The validity of the haematocrit or packed cell volume as an indicator of condition in wild birds has recently been questioned. We reviewed over 300 published papers on haematocrit values for wild birds. These studies show that changes in haematocrit could be caused by a number of different natural factors that include age, sex, geographical elevation, energy expenditure, parasitism, nutrition and genetics. Haematocrit also increased with age from hatching, due to increased erythropoiesis, so that adult birds generally have greater haematocrit values than nestlings or juveniles. Haematocrit values were either independent of elevation or increased with elevation. A meta‐analysis of 36 studies showed no difference in haematocrit between the sexes. Relationships between haematocrit value and both energy expenditure and parasitic infection vary between studies. In temperate climates, haematocrit tended to be higher in winter than in summer, which may be due to dehydration or increased oxygen demand caused by thermogenesis, moult or acquisition of reproductive status. Our review indicates that the use of haematocrit as a sole indicator of condition or health could lead to incorrect conclusions if natural factors that can affect haematocrit are not taken into consideration.
The tradeoff between immunocompetence and development in avian species could have long‐term consequences relating to fitness. This study investigated the developmental cost of mounting a humoral immune response in growing mountain chickadees, Poecile gambeli. We immunologically challenged nestling chickadees using nonpathogenic antigens of either Newcastle disease virus vaccine or sheep red blood cells. Body mass, tarsal length, haematocrit, total plasma protein, and survival did not vary significantly between antigen treatment groups and control groups. Developmental stability was assessed using fluctuating asymmetry (FA) between the right and left ninth primary feather length. FA was increased significantly in the antigen‐challenged birds. This result indicates that the up‐regulation of the humoral immune response was developmentally costly to the nestlings by causing an increase in FA.
Chuviruses (family Chuviridae), which are in the recently discovered order Jingchuvirales, were first identified in arthropods in 2015 and have been detected through metagenomics in numerous invertebrates, but only a few vertebrates. With only few metagenomically based detections in vertebrates, their replication competency in vertebrates remained questioned, let alone their pathological significance. This study identified three novel chuviruses as the etiology of lymphocytic meningoencephalomyelitis in three wild aquatic turtles: an alligator snapping turtle (Macrochelys sp.), a Kemps ridley turtle (Lepidochelys kempii), and a loggerhead turtle (Caretta caretta). The application of random, deep sequencing successfully assembled the complete snapping turtle chuvirus-1 [STCV-1], Kemps ridley turtle chuvirus-1 [KTCV-1] genome, and loggerhead turtle chuvirus-1 [LTCV-1]) genome. The STCV-1 and KTCV-1 sequences were used to create custom RNAscope probes for in situ hybridization, which confirmed STCV-1, KTCV-1, and LTCV-1 (cross reactivity to the KTCV-1 probe) RNA within the inflamed region of the brain and spinal cord. STCV-1 and KTCV-1 were isolated on several turtle-origin cell lines. Phylogenetic analysis illustrated that all three viruses clustered with other vertebrate chuviruses, all within the genus Piscichuvirus. With more than 91% pairwise amino acid identity of the polymerase proteins, STCV-1, KTCV-1, and LTCV-1 belong to the same novel species, putatively named Piscichuvirus testudinae. This study demonstrates the first in situ evidence of chuviral pathogenicity in animals and only the second instance of jingchuviral isolation. The association of these chuviruses in three different chelonians with neurologic disease suggests the possibility that chuviruses are a significant, previously unrecognized cause of lymphocytic meningoencephalomyelitis in freshwater and marine turtles. Additional studies of these viruses are needed to elucidate their role in chelonians and the possibility of related viruses in other related hosts.
We conducted an experiment on eastern fence lizards {Sceloporus iincliilatus) during August-September 1995 near Los Alamos, New Mexico, (1) to ascertain if lizards that were relocated short distances exhibited homing, (2) to investigate a possible barrier to movement, and (3) to detennine the effect of translocating individuals from a transplant area on lizards in a recipient area. We relocated 15 of an estimated population of 39 (95% CI 36-45) lizards an average distance of 46 m. Foin-teen of 15 translocated lizards returned to within 6.81 (s^ = 1.43) m of the original capture location. Movement distances did not vary (F = 0.76; 1,53 df P -0.381) between resident and tianslocated lizards during the pretreatment period and did not vary for resident (F = 2.86; 1,12 df; P -0.1166), but varied between pretreatment and posttreatment periods tor translocated (F = 14.65, 1,7 df P = 0.0065) lizards. Translocated lizards did not affect the resighting probability of resident lizards (F = 0.96; 1,14 df; P = 0.34), but this may be related to low power (1 -P = 0.15) and translocated lizards moving out of the area quickly.
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