Canjun Xia, Wei Liu, Wenxuan Xu, Weikang Yang, Feng Xu, David Blank, The energy-maintenance strategy of goitered gazelles Gazella subgutturosa during rut, Behavioural Processes, Available online 9 November 2013, ISSN 0376-6357, http://dx.doi.org/10.1016/j.beproc.2013.10.009.
In many polygynous ruminant species, males decrease their food intake considerably during the rut. To explain this phenomenon of rut-reduced hypophagia, two main hypotheses, the Foraging-Constraint Hypothesis and Energy-Saving Hypothesis, have been proposed. In our research, we assessed the behavioral strategy of goitered gazelles (Gazella subgutturosa) through the rutting period. According to our findings, male goitered gazelles spent less time feeding during the rut compared to pre- and post-rut feeding times, but then maximized their energy intake during the rutting season when they were not engaged in rut-related behaviors. Females, in contrast, did not change their time budgets across the different stages of the rut. Therefore, rut-induced hypophagia is mainly arising from the constraints of rut-related behaviors for male goitered gazelles, so that the Foraging-Constraint Hypothesis better explains their strategy during rut.
Francisco Ceacero, Tomás Landete-Castillejos, María Miranda, Andrés J. García, Alberto Martínez, Laureano Gallego, Why do cervids feed on aquatic vegetation?, Behavioural Processes, Available online 9 November 2013, ISSN 0376-6357, http://dx.doi.org/10.1016/j.beproc.2013.10.008.
Consumption of aquatic plants is rare among cervids, despite the common occurrence of this form of vegetation. However, the paucity of literature reporting on this feeding behaviour suggests that Na (but also other minerals), protein, and the ubiquitous availability of aquatic vegetation may play a role in its consumption. We present results quantifying those factors that regulate the consumption of aquatic plants in the Iberian red deer. We focussed our study primarily on two questions: (i) what nutritional values are red deer seeking in the aquatic plants?; and (ii) why do red deer primarily use aquatic plants during the summer? A comparison of the seasonal variations in Na content between terrestrial vs. aquatic vegetation did not fully support the hypothesis that aquatic plants are being consumed more in summer because of any seasonal variation in Na availability. The Na content in the aquatic vegetation was adequate all the year-round; whereas, the Na content in the terrestrial vegetation was consistently deficient. However, a greater summer content of essential minerals and protein in the aquatic vegetation may be the cause for their consumption exclusively during the summer. We suggest that seasonal variations in the consumption of aquatic vegetation by cervids is primarily driven by temporal variations in the nutrient content, combined with seasonal variations in the physiological demands for these nutrients.
Hiroki Sato, Shinichiro Ichino, Goro Hanya
Dietary modification by common brown lemurs (Eulemur fulvus) during seasonal drought conditions in western Madagascar
Primates November 2013
Primates often modify dietary composition in relation to seasonal changes in food availability or climate conditions. We studied the feeding patterns of a troop of common brown lemurs (Eulemur fulvus), a semi-frugivorous strepsirhine, in a dry forest in northwestern Madagascar. To understand the mechanism of dietary modification, we recorded daily feeding times of diet items during 101 full-day observations over 1 year, and then conducted a linear model analysis to examine the effects of fruiting tree density in the forest, daily ambient temperature, and weekly rainfall (index of water retained in the forest) on the lemurs‘ daily feeding time. The lemurs spent dramatically more time on leaf-eating as well as total feeding time, and less time on fruit-eating during the late dry season (total 152 min/day, frugivory 56 min/day, folivory 77 min/day), as compared with other seasons when the diet was highly frugivorous (total 96 min/day, frugivory 81 min/day, folivory 8 min/day). Folivory increased as temperatures rose under the condition of low weekly rainfall, whereas frugivory was unrelated to fruiting tree density. Most (97.4 %) diurnal folivory during the late dry season was spent consuming Lissochilus rutenbergianus, chewing the succulent leaves and licking the juice. Because the nutritional analysis showed that L. rutenbergianus is rich in water (80.1 % of fresh weight) but poor in protein and nonstructural carbohydrates, its increased use was probably for rehydration. We conducted 13 full-night observations, because brown lemurs increase nocturnal activities during the dry season. At nighttime, the lemurs tended to spend more time eating fruit in the late dry season (32 min/night) than in the early dry season (14 min/night), and never consumed L. rutenbergianus. Fruits rich in nonstructural carbohydrates can be energy sources for Eulemur. They likely engaged in additional nocturnal frugivory for energy compensation. Brown lemurs have a flexible strategy of modifying their diet and feeding activities to cope with environmental stresses.
