Zootaxa 3682 (4): 501–512 (1 Jul. 2013)
Glyptothorax radiolus, a new species of sisorid catfish (Osteichthyes: Siluriformes) from northeastern India, with a redescription of G. striatus McClelland 1842
HEOK HEE NG; LALRAMLIANA
Glyptothorax radiolus, new species, is described from the Brahmaputra River drainage in West Bengal, northeast India. It differs from most congeners in the Indian subcontinent in possessing plicae on the ventral surfaces of the pectoral spine and first pelvic-fin ray. The following combination of characters serve to distinguish it from congeners in the Indian subcontinent with plicate ventral surfaces of the pectoral spine and first pelvic-fin ray: eye diameter 6.6–7.4% HL interorbital distance 28.3–28.7% HL, head length 23.7–24.3% SL, wedge-shaped central depression in throracic adhesive apparatus
devoid of skin ridges, unculiferous ridges of thoracic adhesive apparatus not extending anteriorly onto gular region, pectoral fin length 21.4–22.8% SL, dorsal-fin spine length 11.6–13.9% SL, dorsal-to-adipose distance 26.6–26.8% SL, body depth at anus 11.2–11.4% SL, pelvic fin length 16.5–18.3% SL, adipose-fin base length 13.1–14.3% SL, anal-fin base length 13.4–14.0% SL, caudal peduncle length 20.9% SL, caudal peduncle depth 7.7% SL (1.4–1.5 times in body depth at anus), absence of distinct pale midlateral stripe on body, and 36 total vertebrae. Glyptothorax striatus, the type species of the genus, is also rediagnosed and redescribed in this study.
Reckordt, M., Ubl, C., Wagner, C., Frankowski, J. and Dorow, M. (2013), Downstream migration dynamics of female and male silver eels (Anguilla anguilla L.) in the regulated German lowland Warnow River. Ecology of Freshwater Fish. doi: 10.1111/eff.12080
In the light of the European wide efforts to increase the spawning biomass of the European eel, a reliable measurement of the escapement of mature silver eel is necessary to prove the effectiveness of the conservation management measures. The seaward migration of mature eel is commonly viewed as a seasonal phenomenon with concentrated migration peaks occurring in spring and autumn. To verify the assumed seasonal silver eel migration events for regulated lowland rivers, a stow-net system was installed in the Warnow River located in north-eastern Germany. Between 2008 and 2011, the stow-net system was operated from March to December each year. The eel harvest was documented on a weekly base including the documentation of weight and length, the silvering stage and the tissue sampling for the molecular identification of the eel species. During the 4 year monitoring period, a continuous downstream migration of female and male silver eels was observed. Additionally, single migration peaks were recorded in each year occurring between April and December. Moreover, female and male silver eels showed varying downstream migration dynamics. Based on a Chi-squared Automatic Interaction Detection (CHAID) tree analysis, it was shown that during periods of a daily minimum air temperature over 10.4 °C, increased discharge levels and increased wind speeds, higher weekly migration rates of silver eels were likely. Furthermore, the results indicated that both sexes differed in their responses to migration triggering environmental factors. The presented results might be helpful to design more efficient eel conservation management strategies in regulated lowland rivers.
