Line transect surveys are widely used to estimate the density and/or size of cetacean populations. Good survey design is essential for obtaining reliable results using standard (design-based) analysis methods. Even more complex (model-based) methods, a good valuable. A ‘good’ one (a) that employs randomisation in laying out transects; (b) stratified if known vary on large scale; (c) where each ...

soil scientists have developed different mathematical equations and indices to be able to quantify soil development and to organize soil data. the main objective of the present research was the comparison of different soil development indices (including forms and ratios of iron, magnetic susceptibility, color indices, and modified harden index) related to different soils located on kerman-baft ...

The absorption of atmospheric carbon dioxide (CO2) into the ocean lowers the pH of the waters. This so-called ocean acidification could have important consequences for marine ecosystems. To better understand the extent of this ocean acidification in coastal waters, we conducted hydrographic surveys along the continental shelf of western North America from central Canada to northern Mexico. We o...

A large-scale survey was conducted in August 2004 to estimate the size of the Barents Sea polar bear subpopulation. We combined helicopter line transect distance sampling (DS) surveys in most of the survey area with total counts in small areas not suitable for DS. Due to weather constraints we failed to survey some of the areas originally planned to be covered by DS. For those, abundance was es...

The acronym PABITRA stands for Pacifi c-Asia Biodiversity Transect. PABITRA is a fl exible design of a transect system that connects a number of island areas in the tropical Pacifi c (i.e. Oceania) into a network of sites as living landscapes. The sites include upland/ inland forests, agro-ecosystems, and coastal habitats with coral reefs, which on islands are close together and interconnected ...

The assessment of fruit abundance is critical for studies of frugivore cology. A variety of methods have been used to estimate habitat-wide fruit abundance. However, since the methods have not been calibrated with each other, it is difficult o compare results of different studies. Here we compare three methods used simultaneously to collect fruit abundance data in the Kibale Forest, Uganda. Est...

Demographic indicators linked to general health have been strongly linked to economic development. However, change in such indicators is also associated with other factors such as climate, water availability, and diet. Here, we use a systems modelling approach, bringing together a range of environmental, economic, dietary, and health factors, to seek possible dominant causes of demographic chan...