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Simple Summary: Orb-weaving spiders can learn to avoid eating unpalatable prey, but what happens when they encounter one that they have never seen before? In the United States, a spider from East Asia has become established (the "jorō spider") in recent years, and their webs are most prominent during the late-summer and fall, which is also when migrating monarch butterflies are in abundance. Since monarch butterflies are unpalatable (because of developing on toxic milkweeds), we wondered if jorō spiders would recognize this and avoid eating them, given that these species do not coexist in East Asia. Using field observations of butterflies deposited into jorō spider webs, we found that these spiders do avoid eating monarchs, and even remove them from their webs in some cases. They readily attack other butterflies, even those that are similarly colored to monarchs. This raises many questions about how they perceive the "distastefulness" of monarchs, even without tasting the butterflies first. An invasive spider from East Asia has established in the U.S. southeast (the "jorō spider," Trichonephila clavata) and is rapidly expanding its range. Studies assessing the impact of this species are needed, including how expansive its diet is. An open question is whether monarch butterflies, Danaus plexippus, are a potential prey item for this spider, given that jorō spiders do not coexist with monarchs in their native range. Since monarch larvae feed on milkweed, they sequester cardiac glycosides into their adult tissues, rendering them unpalatable to many predators. At sites within northeast Georgia, we staged a series of trials (n = 61) where we tossed monarchs into jorō spider webs and, for comparison, performed similar trials with another aposematic species, gulf fritillary (Agraulis vanilla), and a palatable species, tiger swallowtail (Papilio glaucus). We recorded the outcome of the trials, which included whether the spider attacked or did not attack the prey. We also conducted a visual survey during the same fall season to look for evidence of jorō spiders consuming monarchs naturally. Our findings revealed that jorō spiders avoided eating monarchs; spiders only attacked monarchs 20% of the time, which was significantly less than the attack rates of similarly sized or larger butterflies: 86% for gulf fritillaries and 58% for tiger swallowtails. Some jorō spiders even removed monarchs from their webs. From our visual surveys of the surrounding area, we found no evidence of natural monarch consumption and, in general, butterflies made up only a fraction of the jorō spider diet. We conclude that jorō spiders appear to recognize monarch butterflies as being unpalatable, even without having a prior history with the species. This invokes questions about how these spiders can immediately recognize their unpalatability without touching the butterflies. [ABSTRACT FROM AUTHOR]

An invasive orb-weaving spider from east Asia is now spreading through the southeastern United States; Trichonephila clavata (the "jorō spider") makes large, imposing webs seemingly everywhere, including in urban landscapes, and even next to busy roads. However, areas near roads come with frequent disturbances, including auditory and vibrational, which for many animals, leads to physiological or behavioral changes. Here we tested if varying levels of road traffic affect the prey–capture behavior of jorō spiders in northeast Georgia. We visited roadsides that ranged in traffic density and exposed nearby jorō spiders to a simulated prey (a tuning fork at 128 hz frequency, touched to the web), and recorded whether or not the spider attacked it. Out of 357 total trials across 20 different roads, jorō spiders attacked the simulated prey 59% of the time, but at the local scale, there was high variability in this rate; at some roadsides, over 80% of the spiders attacked, while at others, less than 30% did. When all roads were considered collectively, there was a small but significant (negative) correlation between daily road traffic and spider attack rates. Put another way, spiders near moderate- to heavy-traffic roads were slightly less likely to attack than those near low-traffic roads (51% vs. 65%). Jorō spiders appear to be able to live near roads, but this does come with a cost in terms of prey capture. However, spiders near busier roads did not weigh less than those in other sites, suggesting they may be able to compensate for the disturbance. These findings add to the accumulating evidence around this species that points to its ability to exist in human-dominated landscapes, which will likely aid its spread in the introduced range. [ABSTRACT FROM AUTHOR]

Elucidating the adaptations that promote flight in animals can aid the understanding of evolution and species divergence, and/or provide inspiration for aerospace engineering and the design of better aerial vehicles. The famed long-distance migration of monarch butterflies in North America still holds many questions and opportunities for inspiration. For example, there is little research on whether the monarch's primary wing colors themselves (black, orange, or white) have any aerodynamic or migration function. Dark colors on wings of other animals have recently been shown to aid flight by enhancing solar absorption, which reduces drag forces. However, too much black surface could be problematic for monarchs, which are exposed to increasing amounts of solar energy along their flightpath. This paper describes the results of two related investigations that attempt to elucidate the importance of wing color to the monarch migration. By measuring the color proportions of nearly 400 monarch wings collected at different stages of their journey, we found, surprisingly, that successful migrants tended to have less black on their wings (about 3% less), but also more white pigment (about 3% more); monarchs have a band of light-colored marginal wing spots. Second, image analysis of museum specimens revealed migratory monarchs had significantly larger white spots, proportional to the wing area, than most non-migratory, New World Danaid butterflies, which argues spot size has evolved along with migratory behavior. Combined, these findings strongly suggest that the long-distance migration itself selects for larger white spots every fall, so that only those individuals with large spots will survive to pass on their genes. Further experimental work is needed to elucidate how the spots aid the migration, but it is possible that they enhance aerodynamic efficiency; other work by the authors demonstrates how alternating white and black pigment on wings can reduce drag. These results will serve as a useful starting point for such endeavors, which should improve understanding of one of the world's most fascinating animal migrations, and also provide practical knowledge for the field of aerospace engineering. [ABSTRACT FROM AUTHOR]

The jorō spider (Trichonephila clavata, originally from east Asia) has been introduced in the southeastern United States, and is rapidly expanding this range, leading to questions about what facilitates this spread. Meanwhile, its cousin, the golden silk spider (T. clavipes), already has a range that covers most of the southeast. In an ongoing effort to understand the behavior of jorō spiders in their introduced range, we undertook the current project to evaluate how they react to perceived threats, which can inform us on how a species interacts with conspecifics, or how well it can tolerate anthropogenic disturbances. We collected mature females of both Trichonephila species, plus three locally common orb-weaving species in Georgia, and we evaluated the time spent immobile after experiencing a mild disturbance (a brief puff of air). We also collected similar "air puff response" data for five other North American species from the published literature. Collectively, the dataset totaled 453 observations of freezing behavior across 10 spider species. Comparing these data across species revealed that most spiders remained immobile for under a minute after the stimulus. Meanwhile, both Trichonephila spiders remained immobile for over an hour, which appears to be unprecedented, and suggests that spiders in this genus are the "shyest" ever documented. This reaction could also allow Trichonephila spiders to tolerate urban environments by remaining motionless throughout each disturbance instead of fleeing. [ABSTRACT FROM AUTHOR]

