devices. During a 3-day period, parrots offered both regular and over-sized pellets reduced the mass of wooden cubes (through biting/chewing) by approximately 0.13 g; removal of the over-sized pellet option increased this amount 50-fold. These results suggest that parrots offered only regular-size pelleted diets are deprived of an opportunity to engage in foraging behavior. Offering parrots over-sized pellets or enrichment devices that provide foraging-like opportunities can dramatically reduce periods of inactivity and encourage a more naturalistic activity budget, thereby enhancing welfare.

The effect of rope color, size and fray on environmental enrichment device interaction in male and female Orange-winged Amazon parrots ( Amazona amazonica)

Environmental enrichment devices (EDs; a.k.a. cage “toys”) are often provided to captive parrots to mitigate the austerity of their environments, but the basis of attraction to EDs by parrots is poorly understood and many EDs go un-used. Preferences of Orange-winged Amazon parrots ( Amazona amazonica) for various properties of sisal rope were tested by suspending rope EDs from computer-monitored switches attached to cage ceilings, two ED-switches per cage. Separate experiments examined preference for rope fray, length, diameter, and color, as operationalized by switch closures elicited by each ED when EDs of varying parameter quality were offered on either side of the cage. Bradley–Terry analysis contrasting woven vs. frayed rope found that both female and male parrots preferred wound (i.e., non-frayed) over frayed rope, though the extent of the difference was substantially greater for females than males (Cohen's d = 0.86 vs. 0.10, respectively). In contrasts of different rope lengths (6, 16, 26 and 36 cm), females preferred longer over shorter rope in four of six contrasts ( d = 0.45–0.90), while males preferred shorter over longer rope in four of six contrasts ( d = 0.25–0.72). Similarly, in contrasts of three rope diameters (12, 26 and 38 mm), female parrots preferred 38 mm over 26 mm diameter rope ( d = 0.20; other diameter contrasts were not significant), while in all contrasts males consistently preferred smaller over larger rope diameters ( d = 0.20–0.44). Both male and female parrots preferred red rope over green ( d = 0.92, 1.21, respectively) or yellow ( d = 1.23, 1.04, respectively); females additionally favored red rope over brown ( d = 1.34); males additionally preferred brown over both green ( d = 0.87) and yellow ropes ( d = 1.78). Overall, male parrots interacted much more extensively with rope EDs than did female parrots ( t = −3.431, P = 0.006; Cohen's d = −2.11). These results show that Orange-winged Amazon parrots have sex-specific preferences for rope length, diameter and color and that males interact more with EDs more than do females. These results provide the basis for developing EDs that are more likely to engage bird behavior and therefore be more effective in mitigating the austerity of cage environments.

Preferences of Orange-winged Amazon parrots ( Amazona amazonica) for cage enrichment devices

Cage enrichment devices (ED), frequently termed cage “toys,” are often provided to captive parrots as a means of promoting a behaviorally stimulating environment, but it is not clear whether particular properties of EDs are more effective than others in eliciting engagement with them. We tested preference for color, size and hardness of cube-shaped EDs constructed from wood and of color preference for EDs constructed from flat rawhide rectangles. Orange-winged Amazon parrots ( Amazona amazonica; N = 8–10, mixed-sex, 4–5 years of age) were individually housed in cages each equipped with two computer-monitored omni-directional lever-type switches attached to cage ceilings. EDs were attached to the switches; any interactions generating lateral movement and causing switch closure (operationally constituting “use” of EDs) were continuously recorded. Preference for 3.8 cm 3 softwood (Douglas fir) cubes dyed in eight different colors was tested by presenting each bird with all combinations of colors, two colors at a time. Daily switch activity averages were computed for each bird and subjected to repeated-measures ANOVA: yellow cubes elicited greater use than red, green, blue, violet or natural cubes ( P < 0.05; but see below) and orange cubes were preferred over green and blue cubes ( P < 0.05). Color exerted no effect in a comparable trial of rawhide rectangles. Preference for size of yellow hardwood cubes was tested by presenting combinations of cubes of three sizes: 2.5, 3.8, and 5.1 cm 3; the smallest blocks were preferred over the largest size ( P < 0.001). Preference for hardness of wood was tested by presenting birds with 3.8 cm 3 yellow cubes and blue cubes made of either Douglas fir (“soft”) or birch/maple (“hard”) wood; birds preferred softer cubes ( P < 0.0002), but there was no significant preference of yellow over blue. The results show that color, hardness, size and material all influence ED use by captive Amazon parrots. This constellation of preferences may reflect properties of foods native to Orange-winged Amazon natural habitat.

