In visual line transecting, whales are observed when surfacing to breath. Surfacings are short. Point process models for surfacing times are combined with a model for the hazard probability of initial sighting to obtain a likelihood for the observed encounters. Point processes are also useful for describing the clustering of encounters along the track line due to spatial clustering of whales.

This article develops methods for fitting spatial models to line transect data. These allow animal density to be related to topographical, environmental, habitat, and other spatial variables, helping wildlife managers to identify the factors that affect abundance. They also enable estimation of abundance for any subarea of interest within the surveyed region, and potentially yield estimates of ...

the persian gulf is northern part of the ropme sea area (rsa), and is semi-enclosed shallow sea which located in subtropical climate. measuring is 1000km in length, varying in width 60-340km, and average depth is about 35m and maximum depth is 105m. this research was carried out during 2005-2010 for reviewing the corals status and determination of coral reef habitats distribution in the persian...

Investigation of the relationship between plant species and environmental factors plays an important role in plant ecology. The present study aimed to develop the best predicting model for distribution of Prangos uloptera DC. using logistic regression (LR) and Maximum Entropy Methods (MaxEnt) in its habitat in the southern rangeland of Ardabil province, Iran. Vegetation data (presence and absen...

As the largest ocean, the Pacific is intricately linked to major changes in the global climate system that took place during the Cenozoic. Throughout the Cenozoic the Pacific plate has had a northward component. Thus, the Pacific is unique, in that the thick sediment bulge of biogenic-rich deposits from the currently narrowly focused zone of equatorial upwelling is slowly moving away from the e...

With data from line transeot surveys, the pattern of distances at which animals are detected provides the information for estimating the area which the observer effectively surveys. This paper suggests a parametric structure for the problem wherein this area is characterized by an effective half-width parameter which appears as a scale parameter in the distributions of detection distances. Seve...

Distance sampling is a widely used methodology for assessing animal abundance. A key requirement of distance sampling is that samplers (lines or points) are placed according to a randomized design, which ensures that samplers are positioned independently of animals. Often samplers are placed along linear features such as roads, so that bias is expected if animals are not uniformly distributed w...