Some animals react to predation threats or other stressors by adopting a freezing posture in an attempt to avoid detection, and the duration of this behavior usually corresponds with individual personality, such that timid individuals freeze longer. Despite decades of research on this or related behaviors (thanatosis), never has the impact of parasitism been considered. Parasites could prolong the duration, if hosts are less motivated to move (i.e. lethargic), or they could reduce it, if hosts are motivated to forage more to compensate for energy drain. We examined this behavior within a natural beetle-nematode system, where hosts (horned passalus beetles, Odontotaenius disjunctus) are parasitized by a nematode, Chondronema passali. We exposed beetles (n = 238) to four stressors in our lab, including noise, vibration, light and inversion, and recorded how long they adopt a frozen stance. Afterward, we determined nematode burdens, which can range from dozens to hundreds of worms. Beetles tended to freeze for 20 seconds on average, with some variation between stressors. We detected no effect of beetle mass on the duration of freezing, and this behavior did not differ in beetles collected during the breeding or non-breeding season. There was a surprising sex-based difference in the impact of nematodes; unparasitized females remained frozen twice as long as unparasitized males, but for beetles with heavy nematode burdens, the opposite was true. From this we infer that heavily parasitized females are more bold, while males with heavy burdens would be more timid. The explanation for this finding remains elusive, though we can rule out many possibilities based on prior work on this host-parasite system. [ABSTRACT FROM AUTHOR]

A newly‐invasive spider from east Asia, Trichonephila clavata, or "jorō spider", is spreading in the southeastern United States. Little is known about the biology or physiology of this species in this new range. Interestingly, a closely‐related species in the same genus, the "golden silk spider," Trichonephila clavipes, is already successfully established in this same region over the last 160 years. The golden silk spider, which is native to the tropics, has not expanded its range beyond the southeast, likely because of thermal limitations. This investigation is to determine how the biology and physiology of T. clavata compare to T. clavipes. We reason that if their physiologies are similar, then T. clavata would be similarly confined to the southeast. We examine online records submitted to iNaturalist.org to compare seasonal distributions and timing, and we collect females to measure physiological traits that help predict environmental tolerance, including metabolic rates, cardiac functioning (heart rate) during cold‐exposure, and survival during brief (2 min) below‐freezing temperature. Results show the jorō spider has a shorter season than its cousin, indicating it can complete its lifecycle within a narrow period of suitable weather. It has an inherently higher metabolism (twice as high), and has a 77% higher heart rate when exposed to low temperature. Finally, jorō spiders survive better (74% compared to 50%) in a brief freeze. These findings suggest the jorō spider can exist in a colder climatic region than the southeastern USA, which can be useful information for management or planning purposes. [ABSTRACT FROM AUTHOR]

Insect–pathogen dynamics can show seasonal and inter‐annual variations that covary with fluctuations in insect abundance and climate. Long‐term analyses are especially needed to track parasite dynamics in migratory insects, in part because their vast habitat ranges and high mobility might dampen local effects of density and climate on infection prevalence.Monarch butterflies Danaus plexippus are commonly infected with the protozoan Ophryocystis elektroscirrha (OE). Because this parasite lowers monarch survival and flight performance, and because migratory monarchs have experienced declines in recent decades, it is important to understand the patterns and drivers of infection.Here we compiled data on OE infection spanning 50 years, from wild monarchs sampled in the United States, Canada and Mexico during summer breeding, fall migrating and overwintering periods. We examined eastern versus western North American monarchs separately, to ask how abundance estimates, resource availability, climate and breeding season length impact infection trends. We further assessed the intensity of migratory culling, which occurs when infected individuals are removed from the population during migration.Average infection prevalence was four times higher in western compared to eastern subpopulations. In eastern North America, the proportion of infected monarchs increased threefold since the mid‐2000s. In the western region, the proportion of infected monarchs declined sharply from 2000 to 2015, and increased thereafter. For both eastern and western subpopulations, years with greater summer adult abundance predicted greater infection prevalence, indicating that transmission increases with host breeding density. Environmental variables (temperature and NDVI) were not associated with changes in the proportion of infected adults. We found evidence for migratory culling of infected butterflies, based on declines in parasitism during fall migration. We estimated that tens of millions fewer monarchs reach overwintering sites in Mexico as a result of OE, highlighting the need to consider the parasite as a potential threat to the monarch population.Increases in infection among eastern North American monarchs post‐2002 suggest that changes to the host's ecology or environment have intensified parasite transmission. Further work is needed to examine the degree to which human practices, such as mass caterpillar rearing and the widespread planting of exotic milkweed, have contributed to this trend. [ABSTRACT FROM AUTHOR]

Ants, like other insects, have a heart that pumps hemolymph rhythmically. We designed an apparatus and procedure to non‐destructively monitor the rate of cardiac contractions in ants, using a modified light microscope and infrared light. This allowed us to obtain the first baseline heart rate data on three ant species, collected in Georgia, USA. We next describe how ant heart rates can be stimulated, for comparing cardiac reactions among colonies, or for assessing stress responses. The procedures described here may be useful for other researchers interested in ant physiology. [ABSTRACT FROM AUTHOR]

Internal parasites typically are associated with a range of negative effects on their hosts, including reduced energy, which can manifest in behavioral alterations. With this in mind, we examined effects of a naturally-occurring nematode parasite, Chondronema passali, on locomotor activity level in horned passalus beetles, Odontotaenius disjunctus from Georgia, USA. This parasite is not well-studied but can number in the thousands in severely parasitized hosts. Prior study in our lab revealed that parasitized beetles actually consume more wood than unparasitized ones do, leading us to ask here, if parasitized beetles are also more physically active. Beetles were collected from nearby forests and housed individually in our lab. We created a simple tabletop arena to observe beetle locomotor activity, which was gridded and included small stones and paper objects. We allowed individual beetles to traverse the arena for 5 min and recorded the number of grid squares crossed. Then, beetles were dissected to determine parasite presence and level of infection (on a categorical scale). A total of 140 beetles were examined across three collections. Statistical analyses of locomotor activity revealed parasite severity predicted locomotor activity, but paradoxically, lightly-infected beetles were twice as active as those without this nematode. Activity diminished with increasing worm burdens thereafter, but even the group with the most severe burdens did not move less than those with no worms. From these results we conclude that this parasite does not result in overall reduction in activity, but rather it appears to come with heightened locomotion. Alternatively, this result could stem from the fact that more active beetles are simply more likely to contract the parasite. [ABSTRACT FROM AUTHOR]

Diamond-backed Terrapins inhabit coastal salt marshes along the eastern and Gulf coasts of North America. Terrapins are adapted to intermediate salinities yet frequently face saltwater-inundated marsh habitat exceeding 25 ppt (or grams/kilogram). We investigated the effect of salinity on the growth of hatchling terrapins and on their compensatory responses to salinity stress. We randomly assigned 30 terrapin hatchlings each to one of five salinity treatments (1, 5, 10, 20, or 35 ppt). Over 75 d, we regularly monitored behavior, appetite, and changes in growth; and calculated ratios of heterophils to lymphocytes (H:L ratio) to assess responses to prolonged salinity stress. Consistent with prior studies, chronic exposure to high salinity significantly reduced hatchling growth. Hatchlings in 20-ppt and 35-ppt salinities exhibited appetite suppression and saltwater avoidance and were more likely to show freshwater-seeking behaviors. H:L ratios were higher among hatchlings in 20- and 35-ppt salinities, consistent with a corticosterone-driven stress response to sustained high-salinity exposure, which may play a role in limiting growth. Our findings suggest hatchling growth and distribution among local habitats will vary spatially depending on habitat salinity and freshwater accessibility. The growth-limiting effects of chronically high salinity or limited access to freshwater could therefore increase hatchling mortality and be an important driver of spatial variation in terrapin demography and abundance. However, when freshwater sources are available, compensatory behaviors might reduce growth-limiting effects. Terrapin recruitment is likely to be impacted as rising sea levels, increased human water use, land development, and other anthropogenic changes alter freshwater inputs to coastal marshes. [ABSTRACT FROM AUTHOR]

