Kelehear, C., Brown, G. P. and Shine, R. (2013), Invasive parasites in multiple invasive hosts: the arrival of a new host revives a stalled prior parasite invasion. Oikos. doi: 10.1111/j.1600-0706.2013.00292.x
The success of a biological invasion can depend upon other invasions; and in some cases, an earlier invader may fail to spread until facilitated by a second invader. Our study documents a case whereby an invasive parasite has remained patchily distributed for decades due to the fragmented nature of available hosts; but the recent arrival of a broadly distributed alternative invasive host species provides an opportunity for the parasite to expand its range considerably. At least 20 years ago, endoparasitic pentastomids (Raillietiella frenata) were brought with their native host, the invasive Asian house gecko Hemidactylus frenatus, to the port city of Darwin in tropical Australia. These geckos rarely disperse away from human habitation, restricting the transmission of their parasites to urban environments – and thus, their pentastomids have remained patchily distributed and have only been recorded in scant localities, primarily surrounding Darwin. The recent range expansion of the invasive cane toad Rhinella marina into the Darwin area has provided an alternative host for this pentastomid. Our results show that the cane toad is a competent host for Ra. frenata– toads shed fully embryonated pentastomid eggs in their faeces – and that pentastomids are now common in cane toads near Darwin. Likely reflecting the tendency for the parasite’s traditional definitive host (the Asian house gecko) and only known intermediate host (the cockroach) to reside around buildings, we found the prevalence of this parasite follows an urban distribution. Because cane toads are widely distributed through urban and rural habitat and can shed viable pentastomid eggs, the toad invasion is likely to facilitate the parasite’s spread across the tropics, into areas (and additional susceptible hosts) that were previously inaccessible to it.
Parchman, T. L., Gompert, Z., Braun, M. J., Brumfield, R. T., McDonald, D. B., Uy, J. A. C., Jarvis, E. D., Schlinger, B. A. and Buerkle, C. A. (2013), The genomic consequences of adaptive divergence and reproductive isolation between species of manakins. Molecular Ecology. doi: 10.1111/mec.12201
The processes of adaptation and speciation are expected to shape genomic variation within and between diverging species. Here we analyze genomic heterogeneity of genetic differentiation and introgression in a hybrid zone between two bird species (Manacus candei and M. vitellinus) using 59 100 SNPs, a whole genome assembly, and Bayesian models. Measures of genetic differentiation () and introgression (genomic cline center [α] and rate [β]) were highly heterogeneous among loci. We identified thousands of loci with elevated parameter estimates, some of which are likely to be associated with variation in fitness in Manacus populations. To analyze the genomic organization of differentiation and introgression, we mapped SNPs onto a draft assembly of the M. vitellinus genome. Estimates of , α, and β were autocorrelated at very short physical distances (< 100 bp), but much less so beyond this. In addition, average statistical associations (linkage disequilibrium) between SNPs were generally low and were not higher in admixed populations than in populations of the parental species. Although they did not occur with a constant probability across the genome, loci with elevated , α, and β were not strongly co-localized in the genome. Contrary to verbal models that predict clustering of loci involved in adaptation and isolation in discrete genomic regions, these results are consistent with the hypothesis that genetic regions involved in adaptive divergence and reproductive isolation are scattered throughout the genome. We also found that many loci were characterized by both exceptional genetic differentiation and introgression, consistent with the hypothesis that loci involved in isolation are also often characterized by a history of divergent selection. However, the concordance between isolation and differentiation was only partial, indicating a complex architecture and history of loci involved in isolation.
