Born to be wild? Response of an urban exploiter to human-modified environment and fluctuating weather conditions

2015 ◽  
Vol 93 (4) ◽  
pp. 315-322
Author(s):  
Geneviève Turgeon ◽  
Eric Vander Wal ◽  
Ariane Massé ◽  
Fanie Pelletier
Keyword(s):  
Body Mass ◽  
Human Activity ◽  
Environmental Changes ◽  
Spatial Scales ◽  
Somatic Growth ◽  
Food Sources ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Artificial Food ◽  
Winter Severity

Human-driven environmental changes affect behavior, morphology, life history, and population dynamics of wild species. Artificial food sources in anthropogenic environments benefit some species and may lead to faster somatic growth and larger body size, which affects survival and reproduction, thus contributing to a species’ success in modified environments. Using raccoons (Procyon lotor (L., 1758)) as a model, we documented age-specific body-mass pattern and evaluated the influence of human activities (human density, area with artificial food sources, edges of forested area bordering corn (Zea mays L.) fields) and weather (index of winter severity and mean annual precipitation) on body-mass variation at multiple spatial scales. The effect of human-driven changes on raccoon mass varied with age, sex, and spatial scale, suggesting that anthropogenic changes affect raccoons differentially according to gender and life stages. Human activity had consistently opposing effects between the sexes. Weather covariates represented >50% of the total variance in body mass explained by our models. Previous winter severity and mean annual precipitation affected body mass negatively and positively, respectively. Our results emphasize the importance of multiscale, sex- and age-specific analyses when studying influences of human activity on wildlife.

scholarly journals Palynological evidence for gradual vegetation and climate changes during the "African Humid Period" termination at 13° N from a Mega-Lake Chad sedimentary sequence

2012 ◽  
Vol 8 (3) ◽  
pp. 2321-2367
Author(s):  
P. G. C. Amaral ◽  
A. Vincens ◽  
J. Guiot ◽  
G. Buchet ◽  
P. Deschamps ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Climatic Conditions ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Sedimentary Sequence ◽  
Pollen Data ◽  
Lake Chad ◽  
Precipitation Estimates ◽  
Sahel Region ◽  
Humid Period

Abstract. Located at the transition between the Saharian and Sahelian zones, at the center of one of the largest endoreic basins, the Lake Chad is ideally located to record regional environmental changes that occurred in the past. However, until now, no continuous archive from Lake Chad covering the Holocene has been studied. In this paper, we present pollen data from the first Holocene sedimentary sequence collected in Lake Chad (13° N; 14° E; Sahel region). Dated between ca. 6700 and ca. 5000 cal yr BP, this record encompasses the termination of the African Humid Period (AHP). Vegetational reconstructions are based on standard analyses of the pollen diagrams and are strengthened by quantitative approaches. Potential biomes that occurred at that time around Mega-Lake Chad are reconstructed using the biomization method and mean annual precipitation is estimated using the modern analogues technique. Results show that between ca. 6700 and ca. 6050 cal yr BP, a vegetation close to humid woodland or humid savanna, including elements currently found much further southward, thrived in the vicinity and/or the extra-local environment of the Mega-Lake Chad in place of the modern steppe, dry woodland and desert vegetation observed today. At the same time, montane forest populations extended further southward on the Adamawa plateau. This vegetation distribution is supported by biome reconstructions as well as by mean annual precipitation estimates of ca. 800 (−400/+700) mm for the period. The high abundance of lowland humid pollen taxa is interpreted as the result of a northward migration of the corresponding plants during the AHP driven by more favorable climatic conditions. Our interpretation in favor of a regional vegetation response to climatic changes is supported by other pollen data from several Northwestern African records. However, we cannot rule out that an increase of Chari-Logone inputs into the Mega-Lake Chad due to variations in hydrological regime might have contributed to the higher abundance of lowland humid pollen taxa observed in the mid-Holocene sedimentary sequence. Changes in the structure and floristic composition of the vegetation towards more open and drier formations occurred after ca. 6050 cal yr BP. This is also evidenced by a decrease in mean annual precipitation estimates to approximately 600 (−230/+600) mm. This change corresponds to the onset of the AHP termination. The constant presence of lowland humid taxa until ca. 5000 cal yr BP, even if displaying a slight decrease, contemporaneous with an increase in steppic taxa, demonstrates that at ca. 5000 cal yr BP the modern vegetation was not yet established in the vicinity of Lake Chad. Our data indicate that vegetational change during this period must have occurred progressively, at least over 1000 yr, and are inconsistent with an abrupt aridification and a collapse of the vegetation cover in the East-Central Saharan and Sahelian regions at the AHP termination.