Joel Bray, Christopher Krupenye, Brian Hare
Ring-tailed lemurs (Lemur catta) exploit information about what others can see but not what they can hear
Animal Cognition November 2013
Studies suggest that haplorhine primates are sensitive to what others can see and hear. Using two experimental designs, we tested the hypothesis that ring-tailed lemurs (N = 16) are also sensitive to the visual and auditory perception of others. In the first task, we used a go/no–go design that required lemurs to exploit only auditory information. In the second task, we used a forced-choice design where lemurs competed against a human who would prevent them from obtaining food if their approaches were detected. Subjects were given the choice of obtaining food silently or noisily when the competitor’s back was turned. They were also given the choice to obtain food when the competitor could either see them or not. Here, we replicate the findings of previous studies indicating that ring-tailed lemurs are sensitive to whether they can be seen; however, we found no evidence that subjects are sensitive to whether others can hear them. Our findings suggest that ring-tailed lemurs converge with haplorhine primates only in their sensitivity to the visual information of others. The results emphasize the importance of investigating social cognition across sensory domains in order to elucidate the cognitive mechanisms that underlie apparently complex social behavior. These findings also suggest that the social dynamics of haplorhine groups impose greater cognitive demands than lemur groups, despite similarities in total group size.
Gerit Pfuhl, Matthias Gattermayr, Thomas Bugnyar, Will food-handling time influence agonistic behaviour in sub-adult common ravens (Corvus corax)?, Behavioural Processes, Available online 13 November 2013, ISSN 0376-6357, http://dx.doi.org/10.1016/j.beproc.2013.11.003.
Discovering a food source may invoke either competition or cooperation, depending on many factors such as divisibility and accessibility. We experimentally investigated the influence of effort to procure food on the tolerance towards others during feeding. Nine sub-adult captive ravens were tested in different foraging contexts that differed in foraging effort, namely three string-pulling conditions and two without pulling requirement. We expected that the effort to gain access to food would positively affect the tolerance towards others at feeding. As predicted, we found fewer agonistic interactions, fewer displacements of subordinates from food and prolonged feeding bouts in the three string-pulling conditions compared to the two conditions when no pulling was involved. Further, in the string pulling tasks interactions occurred mostly on the perch before pulling and only rarely was pulling interrupted by agonistic interactions. The rate of interactions did not change over trials. Our data suggests that perceived effort influences social behaviour.
Emma McIntyre, Marty L. Leonard, Andrew G. Horn, Ambient noise and parental communication of predation risk in tree swallows, Tachycineta bicolor, Animal Behaviour, Available online 14 November 2013, ISSN 0003-3472, http://dx.doi.org/10.1016/j.anbehav.2013.10.013.
Ambient noise can mask important acoustic signals used in a variety of communication systems, especially if signals are not adjusted to improve transmission in noise. Nestling birds communicate with their parents using loud begging calls that convey their need for food, but that also attract predators to the nest. Parents can reduce this vulnerability by using alarm calls to silence begging nestlings. Noise could, however, mask alarm calls and increase predation risk, unless parents can adjust their calls to circumvent the noise. Here, we determined whether the response of nestling tree swallows to parental alarm calls is altered in the presence of noise, and whether parents adjust alarm calls in noise to improve call transmission. We found that, in noisy conditions, nestlings continued calling and failed to crouch in the nest in response to parental alarm calls, in contrast to their behaviour in quiet conditions. None of the call features that we measured varied in relation to ambient noise levels at the nest. Our results suggest that noise could interfere with the ability of nestlings to respond appropriately to parental alarm calls and, in turn, could increase predation risk, although further work is needed to test this possibility.