Gambaryan, P. P. and Kuznetsov, A. N. (2013), An evolutionary perspective on the walking gait of the long-beaked echidna. Journal of Zoology. doi: 10.1111/jzo.12014
Editor: Andrew Kitchener
The speed, gait and trackway of the long-beaked echidna’s walk are reported for the first time. The gait formula is devised. Despite its sprawling limb posture, echidna’s walking technique shows fundamental differences from that of the classical sprawlers such as urodelans and lizards, which are: (1) the presence of the pace-like lateral stages of support and even their prevalence over the diagonal ones; (2) the narrow, though sprawling, limb posture and, consequently, the narrow trackway; (3) rolling, skidding and yawing of the trunk from side to side; (4) forelimb in-fingerness, which presumably provides the major thrust for these side-to-side movements. On the whole, the echidna’s sprawling type is more upright than in urodelans and lizards and is closer to the parasagittal type of therians. Like therians, echidnas already employ dynamic equilibration instead of the static one. The question is posed of whether mammalian ancestors have ever walked in the manner of urodelans and lizards.
Clutton-Brock, T. and Huchard, E. (2013), Social competition and its consequences in female mammals. Journal of Zoology, 289: 151–171. doi: 10.1111/jzo.12023
Editor: Steven Le Comber
Although competition between females is one of the cornerstones of the theory of natural selection, most studies of reproductive competition have focussed principally on mating competition in males. Here, we summarize our current understanding of adaptive tactics used by competing females in social mammals, and assess the social mechanisms affecting competitive success and the evolutionary consequences of social competition between females. As well as emphasizing the importance of female–female competition in social evolution, recent studies highlight the qualitative similarities in the operation of selection in females and males.
ZIEGLER, T. E., COLMAN, R. J., TARDIF, S. D., SOSA, M. E., WEGNER, F. H., WITTWER, D. J. and SHRESTHA, H. (2013), Development of Metabolic Function Biomarkers in the Common Marmoset, Callithrix jacchus. Am. J. Primatol.. doi: 10.1002/ajp.22126
Metabolic assessment of a non-human primate model of metabolic syndrome and obesity requires the necessary biomarkers specific to the species. While the rhesus monkey has a number of specific assays for assessing metabolic syndrome, the marmoset does not. Furthermore, the common marmoset (Callithrix jacchus) has a small blood volume that necessitates using a single blood volume for multiple analyses. The common marmoset holds a great potential as an alternative primate model for the study of human disease but assay methods need to be developed and validated for the biomarkers of metabolic syndrome. Here we report on the adaptation, development, and validation of commercially available immunoassays for common marmoset samples in small volumes. We have performed biological validations for insulin, adiponectin, leptin, and ghrelin to demonstrate the use of these biomarkers in examining metabolic syndrome and other related diseases in the common marmoset.
SHA, J. C. M. and HANYA, G. (2013), Diet, Activity, Habitat Use, and Ranging of Two Neighboring Groups of Food-Enhanced Long-Tailed Macaques (Macaca fascicularis). Am. J. Primatol.. doi: 10.1002/ajp.22137
We conducted observations of two neighboring groups of food-enhanced long-tailed macaques (Macaca fascicularis) over a period of one year. We examined their diet, behavior, habitat use, and ranging and how within-population variability reflected differential utilization of anthropogenic food resources. The group that consumed more anthropogenic food spent less time feeding on wild fruits and flowers, less time resting, and more time locomoting. They used forest habitats less often, and had a larger total home range and mean monthly home range. Some of these results contrasted with previous studies of food-enhanced primates which reported that food-enhancement resulted in smaller home ranges, shorter daily ranges, less time traveling and feeding, and more time resting. These contrasting patterns may relate to the nature of anthropogenic foods. In most studies of food-enhanced primates, anthropogenic food resources were abundant and concentrated but the macaques in this study used anthropogenic foods mainly from a few refuse sites where they had limited access, and from dispersed and irregular human provisioning. The group consuming more anthropogenic food therefore showed more spatially dispersed feeding activity and home range use, an effect that was likely further enhanced by lower natural food resource availability within their home range. The Singapore macaque population shows small-scale variability in feeding and ranging behavior, contributing to the complexity of their adaptive variability in a human-altered habitat. Our findings could have important implications for mitigating human–macaque conflict as measures applied at a higher spatial or population level may achieve highly inconsistent results, intensifying the challenges for wildlife managers.
