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Inventory and Monitoring Studies
Abstract
Inventory and monitoring are probably the most frequently conducted wildlife studies. Not only are they conducted in the pursuit of new knowledge (e.g., to describe the fauna or habitats [see Sect. 1.5 for definition of habitat and related terms] of a given area, or understand trends or changes of selected parameters), but also they are cornerstones in the management of wildlife resources. In general terms, inventories are conducted to determine the distribution and composition of wildlife and wildlife habitats in areas where such information is lacking, and monitoring is typically used to understand rates of change or the effects of management practices on wildlife populations and habitats. In application to wildlife, inventory and monitoring are typically applied to species’ habitats and populations. Because sampling population parameters can be costly, habitat is often monitored as a surrogate for monitoring populations directly. This is possible, however, only if a clear and direct linkage has been established between the two. By this, we mean that a close correspondence has been identified between key population parameters and one or more variables that comprise a species’ habitat. Unfortunately, such clear linkages are lacking for most species.
... Tiimub et al., (2020) recommended that Wildlife Division should strengthen synergies on community participation in adaptive wildlife management by coopting educational interventions that positively influence indigenous behaviors through seminars, workshops, and face-to-face interactions. Inventory and monitoring are not only conducted in the pursuit of new knowledge but are cornerstones in the management of wildlife resources (Morrison et al., 2008). In general terms, inventories are conducted to determine the distribution and composition of wildlife and wildlife habitats in areas where such information is lacking, and monitoring is typically used to understand rates of change or the effects of management practices on wildlife populations and habitats. ...
Purpose: Information about the status of wildlife in Lekki Conservation Centre (LCC) which is required for biodiversity policy-making is lacking. Methods: Day foot patrol to monitor wildlife in LCC was carried out and the wildlife species present were identified from January to December 2020. Data of animals sighted in the patrol and by the tourists were compared with records of animals sighted from March to July 2010 as recorded in the Protection Report Diary. Results: The findings indicated a decline in the population of squirrel (Heliosciurus gambianus) and bushbuck (Tragelaphus scriptus). Limitation: A list of fauna in LCC forest is provided as a result of the foot patrol although, some parts of the forest were inaccessible. Contribution: The perception of ecotourists is highlighted which can serve as feedback about their experience with the resources useful for biodiversity policy. Conclusion: Species diversity in the Protection Report Diary (in 2010) was higher compared to the total number of wildlife species sighted by visitors (in 2021) and during the patrol (in 2020) indicating that some wildlife species in LCC declined within 10 years.
... Tiimub et al., (2020) recommended that Wildlife Division should strengthen synergies on community participation in adaptive wildlife management by coopting educational interventions that positively influence indigenous behaviors through seminars, workshops, and face-to-face interactions. Inventory and monitoring are not only conducted in the pursuit of new knowledge but are cornerstones in the management of wildlife resources (Morrison et al., 2008). In general terms, inventories are conducted to determine the distribution and composition of wildlife and wildlife habitats in areas where such information is lacking, and monitoring is typically used to understand rates of change or the effects of management practices on wildlife populations and habitats. ...
Purpose: Information about the status of wildlife in Lekki Conservation Centre (LCC) which is required for biodiversity policy-making is lacking. Methods: Day foot patrol to monitor wildlife in LCC was carried out and the wildlife species present were identified from January to December 2020. Data of animals sighted in the patrol and by the tourists were compared with records of animals sighted from March to July 2010 as recorded in the Protection Report Diary. Results: The findings indicated a decline in the population of squirrel (Heliosciurus gambianus) and bushbuck (Tragelaphus scriptus). Limitation: A list of fauna in LCC forest is provided as a result of the foot patrol although, some parts of the forest were inaccessible. Contribution: The perception of ecotourists is highlighted which can serve as feedback about their experience with the resources useful for biodiversity policy. Conclusion: Species diversity in the Protection Report Diary (in 2010) was higher compared to the total number of wildlife species sighted by visitors (in 2021) and during the patrol (in 2020) indicating that some wildlife species in LCC declined within 10years.
