Immobilization of free-ranging nine-banded and great long-nosed armadillos with three anesthetic combinations

Nine-banded (n = 47) and great (n = 31) long-nosed armadillos (Dasypus novemcinctus and Dasypus kappleri) were immobilized for clinical examination and collection of biological samples as part of a wildlife rescue during the filling of a hydroelectric dam (Petit Saut, French Guiana) from May 1994 to April 1995. Three intramuscular (i.m.) anesthetic combinations were evaluated: (1) tiletamine/zolazepam (T/Z) at a dose of 8.5 mg/kg in 12 nine-banded long-nosed armadillos (NBA) and 10 great long-nosed armadillos (GLA), (2) ketamine at 40 mg/kg combined with xylazine at 1.0 mg/kg (K/X) in 18 NBA and nine GLA, and (3) ketamine at 7.5 mg/kg combined with medetomidine at 75 microng/kg (K/M) in 17 NBA and 12 GLA, antagonized by 375 microg/kg atipamezole. Induction was smooth, ranged from mean +/- SD = 2.8+/-0.6 to 4.3+/-1.8 min, and did not differ significantly between protocols, species, or sex. In NBA, immobilization time ranged from 43.8+/-27.8 to 66.5+/-40.0 min and did not differ between protocols or sex. Muscle relaxation was judged to be better with K/X and K/M versus T/Z. In GLA, the response to the anesthetic protocols was more variable and immobilization time ranged from 30.4+/-6.2 to 98.4+/-33.7 min. The main difference was observed in GLA females receiving the T/Z combination, in which immobilization time was significantly longer versus males, but also versus GLA K/M group, and versus NBA T/Z group. Effects on body temperature, heart rate and respiratory rate were limited. Thirty six to 50% of the individuals showed hypoxemia (SpO2 < 85%) throughout anesthesia and values <80% also were recorded but the hypoxemia was not associated with clinical signs. With T/Z and K/X, recovery was irregular and prolonged up to 2 to 3 hr in some individuals. In K/M groups, first standing was observed 1.0 to 16.4 min after i.m. atipamezole injection without adverse effects. Finally, the three anesthetic combinations used in this study were effective and safe agents for 30 to 40 min immobilizations including minor surgery procedures. The ability to antagonize the medetomidine-induced sedation with atipamezole significantly reduces the recovery time, making the K/M combination preferable, especially in field conditions.     

The free lipids of Mycobacterium leprae harvested from experimentally infected nine-banded armadillos

The free lipids of a sample of Mycobacterium leprae were extracted by a procedure designed to produce separate non-polar and polar fractions. The composition of these lipids was analysed semi-quantitatively by five special thin-layer chromatographic systems covering the total range of mycobacterial lipid polarities. In order of increasing polarity, the major lipids were dimycocerosates of phthiocerol A, phthiocerol B and phthiodiolone A, glycosyl phenolphthiocerol dimycocerosates and phospholipids, including monoacylphosphatidylinositol di- and pentamannosides. The diacylated forms of these latter lipids, found in most mycobacteria, were not present. The composition of the free lipids of the leprosy bacillus, surveyed over the total polarity range for the first time, showed that the patterns were particularly related to those of Mycobacterium bovis, Mycobacterium kansasii and Mycobacterium marinum.     

Stress-induced adrenal changes and their relation to reproductive failure in captive nine-banded armadillos (Dasypus novemcinctus)

Histological features of adrenal glands from captive and unstressed free-ranging nine-banded armadillos were compared to determine if undefined stress factors associated with captivity were capable of causing changes in adrenal morphology. Animals in captivity less than 3 mo showed histological features identical to unstressed free-ranging animals. Animals in captivity 6 mo or longer, however, showed adrenal changes like those previously described in other mammals exposed to various types of stress, except that there was no accompanying increase in adrenal weight. Similar adrenal changes were found in free-ranging animals exposed to extremely harsh winter weather. Females from both the chronic captive population and this stressed free-ranging population were seen to suffer reproductive failure. Reproductive function in males was not affected. There was no detectable sex difference in gross or histological adrenal changes; however, previous reports indicate there is a sex difference in the secretory product from the adrenals of captive nine-banded armadillos. A possible relationship between reproductive failure in the female and the sex difference in adrenal secretory products is discussed.     

Survey for leprosy in nine-banded armadillos (Dasypus novemcinctus) from the southeastern United States

Ears from 853 nine-banded armadillos (Dasypus novemcinctus) from Alabama, Arkansas, Florida, Georgia and Mississippi were examined microscopically for evidence of leprosy. All were negative for both acid-fast bacteria (Mycobacterium leprae) and lesions compatible with leprosy.     

