Ecology and Evolutionary Biology Commons^™

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

Ecology Collection

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 …

Causes And Consequences Of Local Variability In Aroga Websteri Clarke Abundance Over Space And Time, Virginia L.J. Bolshakova

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush steppe habitat is rapidly declining in the Intermountain West in both quality and quantity. Observed reductions in animal and bird populations associated with sagebrush, invasion of exotic annual grasses such as cheatgrass (Bromus tectorum), and other concerns with climate change have led to a growing awareness of the need to monitor and better understand the rate of habitat loss. Sagebrush lands are subject to periodic loss caused by insect feeding damage, and human activities have the potential to promote unnaturally high levels of such loss. The sagebrush defoliating Aroga moth, Aroga websteri Clarke (Lepidoptera: Gelechiidae), can kill …

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 Capparella

Scholarship

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 …

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