Ely, C. R., Nieman, D. J., Alisauskas, R. T., Schmutz, J. A. and Hines, J. E. (2013), Geographic variation in migration chronology and winter distribution of midcontinent greater white-fronted geese. The Journal of Wildlife Management. doi: 10.1002/jwmg.573
We evaluated spatial and temporal differences in migratory behavior among different breeding groups of midcontinent greater white-fronted geese (Anser albifrons) using band-recovery data and observations of neck collared geese during migration and winter. Birds from different breeding areas were initially delineated by geographic distance into 6 banding reference areas (BRAs): 1) interior Alaska, 2) North Slope of Alaska, 3) western Northwest Territories (NWT), 4) western Nunavut, 5) central Nunavut, and 6) eastern Nunavut. The banding groups also differed by breeding habitat, with geese from interior Alaska nesting in the boreal forest (taiga), and all other groups breeding in tundra habitats. Geese from interior Alaska migrated earlier during autumn, and were more likely to winter farther south (in Mexico) than geese from other breeding areas. Geese banded in central and eastern Nunavut (Queen Maud Gulf and Inglis River) wintered farther east (in Louisiana) than geese from other breeding areas. Small-scale (within-state) geographic segregation of wintering flocks was evidenced by the recent (post-1990) nearly exclusive use of a new wintering area in north central Texas by geese from interior Alaska. Segregation among BRAs was also apparent in Mexico, where taiga geese were found predominantly in the central Highlands (states of Zacatecas and Durango), whereas tundra geese mostly used states along the Gulf Coast (primarily Tamaulipas). Interior Alaska birds initiated spring migration earlier than geese from other areas, and were more likely than others to stop in the Rainwater Basin of Nebraska, a region where cholera outbreaks periodically kill thousands of geese. Geese from interior Alaska were the first to arrive at spring staging areas in prairie Canada where BRAs exhibited spatial delineation (a longitudinal cline) in relation to breeding areas. Our results show significant geographic and temporal variation among taiga and tundra breeding cohorts during autumn, winter, and spring. Temporal and spatial differences in migratory behavior may allow management practices that accommodate potential demographic differences between taiga and tundra populations.
What makes wild chimpanzees wake up at night?
Primates July 2013
I examined the possible cause of night awakening among wild chimpanzees (Pan troglodytes) in Mahale Mountains National Park, Tanzania. Chimpanzee vocalizations and activity-related sounds (CVSs) were used to indicate awakening because I was unable to visually observe them. Over a 5-night observation period, CVSs (n = 128) were heard every night, and most (n = 91) were observed within 5 min of previous CVSs. Chimpanzees use CVSs as social communication to maintain spatial contact with other chimpanzees who occasionally travel at night. The first sound in a sequence of CVSs (CVS bout) was heard immediately following the vocalization or sound of another animal (n = 11), defecation or urination by a chimpanzee (n = 7), or unknown (n = 19). CVS bouts were longer when preceded by defecation or urination than when preceded by the vocalization or sound of other animals or an unknown factor. This suggests that the degree of wakefulness varies according to the possible cause of the disturbance. CVSs at night may be provoked by various factors, and awakening during the night is probably common among diurnal primates.
Raoul Manenti, Mathieu Denoël, Gentile Francesco Ficetola, Foraging plasticity favours adaptation to new habitats in fire salamanders, Animal Behaviour, Available online 1 July 2013, ISSN 0003-3472,http://dx.doi.org/10.1016/j.anbehav.2013.05.028.
Predators often show strong plasticity of optimal foraging strategies. A major difference in foraging strategies occurs between sit-and-wait and active predators. Models predict that the efficiency of these strategies is affected by environmental conditions, active predators being favoured when prey are scarce and their detection difficult. The shift between the two strategies may occur through both phenotypic plasticity and local adaptations. Larvae of the fire salamander, Salamandra salamandra, are typically stream-dwelling sit-and-wait predators, but some populations breed in caves. We evaluated whether local adaptations or phenotypic plasticity determine shifts in foraging strategy between stream and cave populations. The foraging behaviour of salamander larvae was evaluated under all combinations of three test conditions during trials: light versus darkness, prey presence versus absence and food deprived versus fed; larvae originated from caves and streams and were reared in epigeous photoperiod or in darkness. Observations and video tracking showed that salamander larvae modified their behaviour in response to environmental conditions. In the darkness, larvae showed higher average velocity and moved longer distances. Movements were higher in food-deprived larvae and in the presence of prey compared to fed larvae and prey absent conditions. Furthermore, larvae from cave populations showed higher behavioural plasticity than stream larvae, and better exploited the available space in test environments. Variation in foraging behaviour was strong, and involved complex interactions between plasticity and local adaptations. Larvae from cave populations showed higher behavioural plasticity, supporting the hypothesis that this trait may be important for the exploitation of novel environments, such as caves.