Surveillance for naturally acquired leprosy in a nine-banded armadillo population

Samples from 77 nine-banded armadillos (Dasypus novemcinctus) inhabiting a 16.7 km portion of the East Atchafalaya River Levee, Point Coupee Parish, Louisiana, were serologically tested and/or histopathologically examined for evidence of naturally acquired leprosy. Five of 67 (7.5%) armadillos tested sero-positive with ELISA test for IGM class antibodies to the phenolic-glycolipid-1 antigen of Mycobacterium leprae. One of 74 (1.3%) was histopathologically positive as determined by presence of acid-fast bacteria in nerves.     

VEGF-induced adult neovascularization: recruitment, retention, and role of accessory cells

Adult neovascularization relies on the recruitment of circulating cells, but their angiogenic roles and recruitment mechanisms are unclear. We show that the endothelial growth factor VEGF is sufficient for organ homing of circulating mononuclear myeloid cells and is required for their perivascular positioning and retention. Recruited bone marrow-derived circulating cells (RBCCs) summoned by VEGF serve a function distinct from endothelial progenitor cells. Retention of RBCCs in close proximity to angiogenic vessels is mediated by SDF1, a chemokine induced by VEGF in activated perivascular myofibroblasts. RBCCs enhance in situ proliferation of endothelial cells via secreting proangiogenic activities distinct from locally induced activities. Precluding RBCCs strongly attenuated the proangiogenic response to VEGF and addition of purified RBCCs enhanced angiogenesis in excision wounds. Together, the data suggest a model for VEGF-programmed adult neovascularization highlighting the essential paracrine role of recruited myeloid cells and a role for SDF1 in their perivascular retention.     

Natal philopatry and recruitment of willow ptarmigan in north central and northwestern Canada

Summary Natal philopatry and recruitment were measured in two populations of willow ptarmigan; one near Churchill, Manitoba and the other in northwestern British Columbia. We examined the return of tagged offspring in subsequent years with respect to geographical area, annual variation, their age when tagged, their sex, their body weight, age and number of their parents, and time of hatch (first nest or renest). Most chicks were tagged before they fledged, but chicks tagged after that had the highest rate of return. We also observed a strong positive relationship between fledging success of broods and offspring return in following years.Patterns of offspring return were similar in both populations except that male offspring in Manitoba settled closer to their natal sites than those in British Columbia and more yearling captured in Manitoba had been tagged as chicks. Return of offspring did not vary with year, their body weights shortly after hatch, or with the age or number of parents raising them. However, a significantly higher proportion of offspring hatched from first nests (first-initiated clutches) returned compared to those hatched from renests (replacement clutches). The low return of chicks hatched from renests may due to low survival, low philopatry, or both. We observed no differences in the mating status (recruitment) of returning offspring with respect to the time they hatched or the number of parents that raised them.     

Natal location influences movement and survival of a spatially structured population of snail kites

Despite the accepted importance of the need to better understand how natal location affects movement decisions and survival of animals, robust estimates of movement and survival in relation to the natal location are lacking. Our study focuses on movement and survival related to the natal location of snail kites in Florida and shows that kites, in addition to exhibiting a high level of site tenacity to breeding regions, also exhibit particular attraction to their natal region. More specifically, we found that estimates of movement from post-dispersal regions were greater toward natal regions than toward non-natal regions (differences were significant for three of four regions). We also found that estimates of natal philopatry were greater than estimates of philopatry to non-natal regions (differences were statistically significant for two of four regions). A previous study indicated an effect of natal region on juvenile survival; in this study, we show an effect of natal region on adult survival. Estimates of adult survival varied among kites that were hatched in different regions. Adults experienced mortality rates characteristic of the region occupied at the time when survival was measured, but because there is a greater probability that kites will return to their natal region than to any other regions, their survival was ultimately influenced by their natal region. In most years, kites hatched in southern regions had greater survival probabilities than did kites hatched in northern regions. However, during a multiregional drought, one of the northern regions served as a refuge from drought, and during this perturbation, survival was greater for birds hatched in the north. Our study shows that natal location may be important in influencing the ecological dynamics of kites but also highlights the importance of considering temporal variation in habitat conditions of spatially structured systems when attempting to evaluate the conservation value of habitats. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Genetic maternity and paternity in a local population of armadillos assessed by microsatellite DNA markers and field data