... Biodiversity inventories and monitoring programmes have increased markedly worldwide over the last decade in response to concerns about extinctions and the sustainability of natural ecosystems. In general, inventories are conducted to determine the distribution and composition of wildlife and wildlife habitats in areas where such information is lacking, and monitoring is typically used to understand the rates of change or the effects of management practices on wildlife populations and habitats (Morrison et al. 2008). Making inventories and monitoring biodiversity are crucial to identifying the natural processes and human activities that affect ecosystems. ...
Monitoring programs are evaluation procedures designed to assess the state and evolution of a system over time. In particular, environmental monitoring programs are those that are applied to assess the condition and quality of an ecosystem (or environmental system of the corresponding level) in a given period. Different types of monitoring programs have opportunely been characterized, which are used in different circumstances and situations. Long-term monitoring programs have numerous advantages, and their results are those that allow us to draw the best conclusions as well as provide the best recommendations to the corresponding decision makers. Historical background of the application of this type of environmental monitoring program in different parts of the world is reviewed. Finally, the application of long-term environmental monitoring within the Bahía Blanca Estuary is analyzed as a particular study case.
... They are also the source of new species and new records (Brown et al. 2018). In addition, standardized inventories are the baseline for successful monitoring programs, which are a useful tool to evaluate rates of change of natural populations (Morrison et al. 2008, Silveira et al. 2010. As the data produced by inventories are essential to the establishment of sound conservation plans (Santos 2003), they should preferably be performed in places where the biota is, to some degree, extirpated or vulnerable to extinctions (Kim 1993) or where high species richness, endemism, or biogeographic and phylogenetic significance can be found (Erwin 1991, Vane-Wright et al. 1991, Kim 1993. ...
The present study aims to document the community composition, abundance, and species richness of saprophytic fly species (Mesembrinellidae, Neriidae, Ropalomeridae, and Sarcophagidae) of the Volta Grande region of the Xingu River, a poorly sampled area impacted by the Belo Monte hydroelectric dam. Five collecting trips were carried out between 2014 and 2016, when traps baited with fermenting bananas were used. A total of 154 specimens, three genera, and six species were collected of Mesembrinellidae; 196 specimens, three genera, and seven species of Neriidae; 272 specimens, three genera, and six species of Ropalomeridae; and 624 specimens, 22 species and 10 genera of Sarcophagidae. Species accumulation curves for all families except Sarcophagidae demonstrated a strong tendency towards stabilization, showing that sampling efforts were sufficient to record most of the targeted species. Laneela perisi (Mariluis, 1987) (Mesembrinellidae) is a new record for the state of Pará. Among Ropalomeridae, Apophorhynchus amazonensisPrado, 1966, is a new record for Pará. Among Sarcophagidae, Helicobia aurescens (Townsend, 1927) is newly recorded from the Brazilian Amazon, and Ravinia effrenata (Walker, 1861) and Titanogrypa larvicida (Lopes, 1935) are new records for Pará.
Forests are under pressure and going through rapid changes. However, current inventorying and monitoring (IM) programs are often either disjointed, too narrow in their scope and/or do not operate at fine enough temporal resolutions, which may hinder scientific understanding, the timely supply of information, fast decision making, and may result in the sub-optimal use of resources. For these reasons, there is an urgent need for Advanced Forest Inventorying and Monitoring (AIM) programs to (i) achieve expanded relevance (by augmenting data/information across ecosystem properties and trophic levels), (ii) have increased temporal resolution (by tailored data collection frequency), and (iii) make use of technological advances (by incorporating novel tools and technologies). The Advanced Inventorying and Monitoring for Swiss Forests (SwissAIM) initiative was launched in 2020 to address these needs. SwissAIM builds upon the foundation offered by the existing programs (e.g., national forest inventory, long-term forest ecosystem research, biodiversity monitoring). It aims to offer a collaborative and adaptive framework to enable integrated data collection, evaluation, interpretation, analysis, and modeling. Ideally, it will result in a more responsive system with respect to current and predicted biotic/abiotic stressors that will challenge Swiss forests. Developing such a system implies identifying the information needs of different stakeholders (e.g., science, policy, practice), related technical requirements, and governance frameworks. Here, we present (i) the main features of the SwissAIM initiative (vision, scientific questions and variables, governance and engagement), (ii) the main outcomes of the participatory design process (measurements, sampling, and plot design), (iii) the potential transferability of AIM initiatives outside Switzerland (timing, relevance, practicability), and (iv) the key messages that emerged (i.e., need for advancement, integration and transdisciplinarity, statistical underpinning). Since similar needs related to forest inventorying and monitoring are emerging throughout Europe and elsewhere, the objective of this opinion paper is to share our experience and promote a dialog with those interested in developing AIM initiatives in other countries and regions.
