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Farshid S Ahrestani

Farshid S Ahrestani
Frontier Wildlife Conservation

PhD

About

37
Publications
17,373
Reads
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931
Citations
Citations since 2016
11 Research Items
651 Citations
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
Additional affiliations
September 2012 - present
Pennsylvania State University
Position
  • PostDoc Position
September 2009 - August 2012
February 2005 - August 2009
Wageningen University & Research

Publications

Publications (37)
Article
Stability in population dynamics is an emergent property of the interaction between direct and delayed density dependence, the strengths of which vary with environmental covariates. Analysis of variation across populations in the strength of direct and delayed density dependence can reveal variation in stability properties of populations at the spe...
Article
Full-text available
Seasonal variation in forage availability and quality is understood to affect the annual timing of parturition in large herbivores. In India-where seasonal monsoonal rains define variation in forage availability and quality-chital Axis axis exhibit stronger seasonality in parturition than the larger gaur Bos gaurus. We hypothesized that this differ...
Article
Full-text available
The Convention on Biological Diversity's 2020 targets are an improvement over the 2010 target, but they could be strengthened.
Article
Full-text available
One reason why the gaur Bos gaurus is a poorly understood species is because there are no reliable data to age and sex individuals. We studied captive gaur for two years in Mysore Zoo, India and Omaha Zoo, USA, and determined age-specific differences in morphological features and physical growth, by measuring shoulder height, of male and female gau...
Article
Full-text available
Bos frontalis Lambert, 1804 and Bos gaurus Hamilton-Smith, 1827 are the domestic and wild forms, respectively, of the bovid commonly called the gaur. It is the world's largest cattle species. Bos gaurus is endemic to south and southeastern Asia, and today, the majority of its population occurs in India. It is sexually dimorphic, with adult males ha...
Article
Full-text available
When sighting‐based surveys to estimate population densities of large herbivores in tropical dense forests are not practical or affordable, surveys that rely on animal dung are sometimes used. This study tested one such dung‐based method by deriving population densities from observed dung densities of six large herbivores (chital, elephant, gaur, m...
Article
1.Ecological research produces a tremendous amount of data, but the diversity in scales and topics covered and the ways in which studies are carried out result in large numbers of small, idiosyncratic data sets using heterogeneous terminologies. Such heterogeneity can be attributed, in part, to a lack of standards for acquiring, organizing and desc...
Article
Integrated population models (IPMs) provide a unified framework for simultaneously analyzing data sets of different types to estimate vital rates, population size, and dynamics; assess contributions of demographic parameters to population changes; and assess population viability. Strengths of an IPM include the ability to estimate latent parameters...
Chapter
Understanding a species’ foraging habits and preferences is fundamental to understanding its overall ecology and essential for its management and conservation. In general, large herbivores are classified as either grazers, browsers , or mixed feeders , and a species’ diet preference is related to its body mass and digestive trait syndrome. Here, we...
Chapter
The large herbivores of South and Southeast Asia comprise an ancient and diverse guild with a long history of association with humans. To this day, our knowledge of the ecology of these herbivores, and the ecological roles they play in ecosystems, remains largely inadequate. In this edited collection of chapters, we attempt to synthesize and integr...
Chapter
The countries of South and Southeast Asia (SSEA) are home to a diverse array of large native herbivores, but the majority of these species are currently threatened with extinction. Ensuring the future survival of these species and the integrity of the ecological services they provide will require concerted management efforts, but these need to be b...
Chapter
Names Genus: Bos Linnaeus, 1758 Species: Gaur Bos gaurus C. H. Smith, 1827 Names in other languages: French: Gaur; German: Gaur; Spanish: Gaur; Italian: Gaur; Adi: Tadok; Burmese: Peeoug; Kannada: Kaati, Kaadu kona, Kaadu yemme; Kannada-in Uttara Kannada District kulga: Gameya; Northern Udupi district, Kannada: Duddu; Lao: Meuay; Malay: Seladang; M...
Article
Full-text available
Across the globe, biodiversity loss is occurring at an unprecedented rate. Rare species are especially susceptible to extinction, given that they typically have small population sizes and restricted geographic ranges, are less adaptable to disturbances, and are greater habitat specialists. However, while rare species may be prone to extinction, it...
Article
Full-text available
The majority of species in ecosystems are rare, but the ecosystem consequences of losing rare species are poorly known. To understand how rare species may influence ecosystem functioning, this study quantifies the contribution of species based on their relative level of rarity to community functional diversity using a trait-based approach. Given th...