Irene Amoruso, Luigi Fabbris, Matteo Mazza, Gianumberto Caravello Estimation of Feral Pigeon (Columba livia) population size using a novel Superimposed Urban Strata (SUS) method
Urban Ecosystems July 2013
A reference method to estimate Feral Pigeon (C. livia) population size in urban areas is missing: results of different surveys are difficult to compare due to the wide heterogeneity of approaches. A combined technique, the Superimposed Urban Strata (SUS) method, especially designed to estimate pigeon population size in urban areas, is proposed. SUS implements methods based on stratified sampling layers: its reliability was tested with a pilot study in Padua (Italy). The survey area was split into two superimposed strata and a different survey technique was applied to each stratum. The first stratum consisted of twelve topographic sampling units, identified as critical ornithic-density loci. The second stratum was obtained by selecting 10 % of the survey area with systematic sampling. In the estimate of the population size, different detection probabilities were assigned to the two strata. The SUS method was first applied in 2007, when three-year growth projections for the C. livia population were calculated, with a density-dependent model. In 2010, the survey was repeated to countercheck previous data. Estimated C. livia population size was of 2340 ±93 units in 2007, whereas in 2010 it was of 3679 ±161 units. The 2010 estimated population size resulted in fair accordance with the three-year projections, showing less than a 4 % mismatch. SUS proved to be an adequate estimate method for urban areas: so far it has been tested only in an average Italian urban area, but it could be easily adapted to other cities by calibrating parameters linked to the peculiar urban background.
Gess, S. W., Ellington, E. H., Dzialak, M. R., Duchamp, J. E., Lovallo, M. and Larkin, J. L. (2013), Rest-site selection by fishers (Martes pennanti) in the eastern deciduous forest. Wildlife Society Bulletin. doi: 10.1002/wsb.300
Information on fisher (Martes pennanti) resource selection in deciduous forests of eastern North America is limited. We studied resting habitat selection in a fisher population that recolonized predominantly deciduous forest in Pennsylvania, USA, during 2006–2007. We quantified selection by comparing used and randomly selected available sites at 2 spatial scales: the rest structure and at the rest site (area surrounding rest structures). We identified 79 rest structures used by 15 fishers. The most common rest sites were live trees with cavities or broken tops (69%), with black cherry (Prunus serotina), American beech (Fagus grandifolia), and sugar maple (Acer saccharum) accounting for nearly 65% of tree use. Standing dead trees with cavities or broken tops accounted for 17% of rest structures. Ground-level structures (including burrows, rock piles, and root balls) comprised 14% of observations. Trees selected as rest structures were larger in diameter at breast height (55.3 cm ± 14.9 cm) than were trees at the center of random sites (28.8 cm ± 6.8 cm). Relative to random sites, important components of forest surrounding rest structures included structurally complex forest floors (based on coarse woody debris and rocky ground cover), canopy complexity, and diversity of tree condition class. Maintaining resting habitat for fishers in the eastern deciduous forest can be accomplished through management practices that encourage structurally diverse forests, including retention of coarse woody debris, and variation in tree size and condition.