We studied 282 nesting attempts on 107 territories of Northern Goshawks (Accipiter gentilis) on the Kaibab Plateau in northern Arizona from 1991-1996. Mark-recapture methods were used to estimate recruitment, turnover of adults on territories, fidelity to territories by adults, and apparent annual survival of breeding adults. Territories were regularly spaced at a mean nearest-neighbor distance of 3.9 km. Annual proportion of pairs breeding and recapture rates were high in 1991-1993, sharply declined in 1994, and partially recovered in 1995-1996. Average annual turnover of breeding goshawks was 42% for males and 25% for females. Breeding males stayed on their territories from one breeding year to the next in 97% of cases and females in 95% of cases. Of 64 capture-recapture models evaluated in program SURGE, the model with the lowest AIC {Phis, Pt} showed that, while survival differed between genders, it was constant for both genders over years. Probability of recapturing a goshawk varied with time (0.15 in 1994; 0.66 in 1992) but not with gender; recaptures were lowest in years when few of the territorial goshawks nested and highest when the majority of pairs nested.
Experimentation is a dominant approach in contemporary ecological research, pervading studies at all levels of biological organization and across diverse taxa and habitats. Experimental Ecology assembles an eminent group of ecologists who synthesize insights from these varied sources into a cogent statement about experimentalism as an analytical paradigm, placing experimentation within the larger framework of ecological investigation. The book discusses diverse experimental approaches ranging from laboratory microcosms to manipulation of entire ecosystem, illustrating the myriad ways experiments strengthen ecological inference. Experimental ecologists critique their science to move the field forward on all fronts: from better designs, to better links between experiments and theory, to more realism in experiments targeted at specific systems and questions.
In 1984, a conference called Wildlife 2000: Modeling habitat relationships of terrestrial vertebrates, was held at Stanford Sierra Camp at Fallen Leaf Lake in the Sierra Nevada Mountains of California. The conference was well-received, and the published volume (Verner, J. , M. L. Morrison, and C. J. Ralph, editors. 1986. Wildlife 2000: modeling habitat relationships of terrestrial vertebrates, University of Wisconsin Press, Madison, Wisconsin, USA) proved to be a landmark publication that received a book award by The Wildlife Society. Wildlife 2001: populations was a followup conference with emphasis on the other major biological field of wildlife conservation and management, populations. It was held on July 29-31, 1991, at the Oakland Airport Hilton Hotel in Oakland, California, in accordance with our intent that this conference have a much stronger international representation than did Wildlife 2000. The goal of the conference was to bring together an international group of specialists to address the state of the art in wildlife population dynamics, and set the agenda for future research and management on the threshold of the 21st century. The mix of specialists included workers in theoretical, as well as practical, aspects of wildlife conservation and management. Three general sessions covered methods, modelling, and conservation of threatened species.
Several authors have recently discussed the problems with using index methods to estimate trends in population size. Some have expressed the view that index methods should virtually never be used. Others have responded by defending index methods and questioning whether better alternatives exist. We suggest that index methods are often a cost-effective component of valid wildlife monitoring but that double-sampling or another procedure that corrects for bias or establishes bounds on bias is essential. The common assertion that index methods require constant detection rates for trend estimation is mathematically incorrect; the requirement is no long-term trend in detection “ratios” (index result/parameter of interest), a requirement that is probably approximately met by many well-designed index surveys. We urge that more attention be given to defining bird density rigorously and in ways useful to managers. Once this is done, 4 sources of bias in density estimates may be distinguished: coverage, closure, surplus birds, and detection rates. Distance, double-observer, and removal methods do not reduce bias due to coverage, closure, or surplus birds. These methods may yield unbiased estimates of the number of birds present at the time of the survey, but only if their required assumptions are met, which we doubt occurs very often in practice. Double-sampling, in contrast, produces unbiased density estimates if the plots are randomly selected and estimates on the intensive surveys are unbiased. More work is needed, however, to determine the feasibility of double-sampling in different populations and habitats. We believe the tension that has developed over appropriate survey methods can best be resolved through increased appreciation of the mathematical aspects of indices, especially the effects of bias, and through studies in which candidate methods are evaluated against known numbers determined through intensive surveys.