Toshitaka N. Suzuki, Communication about predator type by a bird using discrete, graded and combinatorial variation in alarm calls, Animal Behaviour, Available online 14 November 2013, ISSN 0003-3472, http://dx.doi.org/10.1016/j.anbehav.2013.10.009.
Many animals use variation in their alarm calls to warn conspecifics about different predatory threats. Information about predators can be encoded by producing discrete types of alarm calls and/or through graded variation in a single call type (i.e. calling rate or note repetitions). Another way to encode predator information is to combine different types of calls or notes into longer structured sequences. However, few studies have examined how individuals use discrete, graded and combinatorial variation in alarm calls to denote specific risks. I investigated the acoustic structure and information content of alarm calls in Japanese great tits, Parus major minor, by exposing their nests to three predator species (snakes, crows and martens) and a nonpredator species (doves). Great tits produced acoustically discrete alarm calls for the different nest predators: ‘jar’ calls for snakes and ‘chicka’ calls for crows and martens. The adults further discriminated between crows and martens by altering the calling rate and note number of the ‘chicka’ calls. A total of 175 types of note combinations were observed in the ‘chicka’ calls, and the tits used these combination types differently for the crows and martens. These results provide the first demonstration that birds can encode information about predator type by using production specificity, graded features and note combinations of discrete alarm calls. Previous studies have shown that parent and nestling Japanese great tits can respond in different, adaptive ways to discrete alarm calls. However, further playback studies are required to determine whether and how conspecifics can extract predator information from graded and combinatorial variation in alarm calls.
Demographic structure and genetic variability of a population of Testudo hermanni hermanni (Reptilia: Testudines: Testudinidae) from Southern Tuscany (Central Italy): a case of “happy-ending” uncontrolled reintroduction
G. Cutuli, M. Vannini, S. Fratini
Italian Journal of Zoology
Testudo hermanni hermanni is becoming seriously endangered throughout its range. It has a scattered distribution, with a small number of residual populations found in Spain, France and Italy. In this study we sampled a population of T. h. hermanni from Southern Tuscany (Massa Marittima, Grosseto), composed of native and introduced individuals (recognizable due to residual signs of previous marking on the carapace). Overall, 95% of the captured individuals were adults and the sex ratio was slightly, but not significantly, biased in favour of females. Population density was relatively high in comparison with other Italian populations, although it was doubled by previous reinforcement. Genetic analysis performed on six polymorphic microsatellite loci revealed a high level of genetic variability and heterozygosity, with no evidence of current inbreeding processes. Moreover, introduced individuals presented genotypes similar to those of the native individuals, thus suggesting that the reinforcement intervention did not cause a significant change in the original genetic pool. Nevertheless, long-term monitoring of the population is necessary to ensure its stability and vitality. Furthermore, to preserve the genetic identity of the local population in the future, uncontrolled translocation events should be avoided.
Ranging behaviour and reproductive rate in the threatened population of roe deer in Gargano, South Italy
V. Aiello, S. Lovari, A. Bocci
Italian Journal of Zoology
The ranging behaviour of Italian roe deer Capreolus capreolus italicus was studied for 2 years in a low density, “vulnerable” population (ca. 6 ind./100 ha), in an Apennine-continental forest of Southern Italy (Gargano National Park), through satellite radiotracking. The seasonal median home range size of does ranged significantly between 16 ha, in spring, and 43 ha, in the cold months. Monthly home range size of does did not change significantly in daylight, night and twilight. The reproductive success (fawns:female) of our radiotagged does was very low (0.8–1.3 vs the expected 2) in both years of study, contrasting with the normal productivity of roe does, especially when density is low.
Spartaco Gippoliti, Andreina D’Alessandro, Great Apes in the Giardino Zoologico of Rome (1910-1998): An Overview, Der Zoologische Garten, Available online 14 November 2013, ISSN 0044-5169, http://dx.doi.org/10.1016/j.zoolgart.2013.10.002.
This work reviews nearly 90 years of ape keeping and housing at the Giardino Zoologico in Rome, and offers an overview of the scientific research carried out on these primates. It may thus contribute to a better historical knowledge of primate zoo management in Italy. Furthermore, particular attention is paid to morphological aspects in orangutan physical development that should deserve further research.