The rigours of the daily lives of insects sometimes lead to minor injuries and wounds, which must be healed to avoid entry of pathogens and to resume normal function. Such healing requires energy, which must be diverted from other bodily reserves. What happens if energy reserves are already low, as would occur in individuals coping with internal parasites? This question is addressed in the presemt study, using horned passalus beetles (Odontotaenius disjunctus) and their naturally‐occurring nematode Chondronema passali. Oxygen consumption rates are tested at rest, as well as after an experimental wound is applied, to evaluate energy requirements of wound‐healing in parasitized and nonparasitized hosts. Furthermore, wound‐healing rates are visually tracked with a numerical scoring system to directly measure the cost of parasitism on healing. At rest, parasitized beetles show no elevation in respiration (oxygen consumption). After wounding, the oxygen consumption of parasitized beetles is 10% higher than that in nonparasitized beetles. Beetles with moderate‐ to heavy worm burdens have slower healing than those with few or no nematodes. These results show that this parasite carries little cost to the host during day‐to‐day activities, whereas, during times of immediate energy demand, there is a cost; hosts require more energy to repair wounds, and the wounds take longer to close. This conclusion leads to the question of whether this parasite is truly benign, and how many other apparently benign parasites, in insects or other animals, have similar 'hidden' effects. [ABSTRACT FROM AUTHOR]

Humans have an especially close connection with the monarch butterfly, Danaus plexippus, and this connection often involves direct handling of larvae, pupae or adults. Monarchs are frequently handled in citizen science programs, education and outreach activities, classroom demonstrations, and when rearing larvae in captivity. A pertinent question is whether monarchs perceive this human handling in the same way as being attacked by a predator, i.e. does it trigger a physiological fight-or-flight reaction? Here, I investigated if brief periods of handling monarch larvae, pupae, or adults elevates their heart rate (a central component of the insect fight-or-flight response), using non-destructive methods: either microscopy or an electronic heart monitor designed for invertebrates. Results are presented from separate investigations on each life stage. Three minutes of gentle handling caused a significant elevation (20%) in heart rates of 30 fifth-instar larvae. Mild physical disturbance for 20 seconds to a collection of 57 pupae elicited brief bursts of heart contractions (∼88 beats/min), a rate which is three times higher than typical contraction periods at this stage. Adult monarchs captured during fall migration (n=72) showed minor heart rate elevations (6%) after 3 minutes of gentle handling for tagging purposes. The differences in reactions across life stages found here is helpful for elucidating the relative sensitivity of each stage to handling. More importantly, these results elucidate the unseen physiological impact of direct human contact on developing monarchs (larvae and pupae); elevation in heart rate is an integral part of the fight-or-flight reaction in animals and a universal sign that an animal perceives an imminent threat. In this sense then, developing monarchs appear to perceive human handling as a threat, which may alter our (human) perception of this practice. [ABSTRACT FROM AUTHOR]

In this project, red-backed salamanders, Plethodon cinereus, were collected from the heart of their range (Mountain Lake, Virginia, USA), in an effort to document the typical, or baseline, leukocyte profile of this species in its natural state. From microscopic examination of thin blood films, we determined relative proportions of all leukocyte types and determined the ratio of neutrophils to lymphocytes, which is a useful index of stress levels. In addition, individuals were examined for three naturally occurring endoparasites: two gastro-intestinal (trematodes and a ciliated protozoan in the genus Cepedietta) and one in the blood (a Rickettsial bacteria). This allowed us to conduct statistical comparisons of leukocyte data across parasite infection groups. Of 36 salamanders, 11 (31%) had trematode parasites, 7 (19%) contained Cepedietta parasites, 6 (17%) were parasitized by Rickettsia, and 12 had no parasites. The most common leukocytes were lymphocytes (87.4%), followed by neutrophils (4.2%), monocytes (3.3%), eosinophils (2.6%), and basophils (2.5%). The average neutrophil/lymphocyte ratio for these salamanders was remarkably low (0.05) for an amphibian population. Statistical comparisons of leukocyte profiles among parasite infection groups indicated parasitized salamanders had twice as many circulating leukocytes as nonparasitized individuals, which could be considered an "inflammation response". There was a slight but significant elevation in relative eosinophil abundance in parasitized salamanders. There were few differences in leukocyte subsets between parasite types, nor was there evidence of any proliferation of phagocytic cells in any parasitized individual. [ABSTRACT FROM AUTHOR]

There are many events in the lives of insects where rapid, effective stress reactions are needed, including fighting conspecifics to defend territories, evading predators, and responding to wounds. A key element of the stress reaction is elevation of heartrate (HR), for enhancing distribution of blood (hemolymph) to body compartments. We conducted two experiments designed to improve understanding of the insect stress reaction and how it is influenced by parasitism in a common beetle species (Odontotaenius disjunctus). By non-destructively observing heartbeat frequency before, during and after applying a stressor (physical restraint) for 10 min, we sought to determine: (1) the exact timing of the cardiac stress reaction; (2) the magnitude of heartrate elevation during stress; and (3) if the physiological response is affected by a naturally-occurring nematode parasite, Chondronema passali. Restraint caused a dramatic increase in heartrate, though not immediately; maximum HR was reached after approximately 8 min. Average heartrate went from 65.5 beats/min to a maximum of 81.5 (24.5% increase) in adults raised in the lab (n = 19). Using wild-caught adults (n = 77), average heartrates went from 54.9 beats/min to 74.2 (35.5% increase). When restraint was removed, HR declined after ~5 min, and reached baseline 50 min later. The nematode parasite did not affect baseline heartrates in either experiment, but in one, it retarded the heartrate elevation during stress, and in the other, it reduced the overall magnitude of the elevation. While we acknowledge that our results are based on comparisons of beetles with naturally-occurring parasite infections, these results indicate this parasite causes a modest reduction in host cardiac output during acute stress conditions. [ABSTRACT FROM AUTHOR]

All animals, whether vertebrate or invertebrate, must be capable of reacting to acute stressors, such as escaping from predators, and most do so with a suite of transient physiological changes that temporarily enhance survival. Some of these changes include mobilization of immune cells and increased cardiac output. A small but growing number of studies have begun to show that certain parasites appear capable of modifying such responses. We addressed this topic using a natural host and parasite system, that is, a nematode (Chondronema passali) that parasitizes horned passalus beetles, Odontotaenius disjunctus (family Passalidae), of the eastern United States.With a series of experiments, we sought to determine whether this parasite affects (1) the immune reaction to stress, (2) the output of stress-induced alarm calls, or (3) the increase in heart rate that occurs in response to acute stressors, with the stressors being mechanical or thermal. Results showed that hemocyte density increased after both stressors in nonparasitized beetles but did not increase in parasitized beetles. While mobilization of immune cells would enhance host immunity during stress, this would also be damaging to the nematode, so this scenario appears to benefit the parasite. We found no evidence that the nematode suppresses the overall reaction to stress (or prevents stress from occurring), since parasitized beetles did not differ from nonparasitized ones in alarm call rates or in heart beat frequency after exposure to mechanical stressors. Suppression of the host's normal immune reaction to stressful stimuli could translate to delayed or even reduced wound healing or pathogen resistance during these events. This project is a rare demonstration of parasite manipulation of host immune response to acute stress and should stimulate further investigations into the interactive nature of stress and parasites. [ABSTRACT FROM AUTHOR]