We believe that starting this volume with a section on methods is altogether appropriate. All the papers in this volume draw conclusions that are only as valid as the methods used to collect and analyze the data. Without valid methods, we can have no confidence that our conclusions are valid.
This chapter is about mapping for planning the wise use of the forest. In many instances, this will involve the integration of timber harvesting together with the protection of forest wildlife. This chapter does not therefore concentrate upon maps of either scientific research plots or timber harvest parcels. It focuses upon modern mapping techniques that can be used for the integrated stewardship of the forests.
Forested ecosystems cover almost 40% of North America and are a dominant, albeit controversial, feature of life in North America, where they are as central to continental culture as they are to the economy (Caldwall et al., 1994; Canadian Council of Forest Ministers, 1992; Fulford, 1992). Forested ecosystems are home to most wildlife species inhabiting the continent. For example, of the estimated 300000 species found in Canada, 200000 meet at least part of their life requirements in forested ecosystems (Natural Resources Canada, 1993:23). From another perspective, 90% of the resident or common migrant vertebrate species in the United States inhabit forested ecosystems at some point in their lives (Flather and Hoekstra, 1989:4).
Gap Analysis identifies the gaps in representation of biological diversity (biodiversity) in areas managed exclusively or primarily for the long-term maintenance of populations of native species and natural ecosystems. Gap Analysis uses vegetation types and vertebrate and butterfly species (and/or other taxa, such as vascular plants, if adequate distributional data are available) as indicators of biodiversity. Maps of existing vegetation are prepared from satellite imagery (Landsat) and other sources and entered into a geographic information system (GIS). -from Authors
Numerous, irrefutable examples of the central role that long-term studies play in ecology now exist (see, e.g., Likens, 1983; Strayer et al., 1986). There is increasing recognition that, because most important questions in ecology ultimately deal with predicting ecosystem responses, testing the correctness of ecological concepts and predictions by observing the future is essential. There are many sophisticated predictive models and general constructs, but few have actually been tested against data. In the final analysis, the most convincing validation comes only from such tests against reality.
Are retrospective studies useful as supplements to long-term ecological studies? Can they serve as substitutes? Retrospective studies have often addressed the same sorts of problems as long-term studies. These include obtaining baseline data for comparison with modern observations, observing very slow processes, and measuring community and ecosystem responses to rare events (Strayer et al., 1986).
Many investigators begin field studies by using convenience sampling and then collect only index values (i.e., raw counts). This combination of poor field practices is nearly certain to yield untrustworthy results. Numbers (i.e., index values) are not always data, and many numbers (large sample size) do not always mean good data. Instead, the word data implies an information content with respect to some objective. Often numbers can be collected, but they may not represent data because they have little meaning and cannot be interpreted without making critical, but very unrealistic, assumptions. Such numbers are not trustworthy and cannot lead to valid inferences about the population of interest. We have made serious errors in ad hoc surveys of many terrestrial populations; efforts are underway to try to alter survey protocol to lessen these deficiencies in some cases. However, new surveys are being planned for reptile, amphibian, and insect populations, and the same fundamental errors may be repeated. Convenience samples are being relied upon without a way to make valid inferences about populations of interest. Index values are being taken without regard for highly variable and perhaps time-trending detection probabilities. Numbers from such surveys will not provide a basis for reliable knowledge and will represent only wasted resources. We must improve our understanding of these 2 fundamental issues and obtain reliable information or professionals in other disciplines will not take us seriously. Delury (1954: 293) commented,"...it is an expensive impropriety to maintain that an untrustworthy estimate is better than none." Professors ought to instill in their students the importance of probabilistic sampling in field studies. Similarly, the use of index values ought to be discouraged strongly because alternatives exist that will provide, under given assumptions, meaningful parameter estimates, measures of their precision, and other forms of reliable hfformation (see Thompson et al. 1998, Seber and Schwarz 1999). Editors and referees must begin to ask whether the sample data were taken in such a way as to allow a formal inductive inference to the population of interest. Such information should appear clearly in the Methods section of papers submitted for publication. Data resulting from convenience sampling are not acceptable on fundamental grounds. Similarly, raw counts as index values are not reliable and should be published only in unusual circumstances. In my opinion, we need a much higher standard for what is intrinsically acceptable in our profession.
