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Ecology and Evolutionary Biology

Selected Works

Abundance

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Full-Text Articles in Life Sciences

Spatial Capture–Recapture: A Promising Method For Analyzing Data Collected Using Artificial Cover Objects, Chris Sutherland, David Mun'oz, David Miller, Evan Grant Dec 2015

Spatial Capture–Recapture: A Promising Method For Analyzing Data Collected Using Artificial Cover Objects, Chris Sutherland, David Mun'oz, David Miller, Evan Grant

Chris Sutherland

Spatial capture–recapture (SCR) is a relatively recent development in ecological statistics that provides a spatial context for estimating abundance and space use patterns, and improves inference about absolute population density. SCR has been applied to individual
encounter data collected noninvasively using methods such as camera traps, hair snares, and scat surveys. Despite the widespread use of capture based surveys to monitor amphibians and reptiles, there are few applications of SCR in the herpetological literature. We demonstrate the utility of the application of SCR for studies of reptiles and amphibians by analyzing capture–recapture data from Red-Backed Salamanders, Plethodon cinereus, collected using …

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Influence Of Current Land Use And Edaphic Factors On Arbuscular Mycorrhizal (Am) Hyphal Abundance And Soil Organic Matter In And Near Serengeti National Park, Geofrey Soka, Mark Ritchie, Emilian Mayemba May 2015

Influence Of Current Land Use And Edaphic Factors On Arbuscular Mycorrhizal (Am) Hyphal Abundance And Soil Organic Matter In And Near Serengeti National Park, Geofrey Soka, Mark Ritchie, Emilian Mayemba

Geofrey Soka

Arbuscular mycorrhizal fungi (AMF) are important microbial symbionts for plants especially when soil phosphorus (P) and nitrogen (N) are limited. Little is known about the distribution of AM hyphae in natural systems of tropical soils across landscapes and their association with different land uses. We studied mycorrhizal hyphal abundance in a wildlife grazed system, a livestock grazed system and under cultivated soils in and near Serengeti National Park, Tanzania. Samples of the upper 15 cm of soil beneath locally dominant plant species were collected. Hyphae were preserved on permanent slides and the length of hyphae per cubic centimeter of soil …

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Modelling Non-Euclideanmovement And Landscape Connectivity In Highly Structured Ecological Networks, Chris Sutherland, Angela Fuller, J. Royle Dec 2014

Modelling Non-Euclideanmovement And Landscape Connectivity In Highly Structured Ecological Networks, Chris Sutherland, Angela Fuller, J. Royle

Chris Sutherland

1. Movement is influenced by landscape structure, configuration and geometry, but measuring distance as perceived by animals poses technical and logistical challenges. Instead, movement is typically measured using Euclidean distance, irrespective of location or landscape structure, or is based on arbitrary cost surfaces. A
recently proposed extension of spatial capture-recapture (SCR)models resolves this issue using spatial encounter
histories of individuals to calculate least-cost paths (ecological distance: Ecology, 94, 2013, 287) thereby relaxing
the Euclidean assumption. We evaluate the consequences of not accounting for movement heterogeneity when
estimating abundance in highly structured landscapes, and demonstrate the value of this approach for …

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Photo-Identification Methods Reveal Seasonal And Long-Term Site-Fidelity Of Risso’S Dolphins (Grampus Griseus) In Shallow Waters (Cardigan Bay, Wales), Marijke N. De Boer, Josephine Clark, Mardik F. Leopold, Mark P. Simmonds, Peter J.H. Reijnders Dec 2014

Photo-Identification Methods Reveal Seasonal And Long-Term Site-Fidelity Of Risso’S Dolphins (Grampus Griseus) In Shallow Waters (Cardigan Bay, Wales), Marijke N. De Boer, Josephine Clark, Mardik F. Leopold, Mark P. Simmonds, Peter J.H. Reijnders