Lepidopteran larvae are often brightly colored to signal their distastefulness to predators. Within most species, there is usually a degree of individual variation in color patterns that has rarely been studied. Here we report observations, across several years, of larval Queen butterflies (Danaus gilippus) in the state of Texas, USA that appeared highly unusual with respect to their color pattern. Queen larvae normally have alternating bands of dark and light stripes and yellow spots, but the Texas caterpillars had patterns of violet-red bands alternating with white bands and minimal yellow spots, giving them an overall red and white appearance. To put these observations into context, we conducted a survey of color patterns of this species by evaluating postings of online photographs from around the country (n=57). In online images, the base color (non-white stripes) of the species was predominantly black (80% of cases), but varied from dark purple to violet. The survey results suggested that the observations of unusual larvae in Texas may represent an extreme form from a naturally occurring, wide spectrum of color patterns in this species. [ABSTRACT FROM AUTHOR]

Monarch butterflies in North America have an exceptionally large breeding distribution, occupying regions west of the Rocky Mountains and throughout the eastern seaboard. An experimental study conducted 17 years ago and published in this journal appeared to show that western monarch larvae tend to have smaller black stripes than those from eastern parents, which at the time was thought to be an adaptation to higher solar exposure in California. Here, we revisit this question by measuring melanism of eastern and western larvae from online photographs submitted to iNaturalist by members of the public. We downloaded over 500 photos of larvae from 10 different states (4 in the west, 6 in the east) and used image analysis to quantify the size of each larva's black stripes (% of surface covered by black). We compared average melanism level between east and west, while also accounting for temperature (at the photo location), seasonal effects, and latitude. Results showed larvae tended to be darker with lower development temperatures, and later in the season, though there was no significant difference between eastern and western larvae in their degree of melanism. It is not yet clear why findings here were different from the prior experimental study. Also, the wild larvae appeared to be notably lighter in color than the captive-reared larvae of the original study, suggesting that the captive environment does not truly replicate the developmental experience of wild larvae, at least in terms of cuticular development. Thus, if there truly are innate tendencies for western larvae to differ (morphologically) from eastern, they are not observable in nature. • Monarch butterflies in North America were once thought to have two distinct eastern and western populations. • Early laboratory work published in this journal showed western larvae were lighter in color than eastern. • Melanism levels of 500+ online photos of wild larvae showed no difference between western and eastern subpopulation larvae. • Monarch larvae tend to be darker with lower temperatures, and, later in the season. • Findings are consistent with more recent evidence for a single population in North America. [ABSTRACT FROM AUTHOR]

Annual estimates of population size are important for tracking long-term population trajectories. There is concern that monarch butterflies (Danaus plexippus L.) in eastern North America are declining because the Mexican overwintering colonies have been shrinking over the past 20yr. We examined a I9-yr data set of fall monarch censuses at a site in northern Michigan (Peninsula Point) to determine if the number of monarchs counted here has changed over time. At this site, volunteers walk a standardized transect daily during the fell to record migratory monarchs. Our secondary goal was to evaluate the relationship between the annual numbers at Peninsula Point and the size of the subsequent overwintering colonies. A statistical model that included multiple predictors of 1,793 census counts revealed a small but significant positive effect of year on counts, but the mean annual count number was not significantly correlated with year. In either case, we found no evidence for declines in monarch abundance. We also found no relationship between annual estimates of abundance at Peninsula Point and annual estimates of overwintering colony size. We interpret the disparity between long-term patterns here versus those in Mexico to be the result of mortality during migration or other factors that reduce migration success. Given this conclusion, we argue that preserving migratory habitats and resources, as well as reducing anthropogenic activities that hinder migration, should be the highest priorities for conserving monarchs in eastern North America. [ABSTRACT FROM AUTHOR]

Declines in overwintering colonies of monarch butterflies (Danaus plexxipus) in Mexico raise questions about other life cycle phases, such as spring migration, where monarchs recolonize their breeding range in the United States and Canada with sequential generations. We used data from a longterm citizen science program, "Journey North" (now with 18 yr), to identify possible changes to the recolonization. This program asks people to report the date and location when they see the first adult monarch annually, and this database now contains >11,000 records. We examined sighting dates and migration range size, the latter based on the number of 2-degree latitude-longitude grid squares with monarch sightings, to look for evidence of change in either of these two parameters over the 18yr. Our analyses used regression models that accounted for increasing volunteer participation over the years. We found monarchs are being sighted later at a rate of 1 d later every 4 yr. This does not appear to be related to later emergence of milkweed, based on examination of milkweed reports. Later sightings could be interpreted as a sign of reductions in monarch abundance (it takes longer to see the first monarch of the year). We also found a potential decline in the geographic range of the initial spring migration wave (a decline of 9% over 18 yr). However we detected no change in the continental area encompassed at the end of recolonization, indicating monarchs are still successfully f illing their traditional breeding range in eastern North America. [ABSTRACT FROM AUTHOR]

Objectives Several lines of evidence suggest that abnormalities within portions of the extended limbic network involved in affective regulation and expression contribute to the neuropathophysiology of bipolar disorder. In particular, portions of the prefrontal cortex have been implicated in the appearance of manic symptomatology. The effect of atypical antipsychotics on activation of these regions, however, remains poorly understood. Methods Twenty-two patients diagnosed with bipolar mania and 26 healthy subjects participated in a baseline functional magnetic resonance imaging scan during which they performed a continuous performance task with neutral and emotional distractors. Nineteen patients with bipolar disorder were treated for eight weeks with quetiapine monotherapy and then rescanned. Regional activity in response to emotional stimuli was compared between healthy and manic subjects at baseline; and in the subjects with bipolar disorder between baseline and eight-week scans. Results At baseline, functional activity did not differ between subjects with bipolar disorder and healthy subjects in any region examined. After eight weeks of treatment, subjects with bipolar disorder showed a significant decrease in ratings on the Young Mania Rating Scale ( YMRS) (p < 0.001), and increased activation in the right orbitofrontal cortex ( OFC) (p = 0.002); there was a significant association between increased right OFC activity and YMRS improvement (p = 0.003). Conclusions These findings are consistent with suggestions that mania involves a loss of emotional modulatory activity in the prefrontal cortex-restoration of the relatively greater elevation in prefrontal activity widely observed in euthymic patients is associated with clinical improvement. It is not clear, however, whether changes are related to quetiapine treatment or represent a non-specific marker of affective change. [ABSTRACT FROM AUTHOR]

Recent declines in the size of overwintering colonies of monarch butterflies ( Danaus plexippus) in eastern North America have stimulated calls for greater conservation efforts of the migratory phenomenon. Conservation decisions, however, should be guided by sound science, and the migratory phase of this population is the least-studied part of its life cycle., Data from large-scale citizen science programs can help address this knowledge gap. For over 20 years, volunteers have been tagging migrating monarchs with numbered stickers from MonarchWatch (), who oversees the management of tagging and recovery records. These data have the potential to vastly improve scientific understanding of the migratory phase (such as identifying spatial and temporal trends in mortality) and help target conservation efforts, but this potential has not yet been fully realised, based on a review of published studies in the last 20 years., Since citizen science programs are often understaffed and operate on minimal budgets, data analysis may not be a high priority for project staff. To stimulate scientific investigations using tagging data, there are alternative solutions that could be implemented including making data publicly available or soliciting assistance from external scientists. Such efforts would not only benefit research into monarch biology, but would lend scientific credibility to tagging activities., Tagging monarchs is a popular activity with clear educational value. In my opinion these data could be, however, better utilised to improve the conservation of the migratory phenomenon itself. [ABSTRACT FROM AUTHOR]