Ornithologists have played a key role in the development of the habitat concept. The conspicuous nature of birds has allowed ornithologists to assemble a vast amount of information relating the distribution and abundance of birds to aspects of the environment (Brown, 1984; Mayr, 1988; Konishi et al., 1989; Morrison et al., 1992). The application of the term “habitat” has been used as a unifying, theoretical concept to explain the diversity of avian life-history patterns (Rotenberry, 1981). However, specific definitions of the term “habitat” are often vague. Definitions have ranged from, for example, how species are associated with broad, landscape-scaled vegetation types, to very detailed descriptions of immediate physical environments used by species (Karr, 1980; Verner et al., 1986; Harris and Kangas, 1988).
An age-old pursuit of biologists has been to relate the distribution and abundance of organisms to some aspect of their environment. Factors influencing their evolution, reproductive success, dispersal and migration, and other aspects of their ecology have been investigated. These pursuits have ranged from qualitative descriptions of plant and animal distributions and associations to quantitative statistical analyses of the interrelationships of plants, animals, and their environment.
It sometimes seems natural to separate ecologists by a dichotomy of data- collecting, direct-observation oriented scientists and computer-oriented modelers. However, in the most general sense, any ecologist regularly uses conceptual models to structure scientific endeavor. It is these models that give intrinsic meaning to ecological data. Most scientists realize that the reason one collects the information needed for a particular study comes from a long tradition of concepts built over some number of years. The importance of conceptual models to scientists should not be underestimated in any ecological studies, long- term or otherwise.
Indices, or relative measures of abundance, provide the practical basis for most management actions but have not been studied quantitatively. A survey sampling technique, known as "double sampling," offers a way to calibrate indices against direct estimates of absolute numbers in a population. This technique is based on an approach known as "ratio estimation," which depends on knowing the values of an auxiliary variable (here, the index of abundance) over all sampling units on a study area. Applications of both techniques to field data on a number of species suggest that they offer opportunities to substantially strengthen the use of population indices. Since the available theory for double sampling (and, to a lesser extent, ratio estimation) is limited in scope, several simulations were conducted to check the existing equations for estimating means and variances. The results indicate that these equations will perform satisfactorily under the circumstances tested. Similar simulations should be conducted in conjunction with field use of the methods.
This chapter presents analytic methods for matched studies with multiple risk factors of interest. We consider matched sample designs of two types, prospective (cohort or randomized) and retrospective (case-control) studies. We discuss direct and indirect parametric modeling of matched sample data and then focus on conditional logistic regression in matched case-control studies. Next, we describe the general case for matched samples including polytomous outcomes. An illustration of matched sample case-control analysis is presented. A problem solving section appears at the end of the chapter.
Plant and animal species have been used for decades as indicators of air and water quality and agricultural and range conditions. Increasingly, vertebrates are used to assess population trends and habitat quality for other species. In this paper we review the conceptual bases, assumptions, and published guidelines for selection and use of vertebrates as ecological indicators. We conclude that an absence of precise definitions and procedures, confounded criteria used to select species, and discordance with ecological literature severely weaken the effectiveness and credibility of using vertebrates as ecological indicators. In many cases the use of ecological indicator species is inappropriate, but when necessary, the following recommendations will make their use more rigorous: (1) clearly state assessment goals, (2) use indicators only when other assessment options are unavailable, (3) choose indicator species by explicitly defined criteria that are in accord with assessment goals, (4) include all species that fulfill stated selection criteria (5) know the biology of the indicator in detail, and treat the indicator as a formal estimator in conceptual and statistical models, (6) identify and define sources of subjectivity when selecting monitoring and intetpreting indicator species, (7) submit assessment design, methods of data collection and statistical analysis, interpretations, and recommendations to peer review and (8) direct research at developing an overall strategy for monitoring wildlife that accounts for natural variability in population attributes and incorporates concepts from landscape ecology.
