A Review of the Population Estimation Approach of the North American Landbird Conservation Plan

Thogmartin, Wayne E.; Howe, Frank P.; James, Frances C.; Johnson, Douglas H.; Reed, Eric T.; Sauer, John R.; Thompson, Frank R.

doi:10.1093/auk/123.3.892

Cited by 37 publications

(46 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the exception of trapping-based methods, biologists have traditionally quantified wildlife populations via counts of animal sign (e.g., nests or scat) as indices, or actual counts of animals via the "naked" eye, or visual counts aided by binoculars, spotlights, or nightvision devices. However, whether the objective is a population index (which is assumed to have some correlation with population size or density; Caughley 1977, Thogmartin et al 2006 or a sampling design by which an unbiased estimate of population size or density is obtained (see Buckland et al 1993, Thogmartin et al 2006, the accuracy of the statistic or estimate is improved by increased probability of animal detection. Today, infrared technology (IT) has become a standard tool in a variety of practices (e.g., industrial, law enforcement, veterinary medicine) because any material with a temperature above absolute zero (i.e., -273.3°C) emits infrared light (i.e., the electromagnetic spectrum >0.70 µm), and that emission can be quantified relative to surrounding sources of infrared emission (e.g., see IEC Infrared Imaging Systems at: http://www.iecinfrared.com ./FAQ.html).…”

Section: Introductionmentioning

confidence: 99%

Use of Infrared Technology in Wildlife Surveys

Blackwell¹,

Seamans²,

Washburn³

et al. 2006

vertebrate_pest_conference

View full text Add to dashboard Cite

With the exception of trapping-based methods, quantification of wildlife populations has traditionally involved counts of animal sign (e.g., nests, scat, or calls) or cues (e.g., breeches by marine mammals) as indices, or counts of individual animals or groups (i.e., direct counts). In addition to the "naked" eye, researchers have used binoculars, spotlights, and more recently, night-vision and infrared technology (IT) to aid direct counts. However, IT has become a standard tool in a variety of practices (e.g., industrial, law enforcement, veterinary medicine) because any material with a temperature above absolute zero (i.e., -273.3°C) emits infrared light (i.e., the electromagnetic spectrum >0.70 µm), which can be quantified. The application of IT to wildlife management and research allows one to discern infrared emissions from target animals against background vegetation or habitat and, therefore, offers an improvement over traditional sighting methods. Use of IT in wildlife surveys also has inherent logistical requirements that must be considered in survey design. The purpose of this paper is to provide insight into the application of IT in wildlife management and research, particularly as related to quantifying populations of wildlife active during the night or periods of low-light conditions. Our objectives are to 1) briefly review methods and assumptions associated with conducting wildlife surveys, 2) review research and management efforts that have incorporated IT in surveys of wildlife populations, 3) discuss new opportunities for the incorporation of IT into wildlife research and management, and 4) provide guidance on purchasing IT. We suggest that IT, in combination with valid scientific sampling methods, can potentially increase the ability of wildlife researchers and managers to accurately estimate densities of wildlife populations.

show abstract

Section: Introductionmentioning

confidence: 99%

Use of Infrared Technology in Wildlife Surveys

Blackwell¹,

Seamans²,

Washburn³

et al. 2006

vertebrate_pest_conference

View full text Add to dashboard Cite

show abstract

“…Because not all routes had observations in all years, the datum analyzed was mean number of birds of a species observed over the routes available in that year. This is an index of population change based on samples rather than an extrapolation to total population (as in Thogmartin et al 2006). No attempt was made to correct for observer skill over time, change in observers, or other route-level biases (per Sauer 1997, 1998;Thogmartin et al 2006;Kéry et al 2010).…”

Section: Methodsmentioning

confidence: 99%

“…This is an index of population change based on samples rather than an extrapolation to total population (as in Thogmartin et al 2006). No attempt was made to correct for observer skill over time, change in observers, or other route-level biases (per Sauer 1997, 1998;Thogmartin et al 2006;Kéry et al 2010). Results obtained are thus only representative of biological data rather than allowing speciic inferences to be drawn about the populations.…”

Section: Methodsmentioning

confidence: 99%

Bounded random walks as a null model for evaluating population trends

Loehle

Arghami²

2017

Population Ecology

View full text Add to dashboard Cite

show abstract

“…While BBS data have value for monitoring population trends (Link & Sauer, 1998), these surveys have important limitations. For example, BBS surveys were not designed to account for imperfect detection and survey results may be sensitive to roadside bias (Thogmartin et al, 2006) rendering it difficult to estimate occurrence or density. Currently, precision and resolution of existing BBS data is not 5.…”

Section: Introductionmentioning

confidence: 99%

Broad‐scale occurrence of a subsidized avian predator: Reducing impacts of ravens on sage‐grouse and other sensitive prey

O’Neil

Coates

Brussee

et al. 2018

Journal of Applied Ecology

View full text Add to dashboard Cite

Expanding human enterprise across remote environments impacts numerous wildlife species. Anthropogenic resources provide subsidies for generalist predators that can lead to cascading effects on prey species at lower trophic levels. A fundamental challenge for applied ecologists is to disentangle natural and anthropogenic influences on species occurrence, and subsequently develop spatially explicit models to help inform management and conservation decisions. Using Bayesian hierarchical occupancy models, we mapped the broad‐scale occurrence of common ravens Corvus corax as a function of natural and anthropogenic landscape covariates using >15,000 point count surveys performed during 2007–2016 within the Great Basin region, USA. Raven abundance and distribution is substantially increasing across the American west due to unintended anthropogenic resource subsidies. Importantly, ravens prey on eggs and chicks of numerous species including greater sage‐grouse Centrocercus urophasianus, an indicator species whose decline is at the centre of national conservation strategies and land‐use policies. Anthropogenic factors that contributed to greater raven occurrence were: increased road density, presence of transmission lines, agricultural activity, and presence of roadside rest areas. Natural landscape characteristics included lower elevations with greener vegetation (Normalized Difference Vegetation Index), greater stream and habitat edge densities, and lower percentages of big sagebrush Artemisia tridentata spp. Interactions between anthropogenic sources of nesting substrate and food subsidies suggested that raven occurrence increased multiplicatively when these resource subsidies co‐occurred. Overall, the average probability of raven occurrence estimated within sagebrush ecosystems of the study area was c. 0.83. Synthesis and applications. We demonstrate how anthropogenic factors can be disentangled from natural effects when making spatially explicit predictions of subsidized predators occurring across expansive landscapes. This approach can guide management decisions where subsidized predators overlap sensitive prey habitats. For example, we identify areas where elevated raven occurrence coincides with breeding sage‐grouse concentration areas and appears to be largely driven by anthropogenic factors. Management applications could focus on reducing raven access to anthropogenic subsidies in these areas, while prioritizing habitat improvements for sage‐grouse elsewhere. Our approach is applicable to other species where widespread survey data are available.

show abstract

A Review of the Population Estimation Approach of the North American Landbird Conservation Plan

Abstract: BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Cited by 37 publications

References 17 publications

Use of Infrared Technology in Wildlife Surveys

Use of Infrared Technology in Wildlife Surveys

Bounded random walks as a null model for evaluating population trends

Broad‐scale occurrence of a subsidized avian predator: Reducing impacts of ravens on sage‐grouse and other sensitive prey

Contact Info

Product

Resources

About