The physiological basis for pigment synthesis in lepidopteran wing scales is well-studied, although less is known about the reasons why individuals of the same species vary in pigmentation. Monarch butterflies (Danaus plexippus L.) show subtle variations in the shade of orange on their wings and this is known to predict flight ability and mating success. The present study tests the possibility that the shade of orange is associated with the amount of residual energy reserves carried over from the larval stage. Using monarchs reared in captivity under identical conditions (n = 207), the residuals of a regression of wing size and mass at eclosion, which indicate larval energy reserves, are obtained. This measure is positively related to adult longevity without feeding, indicating the importance of this reserve to the monarchs, as well as the value of the measure for this investigation. The shade of orange (i.e. hue) is determined on scanned wings using image analysis. Importantly, orange hue is predicted significantly by residual mass at eclosion (individuals with more mass are redder). The linkage between these traits may explain previous findings whereby redder monarchs fly further and mate more because both behaviours would be enhanced with greater energy stores. The findings of the present study add to a growing body of work showing how intraspecific variation in pigmentation has biological significance to monarchs, and possibly other butterflies. Although much remains to be investigated regarding the physiological underpinnings of this variation, the results of the present study indicate that future efforts should be rewarding. [ABSTRACT FROM AUTHOR]

Current evidence suggests that the health effect of avian feather mites is minimal. However, feather mites can still proliferate without effective preening, such as might occur during sickness. House Finches (Haemorhous mexicanus) are prone to infection by Mycoplasma gallisepticum, symptoms of which include conjunctivitis. Impaired vision and lethargy associated with the disease may limit preening ability. We examined trapping data from a 4-year study of Mycoplasma infection dynamics in House Finches in Atlanta, Georgia, to determine whether birds with conjunctivitis had higher feather mite loads. Abundance of feather mites (Proctophyllodes spp.) and conjunctivitis severity were visually scored on >800 House Finches of known age and sex. Feather mite abundance showed a distinct seasonal pattern: mite loads increased in July and remained high through January. Limiting the analyses to these months, we found that average mite scores were higher in birds with (n = 94) than in those without (n = 275) conjunctivitis, and mite loads increased with conjunctivitis severity. Although not significant, the mite scores in recaptured birds in relation to infection status support the other findings in the present study. Although these results from field-collected birds do not demonstrate cause and effect, they are consistent with prior studies in which feather mites increased in experimentally infected birds. The implications of this proliferation for the birds require further study, but given that feather mites consume oil and debris from feathers, their high numbers during illness could be beneficial. [ABSTRACT FROM AUTHOR]

When the wing sizes of all collections are plotted side by side (Figure 1), it becomes obvious that the traditionally migratory western North American monarchs have wings that are as large as those from the east, which is consistent with the current evidence that eastern and western monarchs are not dissimilar [[24]], and that the demands of long-distance migration select for large wing size [[26]]. Here, I contest this claim by showing how the monarchs reared in that study were smaller than traditionally-migratory western monarchs, and in fact resembled the size of every other non-migratory population of monarchs studied. Table 1 Summary of published data on monarch wing lengths from around the world for comparison with James et al., 2021, who reared monarchs in winter in California. Monarchs Reared in Winter in California Are Not Large Enough to Be Migrants. [Extracted from the article]

Museum collections have great value for zoological research, but despite careful preservation, over time specimens can show subtle changes in color. We examined the effect of storage time on fur color of two reddish-brown species, golden mice (Ochrotomys nuttalli) and eastern chipmunk (Tamias striatus). Using image analysis, we obtained color data (hue, saturation, and density) on 91 golden mice and 49 chipmunks from Georgia, USA. Analyses that considered body size, gender, and collection year showed significant effects of year on fur color of golden mice (hue and saturation) and of agouti color of chipmunks. Older specimens tended to be redder in color than newer specimens, consistent with a prior study of red bats (Lasiurus borealis). Hair samples showed reddening of fine body hairs, but not in thicker guard hairs. There was no temporal change in black or white stripe color in chipmunks, indicating that this temporal effect would be limited to species with reddish-brown fur. This effect may be caused by breakdown of eumelanin pigments (which make dark colors) over time, leaving a greater proportion of pheomelanin pigments (which make red colors). These results show that storage time needs to be considered in research projects where fur color is of importance. [ABSTRACT FROM AUTHOR]

The distinctive orange and black wings of monarchs (Danaus plexippus) have long been known to advertise their bitter taste and toxicity to potential predators. Recent work also showed that both the orange and black coloration of this species can vary in response to individual-level and environmental factors. Here we examine the relationship between wing color and flight performance in captive-reared monarchs using a tethered flight mill apparatus to quantify butterfly flight speed, duration and distance. In three different experiments (totaling 121 individuals) we used image analysis to measure body size and four wing traits among newly-emerged butterflies prior to flight trials: wing area, aspect ratio (length/width), melanism, and orange hue. Results showed that monarchs with darker orange (approaching red) wings flew longer distances than those with lighter orange wings in analyses that controlled for sex and other morphometric traits. This finding is consistent with past work showing that among wild monarchs, those sampled during the fall migration are darker in hue (redder) than non-migratory monarchs. Together, these results suggest that pigment deposition onto wing scales during metamorphosis could be linked with traits that influence flight, such as thorax muscle size, energy storage or metabolism. Our results reinforce an association between wing color and flight performance in insects that is suggested by past studies of wing melansim and seasonal polyphenism, and provide an important starting point for work focused on mechanistic links between insect movement and color. [ABSTRACT FROM AUTHOR]

. 1. The status of the eastern North American monarch butterfly population is a highly sensitive issue, given that winter and breeding habitats are being lost at an alarming rate each year, and because of this, most believe the population to be declining, although there has been little empirical data to support this idea. In a recent forum article of this journal, Brower et al. (2011) report a statistically significant decline in winter colony size over a 17-year period and suggest that this is the first sign of impending collapse. 2. I conducted an analysis of numbers of migrating monarchs from two fall monitoring stations in the United States (Cape May, NJ and Peninsula Point, MI), which span 15 and 19 years, respectively, and at both locations there was no significant linear trend in average monarch numbers counted over time, which is in marked contrast to the conclusion drawn by Brower et al. (2011). 3. Although I identify several possible reasons for the discrepancy between the fall census counts and size of the overwintering areas, these differing patterns argue for a more balanced perspective regarding the status of this population, and certainly for considering more than one phase of the life cycle. Even though it is difficult to imagine how monarchs will fare in the future with so many threats to their population, the data presented here suggest that the population remains stable for now, probably because of the high fecundity of the species and its ability to rebound from small winter numbers. [ABSTRACT FROM AUTHOR]