Mark P. Simmonds, OBE

A photo-identification study on Risso’s dolphins was carried out off Bardsey Island in Wales (July to September, 1997-2007). Their local abundance was estimated using two different analytical techniques: 1) mark-recapture of well-marked dolphins using a “closed-population” model; and 2) a census technique based on the total number of iden-tified individual dolphins sighted over the study period. The mark-recapture estimates of 121 (left sides; 64 - 178, 95% CI; CV 0.24) and 145 dolphins (right sides; 78 - 213, 95% CI; CV 0.24) closely matched the census technique estimates (population size of 90 - 151). It was found that the dolphins …

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Interactions Between Short-Beaked Common Dolphin (Delphinus Delphis) And The Winter Pelagic Pair-Trawl Fishery Ff Southwest England (Uk), Marijke N. De Boer, James T. Saulino, Mardik F. Leopold, Peter J.H. Reijnders, Mark P. Simmonds Dec 2014

Interactions Between Short-Beaked Common Dolphin (Delphinus Delphis) And The Winter Pelagic Pair-Trawl Fishery Ff Southwest England (Uk), Marijke N. De Boer, James T. Saulino, Mardik F. Leopold, Peter J.H. Reijnders, Mark P. Simmonds

Mark P. Simmonds, OBE

During offshore and onshore studies (2004 to 2009), the interactions between pair-trawls and short-beaked common dolphins (Delphinus delphis) were studied to better understand the impact of bycatch. A ‘hotspot’ area where pair-trawls overlapped with high dolphin abundance was identified. We made comparisons between boat-based data collected in absence and presence of pair-trawlers. The relative abundance and group-size of dolphins was significantly higher in the presence of pair-trawlers. Dolphins were observed associating with towing and hauling procedures. Significantly, more carcasses occurred in areas with hauling-activity than those without. Body-temperatures obtained from carcasses found near operating pair-trawlers indicated that bycatch mostly occurred …

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Influence Of Latitude On The Winter Abundance Of Red-Tailed Hawks (Buteo Jamaicensis) And American Kestrels (Falco Sparverius) In Illinois, Given Harper, Anna Groves, Vic Berardi, Paul Sweet, Jance Sweet, Angelo P. Capparella Dec 2012

Influence Of Latitude On The Winter Abundance Of Red-Tailed Hawks (Buteo Jamaicensis) And American Kestrels (Falco Sparverius) In Illinois, Given Harper, Anna Groves, Vic Berardi, Paul Sweet, Jance Sweet, Angelo P. Capparella

Given Harper

We use five years of data from 18 routes surveyed to determine the temporal stability of a first reported 100 years pattern, and reconfirmed that the abundance of winter 50 years ago tailed Hawk and American Kestrel decreases with increasing latitude, being more high in the central regions of Illinos in the northern regions. Trained volunteers conducted sampling ( n  = 143) a month driving along selected routes from December to February, from 2004-2005 to 2008-2009. We found significant increases in the abundance of both species from the northern regions to the central regions of Illinois. No significant effects of …

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Linear And Nonlinear Effects Of Habitat Structure On Composition And Abundance In The Macroinvertebrate Community Of A Large River, Timothy W. Stewart, Tammy L. Shumaker, Thomas A. Radzio Jan 2003

Linear And Nonlinear Effects Of Habitat Structure On Composition And Abundance In The Macroinvertebrate Community Of A Large River, Timothy W. Stewart, Tammy L. Shumaker, Thomas A. Radzio

Timothy W. Stewart

We used an experiment and regression analyses to quantify effects of spatial variation in habitat structure abundance on a riverine macroinvertebrate community under winter conditions. Concrete slabs (0.21 m2; n 5 24) with different numbers of stones (mean individual stone surface area 5 6.44 cm2) attached to upper faces were placed in the James River and retrieved after 28 d. Macroinvertebrate abundance and taxonomic richness on slabs were significantly positively related to stone abundance. Total macroinvertebrate abundance and abundance of oligochaetes (Nais spp.), Asiatic clams (Corbicula fluminea), caddisflies (Leptoceridae), riffle beetles (Elmidae) and stoneflies (Strophopteryx sp.) were linearly related to …

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