Timmer, J. M., Butler, M. J., Ballard, W. B., Boal, C. W. and Whitlaw, H. A. (2013), Abundance and density of lesser prairie-chickens and leks in texas. Wildlife Society Bulletin. doi: 10.1002/wsb.304
Lesser prairie-chickens (LEPCs; Tympanuchus pallidicinctus) have experienced population declines due to both direct and indirect habitat loss, including conversion of native rangeland to cropland and disturbance from energy development. Our objectives were to 1) determine the current density of LEPC leks and LEPCs within the Texas (USA) occupied range, including areas with high potential for wind-energy development; and 2) find new leks. To estimate lek and LEPC density, we employed a line-transect-based aerial survey method using a Robinson 22 helicopter to count leks. We surveyed 26,810.9 km of transect in the spring of 2010 and 2011 and we detected 96 leks. We estimated a density of 2.0 leks/100 m2 (90% CI = 1.4–2.7 leks/100 km2) and 12.3 LEPCs/100 km2 (90% CI = 8.5–17.9 LEPCs/100 km2) and an abundance of 293.6 leks (90% CI = 213.9–403.0 leks) and 1,822.4 LEPCs (90% CI = 1,253.7–2,649.1 LEPCs) for our sampling frame. Our best model indicated that lek size and lek type (AICc wt = 0.235) influenced lek detectability. Lek detectability was greater for larger leks and natural leks versus man-made leks. Our statewide survey efforts provide wildlife managers and biologists with population estimates, new lek locations, and areas to target for monitoring and conservation.
Svein Jakob Saltveit, Åge Brabrand, Incubation, hatching and survival of eggs of Atlantic salmon (Salmo salar) in spawning redds influenced by groundwater, Limnologica – Ecology and Management of Inland Waters, Available online 1 July 2013, ISSN 0075-9511, http://dx.doi.org/10.1016/j.limno.2013.05.009.
Many west coastal and northern Norwegian rivers run through deep, confined valleys with permeable layers of glacial and alluvial deposits. Groundwater flows through these permeable layers and enter lakes and rivers as underwater seepage and springs. Groundwater inflow to inland Norwegian rivers may constitute 40–100% of total water discharge during low flow periods in late summer and winter. Juvenile salmonids may take advantage of groundwater upwellings and actively seek out such patches. In regulated rivers groundwater influx may create refuges during low flow or hydropeaking episodes. The importance of groundwater for salmon redd site selection and egg survival is also clear, although less known and documented in regulated rivers.
Eggs of Atlantic salmon (Salmo salar) are deposited in redds in river bed gravels lacking fine sediments and with high oxygen levels. Egg development is therefore dependent on the interaction of a number of environmental factors such as groundwater influx, oxygen and temperature. Atlantic salmon in the regulated River Suldalslågen, Western Norway, spawn relatively late compared to other Norwegian rivers, with a peak in early January. Newly emerged fry are found from the end of May to the beginning of June, i.e. “swim up” one month earlier than expected using models for egg and alevin development and river water temperatures. The most plausible explanation is that groundwater has a higher and more stable temperature than surface river water. In field experiments, fertilized salmon eggs were placed in boxes close to natural spawning redds in the river bed at sites influenced and those not influenced by groundwater. A difference of up to 40 days in 50% hatching was found, and “swim up” occurred at the end of May in boxes influenced by groundwater.
Preliminary studies have revealed that groundwater also plays an important role in survival of salmon eggs in the River Suldalslågen when dewatered in winter. Eggs placed in boxes in groundwater seepage areas during winter in the dewatered river bed survived even when covered by ice and snow. The survival from fertilization until 30 April, one month before hatching, was 91%, the same survival as found for eggs placed in boxes in the wetted river bed. However, mortality from fertilization to hatching was higher compared to the eggs placed in wetted river bed, 57 and 91% respectively.
Groundwater creates a horizontal and vertical mosaic of temperatures in spawning redd areas leading to potentially greater variation in spawning sites, time of hatching and “swim up”. This is likely to increase egg survival during low flow periods in regulated rivers. In conclusion, the interaction between groundwater and surface river water should therefore be considered when managing fish populations in regulated rivers.