Monarch butterflies (Danaus plexippus) in eastern North America must make frequent stops to rest and refuel during their annual migration. During these stopovers, monarchs form communal roosts, which are often observed by laypersons. Journey North is a citizen science program that compiles roost observations, and we examined these data in an attempt to identify habitat characteristics of roosts. From each observation we extracted information on the type of vegetation used, and we used GIS and a national landcover data set to determine land cover characteristics within a 10 km radius of the roost. Ninety-seven percent of roosts were reported on trees; most were in pines and conifers, maples, oaks, pecans and willows. Conifers and maples were used most often in northern flyway regions, while pecans and oaks were more-frequently used in southern regions. No one landcover type was directly associated with roost sites, although there wasmore open water near roost sites than around random sites. Roosts in southern Texas were associated primarily with grasslands, but this was not the case elsewhere. Considering the large variety of tree types used and the diversity of landcover types around roost sites, monarchs appear highly-adaptable in terms of roost site selection. [ABSTRACT FROM AUTHOR]

In polymorphic mammalian species that display multiple color forms, those with dark, or melanic pelage would be prone to overheating, especially if they live in warm climates, because their fur absorbs solar energy at a higher rate. However, experimental studies indicate that certain physical properties of fur of dark individuals appear to prevent, or minimize heat stress, although it is not clear what properties do so. Here, we tested the possibility that black-furred individuals simply have shorter or thinner hair fibers, which would create a lighter (in terms of weight) coat or one that allows greater air flow for evaporative cooling. We examined museum specimens of eastern fox squirrels Sciurus niger, a species native to the United States and one that displays brown, grey or all-black pelage color, and used image analysis procedures to quantify hairs from the dorsal surface and tail. From examination of 43 specimens (19 brown, 9 black and 15 grey), and 1,720 hairs, we found no significant difference in hair lengths across color morphs, but significant differences in hair fiber widths. Black squirrels had thinner body hairs than other forms (7% thinner), but thicker tail hairs (9% thicker) than the others. Given that the dorsal surface would be directly exposed to solar radiation, we interpret this to be an adaptation to prevent heat stress during the day. The thicker tail hairs may be an adaptation for nighttime thermoregulation, since squirrels sleep with their tails wrapped around their bodies. These results add to a growing literature body of the functional significance of mammalian pelage. [ABSTRACT FROM AUTHOR]

One of the most well-studied avian diseases is the annual outbreak of Mycoplasma gallisepticum (MG) infections in house finches (Carpodacus mexicanus) in North America. This is a bacterial disease that causes conjunctivitis in one or both eyes of the host. While studying this disease in a New York finch population, researchers observed that there was a tendency for the conjunctivitis to be more prominent in the left eye of infected birds, although the small sample size of that study made it difficult to draw conclusions regarding this unusual observation. Here, this idea is tested further using a larger data set from a 4-year trapping study of house finches in Atlanta, Georgia, USA, a location with a high prevalence of MG infections. The severity of conjunctivitis in each eye of infected birds was scored on a 0-3 scale, and these data were statistically examined to identify possible side-biases in severity. Out of 254 house finches with conjunctivitis, the eye scores of all left eyes were significantly higher than right eye scores. There was no evidence for differential effects of conjunctivitis in left-bias or right-biased infections, and the left-biased pattern was similar in both sexes and in adult and young birds. These results confirm the anecdotal observation from the New York population and suggest that this is a universal phenomenon in the house finch-MG system. The significance of the finding is unknown, although the possibility exists that house finches display a degree of 'handedness' that causes their left sides to be exposed more frequently to potential fomites (i.e. bird feeders). [ABSTRACT FROM AUTHOR]

The article examines the sexual differences in guard hair morphology from the coyote Canis latrans and white tailed deer Odocoileus virginianus, two distinct species of mammals from North America. It cites the functions of the fur of mammals including thermoregulation. Species of wool-bearing mammals that are studied because of the economic importance of their fur are mentioned including blue foxes, cashmere goats, and domestic sheep.

Mammalian pelage color can vary among individuals of many species, although this intraspecific variation is often overlooked by researchers, perhaps because of its sometimes subtle nature and difficulty in assessing it quantitatively. Thus, such variation is rarely studied in mammals, and this is especially true within the order Chiroptera, where there has been very little empirical research. We examined museum specimens of red bats (Lasiurus borealis, family Vespertilionidae) from Georgia, USA, to determine the extent of sexual dimorphism in pelage color and to explore possible associations between body size and pelage color. We photographed 54 specimens under uniform lighting, and used an image analysis program to measure pelage hue on the uropatagium region, which is fully furred in members of the genus Lasiurus. Statistical analyses of pelage hue scores showed males had significantly redder pelage than females when considered alone, but when examined together with effects of body size and collection year, sex was not significant, and collection year and body size were. More recent specimens tended to be less red than older specimens, which might indicate a wearing of the buffy tips of hairs from older specimens, and smaller bats of both sexes tended to be more red. These interesting findings are encouraging and we suggest that future explorations into intraspecific variation in pelage color of bats using this or similar approaches are warranted to clarify the significance of the patterns. This study also demonstrated that care must be taken in analyses of mammalian pelage color from older museum skins, or at least that researchers must take into account the age of the specimens [Current Zoology 56 (4): 401-405, 2010]. [ABSTRACT FROM AUTHOR]

The article discusses a study on the use of a method for quantifying mammal hair morphology and assessing morphological characteristics of mammalian hair for zoological research. In this study, morphological measurements were obtained on 120 hair samples from white-tailed deer Odocoileus virginianus using a standard flatbed scanner and an image analysis software program. Results show that the width of hair shafts ranged from 0.08 millimeter (mm) to 0.21 mm with normal distribution and a 2.2 mm average length of color bands measured by hue and brightness scores. Data also include the two-dimensional surface area measurement. The study suggests the importance of these parameters to examining factors influencing the morphology of mammalian hair, or assessing nutritional status.

The demands of long-distance flight represent an important evolutionary force operating on the traits of migratory species. Monarchs are widespread butterflies known for their annual migrations in North America. We examined divergence in wing morphology among migratory monarchs from eastern and western N. America, and nonmigratory monarchs in S. Florida, Puerto Rico, Costa Rica, and Hawaii. For the three N. American populations, we also examined monarchs reared in four common environment experiments. We used image analysis to measure multiple traits including forewing area and aspect ratio; for laboratory-reared monarchs we also quantified body area and wing loading. Results showed wild monarchs from all nonmigratory populations were smaller than those from migratory populations. Wild and captive-reared eastern monarchs had the largest and most elongated forewings, whereas monarchs from Puerto Rico and Costa Rica had the smallest and roundest forewings. Eastern monarchs also had the largest bodies and high measures of wing loading, whereas western and S. Florida monarchs had less elongated forewings and smaller bodies. Among captive-reared butterflies, family-level effects provided evidence that genetic factors contributed to variation in wing traits. Collectively, these results support evolutionary responses to long-distance flight in monarchs, with implications for the conservation of phenotypically distinct wild populations. [ABSTRACT FROM AUTHOR]