Dextrocardia in Short-Nosed Fruit Bats (Cynopterus sphinx) and Their Relative Heart Masses
Qian Yao, Guangjian Zhu, Jon R. Flanders, and Libiao Zhang
Acta Chiropterologica 2012 14 (2), 497-499
Autopsies carried out on 26 short-nosed fruit bats (Cynopterus sphinx, Pteropodidae, Chiroptera) from Guangdong Province, South China, revealed that the hearts of three individuals were found lying in the right hemithoracic cavity with their base-to-apex axes directed to the right. This is the reverse of what is normally seen in mammals and is similar to the rare congential heart defect known as dextrocardia which has been described in humans. A comparison of the two orientated hearts found that there was no significant difference in heart mass (MH) or relative heart mass (RHM). We observed that the short-nosed fruit bat has higher RHM compared to non-flying mammals but lower RHM when compared to insectivorous bats, and similar RHM when compared to those of other fruit bats.
Distribution Patterns of Bats in the Eastern Mediterranean Region Through a Climate Change Perspective
Raşit Bilgin, Ari Keşişoğlu, and Hugo Rebelo
Acta Chiropterologica 2012 14 (2), 425-437
The impact of climate change on different species has been analyzed many times in various geographical areas. However, some areas still have a large knowledge gap while harbouring significant levels of biodiversity. The main aim of this study was to determine how climate change will affect 16 different bat species in the Eastern Mediterranean Region. Using presence only modelling techniques and relevant bioclimatic data forecasts according to two different climate change scenarios (A2A and B2A) of the Intergovernmental Panel on Climate Change (IPCC), the potential geographic distribution of bat species in the eastern Mediterranean region for the current period and the years 2020, 2050 and 2080 were modelled. The results suggest that climate change can affect bats negatively throughout the 21st century in the studied area on two fronts: i) species richness will deteriorate, and ii) the total area occupied by bats will decline. These impacts are likely to be more severely observed in Turkey’s coastal areas, northwest Turkey, Red Sea coasts, Israel, and the west of Syria and Jordan. Using only bioclimatic variables as factors, and thus not using any land cover (or habitat) data, was the main limitation of the study. Hence the models and results of the study present ‘best case’ scenarios.
Clustering Behavior in Wintering Greater Mouse-Eared Bats Myotis myotis — the Effect of Micro-Environmental Conditions
Jan S. Boratyński, Marcin Rusiński, Tomasz Kokurewicz, Andrzej Bereszyński, and Michał S. Wojciechowski
Acta Chiropterologica 2012 14 (2), 417-424
During monthly bat surveys carried out in winters of 2008/2009 and 2009/2010 we studied clustering behavior of greater mouseeared bats (Myotis myotis) hibernating in the Międzyrzecz Fortified Front (MFF) in western Poland. Since the behavior of hibernating bats is usually affected by varying environmental conditions we measured changes in the ambient temperature (Ta and water vapor pressure (WVP) and their variability in the selected areas and analyzed the relationship between clustering behavior of hibernating bats and abiotic conditions. In both winters, the number of solitarily roosting individuals of M. myotis decreased from autumn to spring while the highest number of bats hibernating in clusters was recorded in the middle of winter. The number of clusters did not change significantly over the winter, but the number of individuals within a particular cluster increased from November (median = 5, inter-quartile range, IQR = 5-8) to March (median = 20, IQR = 14-35.5). The changes of the clusters‘ size were best explained by a mixed model with WVP and the variability in WVP over the 20 days prior to the bat survey as explanatory variables. As WVP and the variability in WVP decreased, the number of individuals in a cluster increased. Also, Ta affected the size of clusters. However, neither of the models supported the hypothesis of the effect of variability of Ta on clustering of M. myotis. We propose that huddling enables bats to reduce evaporative water loss during the middle and at the end of the hibernation and reduces costs of spring arousals, perhaps by synchronizing them between clustered individuals and thus allowing the use of passive re-warming.
Vocalizations in the Malagasy Cave-Dwelling Fruit Bat, Eidolon dupreanum: Possible Evidence of Incipient Echolocation?