Female mate choice in convict cichlids is transitive and consistent with a self-referent directional preference
Dechaume-Moncharmont F, Freychet M, Motreuil S, Cézilly F
Frontiers in Zoology 2013, 10:69 (11 November 2013)
One of the most important decisions that an animal has to make in its life is choosing a mate. Although most studies in sexual selection assume that mate choice is rational, this assumption has not been tested seriously. A crucial component of rationality is that animals exhibit transitive choices: if an individual prefers option A over B, and B over C, then it also prefers A over C.
We assessed transitivity in mate choice: 40 female convict cichlids had to make a series of binary choices between males of varying size. Ninety percent of females showed transitive choices. The mean preference index was significantly higher when a female chose between their most preferred and least preferred male (male 1 vs. male 3) compared to when they chose between males of adjacent ranks (1 vs. 2 or 2 vs. 3). The results are consistent with a simple underlying preference function leading to transitive choice: females preferred males about one third larger than themselves. This rule of thumb correctly predicted which male was preferred in 67% of the cases and the ordering in binary choices in 78% of cases.
This study provides the first evidence for strong stochastic transitivity in a context of mate choice. The females exhibited ordinal preferences and the direction and magnitude of these preferences could be predicted from a simple rule. The females do not necessarily compare two males to choose the best; it is sufficient to use a self-referent evaluation. Such a simple decision rule has important implications for the evolution of the mating strategies and it is consistent with patterns of assortative mating repeatedly observed at population level.
Genetic evidence of extra-pair paternity and intraspecific brood parasitism in the monk parakeet Martínez JJ, de Aranzamendi MC, Masello JF, Bucher EH
Frontiers in Zoology 2013, 10:68 (9 November 2013)
The monk parakeet (Myiopsitta monachus) is a widespread invasive species native to southern South America that has become established in many regions of the world. Monk parakeets breed in a large, fully enclosed structure built from twigs, which consist of one to many individual brooding chambers. The species has been considered to be socially and genetically monogamous. However, genetic relatedness of adults to juveniles in the native area was found to be lower than expected for monogamy. To assess the significance of this discrepancy, we examined individual and population genetic patterns of microsatellite loci at two sites in Córdoba province, Argentina.
We sampled 154 nestlings and 42 adults in Córdoba, Argentina. Mean value of pairwise relatedness of nestlings within chambers was about 0.40. Contrarily, relatedness of nestlings between chambers was close to zero. We found a considerable degree of variation in nestling pairwise relatedness and parentage within chambers, including chambers with combinations of unrelated, half-sib, and full-sib nestlings. The proportion of sibling relatedness indicated monogamy in 47% and extra pair-paternity in 40% of the chambers. We also found intra-brood parasitism in 3% of the chambers.
Our results indicate that the monk parakeet is sexually polygamous in its native range in Argentina, which is consistent with the observed mean value of relatedness of adults to juveniles of about 0.4. We also confirm the existence of intra-brood parasitism. High density of monk parakeets may favor occurrence of extra-pair paternity and intra-brood parasitism in the native sites.
Tadpole transport logistics in a Neotropical poison frog: indications for strategic planning and adaptive plasticity in anuran parental care
Ringler E, Pa¿ukonis A, Hödl W, Ringler M
Frontiers in Zoology 2013, 10:67 (9 November 2013)
Individuals should aim to adjust their parental behaviours in order to maximize the success of their offspring but minimize associated costs. Plasticity in parental care is well documented from various bird, mammal and fish species, whereas amphibians were traditionally assumed as being highly instinct-bound. Therefore, little is known about ‘higher’ cognitive abilities of amphibians, such as strategic planning and behavioural flexibility. Dendrobatid frogs have evolved a remarkable diversity of parental behaviours. The most noticeable of these behaviours is tadpole transport, which is obligatory in almost all species. Nonetheless, there is limited knowledge about spatial and temporal patterns of tadpole transport and the possible existence of behavioural plasticity on the individual level. In this study, we investigated correlates of tadpole transport behaviour in a natural population of the dendrobatid frog Allobates femoralis during five years.
