240 research outputs found
Spatial and Temporal Habitat Use of an Asian Elephant in Sumatra
Increasingly, habitat fragmentation caused by agricultural and human development has forced Sumatran elephants into relatively small areas, but there is little information on how elephants use these areas and thus, how habitats can be managed to sustain elephants in the future. Using a Global Positioning System (GPS) collar and a land cover map developed from TM imagery, we identified the habitats used by a wild adult female elephant (Elephas maximus sumatranus) in the Seblat Elephant Conservation Center, Bengkulu Province, Sumatra during 2007–2008. The marked elephant (and presumably her 40–60 herd mates) used a home range that contained more than expected medium canopy and open canopy land cover. Further, within the home range, closed canopy forests were used more during the day than at night. When elephants were in closed canopy forests they were most often near the forest edge vs. in the forest interior. Effective elephant conservation strategies in Sumatra need to focus on forest restoration of cleared areas and providing a forest matrix that includes various canopy types
Wildlife Diversity and Relative Abundance Among a Variety of Adjacent Protected Areas in the Northern Talamanca Mountains of Costa Rica
Protected areas are intended to achieve the long-term conservation of nature, but not all such areas are equal in their effectiveness because of their varying regulation of human activities. In Costa Rica, we assessed mammal and bird species presence and relative abundance in three protected areas in the northern Talamanca Mountains. In this humid tropical forest area, we placed camera traps in an adjacent national park, forest reserve, and indigenous territories, each with a different mix of human activities. In 10,120 trap nights, we obtained 6181 independent photos of mostly mammals (34 species other than humans) and birds (34 species). Species with greater abundance or only occurrence in the national park were mammals and birds commonly hunted outside of the park, large carnivores rarely documented in other areas, and poachers. Species found more often outside of the park were medium-sized mammals, some birds, and domestic mammals. We conclude that even in the same ecological area, varying regulations related to type of protected area have significant effects on some mammal and bird species abundances and occurrences, and thus need to be considered when assessing the overall effectiveness of protection as a conservation strategy
Wolf Population Dynamics
A LARGE, DARK WOLF poked his nose out of the pines in Yellowstone National Park as he thrust a broad foot deep into the snow and plowed ahead. Soon a second animal appeared, then another, and a fourth. A few minutes later, a pack of thirteen lanky wolves had filed out of the pines and onto the open hillside.
Wolf packs are the main social units of a wolf population. As numbers of wolves in packs change, so too, then, does the wolf population (Rausch 1967). Trying to understand the factors and mechanisms that affect these changes is what the field of wolf population dynamics is all about. In this chapter, we will explore this topic using two main approaches: (1) meta-analysis using data from studies from many areas and periods, and (2) case histories of key long-term studies. The combination presents a good picture-a picture, however, that is still incomplete. We also caution that the data sets summarized in the analyses represent snapshots of wolf population dynamics under widely varying conditions and population trends, and that the figures used are usually composites or averages. Nevertheless, they should allow generalizations that provide important insight into wolf population dynamics
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Livestock depredation by large carnivores in northern Botswana
Often, however, conservation agencies and governments do not have a proper understanding of conflicts prior to establishing mitigation programs or are unable to collect the appropriate data to verify claims of livestock loss. We investigated livestock depredation events in the Eastern Panhandle of the Okavango Delta, Botswana between October 2014 and December 2016 and compared these investigations with concurrent Problem Animal Control (PAC) information from the Botswana Department of Wildlife and National Parks (DWNP) compensation program. Only animals killed in livestock enclosures or while being herded qualify for reimbursement through the compensation program, but DWNP is typically unable to verify claims. We identified wildlife sign at the depredation event location and collected information from the livestock owner to determine the species responsible for the attack, time of the attack, the livestock lost, and the husbandry methods employed. In total, 116 livestock were killed and 13 more injured in 102 confirmed wild carnivore attacks. Most (90%) attacks occurred while livestock were unattended and freely grazing in multi-use, communal areas. Cows, oxen (castrated male cows) and calves (Bos taurus and B. t. indicus) were killed most often and African lions (Panthera leo) were responsible for 74% of investigated attacks, while African wild dogs (Lycaon pictus) accounted for 13%, leopard (Panthera pardus) 8%, and spotted hyena (Crocuta crocuta) 5%. Valuation of verified losses totaled ∼$30,000 over the study period. There were 50% more events reported to DWNP for compensation than we confirmed through independent investigations. In its current form, the compensation program does not seem sustainable, nor does it enable the verification of claims. While compensation programs should not be abandoned, programs designed to provide monetary reimbursement for losses caused by predators should require timely reporting and in-depth investigation of depredation events. Additional conflict mitigation strategies should target increasing livestock husbandry methods in the area, with a specific focus on herding