M. Corrie Schoeman and Steven M. Goodman
Acta Chiropterologica 2012 14 (2), 409-416
The vocalizations of the Malagasy endemic fruit bat, Eidolon dupreanum (family Pteropodidae) were previously not documented. Individuals of this species, which make day roost sites in rock crevices or the dark zones within caves, were recorded while exiting a cave in the Parc National d’Ankarana. Individuals leaving a roost at dusk were recorded 200 m and 35 m inside the cave, as well as two sites outside the cave. Visible light in the cave dropped to 0 lux about 50 m from the entrance. While exiting, individuals flew within 50–100 cm of the ceiling, often settling and perching every 5–10 m along their flight patch and displacing in a leapfrog manner towards the cave entrance. Three distinct call types were identified: social calls 1, social calls 2 and echo clicks. Bats produce the echo clicks while flying towards the entrance, while the other two calls were emitted at roost sites and near the cave entrance. Although the results are preliminary, we suggest that the social calls 1 and 2 were employed for social communication, whilst echo clicks may have been used in a sensory context, potentially as incipient echolocation to navigate in the dark cave.
Ranging Patterns and Habitat Use of a Solitary Flying Fox (Pteropus dasymallus) on Okinawa-jima Island, Japan
Atsushi Nakamoto, Kazumitsu Kinjo, and Masako Izawa
Acta Chiropterologica 2012 14 (2), 387-399
Most flying fox species (genus Pteropus) exhibit strong coloniality. They are highly mobile animals and commonly forage over vast areas. Only a small number of species are solitary, and their foraging and roosting patterns are not well understood. Here, we examined ranging patterns and habitat use of Orii’s flying fox, Pteropus dasymallus inopinatus, a solitary fruit bat, using radiotracking from April 2002 to January 2006 on Okinawa-jima Island, Ryukyu Archipelago, Japan. The daily home range size for this species was very small (mean 52.5 ha) compared to other Pteropus species, although home range size was highly variable among individuals and seasons. The distance between a day roost and feeding trees was 621 m on average, with a maximum of 6,875 m. Day roost site shifted frequently (every 1.6 ±0.8 days) to a nearby site in the current foraging area. The distance between consecutive day roost sites was 792 m on average, with a maximum of 6,000 m. These bats favored forest habitats for roosting sites, whereas they often used residential areas as feeding sites. Our results suggest that they regularly shifted the location of their personal activity range, a small home range with roost switching, probably to track changes in food availability and to avoid local competition for food. The solitary roosting system of this species links to its flexible foraging system, which likely provides an advantage for using limited food resources on a small island, even when food is patchily distributed in urbanized habitats.
Fly-and-Forage Strategy in the Bat Pipistrellus nathusii During Autumn Migration
Jurgis Šuba, Gunars Petersons, and Jens Rydell
Acta Chiropterologica 2012 14 (2), 379-385
Populations of Pipistrellus nathusii (Nathusius’s bat), an insectivorous aerial-hawking species that breeds in north-eastern Europe, perform long-distance migrations between breeding sites and hibernation areas in central and southern Europe. The feeding strategy of migrating P. nathusii was investigated in Latvia on the east coast of the Baltic Sea, exploring evidence for and against two non-mutually exclusive predictions that i) the bats feed shortly after dusk at highest aerial insect activity and continue to migrate thereafter or ii) apply a ‘fly-and-forage’ strategy and frequently interrupt their migration flight to feed. Echolocation calls and feeding buzzes of P. nathusii were recorded throughout the night from August until September on a known migration flyway over coastal dunes and at potential foraging sites in adjacent woodlands, over meadows and wetlands. The results indicate that P. nathusii applies a fly-and-forage strategy along the Baltic coast. However, a threshold in aerial insect availability may exist, below which no foraging occurs and migration continues.