Tadpole transport was predominantly observed during morning hours. Although tadpoles were carried almost exclusively by males (N = 119), we also observed ten females performing this task. The parentage analysis revealed that in all cases females transported their own offspring. In contrast, four tadpole-carrying males were not the genetic fathers of the larvae they were transporting. The average clutch size of 20 eggs and our observation of an average of 8 tadpoles on the back of transporting individuals indicate that frogs do not carry entire clutches at once, and/or that they distribute their larvae across several water bodies. Contrary to the predictions from a hypothetical random search for deposition sites, the number of transported tadpoles was higher in males that travelled over longer distances.
Our results suggest a strong selective pressure on males to shift the time invested in tadpole transport to periods of low intra-specific competition. The number of tadpoles on the back of the males significantly correlated with displacement distance from the respective home territories, indicating a strategic non-random tadpole transport rather than random search for suitable tadpole deposition sites during tadpole transport. The observation of females who occasionally transported larvae supports the prevalence of adaptive plasticity in parental behaviours even in a species with a rather low level of parental care.
Sexual size dimorphism in anurans: roles of mating system and habitat types
Liao WB, Zeng Y, Yang JD
Frontiers in Zoology 2013, 10:65 (7 November 2013)
Sexual size dimorphism (SSD) is widespread and variable among animals. Sexual selection, fecundity selection and ecological divergence between males and females are the major evolutionary forces of SSD. However, the influences of mating system and habitat types on SSD have received little attention. Here, using phylogenetic comparative methods, we at first examine the hypotheses to that mating system (intensity of sexual selection) and habitat types affect significantly variation in SSD in anurans (39 species and 18 genera).
Our data set encompass 39 species with female-biased SSD. We provide evidence that the effects of mating system and habitat types on SSD were non-significant across species, also when the analyses were phylogenetically corrected.
Contrast to the hypotheses, our findings suggest that mating system and habitat types do not play an important role in shaping macro-evolutionary patterns of SSD in anurans. Mating system and habitat types cannot explain the variation in SSD when correcting for phylogenetic effects.
Zootaxa 3736 (1): 054–068 (11 Nov. 2013)
Taxonomic revision of the ornate skink (Oligosoma ornatum; Reptilia: Scincidae) species complex from northern New Zealand
GEOFF B. PATTERSON, ROD A. HITCHMOUGH & DAVID G. CHAPPLE
Although the New Zealand skink fauna is known to be highly diverse, a substantial proportion of the recognised species
remain undescribed. We completed a taxonomic revision of the ornate skink (Oligosoma ornatum (Gray, 1843)) as a previous molecular study indicated that it represented a species complex. As part of this work we have resolved some nomenclatural issues involving this species and a similar species, O. aeneum (Girard, 1857). A new skink species, Oligosoma roimata sp. nov., is described from the Poor Knights Islands, off the northeast coast of the North Island of New Zealand. This species is diagnosed by a range of morphological characters and genetic differentiation from O. ornatum. The conservation status of the new taxon appears to be of concern as it is endemic to the Poor Knights Islands and has rarely been seen over the past two decades.
Zootaxa 3736 (1): 082–088 (11 Nov. 2013)
A new species of the genus Pethia from Mizoram, northeastern India (Teleostei: Cyprinidae)
MAYANGLAMBAM DISHMA & WAIKHOM VISHWANATH
The paper describes Pethia expletiforis, a new cyprinid species from the Ka-ao River, Kaladan drainage, Mizoram, India.It is distinguished from its congeners in the Chindwin-Irrawaddy and Ganga-Brahmaputra drainages by the combination of: a complete lateral line, nine predorsal scales, 12 circumpeduncular scales, ½4/1/3½ transverse scales, a black blotch on the caudal peduncle, and the absence of a humeral mark and barbels.