Throughout the animal kingdom there are species that have two or more phenotypic forms or 'morphs', and many of these are amphibians. In North America, the red-backed salamander Plethodon cinereus can have either a red dorsal stripe or no dorsal stripe (lead-phase form), and evidence to date indicates the lead-phase form incurs a greater number of attacks from predators. In a recent collection of 51 P. cinereus, blood smears of both color morphs (35 red-stripe, 16 lead-phase) were examined to obtain numbers of circulating leukocytes (via light microscopy), which can be used to indirectly estimate levels of stress hormones in vertebrates via a 'hematological stress index', which is the ratio between the number of two leukocyte types (neutrophils and lymphocytes). Our results showed that lead-phase salamanders tended to have greater numbers of circulating neutrophils and lower numbers of circulating lymphocytes than red-stripe morphs, leading to higher average neutrophil-lymphocyte ratios in lead-phase individuals. Since the salamanders were held (refrigerated) for 7 days before sampling, we cannot be certain if this effect is a stress reaction to the captivity or the normal level for this morph. However comparison with two sets of related salamanders that were captured and sampled immediately indicates the red-stripe salamanders were either not stressed from the captivity at all, or their white blood cell distributions had returned to normal after 7 days of captivity. Taken together, our results indicate that lead-phase forms of P. cinereus have higher stress levels than the red-stripe forms, which may be a consequence of their higher exposure to, and/or attacks from, predators. They may also indicate that the lead-phase form is less-suited to captivity than the red-stripe form of this species [Current Zoology 56 (2): 238-243, 2010]. [ABSTRACT FROM AUTHOR]

Bullfrogs ( Rana catesbeiana) are widely believed to be nonclinical carriers of Batrachochytrium dendrobatidis (Bd), the fungal pathogen that invades keratinized tissues of amphibians and causes the disease, chytridiomycosis. Although most research on this disease focuses on adults, larval anurans are also susceptible to infections in their keratinized mouthparts, and this allows for visual diagnosis of the disease via the degree of mouthpart depigmentation. When an unplanned outbreak of chytridiomycosis occurred in a set of captive bullfrog tadpoles in our lab, we conducted the current investigation into its effects on the nonspecific immune system (i.e., the leukocyte populations) of the tadpoles. We compared leukocyte counts from blood smears of 27 tadpoles that had contracted the disease (evidenced by severe mouthpart depigmentation and confirmed by histology) to those of 21 tadpoles that had little depigmentation (i.e., with little evidence of the disease). Tadpoles with severe depigmentation had significantly more neutrophils and less eosinophils than those with little depigmentation, while numbers of lymphocytes, basophils, and monocytes were not statistically different. That there was any effect at all on circulating leukocyte numbers is surprising since leukocytes are usually not seen migrating to sites of infection in tissue sections of amphibians infected with Bd, and since most research points to this disease having little outward effect on bullfrogs. Since monocyte numbers were unchanged, the leukocyte alterations were likely not due to a simple inflammation response. It is possible that Bd infections elicit increases in glucocorticoid hormones, which can cause increased numbers of circulating neutrophils and lower numbers of eosinophils, although this is often accompanied by a reduction in lymphocyte numbers, which we did not see. Further research is warranted to clarify if this effect is limited to this species. [ABSTRACT FROM AUTHOR]

When animals become stressed, their levels of glucocorticoid hormones increase, causing white blood cells to move from tissues to circulation or vice versa. The primary alteration is an increase in the abundance of circulating neutrophils and a decrease in lymphocytes in circulation. A lesser-known effect is a decrease in the number of circulating eosinophils. Salamanders in the genus Ambystoma have unusually high numbers of circulating eosinophils, and as such, any effect of stress hormones on circulating leukocytes (especially eosinophils) of these species should be especially pronounced. We conducted an experiment to determine the effect of corticosterone administration on leukocyte counts (from blood smears) of A. talpoideum salamanders. Salamanders were captured and sampled as reference animals (n = 11), given a sham injection (n = 8), or injected with 0.1cc of a 1μg/mL corticosterone solution (n = 28). After 24 hours, relative neutrophil counts were higher and relative lymphocyte counts lower, in the corticosterone group than the sham and control groups. Absolute counts showed that this effect was driven by a reduction in lymphocytes, since neutrophil counts were statistically similar across treatments. Importantly, relative and absolute numbers of eosinophils decreased in the sham and corticosterone groups, confirming the sensitivity of this cell to stress in amphibians. [ABSTRACT FROM AUTHOR]

Heart rates of insects reflect the current level of activity and stress individuals are experiencing, and therefore this information can be useful from a research perspective. In Lepidoptera, as with most insects, the 'heart' consists of a transverse longitudinal tube that runs along the abdomen, just under the abdominal tergites, which pumps or contracts rhythmically to distribute hemolymph. Here, we describe a simple method we developed to observe heart contractions in adult monarch butterflies, Danaus plexippus. The procedure involves stabilizing the live specimen in a pre-prepared plastic bag, while positioning the abdomen in such a way so that the beating heart can be seen (with magnification) through the intersegmental membranes. With this procedure, no harm comes to the specimen, making the technique useful in both lab and field studies. The technique also requires little equipment, except for a dissecting microscope (or other magnifier). Moreover, the procedure should be useful for monitoring other similarly-sized Lepidoptera, and we confirmed this with a Papilio glaucus specimen. Using this method on 10 male and 10 female monarch specimens from captive-reared stock, we found the resting heart rate was 63 beats/min on average (range: 35-86). This information will be useful for comparative purposes, or as a reference point for future studies of monarch physiology. [ABSTRACT FROM AUTHOR]

Milkweed bugs are aposematically colored, with orange and black on their forewings, and the degree of both colors varies among individuals. Despite the attention given to the warning nature of this color, there has been little research directed at this variation. In this study, the subtle variation in wing colors of one species of milkweed bug, Oncopeltus fasciatus (Large Milkweed Bug) was measured to determine if the color variation was related to sex or body size. Fifty-eight bugs were hand-collected at three sites in northeast Georgia, and their wings scanned using a slide scanner and measured digitally using image analysis software. Wings of females were larger than those of males in general, and the color analyses showed statistically significant differences in wing hue between males and females. Females also had darker black wing sections than males, which could be evidence of a sex-related difference in immune function. Regardless of sex, wings of larger bugs; had deeper orange color and darker black, which may increase the aposematic contrast. Finally, several differences in wing color were found between sites, suggesting either site-level variation in host-plant quality or relatedness among individuals within sites. This study is the first to quantify in detail the wing colors of milkweed bugs and forms the basis for future research into this little-studied aspect of this insect. [ABSTRACT FROM AUTHOR]

Herpetologists are becoming increasingly aware of the importance of hematological parameters for evaluating the welfare of their study animals. In particular, differential counts of white blood cells (from blood smears) are now commonly performed on amphibians, although interpretation of such counts relies on some knowledge of the normal range for the species in question, and for many species this range is not known. In this study we examined blood smears from 79 cricket frogs (Acris c. crepitans) from two ponds in northeastern Georgia to establish reference ranges of white blood cell differentials for this species and to explore possible differences in relative white blood cell numbers between sexes, ponds, and body sizes. For comparison, we also compiled values of many other amphibians from published and unpublished records. We found that lymphocytes made up the majority (68.3%) of white blood cells in cricket frogs, followed by neutrophils (22.4%). There was no difference in relative cell numbers of any type between sexes, nor was there an association with body size. Relative numbers of certain cell types (lymphocytes and neutrophils) varied between ponds. In general the values for cricket frogs resembled those of other amphibians, with high numbers of lymphocytes and neutrophils and low numbers of eosinophils, basophils and monocytes. However, in assembling the records for other species we discovered that all Ambystomatid salamanders examined thus far have markedly elevated values of eosinophils compared to other amphibian species. Moreover, their eosinophil counts may be the highest of all vertebrates, and clearly warrant further study to determine their significance. [ABSTRACT FROM AUTHOR]