Diet of Mormoopid Bats on the Caribbean Island of Puerto Rico
Ashley K. Rolfe and Allen Kurta
Acta Chiropterologica 2012 14 (2), 369-377
Dietary differentiation can be a key mechanism for the coexistence of syntopic species with similar niches. On the Caribbean island of Puerto Rico, three species of bat from the family Mormoopidae — the Antillean ghost-faced bat (Mormoops blainvillei), sooty mustached bat (Pteronotus quadridens), and Parnell’s mustached bat (Pteronotus parnellii portoricensis) — are aerial insectivores that roost in the same caves. To investigate the possibility of dietary differentiation, we estimated the percent volume and percent frequency of occurrence of the orders of arthropods consumed by these three species of bat, using standard fecal analysis. We also compared dietary diversity among species, as well as the amount of dietary overlap, with respect to season and habitat. Lastly, this study used canonical correspondence analysis (CCA), a method of ordination, to assess the effects of species, sex, age, reproductive condition, season, and habitat on intraspecific differences in the diet of the Puerto Rican Mormoopidae. Eight orders of arthropods were found in the diet of these mormoopids, with Lepidoptera, Hymenoptera, and Coleoptera being major staples. The CCA revealed differences in diet among the three species, suggesting that dietary differentiation is at least one mechanism for coexistence. In addition, the variables habitat and season correlated significantly with the diet of M. blainvillei and P. quadridens, whereas habitat and sex correlated with the diet of P. p. portoricensis. Thus, our study shows dietary differences among the three species of Mormoopidae living in the same caves on Puerto Rico, as well as intraspecific differences within the diet of each species.
High Trophic Similarity in the Sympatric North European Trawling Bat Species Myotis daubentonii and Myotis dasycneme
Frauke Krüger, Inka Harms, Andreas Fichtner, Irmhild Wolz, and Robert S. Sommer
Acta Chiropterologica 2012 14 (2), 347-356
Most European bat species are insectivorous and share foraging areas to some extent. Where similar species rely on similar resources in the same foraging habitat, they are likely to interact. This study addresses the trophic niche of the Northern European trawling bat species Myotis dasycneme (Boie, 1825) and Myotis daubentonii (Kuhl, 1817), occurring in the same habitat, and possible interactions or differences within their dietary behaviour. Dietary data of both species were analysed to draw conclusions on their ecology, possible dietary overlap, hints for coexistence mechanisms and community structure. In this study, M. dasycneme and M. daubentonii fed mainly on Chironomidae (M. dasycneme: 44.4%; M. daubentonii: 32.8%) and Trichoptera (M. dasycneme: 20.4%; M. daubentonii: 22.2%), showing a high trophic niche overlap and similar niche breadth. Nevertheless, there were differences in the diet of the two species concerning the predation of chironomids. Differences also occur regarding the prey types, referring to the terrestrial or aquatic life-cycle of prey groups. This could be evidence for different foraging habitats and a spatial segregation of both species. High resource abundance is also likely to allow the coexistence of both species within the same hunting habitat.
Gundula Hoffmann, Annika Bentke, Sandra Rose-Meierhöfer, Christian Ammon, Petra Mazetti, Grétar H. Hardarson, Estimation of the Body Weight of Icelandic Horses, Journal of Equine Veterinary Science, Available online 27 February 2013, ISSN 0737-0806, 10.1016/j.jevs.2013.01.002.
The body weight of horses is an interesting variable for horse owners, as well as for veterinarians. It is useful to have methods of estimation like weight tape or formula, rather than visual estimation, when a weight scale is not available. Different methods of weight estimation exist for adult horses, but to date, there has been no validation of these methods in Icelandic horses. Therefore, three different methods of weight determination (weight scale, weight tape, and weight formula) were compared in this study to investigate whether it is possible to obtain reliable weight measurements of Icelandic horses by using an estimation method. Both the weight pursuant to weight tape and pursuant to weight formula showed no significant differences (P = 1.00 and P = 0.37, respectively) from the actual weight. The correlation between estimated and actual weights was r = 0.94 for weight tape and r = 0.93 for weight formula. However, the differences between the estimated and actual weights were smallest when estimated using an adjusted weight formula: weight (kg) = girth² × length (both in cm)/11,400. In conclusion, the body weight of Icelandic horses can be estimated from the measurements of body girth and length, and weight tape also seems to be a suitable method.