Zootaxa 3736 (1): 089–098 (11 Nov. 2013)
A new species of Hemiphyllodactylus (Reptilia: Gekkonidae) from northern Vietnam
TRUONG QUANG NGUYEN, TANJA LEHMANN, MINH DUC LE, HA THUY DUONG, MICHAEL BONKOWSKI & THOMAS ZIEGLER
We describe a new species of the genus Hemiphyllodactylus on the basis of four specimens from Cao Bang Province,
northern Vietnam. Hemiphyllodactylus zugi sp. nov. is distinguished from the remaining congeners by a combination of
the following characters: a bisexual taxon; average SVL of adult males 41 mm, of adult female 46.6 mm; chin scales bordering mental and first infralabial distinctly enlarged; digital lamellae formulae 3-4-4-4 (forefoot) and 4-5-5-5 (hindfoot); femoral and precloacal pore series continuous, 18–21 in total in males, absent in female; cloacal spur single in males; dorsal trunk pattern of dark brown irregular transverse bands; dark lateral head stripe indistinct; upper zone of flank with a series of large light spots, edged above and below in dark grey; caecum and gonadal ducts unpigmented.
Zootaxa 3736 (3): 236–248 (13 Nov. 2013)
A new species of Physoschistura (Pisces: Nemacheilidae) from northern Thailand
Physoschistura chulabhornae, new species, is described from Maechaem River, a tributary of Ping River, upper Chaophraya River drainage, Chiangmai province, Thailand. It is distinguished from all other known species of Physoschistura in having an incomplete lateral line reaching at least to the origin of the anal fin with 62–83 lateral-line canal pores, the dorsal-fin origin slightly in front of the pelvic-fin origin, no axillary pelvic lobe, and a suborbital flap in the shape of a hammer head in the male.
Zootaxa 3736 (5): 587–597 (15 Nov. 2013)
The mammal type specimens at the Natural History Museum, University of Oslo, Norway
ØYSTEIN WIIG & LUTZ BACHMANN
A catalog of mammalian type specimens in the collections of Natural History Museum, University of Oslo, Norway, is
presented. All type specimens in the Museum’s mammal collection were revisited and the respective label information
was compared with the data provided in the original descriptions. Most taxa were described from type series with no specimen particularly assigned to holotype. The compiled catalog of the type specimens is not intended as a taxonomic revision of the respective taxa, which is why we have not designated lectotypes from the collection’s type series. Specimens that were clearly marked as “the type” in the original description were considered holotypes. The catalog consists of 19 taxa, with the year of authority corrected for three taxa.
Morelli F (2013) Are the nesting probabilities of the red-backed shrike related to proximity to roads?. Nature Conservation 5: 1-11. doi: 10.3897/natureconservation.5.4511
Roads are a pervasive feature in the landscape, and their ecological effects on vertebrate wildlife have been well documented. The main types of effect described are mainly negative consequences on birds and other vertebrates. The major impact of roads on birds includes habitat fragmentation, traffic noise and direct mortality from road kills. However, some passerines, such as the Red-backed Shrike, seem to often use areas close to roads for nesting and hunting purposes.
The aim of this paper is to study the importance of road proximity for the selection of suitable shrubs for nesting by the Red-backed Shrike in the farmland landscapes of central Italy. To achieve this goal, the hierarchical partitioning procedures of Generalized Linear Models (GLM) are applied in order to quantify the relative effects of a number of independent variables.
At least 77% of the nests we identified were positioned less than 25 meters from roads. The mean distance from the nest to the nearest road was 12.9 ± 18.1 m. The analysis of the relative importance of each variable revealed that “road distance” is one of variables most associated with nesting probability in suitable shrubs. It is reasonable to argue that suitable shrubs and the presence of open spaces for hunting, both of which exist close to countryside roads, might represent the favourable components of the breeding habitat selections of Red-backed Shrikes. Our results can provide useful indications for census techniques and for the planning of conservation measures for the species in agricultural landscapes.