Andrew Charles Michael Smith, Ursula Munro, Will F. Figueira
Modelling urban populations of the Australian White Ibis (Threskiornis molucca) to inform management
Population Ecology July 2013
Since the 1970s, populations of the Australian White Ibis (Threskiornis molucca) have dramatically increased in many Australian urban centres. Managers of ibis are currently focusing on limiting this bird’s reproductive success in order to reduce population sizes or at least halt further increases in urban areas. Here we use data on nesting success and survival for three populations of ibis around greater Sydney to develop an age-structured population model. The estimated growth rate for all populations combined was about 1.5 % per year and for individual sites were more variable at −1, −7, and 9 %. For all populations, growth rates were most sensitive (based on elasticity analyses) to the survival of adults and least sensitive to fecundity, especially of 3 year olds. Further exploration of the importance of fecundity rates, which are relatively poorly known for these populations, suggests that rates of 0.7 fledgling per nest per year. The results suggest that ibis from other locations (probably their traditional breeding areas in inland Australia) have immigrated into urban environments as estimated growth rates cannot account for current population sizes. Management strategies must take these findings into account and also consider that ibis are declining in their traditional habitats to avoid exacerbating their decline at a regional scale.
Sophie Lorioux, Hélène Lisse, Olivier Lourdais, Dedicated mothers: predation risk and physical burden do not alter thermoregulatory behaviour of pregnant vipers, Animal Behaviour, Available online 2 July 2013, ISSN 0003-3472, http://dx.doi.org/10.1016/j.anbehav.2013.05.031.
Escape tactics and optimal refuge use have attracted considerable interest, but the influence of pregnancy on escape tactics remains understudied. For instance, embryonic sensitivity to environmental conditions and maternal constraints vary dramatically across pregnancy, and these dynamics should modulate the cost–benefit balance of refuge use. We experimentally studied thermoregulation and refuge use in pregnant and nonreproductive aspic vipers, Vipera aspis, at different stages of gestation (first, middle and last third). We determined preferred body temperatures (Tset) in a cost-free environment to test for fecundity and stage dependencies of maternal Tset. Then, we examined behavioural responses to repeated simulated predatory attacks. Pregnant females were extremely precise thermoregulators compared with nonreproductive females, and Tset was independent of litter size or gestation stage. After simulated attacks, pregnant females limited their time spent in the refuge and thereby their deviation from Tset. By contrast, nonreproductive females had a greater response to predation exposure and adjusted their response to risk level. Contrary to our predictions, pregnant females did not vary their behaviour based on gestation stage, despite increasing physical burden as pregnancy progressed. Overall, our results illustrate that pregnant females alter their behaviour to benefit their developing embryos thermally despite risk to themselves (increased exposure). By doing so, however, the female realizes a benefit by accelerating temperature-sensitive developmental time and thus reducing the duration of pregnancy and associated physical burden.
Antonia S. Müller, Patrick P. Lenhardt, Kathrin Theissinger
Pros and cons of external swabbing of amphibians for genetic analyses
European Journal of Wildlife Research July 2013
Non-invasive DNA sampling is an important tool in amphibian conservation. Buccal swabs are nowadays replacing the wounding toe-clipping method. Skin and cloaca swabbing are even less invasive and easier to handle than buccal swabbing, but could result in contaminations of genetic material. Therefore, we test if external skin and cloaca swabs are as reliable as buccal swabs for genetic analysis of amphibians. We analysed eight microsatellite loci for the common frog (Rana temporaria, Linnaeus 1758) and compared genotyping results for buccal, skin and cloaca swabs regarding allelic dropouts and false alleles. Furthermore, we compared two DNA extraction methods regarding efficiency and cost. DNA quality and quantity (amplification success, genotyping error rate, in nanogram per microlitre) were comparable among DNA sources and extraction methods. However, skin and cloaca samples exhibited high degrees of contamination with foreign individuals, which was due to sample collection during mating season. Here, we established a simple low budget procedure to receive DNA of amphibians avoiding stressful buccal swabbing or harmful toe clipping. However, the possibility of contaminations of external swabs has to be considered.
