Blood Biochemical Values of Wild Scarlet Macaw ( Ara macao macao) Nestlings and Adults.

Blood biochemical values are useful as indicators of disease in veterinary practice and for health assessments of free-ranging animal populations. We analyzed blood biochemical values for free-living nestling and adult scarlet macaws ( Ara macao macao) in southeastern Peru with an Abaxis VetScan VS2 portable analyzer with Avian/Reptilian Profile Plus rotors. The resulting data were used to create provisional age-independent reference intervals for this instrument for wild scarlet macaw nestlings, calculate blood biochemical ranges for this instrument for wild adults, and examine age-related trends in nestlings. Levels of 11 parameters were studied: albumin, aspartate aminotransferase, calcium, creatine kinase, globulin, glucose, phosphorus, potassium, total protein, sodium, and uric acid. Bile acid levels were generally below the instrument detection level and were not evaluated. Most values and their trends with bird age were comparable to those observed in captive large macaw nestlings. Albumin, aspartate aminotransferase, globulin, glucose, total protein, sodium, and uric acid levels increased with nestling age to adulthood. Creatine kinase, phosphorus, and potassium concentrations decreased with age to adulthood. Calcium concentrations did not change between nestlings and adults. These changes in values with age are broadly in agreement with values in other avian species and likely reflect physiologic and developmental changes as nestlings mature.

Impact of Delayed Analysis in Avian Blood Biochemical Values Measured With the Abaxis VetScan VS2.

For biochemical analysis with a point-of-care biochemical analyzer, standard procedure is to analyze the sample as rapidly as possible (<1 hour) after venipuncture to minimize any changes in analyte concentrations that might occur over time. However, under some circumstances, such as when collecting blood at remote field sites, a longer delay may be unavoidable. This study evaluates the effect of delayed analysis time under unrefrigerated conditions on avian (psittacine) biochemical analyte concentrations obtained with the VetScan VS2 using Avian/Reptilian Profile Plus rotors. Venipuncture was performed on a group of 36 psittacine birds as part of routine health checks in a research aviary (Texas A&M University, College of Veterinary Medicine, College Station, TX, USA). Whole blood was kept at room temperature and analyzed at 4 time intervals: <1, 3, 6, and 24 hours after venipuncture. At 3 hours or less after collection, most biochemical parameters changed by <2%, with the exception of phosphorus (decrease of about -9%). Major increases by 24 hours after collection were observed in phosphorus (+67%) and potassium (+103%) concentrations, whereas aspartate aminotransferase (AST), uric acid, glucose, and sodium concentrations also showed statistically significant changes. Our results suggest that accurate information from analyses using the VetScan VS2 may be obtained for up to 3 hours after venipuncture without refrigeration, but researchers and clinicians do need to exercise care when interpreting blood chemistry analyte concentrations obtained after multihour delays between venipuncture and sample analysis.

Error properties of Argos satellite telemetry locations using least squares and Kalman filtering.

Study of animal movements is key for understanding their ecology and facilitating their conservation. The Argos satellite system is a valuable tool for tracking species which move long distances, inhabit remote areas, and are otherwise difficult to track with traditional VHF telemetry and are not suitable for GPS systems. Previous research has raised doubts about the magnitude of position errors quoted by the satellite service provider CLS. In addition, no peer-reviewed publications have evaluated the usefulness of the CLS supplied error ellipses nor the accuracy of the new Kalman filtering (KF) processing method. Using transmitters hung from towers and trees in southeastern Peru, we show the Argos error ellipses generally contain <25% of the true locations and therefore do not adequately describe the true location errors. We also find that KF processing does not significantly increase location accuracy. The errors for both LS and KF processing methods were found to be lognormally distributed, which has important repercussions for error calculation, statistical analysis, and data interpretation. In brief, "good" positions (location codes 3, 2, 1, A) are accurate to about 2 km, while 0 and B locations are accurate to about 5-10 km. However, due to the lognormal distribution of the errors, larger outliers are to be expected in all location codes and need to be accounted for in the user's data processing. We evaluate five different empirical error estimates and find that 68% lognormal error ellipses provided the most useful error estimates. Longitude errors are larger than latitude errors by a factor of 2 to 3, supporting the use of elliptical error ellipses. Numerous studies over the past 15 years have also found fault with the CLS-claimed error estimates yet CLS has failed to correct their misleading information. We hope this will be reversed in the near future.