Pontoppidan MB, Nachman G (2013) Changes in behavioural responses to infrastructure affect local and regional connectivity – a simulation study on pond breeding amphibians. Nature Conservation 5: 13-28. doi: 10.3897/natureconservation.5.4611
An extensive and expanding infrastructural network destroys and fragments natural habitat and has detrimental effect on abundance and population viability of many amphibian species. Roads function as barriers in the landscape. They separate local populations from each other or prevent access to necessary resources. Therefore, road density and traffic intensity in a region may have severe impact on regional as well as local connectivity. Amphibians may be able to detect and avoid unsuitable habitat. Individuals’ ability to avoid roads can reduce road mortality but at the same time road avoidance behaviour, can increase the barrier effect of the road and reduce connectivity. We use an individual based model to explore how changes in road mortality and road avoidance behaviour affect local and regional connectivity in a population of Moor frogs (Rana arvalis). The results indicate that road mortality has a strong negative effect on regional connectivity, but only a small effect on local connectivity. Regional connectivity is positively affected by road avoidance and the effect becomes more pronounced as road mortality decreases. Road avoidance also has a positive effect on local connectivity. When road avoidance is total and the road functions as a 100% barrier regional connectivity is close to zero, while local connectivity exhibit very elevated values. The results suggest that roads may affect not only regional or metapopulation dynamics but also have a direct effect on local population dynamics.
Pontoppidan MB, Nachman G (2013) Spatial Amphibian Impact Assessment – a management tool for assessment of road effects on regional populations of Moor frogs (Rana arvalis). Nature Conservation 5: 29-52. doi: 10.3897/natureconservation.5.4612
An expanding network of roads and railways fragments natural habitat affecting the amount and quality of habitat and reducing connectivity between habitat patches with severe consequences for biodiversity and population persistence. To ensure an ecologically sustainable transportation system it is essential to find agreement between nature conservation and land use. However, sustainable road planning requires adequate tools for assessment, prevention and mitigation of the impacts of infrastructure. In this study, we present a spatially explicit model, SAIA (Spatial Amphibian Impact Assessment), to be used as a standardized and quantitative tool for assessing the impact of roads on pond-breeding amphibians. The model considers a landscape mosaic of breeding habitat, summer habitat and uninhabitable land. As input, we use a GIS-map of the landscape with information on land cover as well as data on observed frog populations in the survey area. The dispersal of juvenile frogs is simulated by means of individual-based modelling, while a population-based model is used for simulating population dynamics. In combination the two types of models generate output on landscape connectivity and population viability. Analyses of maps without the planned road constructions will constitute a “null-model” against which other scenarios can be compared, making it possible to assess the effect of road projects on landscape connectivity and population dynamics. Analyses and comparisons of several alternative road projects can identify the least harmful solution. The effect of mitigation measures, such as new breeding ponds and underpasses, can be evaluated by incorporating them in the maps, thereby enhancing the utility of the model as a management tool in Environmental Impact Assessments. We demonstrate how SAIA can be used to assess which management measures would be best to mitigate the effect of landscape fragmentation caused by road constructions by means of a case study dedicated to the Moor frog (Rana arvalis).
Pacifici M, Santini L, Di Marco M, Baisero D, Francucci L, Grottolo Marasini G, Visconti P, Rondinini C (2013) Generation length for mammals. Nature Conservation 5: 89-94. doi: 10.3897/natureconservation.5.5734
Generation length (GL) is defined as the average age of parents of the current cohort, reflecting the turnover rate of breeding individuals in a population. GL is a fundamental piece of information for population ecology as well as for measuring species threat status (e.g. in the IUCN Red List). Here we present a dataset including GL records for all extant mammal species (n=5427). We first reviewed all data on GL published in the IUCN Red List database. We then calculated a value for species with available reproductive parameters (reproductive life span and age at first reproduction). We assigned to missing-data species a mean GL value from congeneric or confamilial species (depending on data availability). Finally, for a few remaining species, we assigned mean GL values from species with similar body mass and belonging to the same order. Our work provides the first attempt to complete a database of GL for mammals; it will be an essential reference point for all conservation-related studies that need pragmatic information on species GL, such as population dynamics and applications of the IUCN Red List assessment.
Duško Ćirović, Aleksandra Penezić, Miroljub Milenković, Milan Paunović, Winter diet composition of the golden jackal (Canis aureus L., 1758) in Serbia, Mammalian Biology – Zeitschrift für Säugetierkunde, Available online 14 November 2013, ISSN 1616-5047, http://dx.doi.org/10.1016/j.mambio.2013.11.003.