Zootaxa 3683 (2): 117–132 (3 Jul. 2013)
Description of new andean species of the genus Phymaturus (Iguania: Liolaemidae) from Northwestern Argentina
FERNANDO LOBO, ALEJANDRO LASPIUR & JUAN CARLOS ACOSTA
As a result of several field trips and studies of collections of Phymaturus samples from Andean areas of central western Argentina (San Juan province), we discovered two populations that exhibit a particular character combination not seen in other species formally recognized in the literature. Based on a detailed analysis of an extended list of morphological characters (93), including scalation, color pattern, gular and nuchal folds, precloacal pores, and morphometric data, we conclude that these populations represent independent lineages that deserve to be considered as new species. According
to the most recent revision of the genus and considering the descriptions made in another recent contribution, the taxonomic composition of the genus was increased to 38 species. In this study we provide the formal description of two additional new taxa, including their diagnosis and detailed comparisons with other members of their species group. The two new species belong to the palluma group, and can be assigned to the Puna subclade because they present the typical dorsal “spray” pattern. Other characters described in this study suggest their close phylogenetic relationship with other species
of this subclade inhabiting the southern Puna region of Argentina, such as Phymaturus punae. Within the Puna subclade, Phymaturus aguanegra sp. nov. differs from all other members (P. antofagastensis, P. denotatus, P. laurenti, P. punae, P. extrilidus, P. mallimaccii and P. paihuanense) exhibiting the following combination of diagnostic characters: a complete melanism over the dorsum of neck, the presence of enlarged scales at the base of tail in males, having strongly keeled tarsal scales, lacking enlarged scales on the anterior margin of the antehumeral fold and centre of chest, females without
flank coloration, a vertebral dark gray stripe usually present on the dorsum, females exhibiting a tricolor dorsal pattern, with two types of brown and scattered ferriferous oxide spots, and the absence of a scapular spot. Phymaturus williamsi sp. nov. differs from all other members of the Puna clade because: exhibits an “aggregate” dorsal pattern, unlike the homogeneous spray of most Puna species, lacks enlarged scales on the anterior margin of the antehumeral fold and in the centre of chest, flank coloration in females is absent, females of Phymaturus williamsi sp. nov. lack white transversal
stripes on the dorsal pattern, preocular scale in contact with canthal scale in Phymaturus williamsi sp. nov., rostral scale can be divided in Phymaturus williamsi sp. nov. and shows the largest number of scales counted around midbody within the Puna subclade (x= 213.4; 186-235).
S.T. Vilaça, P. Lara-Ruiz, M.A. Marcovaldi, L.S. Soares, F.R. Santos, Population origin and historical demography in hawksbill (Eretmochelys imbricata) feeding and nesting aggregates from Brazil, Journal of Experimental Marine Biology and Ecology, Volume 446, August 2013, Pages 334-344, ISSN 0022-0981, http://dx.doi.org/10.1016/j.jembe.2013.06.004.
We studied hawksbills from Brazilian feeding aggregates and nesting colonies to ascertain the origin and genealogical relationship of individuals in the largest southern Atlantic remnant population by using sequences of the mitochondrial (mtDNA) control region and five autosomal genes. A phylogeographic analysis of 246 hawksbills showed four distinct mtDNA haplogroups in the feeding grounds, while only one was found in Brazilian rookeries. We found significant differences among nesting sites in Brazil, and among them and other rookeries worldwide. Differences among Brazilian feeding aggregation sites and others around the world were also found. We were able to show that hawksbills from feeding aggregates at the Brazilian islands of Fernando de Noronha and Rocas Atoll were mainly derived from Brazilian and Caribbean rookeries, although some were related to individuals from the eastern Atlantic and Indo-Pacific, indicating large transoceanic migrations for this species. The nuclear data presented no structure and no signal of demographic change. Mixed stock analyses indicated that Brazilian rookeries contribute mostly to Brazilian feeding grounds, and in a smaller proportion to feeding aggregations in the Caribbean and eastern Atlantic. Finally, hybrids found frequently in rookeries of the Bahia State are not present in the feeding grounds, and thus, may display different feeding and migratory behaviors.