Modeling relationships between landscape-level attributes and snorkel counts of chinook salmon and steelhead parr in Idaho

2000 ◽  
Vol 57 (9) ◽  
pp. 1834-1842 ◽  
Author(s):  
William L Thompson ◽  
Danny C Lee
Keyword(s):  
Chinook Salmon ◽  
Spatial Scales ◽  
Geometric Mean ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Theoretic Approach ◽  
Road Density ◽  
Starting Point ◽  
Salmon Parr ◽  
Landscape Level

Knowledge of environmental factors impacting anadromous salmonids in their freshwater habitats, particularly at large spatial scales, may be important for restoring them to previously recorded levels in the northwestern United States. Consequently, we used existing data sets and an information-theoretic approach to model landscape-level attributes and snorkel count categories of spring-summer chinook salmon (Oncorhynchus tshawytscha) and steelhead (Oncorhynchus mykiss) parr within index areas in Idaho. Count categories of chinook salmon parr were negatively related to geometric mean road density and positively related to mean annual precipitation, whereas those for steelhead parr were negatively related to percent unconsolidated lithology. Our models predicted that chinook salmon parr would be in low count categories within subwatersheds with >1 km·km-2 geometric mean road densities and (or) <700 mm mean annual precipitation. Similarly, steelhead parr were predicted to be in low count categories in subwatersheds with >30% unconsolidated lithology. These results provide a starting point for fish biologists and managers attempting to map approximate status and quality of rearing habitats for chinook salmon and steelhead at large spatial scales.

scholarly journals Quantifying Southern Pacific Rattlesnake (Crotalus oreganus helleri) Hunting Behavior through Community Science

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 349
Author(s):  
Emily R. Urquidi ◽  
Breanna J. Putman
Keyword(s):  
Habitat Loss ◽  
Human Activity ◽  
Age Differences ◽  
Environmental Changes ◽  
Microhabitat Use ◽  
Ontogenetic Shift ◽  
Community Members ◽  
Hunting Behavior ◽  
Crotalus Oreganus ◽  
Community Science

It is increasingly important to study animal behaviors as these are the first responses organisms mount against environmental changes. Rattlesnakes, in particular, are threatened by habitat loss and human activity, and require costly tracking by researchers to quantify the behaviors of wild individuals. Here, we show how photo-vouchered observations submitted by community members can be used to study cryptic predators like rattlesnakes. We utilized two platforms, iNaturalist and HerpMapper, to study the hunting behaviors of wild Southern Pacific Rattlesnakes. From 220 observation photos, we quantified the direction of the hunting coil (i.e., “handedness”), microhabitat use, timing of observations, and age of the snake. With these data, we looked at whether snakes exhibited an ontogenetic shift in behaviors. We found no age differences in coil direction. However, there was a difference in the microhabitats used by juveniles and adults while hunting. We also found that juveniles were most commonly observed during the spring, while adults were more consistently observed throughout the year. Overall, our study shows the potential of using community science to study the behaviors of cryptic predators.

Environmental evolution and anthropogenic forcing in the Garigliano coastal plain (Italy) during the Holocene

The Holocene ◽  
2021 ◽  
pp. 095968362110032
Author(s):  
Halinka Di Lorenzo ◽  
Pietro Aucelli ◽  
Giuseppe Corrado ◽  
Mario De Iorio ◽  
Marcello Schiattarella ◽  
...  
Keyword(s):  
Human Activity ◽  
Coastal Plain ◽  
Forest Cover ◽  
Environmental Changes ◽  
Pollen Data ◽  
Human Environment ◽  
The Holocene ◽  
Natural Processes ◽  
History Of ◽  
The Rich

The Garigliano alluvial-coastal plain, at the Latium-Campania border (Italy), witnessed a long-lasting history of human-environment interactions, as demonstrated by the rich archaeological knowledge. With the aim of reconstructing the evolution of the landscape and its interaction with human activity during the last millennia, new pollen results from the coastal sector of the Garigliano Plain were compared with the available pollen data from other nearby sites. The use of pollen data from both the coastal and marine environment allowed integrating the local vegetation dynamics within a wider regional context spanning the last 8000 years. The new pollen data presented in this study derive from the analysis of a core, drilled in the coastal sector, which intercepted the lagoon-marshy environments that occurred in the plain as a response to the Holocene transgression and subsequent coastal progradation. Three radiocarbon ages indicate that the chronology of the analyzed core interval ranges from c. 7200 to c. 2000 cal yr BP. The whole data indicate that a dense forest cover characterized the landscape all along the Prehistoric period, when a few signs of human activity are recorded in the spectra, such as cereal crops, pasture activity and fires. The main environmental changes, forced by natural processes (coastal progradation) but probably enhanced by reclamation works, started from the Graeco-Roman period and led to the reduction of swampy areas that favoured the colonisation of the outer plain.