The winter diet composition of golden jackals was determined by analysing the stomach contents of 248 specimens collected between December and February 2005-2009 at six localities in Serbia. The average weight of stomach contents was 189.9 ± 137.3 g. At all localities, livestock carcasses were the primary food category (frequency 56.1%, biomass 77.7%). The secondary food category consisted of small mammals taken as live prey (frequency 20.7%, biomass 5.2%). Other food categories were present less frequently (roe deer, wild boar, hare, and birds), and rarely (plant material, dogs, carnivores, lizards, and inedible inorganic material). No statistically significant differences were found in diet between jackals from different localities. The only difference was found between yearlings and adults with regard to the consumed biomass (%B). The analysis of the winter diet of golden jackals in Serbia indicates that the species has opportunistic feeding habits consisting primarily of easily accessible food sources.
Pirius, N. E., Boal, C. W., Haukos, D. A. and Wallace, M. C. (2013), Winter habitat use and survival of lesser prairie-chickens in West Texas. Wildlife Society Bulletin. doi: 10.1002/wsb.354
The lesser prairie-chicken (Tympanuchus pallidicinctus) has experienced declines in population and occupied range since the late 1800s and is currently proposed for Federal protection under the Endangered Species Act. Populations and the distribution of lesser prairie-chickens in Texas, USA, are thought to be at or near all-time lows. Currently, there is a paucity of data on the wintering ecology of the species. We measured home range, habitat use, and survival of lesser prairie-chickens during the non-breeding seasons (1 Sep–28 Feb) of 2008–2009, 2009–2010, and 2010–2011 in sand shinnery oak (Quercus havardii) landscapes in the West Texas panhandle region. Home range size did not differ among years or between females (503 ha) and males (489 ha). Over 97% of locations of both male and female prairie-chickens were within 3.2 km of the lek of capture, and 99.9% were within 3.2 km of an available water source (i.e., livestock water tank). Habitat cover types were not used proportional to occurrence within the home ranges; grassland-dominated areas with co-occurring sand shinnery oak were used more than available, but sand sagebrush (Artemisia filifolia)-dominated areas with grassland and sand sagebrush-dominated areas with bare ground were both used less than available. Survival rates during the first 2 non-breeding seasons (>80%) were among the highest reported for the species. However, survival during the third non-breeding season was only 57%, resulting in a 3-year average of 72%. It does not appear that non-breeding season mortality is a strong limiting factor in lesser prairie-chicken persistence in the study area.
Aonghais S.C.P. Cook, Daria Dadam, Ian Mitchell, Viola H. Ross-Smith, Robert A. Robinson, Indicators of seabird reproductive performance demonstrate the impact of commercial fisheries on seabird populations in the North Sea, Ecological Indicators, Volume 38, March 2014, Pages 1-11, ISSN 1470-160X, http://dx.doi.org/10.1016/j.ecolind.2013.10.027.
In a world of growing anthropogenic pressures on biodiversity, effective indicators need to be specific and sensitive to the pressures in the ecosystem concerned, yet be simple enough to be interpreted by non-experts and straightforward enough to facilitate routine monitoring. Globally, seabirds are under increasing pressure as a result of anthropogenic activities and environmental variation. Traditionally, seabird indicators have been based on abundance at breeding colonies. However, as many species do not reach sexual maturity for several years, and may not attend the colony over this time period, such indicators may fail to capture the ecological complexity of the system concerned.
We constructed two indicators of the state of nine seabird species that breed along the UK coast of the North Sea: (i) abundance of seabirds at breeding colonies, and (ii) probability of seabird breeding failure. The indicators were significantly and strongly correlated with each other for eight out of nine species, but the abundance indicator typically lagged the indicator on seabird breeding failure by two to three years. We then considered a third indicator which compared kittiwake (Rissa tridactyla) breeding success to the levels expected given the underlying environmental conditions; changes in the abundance indicator also lagged this by three years. We investigate how sensitive each of these indicators was to the impacts of fishing. We found that the species which had seen the greatest increases in breeding failure rate over the study period were those species which were most sensitive to fisheries pressure.
By focussing on demographic parameters, and correcting for the underlying environmental conditions, we can detect potentially important population level changes at an earlier stage than by focussing on abundance alone. These indicators are able to more accurately capture the complexity of the ecosystem concerned and can be readily interpreted by policy-makers.