Peoples, B. K., McManamay, R. A., Orth, D. J. and Frimpong, E. A. (2013), Nesting habitat use by river chubs in a hydrologically variable Appalachian tailwater. Ecology of Freshwater Fish. doi: 10.1111/eff.12078
As hydrologic alteration continues to affect aquatic biodiversity, knowledge of the spawning requirements of fishes, especially ‘keystone’ or ‘foundation’ species, is critical for conservation and management. The objectives of this study were to quantify the spawning micro- and mesohabitat use of river chub Nocomis micropogon, a gravel mound nesting minnow, in a hydrologically regulated river in North Carolina, USA. At the microhabitat scale, substrate sizes on nests were compared with pebble counts in 1-m2 adjacent quadrats. Average depths and current velocities at nests were compared with measurements from paired transects. At the mesohabitat scale, generalised linear mixed models (GLMMs) were used to identify the importance of average bed slope, average depth and percentages of rock outcrops (a measure of flow heterogeneity and velocity shelters) for predicting nest presence and abundance. To relate nesting activities to hydrologic alteration from dam operation, nest dimensions were measured before and after a scheduled discharge event approximately six times that of base flow. Additionally, linear regression was used to predict changes in the use of flow refugia and overhead cover with increased fluvial distance from the dam. Microhabitats in which nests were placed had, on average, slower current velocities and shallower depths. Gravel diameters of nests were significantly smaller than substrate particles adjacent to nests. GLMMs revealed that mesohabitats with nests were shallower, had more moderate slopes and greater proportions of rock outcrops than mesohabitats without nests. The scheduled discharge event significantly flattened nests. Near the dam, nests were built in close proximity (≤2 m) to velocity shelters; this relationship diminished with distance from the dam. River chubs are spawning habitat specialists. Because multiple species rely on river chub nests for reproduction and food, the needs of this species should be considered when managing instream flows.
Mariano Rodriguez Recio, Renaud Mathieu, M. Cecilia Latham, A. David M. Latham, Philip J. Seddon
Quantifying fine-scale resource selection by introduced European hedgehogs (Erinaceus europaeus) in ecologically sensitive areas
Biological Invasions August 2013, Volume 15, Issue 8, pp 1807-1818
Introduced predators are important drivers of ecosystem change and can threaten native species. The European hedgehog (Erinaceus europaeus) was introduced from Britain into New Zealand where it is currently widespread, including in braided-river environments of the interior cold drylands where it might threaten native species such as riparian ground-nesting birds. The establishment of hedgehogs in braided-river environments may be facilitated by adjacent pastoral landscapes that provide food, primarily invertebrates, and dry shelter. Forays by hedgehogs into native prey habitats, such as riverbed floodplains, increase predation pressure. Understanding the spatial ecology of introduced predators can improve effectiveness of control measures. We assessed spatial resource selection by hedgehogs in a braided-river environment by tracking 27 individuals for 4–8 days in summer and autumn using microGPS-backpacks. We extracted fine-scale landscape variables from a map created using very high resolution satellite imagery to model home range placement within the study area. We also assessed habitat composition and ranking within high-use areas using compositional analysis. Hedgehogs established home ranges in pastoral landscapes containing abundant edges and high vegetation productivity (mainly green pastures and shrubs), and selected pastures and patches of shrubs as high-use areas. Hedgehogs avoided riverbed floodplains, suggesting that reported predation events on ground-nesting birds might be a consequence of secondary predation or individual specialization. We recommend that predation of native species by hedgehogs might be best alleviated if trapping is focused on those areas selected by native fauna of conservation concern (e.g. riverbed floodplains), as well some biologically-determined buffer surrounding these sites.