Ecological Niche Modeling Predicting the Potential Distribution of African Horse Sickness Virus from 2020 - 2060

2021 ◽  
Author(s):  
Ayalew Assefa ◽  
Abebe Tibebu ◽  
Amare Bihon ◽  
Alemu Dagnachew ◽  
Yimer Muktar
Keyword(s):  
Solar Radiation ◽  
Ecological Niche ◽  
Annual Precipitation ◽  
Maximum Temperature ◽  
Mean Annual Precipitation ◽  
African Horse Sickness ◽  
Diurnal Range ◽  
Annual Minimum Temperature ◽  
Precipitation Seasonality ◽  
Vector Borne

Abstract African horse sickness is a vector-borne, non-contagious and highly infectious disease of equines caused by African Horse Sickness viruses (AHSv) that mainly affect horses. The occurrence of the disease causes huge economic impacts because of its fatality rate is high, trade ban and disease control costs. In planning of vectors and vector borne diseases, the application of Ecological niche models (ENM) used an enormous contribution in exactly delineating the suitable habitats of the vector. We developed an ENM with the objective of delineating the global suitability of AHSv outbreaks retrospective based on data records from 2005–2019. The model was developed in R software program using Biomod2 package with an Ensemble modeling technique. Predictive environmental variables like mean diurnal range, mean precipitation of driest month(mm), precipitation seasonality (cv), mean annual maximum temperature (oc), mean annual minimum temperature (oc) mean precipitation of warmest quarter(mm), mean precipitation of coldest quarter (mm) mean annual precipitation (mm), solar radiation (kj /day), elevation/altitude (m), wind speed (m/s) were used to develop the model. From these variables, solar radiation, mean maximum temperature, average annual precipitation, altitude and precipitation seasonality contributed 36.83%, 17.1%, 14.34%, 7.61%, and 6.4%, respectively. The model depicted the sub-Sahara African continent as the most suitable area for the virus. Mainly Senegal, Burkina Faso, Niger, Nigeria, Ethiopia, Sudan, Somalia, South Africa, Zimbabwe, Madagascar and Malawi are African countries identified as highly suitable countries for the virus. Besides, OIE-listed disease-free countries like India, Australia, Brazil, Paraguay and Bolivia have been found suitable for the virusThis model can be used as an epidemiological tool in planning control and surveillance of diseases nationally or internationally.

scholarly journals Student Column: The Relationship between Local Food Sources and Open Space to Body Mass Index in Urban Children

2011 ◽  
Vol 126 (6) ◽  
pp. 890-900 ◽  
Author(s):  
James J. Burns ◽  
Sarah Goff ◽  
Greg Karamian ◽  
Coleen Walsh ◽  
Lela Hobby ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Open Space ◽  
Local Food ◽  
Urban Children ◽  
Food Sources ◽  
The Relationship

scholarly journals Macroecological analyses support an overkill scenario for late Pleistocene extinctions

2004 ◽  
Vol 64 (3a) ◽  
pp. 407-414 ◽  
Author(s):  
J. A. F. Diniz-Filho
Keyword(s):  
Body Mass ◽  
Population Dynamic ◽  
High Selectivity ◽  
Environmental Changes ◽  
Dynamic Parameters ◽  
Allometric Relationships ◽  
Ecological Data ◽  
Predator Prey ◽  
A Value ◽  
Complex Models

The extinction of megafauna at the end of Pleistocene has been traditionally explained by environmental changes or overexploitation by human hunting (overkill). Despite difficulties in choosing between these alternative (and not mutually exclusive) scenarios, the plausibility of the overkill hypothesis can be established by ecological models of predator-prey interactions. In this paper, I have developed a macroecological model for the overkill hypothesis, in which prey population dynamic parameters, including abundance, geographic extent, and food supply for hunters, were derived from empirical allometric relationships with body mass. The last output correctly predicts the final destiny (survival or extinction) for 73% of the species considered, a value only slightly smaller than those obtained by more complex models based on detailed archaeological and ecological data for each species. This illustrates the high selectivity of Pleistocene extinction in relation to body mass and confers more plausibility on the overkill scenario.

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