Ovarian Hemangiosarcoma in an Orange-winged Amazon Parrot (Amazona amazonica)

A 25-year-old intact female orange-winged Amazon parrot (Amazona amazonica) presented for a 2-week history of straining to defecate, lethargy, open-beak breathing, decreased vocalization, and ruffled feathers. On physical examination, the parrot had a heart murmur, increased air sac and lung sounds, open-beak breathing, increased respiratory rate and effort, and coelomic distension. An ultrasound revealed intracoelomic fluid, and hemorrhagic fluid was aspirated from the coelom. Cytologic analysis indicated hemocoelom. Pericardial effusion was observed during the sonogram, and pericardiocentesis was performed. The bird was euthanatized upon the owner's request because of a poor prognosis. At necropsy, several masses that involved the ovary and oviduct were observed, as well as a thickened pericardium and a thickened, fibrinous epicardium. Results of a histopathologic examination of the masses that involved the reproductive tract revealed ovarian hemangiosarcoma, which was confirmed by immunohistochemical staining. To our knowledge, ovarian hemangiosarcoma has not been reported in a psittacine species, nor has immunohistochemistry confirmed ovarian hemangiosarcoma in avian species, specifically in an orange-winged Amazon parrot.

Novelty and individual differences influence neophobia in orange-winged Amazon parrots (Amazona amazonica)

Environmental enrichment both improves the welfare of captive animals and increases the validity of research using these animals. Enrichment programs have been shown to prevent or reduce the development of behavioral vices, stereotypy, and fearfulness. However, the protocols used in enrichment studies can be inconsistent: under some protocols, enrichments are provided but not changed, while under others, enrichments are rotated frequently. Enrichment experiments to date have also largely ignored the influence of individual differences on fearfulness. The aim of this study was to determine whether frequent rotation of enrichment objects (“high novelty”) was more effective than simply providing enrichment objects (“low novelty”) in reducing neophobia in juvenile orange-winged Amazon parrots and to determine whether individual differences significantly affected neophobia. Thirty-four juvenile orange-winged Amazon parrots received both an 11-week high-novelty (HN) treatment and an 11-week low-novelty (LN) treatment, which were given in random order. Neophobia was assessed by measuring birds’ latency to feed from a dish of highly favored food in the presence of various novel objects at approximately 10-day intervals. Our results indicate that the HN treatment significantly reduced neophobia in juvenile orange-winged Amazons. We also found that both individual variation in fearfulness and the novel object used for testing significantly affected birds’ latency to feed in the presence of novel objects. Our results indicate that rotation of enrichment objects is more effective than simply providing enrichments in reducing fearful behavior in parrots. The effect of rotating enrichments was strong enough to overcome approximately four-fold differences in birds’ latency to feed in the presence of different novel objects and even greater individual differences in neophobia. However, we also found that in highly fearful individuals, HN actually increased birds’ latency to feed in the presence of novel objects. Our results indicate that rotation of enrichment objects is more effective than simply providing enrichments in reducing fearful behavior in parrots, but that both enrichment object properties and individual differences should be carefully considered in the design of future enrichment studies and protocols.

Comparison of biochemical values in serum and plasma, fresh and frozen plasma, and hemolyzed samples from orange‐winged Amazon parrots (Amazona amazonica)

To the authors' knowledge, on the basis of sample type, storage condition, or hemolysis, differences in serum and plasma biochemical values have not been evaluated in orange-winged Amazon parrots (Amazona amazonica). The purpose of this study was to compare values for biochemical analytes in serum vs plasma, fresh vs frozen plasma, and nonhemolyzed vs hemolyzed samples in orange-winged Amazon parrots. We also compared differences in serum and plasma yield from whole-blood aliquots. Fifteen biochemical analytes were evaluated in paired serum and plasma, fresh and frozen plasma, nonhemolyzed and hemolyzed serum and plasma samples from orange-winged Amazon parrots (n = 10) using a wet reagent analyzer. Hemolysis was assessed qualitatively (visually) and quantitatively (hemoglobin [Hgb] measured spectrophotometrically). Serum and plasma yields from 500-microl whole-blood aliquots were determined from centrifuged samples. Analyte values significantly differed among sample groups, but were still within published reference intervals, with the exception of increases in potassium concentration in markedly hemolyzed serum and plasma samples. Clinically important changes in hemolyzed serum and plasma samples included increases in potassium, phosphorus, and albumin concentrations and lactate dehydrogenase activity. The degree of hemolysis assigned qualitatively did not correlate with quantitative Hgb concentration. A significantly greater yield of plasma (288 +/- 13 microL) than serum (241 +/- 44 microL) was obtained. Significant differences may occur in different sample types, however, only changes in potassium, phosphorus, albumin, and lactate dehydrogenase values in hemolyzed samples were considered clinically relevant. Lack of agreement between qualitative and quantitative Hgb concentration indicates the unreliability of visual estimation. Based on higher sample yield, and lack of clinically relevant differences from serum, plasma is a better sample choice for clinical chemistry analysis in birds.