Genetic data from polymorphic microsatellite loci were employed to estimate paternity and maternity in a local population of nine-banded armadillos (Dasypus novemcinctus) in northern Florida. The parentage assessments took advantage of maximum likelihood procedures developed expressly for situations when individuals of neither gender can be excluded a priori as candidate parents. The molecular data for 290 individuals, interpreted alone and in conjunction with detailed biological and spatial information for the population, demonstrate high exclusion probabilities and reasonably strong likelihoods of genetic parentage assignment in many cases; low mean probabilities of successful reproductive contribution to the local population by individual armadillo adults in a given year; and statistically significant microspatial associations of parents and their offspring. Results suggest that molecular assays of highly polymorphic genetic systems can add considerable power to assessments of biological parentage in natural populations even when neither parent is otherwise known.     

Long‐distance dispersal and local retention of larvae as mechanisms of recruitment in an island population of a coral reef fish

Abstract Although recruitment of pelagic larvae is a fundamental and well‐documented process in the dynamics of benthic marine populations, identifying the sources of recruitment, or the degree to which populations are connected via dispersal of larvae, has remained elusive for most marine taxa. In this study we used natural environmental markers (trace elements) recorded in fish otoliths (ear stones) as tags of natal origin. Specifically, we used the otolith core and edge chemistries of a locally endemic wrasse (Coris bulbifrons) from Lord Howe Island (LHI), Australia, and a widely distributed species (Coris picta) from three potential mainland source regions, to determine the likely sources of recruitment to C. picta populations on LHI. The use of a local endemic species, which is by definition self‐recruiting, is a novel approach for ground‐truthing the dispersal history of non‐endemic coral reef fish. Discriminant function analyses were able to separate LHI from mainland fish, using both edge and core signatures, with a high degree of accuracy, suggesting at least some of the C. picta collected on LHI were of local origin. This result was corroborated when half of the C. bulbifrons and LHI C. picta were introduced as unknowns into a discriminant function analysis using the remaining C. bulbifrons, LHI C. picta, and the mainland C. picta as a training data set. Overall, our findings suggest that both long distance dispersal and local retention are important sources of recruitment to populations of C. picta on LHI and that otolith chemistry of endemic species could be a useful benchmark for determining the prevalence of self‐recruitment in insular populations of other widespread species.     

Turnover and recruitment in a tundra population of Peregrine Falcons Falco peregrinus

The population dynamics of tundra-nesting Peregrine Falcons Falco peregrinus tundrius was studied over 7 years on a 450 km² study area in the Keewatin District of Canada's Northwest Territories. Peregrines showed strong fidelity to nest sites; none of 25 males ringed changed territories, while five of 38 females ringed were recorded changing territories. Such changes usually occurred after nesting failure. Annual turnover of territorial adults was estimated to be 22% (15% for males and 26% for females). Annual mortality of adults was estimated to be 17% (15% for males and 19% for females). If we assumed that territory vacancies, in addition to mate replacements, were indicative of mortality, then maximum annual mortality was estimated at 24% for each sex. Territories were held only by adult Peregrines. The oldest male on territory was at least 7 years old, the youngest was 2. The oldest female on territory was at least 7 years old, the youngest was 3. Territories were held by individuals of each sex for at least 6 years. One pair remained together for at least 4 years. Less than 4% of all young Peregrines produced on the study area in the first 5 years of the study were recruited into the breeding population. More male than female young were recruited despite an even sex ratio among nestlings. Peregrines did poorly in their first breeding attempts. The single young female recruited into the study population dispersed more than three times the median dispersal distance of six recruited males, suggesting that other females probably dispersed beyond the boundaries of the study area.     

Natal dispersal and genetic structure in a population of the European wild rabbit (Oryctolagus cuniculus)

A combination of behavioural observation, DNA fingerprinting, and allozyme analysis were used to examine natal dispersal in a wild rabbit population. Rabbits lived in territorial, warren based social groups. Over a 6-year period, significantly more male than female rabbits moved to a new social group before the start of their first breeding season. This pattern of female philopatry and male dispersal was reflected in the genetic structure of the population. DNA fingerprint band-sharing coefficients were significantly higher for females within the same group than for females between groups, while this was not the case for males. Wrighfs inbreeding coefficients were calculated from fingerprint band-sharing values and compared to those obtained from allozyme data. There was little correlation between the relative magnitudes of the F-statistics calculated using the two techniques for comparisons between different social groups. In contrast, two alternative methods for calculating F_ST from DNA fingerprints gave reasonably concordant values although those based on band-sharing were consistently lower than those calculated by an ‘allele’ frequency approach. A negative F_IS value was obtained from allozyme data. Such excess heterozygosity within social groups is expected even under random mating given the social structure and sex-biased dispersal but it is argued that the possibility of behavioural avoidance of inbreeding should not be discounted in this species. Estimates of genetic differentiation obtained from allozyme and DNA fingerprint data agreed closely with reported estimates for the yellow-bellied marmot, a species with a very similar social structure to the European rabbit.     