Amphibians have long been known to display wide variation in erythrocyte morphology across species, but within species there has been little attention given to individual variation in red blood cell morphology. We captured 49 red-backed salamanders (Plethodon cinereus) from central Pennsylvania, USA and used image analysis procedures to measure erythrocyte morphology (size and shape) on blood smears made from all individuals. We then statistically examined whether variation in snout-vent-length, sex, tail loss, or capture location influenced these cell variables. Only snout-vent-length affected erythrocyte size and shape, with increasing body sizes associated with increasing cell areas and increasingly rounder cells. Further, erythrocyte shape was also associated with a measure of body condition that was corrected for body size, such that individuals with high body condition scores had rounder cells. Given the oxygen-carrying role of erythrocytes in all vertebrates, we suspect this discovery is related to size-related changes in oxygen demand, since total oxygen consumption increases with body size in an allometric manner. While our results warrant further investigation to understand the mechanism, the association we found between cell roundness and both body size and condition nevertheless indicates this parameter could be used to assess the health state of plethodontid salamanders in future research, provided non-destructive sampling is employed. Our results also underscore the value of hematological investigations in the study of animal biology. [ABSTRACT FROM AUTHOR]

Metamorphosis in amphibians is a fascinating phenomenon that offers physiologists a number of opportunities to study aspects of tissue growth and lysis in animals. In larval amphibians, tissues are formed early on during larval growth, then are vastly reorganized and broken down during metamorphosis, and the effects of this phenomenon on the relative distribution of white blood cells in circulation (i.e., leukocyte profiles) was first examined in the 1920s. Nearly a century later, there has been little work to continue this research avenue, although our knowledge of the roles of certain leukocyte types has improved. Moreover, recent interest in counts of leukocytes in amphibians for environmental monitoring purposes emphasizes the need to understand how white blood cells naturally vary throughout larval life. In this study, I examined blood smears from wild-caught larval and adult bullfrogs ( Rana catesbeiana) of varying developmental stages and quantified the proportions and abundance (estimated from blood smears) of all leukocyte types at each stage. Lymphocytes were the most common cell found and appeared most abundant during the early growth phases of larvae. Neutrophils were the second most common cell and were also associated most with earlier phases. Eosinophils appeared directly associated with metamorphosis, generally increasing in abundance to a peak at metamorphic climax. Monocytes were also found most frequently in individuals experiencing metamorphic climax. Results in this study concerning eosinophils are consistent with those of urodeles and point to their role in the breakdown of tissues, which may resemble their role in modulating inflammation responses. [ABSTRACT FROM AUTHOR]

Monarch butterflies are famous among insects for their unique migration in eastern North America to overwinter sites in Mexico and their bright orange wing color, which has an aposematic function. While capturing migrating monarchs in northeast Georgia, USA, I noticed that many appeared to have unusually deep orange wings. I initiated the current study to compare wing hues (obtained using image analysis of scanned wings) of migrants (captured in 2005 and 2008) to samples of breeding and overwintering monarchs. Consistent with initial observations, migrants had significantly lower orange hues (reflecting deeper, redder orange colors) than breeding and overwintering monarchs. There was also a difference in hue between sexes and a relationship with wing size, such that largermonarchs had deeper, redder hues. The reasons for the color difference of migrants are not apparent, but one possibility is that the longer-lived migrant generation has denser scalation to allow for scale loss over their lifespan. Alternatively, this effect could be confined to the subpopulation of monarchs in the Southeastern United States, which may not be well represented at the Mexican overwintering sites. In any case, this discovery highlights the many questions emerging on the significance of wing color variation in this species. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including monarch butterflies, migrating animals and value of monarchs.

Measuring stress in animals is an important component of many research studies, and it has traditionally been performed via sampling levels of corticosterone in plasma. A secondary, "hematological" approach used most commonly by researchers of birds, mammals, and other taxa involves evaluating leukocyte profiles from blood smears. Such research has shown that leukocytes have a characteristic response to stress, although in amphibians this phenomenon is not as well studied. In general, stress can induce a rise in the ratio of neutrophils to lymphocytes. We evaluated the hematological response of paedomorphic Mole Salamanders (Ambystoma talpoideum) to captivity stress, specifically focusing on this parameter, but also examining other white blood cell types. Individuals captured in the wild and held in captivity for ten days before sampling had significantly more neutrophils, fewer lymphocytes, and higher ratios of neutrophils to lymphocytes than those captured from the same locations and sampled within one hour. Captive individuals also had significantly higher numbers of eosinophils. These results are consistent with hematological research in birds and other taxa and highlight the utility of this approach for measuring stress in amphibians. [ABSTRACT FROM AUTHOR]

House Finches (Carpodacus mexicanus) in North America are a commonly-studied species, but basic aspects of their life history remain poorly understood. I banded and observed marked House Finches at a backyard feeding site in a suburban neighborhood in Atlanta, Georgia from August 2002 through July 2004 to address how age, gender, mycoplasmal conjunctivitis, and time of year affected fidelity of individual House Finches to this site. Of 386 House Finches banded. I recaptured 77 and recorded 1,210 reobservations. More than half (55%) of all birds banded were not seen again and, of those that were, almost half (44%) were seen for less than 2 months. A House Finch's age. gender, and month of capture significantly affected how many times it was subsequently encountered (recaptured or reobserved), but not the duration of time it spent at the site of banding. Young birds (HYs) were encountered more often than adults (AHYs), and females more than males. Young birds with mycoplasmal conjunctivitis were encountered less often than those without, but this was not true for adults. These data indicate high site fidelity of adults during the breeding season and low site fidelity of juveniles early in the summer that becomes higher in late summer. Most birds captured in fall were encountered for up to 3 months. These results are discussed in relation to previous studies and their implications for transmission of Mycoplasma gallisepticum among House Finches. [ABSTRACT FROM AUTHOR]

The use of fluctuating asymmetry (FA) estimates in animal research is increasing, but most studies thus far have focused on birds, amphibians and insects. Turtles have bilateral shell scutes that can be easily measured with modern imaging techniques and, therefore, should serve as ideal candidates for FA research, although identifying the most appropriate characters to measure must first be determined. With this issue in mind we undertook the current project to assess levels of plastron scute asymmetry in a common freshwater turtle species, specifically examining the level of variation among scutes and the effects of age (size) and gender on our estimates of scute FA. We photographed 86 museum specimens of adult yellow-bellied sliders, Trachemys seripta (32 males, 54 females) and used image analysis software to measure their carapace lengths and absolute differences in left-right surface areas of plastron scutes. We found that scutes varied in the degree of FA, but the magnitude of the variation tended to be higher among males and there was higher FA in general in the forward-most plastron scutes. We also found that scute asymmetry increased with carapace size, indicating that turtle shells become increasingly asymmetrical with age. This may be the result of adjacent scutes growing against each other over time, leading to random flux in symmetrical growth, or from age-related bioaccumulation of pollutants, which could interfere with normal symmetrical shell production. [ABSTRACT FROM AUTHOR]