Managing hybridization of a recovering endangered species: The red wolf \u3ci\u3eCanis rufus\u3c/i\u3e as a case study
Hybridization presents a unique challenge for conservation biologists and managers. While hybridization is an important evolutionary process, hybridization is also a threat formany native species. The endangered species recovery effort for the red wolf Canis rufus is a classic system for understanding and addressing the challenges of hybridization. From 1987‒1993, 63 red wolves were released from captivity in eastern North Carolina, USA, to establish a free-ranging, non-essential experimental population. By 1999, managers recognized hybridization with invasive coyotes Canis latrans was the single greatest threat to successful recovery, and an adaptive management plan was adopted with innovative approaches for managing the threat of hybridization. Here we review the application and results of the adaptive management efforts from 1993 to 2013 by comparing: (1) the numbers of wolves, coyotes, and hybrids captured, (2) the numbers of territorial social groups with presumed breeding capabilities, (3) the number of red wolf and hybrid litters documented each year and (4) the degree of coyote introgression into the wild red wolf gene pool. We documented substantial increases in the number of known red wolves and red wolf social groups from 1987–2004 followed by a plateau and slight decline by 2013.The number of red wolf litters exceeded hybrid litters each year and the proportion of hybrid litters per year averaged 21%. The genetic composition of the wild red wolf population is estimated to include \u3c 4% coyote ancestry from recent introgression since reintroduction. We conclude that the adaptive management plan was effective at reducing the introgression of coyote genes into the red wolf population, but population recovery of red wolves will require continuation of the current management plan, or alternative approaches, for the foreseeable future. More broadly, we discuss the lessons learned from red wolf adaptive management that could assist other endangered species recovery efforts facing the challenge of minimizing hybridizatio
Simulation of primordial object formation
We have included the chemical rate network responsible for the formation of
molecular Hydrogen in the N-body hydrodynamic code, Hydra, in order to study
the formation of the first cosmological at redshifts between 10 and 50. We have
tested our implementation of the chemical and cooling processes by comparing
N-body top hat simulations with theoretical predictions from a semi-analytic
model and found them to be in good agreement. We find that post-virialization
properties are insensitive to the initial abundance of molecular hydrogen. Our
main objective was to determine the minimum mass () of perturbations
that could become self gravitating (a prerequisite for star formation), and the
redshift at which this occurred. We have developed a robust indicator for
detecting the presence of a self-gravitating cloud in our simulations and find
that we can do so with a baryonic particle mass-resolution of 40 solar masses.
We have performed cosmological simulations of primordial objects and find that
the object's mass and redshift at which they become self gravitating agree well
with the results from the top hat simulations. Once a critical
molecular hydrogen fractional abundance of about 0.0005 has formed in an
object, the cooling time drops below the dynamical time at the centre of the
cloud and the gas free falls in the dark matter potential wells, becoming self
gravitating a dynamical time later.Comment: 45 pages, 17 figures, submitted to Ap
Assessing estimators of snow leopard abundance
ABSTRACT The secretive nature of snow leopards (Uncia uncia) makes them difficult to monitor, yet conservation efforts require accurate and precise methods to estimate abundance. We assessed accuracy of Snow Leopard Information Management System (SLIMS) sign surveys by comparing them with 4 methods for estimating snow leopard abundance: predator:prey biomass ratios, capture-recapture density estimation, photo-capture rate, and individual identification through genetic analysis. We recorded snow leopard sign during standardized surveys in the SaryChat Zapovednik, the Jangart hunting reserve, and the Tomur Strictly Protected Area, in the Tien Shan Mountains of Kyrgyzstan and China. During June-December 2005, adjusted sign averaged 46.3 (SaryChat), 94.6 (Jangart), and 150.8 (Tomur) occurrences/km. We used counts of ibex (Capra ibex) and argali (Ovis ammon) to estimate available prey biomass and subsequent potential snow leopard densities of 8.7 (SaryChat), 1.0 (Jangart), and 1.1 (Tomur) snow leopards/100 km 2 . Photo capture-recapture density estimates were 0.15 (n ¼ 1 identified individual/1 photo), 0.87 (n ¼ 4/13), and 0.74 (n ¼ 5/6) individuals/100 km 2 in SaryChat, Jangart, and Tomur, respectively. Photo-capture rates (photos/100 trap-nights) were 0.09 (SaryChat), 0.93 (Jangart), and 2.37 (Tomur). Genetic analysis of snow leopard fecal samples provided minimum population sizes of 3 (SaryChat), 5 (Jangart), and 9 (Tomur) snow leopards. These results suggest SLIMS sign surveys may be affected by observer bias and environmental variance. However, when such bias and variation are accounted for, sign surveys indicate relative abundances similar to photo rates and genetic individual identification results. Density or abundance estimates based on capture-recapture or ungulate biomass did not agree with other indices of abundance. Confidence in estimated densities, or even detection of significant changes in abundance of snow leopard, will require more effort and better documentation
The Otterbein Miscellany - May 1967
https://digitalcommons.otterbein.edu/miscellany/1008/thumbnail.jp
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