Article
Full-text available
We examine the potential of trait-based parameters of taxa for linking above-ground and below-ground ecological networks (hereafter ‘green’ and ‘brown’ worlds) to understand and predict community dynamics. This synthesis considers carbon, nitrogen and phosphorus-related traits, the abundance of component species and their size-distribution across t...
Poster
Full-text available
Population dynamics are regulated by either density-dependent or -independent (environmental) factors. Vegetation dynamics and nutrient content are among these key factors, and although they are environmental factors, they have the potential to impact the degree of density dependence that might regulate population dynamics. To understand this botto...
Article
Full-text available
Population abundance data vary widely in quality and are rarely accurate. The two main components of error in such data are observation and process error. We used Bayesian state space models to estimate the observation and process error in time-series of 55 globally distributed populations of two species, Cervus elaphus (elk/red deer) and Rangifer...
Book
We examine the potential of trait-based parameters of taxa for linking above- and below-ground ecological networks (hereafter 'green' and 'brown' worlds) to understand and predict community dynamics. This synthesis considers carbon, nitrogen and phosphorus-related traits, the abundance of component species and their size distribution across trophic...
Article
Full-text available
There is little understanding of how large mammalian herbivores in Asia partition habitat and forage resources, and vary their diet and habitat selection seasonally in order to coexist. We studied an assemblage of four large herbivores, chital (Axis axis), sambar (Cervus unicolor), gaur (Bos gaurus) and Asian elephant (Elephas maximus), in the seas...
Article
Full-text available
This study’s goal was to better understand the growth pattern and limitations of the herbaceous production that supports South India’s rich large herbivore grazer assemblage. We conducted a fully factorial nitrogen and water (three levels each) treatment field experiment in the herbivore rich South Indian Western Ghats region to determine the seaso...
Article
The goal of this study was to test whether body-mass based foraging principles, guided by plant available moisture (PAM) and plant available nutrients (PAN), could explain large mammalian herbivore species distribution and richness in India. We tested (1) whether the occurrence of larger-bodied herbivore species increases with PAM, but is independe...
Article
Full-text available
After the collective failure to achieve the Convention on Biological Diversity’s (CBD’s) 2010 target to substantially reduce biodiversity losses, the CBD adopted a plan composed of five strategic goals and 20 “SMART” (Specific, Measurable, Ambitious, Realistic, and Time-bound) targets, to be achieved by 2020. Here, an interdisciplinary group of sci...
Article
In this first detailed analysis of gaur Bos gaurus life-history traits, data were collected from a 20-month field study in South India and from captive gaur populations. Mean age of females at first parturition was 3 years; females remained fertile beyond the age of 15 years. Adult females were three times more abundant than adult males in the wild...
Conference Paper
Background/Question/Methods Seasonal variation in forage availability and quality is understood to affect the annual timing of parturition in large herbivores. The forage quantity and quality requirements of these large herbivores are determined by their body mass. In India—where seasonal variation in forage availability is defined by monsoonal r...
Thesis
Full-text available
The study of large mammalian herbivore ecology has a strong allometric tradition. The majority of studies that have helped better understand how body mass affects large herbivore ecology in the tropics, from a biological, functional, and ecological perspective, are from Africa. India’s large herbivore assemblage—the richest outside of Africa and wi...
Thesis
There exists practically no scientific data to help direct future conservation in one of India’s newest Project Tiger Reserve, Bhadra Wildlife Sanctuary (493 km2, 13°22′-47′ N, 75°30′-45′ E), Karnataka. To redress this lacuna, I estimated densities and biomass of nine herbivorous mammalian species in Bhadra using line transect surveys. This enabled...

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Projects

Projects (2)
Project
Developing and refining scientific methods and models that help improve our capacity to estimate the abundance and distribution of large herbivores in habitats where their direct observation is difficult. Within the scope of this overarching goal, this project aims to achieve two specific objectives: 1) Develop methods and models that allow extrapolating counts of a reliable surrogate (i.e., dung piles) to actual densities in habitats where it is difficult to detect large herbivores. 2) Develop single-species and community occupancy models that determine the abundance of large herbivores in relation to different levels of human activity and protection.