Neuronal recruitment in adult zebra finch brain during a reproductive cycle

Previous studies suggest that adult neurogenesis and neuronal replacement are related to the acquisition of new information. The present study supports this hypothesis by showing that there is an increase in new neuron recruitment in brains of adult male and female zebra finches that coincides with the need to memorize vocalizations of nestlings before they fledge. We counted [(3)H]-Thymidine labeled neurons 40 days after [(3)H]-Thymidine injections. These counts were made in the parents' brains at the time eggs hatched, at the time juveniles fledged and still needed parental care, and at the time juveniles were already independent. We focused on nidopallium caudale (NC), a brain region which plays a role in sound processing. Recruitment of new NC neurons increased at the time the young fledged, followed by a significant decrease when the young reached independence. We suggest that this increase enables parents to recognize their own young when they are still dependent on parental feeding, yet easily lost among other fledglings in the colony. We saw no such increase in neuronal recruitment in the olfactory bulb, suggesting anatomical specificity for the effect seen in NC. We also found a preliminary, positive correlation between number of fledglings and number of new NC neurons in the parents' brain at fledging, suggesting that the number of neurons recruited is sensitive to the number of young fledged.     

Identifying demographic and environmental drivers of recruitment and population growth in a cavity‐nesting sea duck population

Traits with the greatest proportional effects on fitness are typically conserved, and traits with larger temporal variation frequently play a dominant role in population dynamics. We examined recruitment patterns and population growth in common goldeneyes Bucephala clangula (hereafter goldeneye), using Pradel mark–recapture models from a long‐term nest box study (1997–2010). Our objectives were to estimate recruitment (f ) and population growth (λ) relative to recruitment origin group (in‐situ or unknown), investigate environmental and density dependent effects on these parameters, and evaluate potential immigration patterns. We detected group‐specific differences for f (in‐situ: 0.47 ± 0.13 SE, unknown: 0.31 ± 0.04), and the proportion of boxes occupied by goldeneyes the year prior to recruitment had a significant negative effect on recruitment for the in‐situ group (β = –1.04; 85% CI –1.29, –0.78), and a positive effect for the unknown group (β = 0.45; 85% CI 0.30, 0.61). The negative box occupancy effect in the year prior to recruitment, when in‐situ yearling goldeneyes prospect for potential nest sites, suggests that local nesting densities may limit recruitment of locally hatched females. We identified two competitive models for λ, which averaged 1.04 ± 0.03 and included interactions between recruitment origin group and a linear temporal trend, and the proportion of ducklings marked two years prior. By evaluating all levels of marking effort on λ, we determined that even if all hatched ducklings were marked in a given year, the resulting in‐situ λ was consistently lower than all observed population‐level λs during the study, indicating that individuals produced outside of study area nest boxes contributed to λ. Though female goldeneyes are considered highly philopatric, our results suggest that female natal and breeding dispersal may be more prevalent than previously thought, and the spatial scale at which these processes occur requires further investigation.     

Queen recruitment in a multiple-queen population of the fire ant Solenopsis invicta

We assessed patterns of new queen recruitment in a polygyne(multiple queens per nest) population of the fire ant Solenopsisinvicta in its introduced range. Newly recruited queens wereidentified using four physiological markers, and genotypic datafrom nuclear and mitochondrial markers were used to estimaterelatedness of new nest mate queens to each other and to theolder nest mate queens. In total, 1.7% of the queens collectedin late spring and early summer were deemed to be new recruits.The relatedness of these queens to each other and to the olderqueens within nests was not significantly different from zero,suggesting that newly recruited queens represent a random sampleof potential reproductive queens in the population. Moreover,the number of new queens recruited within nests was not correlatedwith the number of older queens present and did not differ significantlyfrom a Poisson distribution. Thus, queen recruitment in this populationof S. invicta appears to occur at random with respect to thenumber of older queens present within nests.