Tim S. Jessop, Michael R. Kearney, Joslin L. Moore, Tim Lockwood, Michael Johnston
Evaluating and predicting risk to a large reptile (Varanus varius) from feral cat baiting protocols
Biological Invasions, August 2013, Volume 15, Issue 8, pp 1653-1663
Control of introduced predators to mitigate biodiversity impacts is a pressing conservation challenge. Across Australia feral cats (Felis catus) are a major threat to terrestrial biodiversity. Currently feral cat control is hindered by the limited utility of existing predator baiting methods. Further proposed control methods include use of the novel poison para-aminopropiophenone (PAPP) which may present a hazard to some native animal populations. Here we used experimental and predictive approaches to evaluate feral cat bait take by a large native Australian predatory reptile the Lace monitor (Varanus varius). These lizards would be expected to readily detect, ingest and consume a lethal dose (depending on toxin) from surface-laid baits intended for feral cat control if a precautionary approach was not adopted when baiting. We modelled V. varius bait take using experimental and predictive biophysical modelling approaches to evaluate temporal effects of climate variables on V. varius activity and hence potential for bait removal. Finally we conducted a pre-PAPP baiting site occupancy assessment of V. varius within Wilson Promontory National Park (WPNP) to provide a basis for monitoring any longer term population effects of cat baiting. V. varius removed 7 % of deployed baits from 73 % of bait stations across another study area in Far Eastern Victoria. Daily bait removal was positively correlated with maximum temperature and solar radiation. Biophysical modelling for Far Eastern Victoria predicted that maximum temperatures
L.J. Bridgman, J. Innes, C. Gillies, N.B. Fitzgerald, S. Miller, C.M. King, Do ship rats display predatory behaviour towards house mice?, Animal Behaviour, Available online 2 July 2013, ISSN 0003-3472, http://dx.doi.org/10.1016/j.anbehav.2013.05.013.
Control operations for invasive ship rats, Rattus rattus, in New Zealand forests are often followed by increased house mouse, Mus musculus, detections suggesting rats suppress mice. A potential mechanism is intraguild predation, either by interference competition or as simple predatory behaviour. If aggression by rats towards mice is mainly competitive, it should include threat and display features associated with, for example, intraspecific fighting. If predatory, it should lack these features and be associated with feeding. In the first of two captive experiments we observed interactions between paired, live rodents, either side of a wire-mesh screen, and found that most rats were aggressive to mice. This aggression lacked threat and display characteristics typical of encounters with conspecifics and was rarely reciprocated by mice. In a second experiment, euthanized mice were drawn by a line through cages occupied by rats fed either a restricted or unrestricted diet. Rats of both groups attacked and restrained the euthanized mice, and all rats that interacted with the mice ate at least part of them, although food-restricted rats tended to eat more. As the aggressive response of ship rats towards mice lacked threat and display features and was related to feeding, we conclude that it resembles predatory behaviour. Our findings provide a better understanding of the interactions between ship rats and house mice, which hinder their management where they coexist as damaging invaders. However, further research is required to determine whether the results of our captive experiments are consistent with wild rat behaviour.
Jenkins PD, Abramov AV, Bannikova AA, Rozhnov VV (2013) Bones and genes: resolution problems in three Vietnamese species of Crocidura (Mammalia, Soricomorpha, Soricidae) and the description of an additional new species. ZooKeys 313: 61–79. doi: 10.3897/zookeys.313.4823
Recent investigations of Southeast Asian white toothed shrews belonging to the genus Crocidura have revealed discrepancies between the results of morphological and molecular studies. The following study concerns three species of Crocidura occurring in Vietnam, namely Crocidura attenuata, Crocidura tanakae and Crocidura wuchihensis, and an undescribed fourth species revealed by molecular analysis. For many years Crocidura attenuata has been known to occur in Vietnam but, until very recently, the morphologically similar and comparably sized Crocidura tanakae was believed to be restricted to Taiwan. Following several molecular studies over the last few years, this species is now believed to be considerably more widespread and recognised as occuring also in Vietnam. The results of one of these recent molecular studies also revealed the presence of an undescribed species of Crocidura, similar in size and morphology to Crocidura wuchihensis, which is herein described. Data are provided on geographical variation in Vietnam and the problems of defining morphologically similar yet molecularly disparate species are discussed.