The use of indices to evaluate small-mammal populations has been heavily criticized, yet a review of small-mammal studies published from 1996 through 2000 indicated that indices are still the primary methods employed for measuring populations. The literature review also found that 98% of the samples collected in these studies were too small for reliable selection among population-estimation models. Researchers therefore generally have a choice between using a default estimator or an index, a choice for which the consequences have not been critically evaluated. We examined the use of a closed-population enumeration index, the number of unique individuals captured (Mt+1), and 3 population estimators for estimating simulated small populations (N = 50) under variable effects of time, trap-induced behavior, individual heterogeneity in trapping probabilities, and detection probabilities. Simulation results indicated that the estimators produced population estimates with low bias and high precision when the estimator reflected the underlying sources of variation in capture probability. However, when the underlying sources of variation deviated from model assumptions, bias was often high and results were inconsistent. In our simulations, Mt+1 generally exhibited lower variance and less sensitivity to the sources of variation in capture probabilities than the estimators.L'utilisation d'indices pour évaluer les populations de petits mammifères est très critiquée et pourtant les études publiées entre 1996 et 2000 sur les petits mammifères démontrent que l'utilisation d'indices est toujours la méthode la plus courante d'évaluation des populations. Dans la littérature, 98 % des échantillons recueillis pour les études étaient trop petits pour permettre le choix judicieux d'un modèle d'estimation de population. Les chercheurs se retrouvent donc devant un choix à faire entre une méthode par défaut ou un indice, choix dont les conséquences n'ont pas été évaluées de façon formelle. Nous avons examiné les résultats de l'utilisation d'un indice de dénombrement d'une population fermée, du nombre d'individus particuliers capturés (Mt+1), et de 3 estimateurs de population pour estimer de petites populations simulées (N = 50) soumises à des effets divers du temps, du comportement relié au piégeage, de l'hétérogénéité dans la probabilité de capture des individus et des probabilités de détection. Les résultats de cette simulation ont démontré que les estimateurs donnent des évaluations qui comportent peu d'erreur et qui sont d'une grande précision lorsque l'estimateur utilisé reflète les sources de variation sous-jacentes des probabilités de capture. Cependant, lorsque les sources de variation sous-jacentes s'éloignent des présuppositions du modèle, les chances d'erreur sont souvent élevées et les résultats sont changeants. Dans nos simulations, Mt+1 a généralement une faible variance et manifeste moins de sensibilité aux sources de variation des probabilités de capture que les autres estimateurs.[Traduit par la Rédaction]
While Engeman (2003) makes a good case for the importance of study design and that studies that provide only index values are sometimes easier and less expensive, I find I do not agree with his central comments concerning the value of indices. Without estimates of detection probabilities, the use of index values is without a scientific or logical basis. Index values, almost by definition, are not "appropriately constructed"; they are fundamentally flawed. I believe we must focus increased attention on empirical estimates of detection probabilities as an integral part of study design, data collection, estimation, and valid inference.
On the grounds of "the need to get the basics right in wildlife field studies," Anderson (2001:1294-1297) recently included a general condemnation of the use of population indices. My purpose in this brief note is to add a few paragraphs of my thoughts to the comments by Anderson (2001) with respect to indexing animal populations. In general, I agree with the quantitative concepts described by Anderson (2001); however, I would like to place his comments into a broader perspective of general statistical rigor, without condemning the use of population indices if they are appropriately constructed.
This manual details standard field methods for qualitative and quantitative sampling of amphibian biological diversity. An introductory chapter is followed by an overview of amphibian diversity and natural history. Essentials of standardization and quantification are then covered. Next research design for quantitative amphibian studies is outlined. Chapter five looks at project planning and data acquisition and handling. Chapter six covers standard techniques for inventory and monitoring. Supplementary approaches are examined in the next chapter: artifical habitats; acoustic monitoring; tracking; night driving; GIS; and group activities/field trips. The ninth chapter looks at mark-recapture and removal sampling as methods of population estimation, followed by a chapter on data analysis. A conclusions and recommendations chapter is followed by seven appendices: handling live amphibians; techniques for marking amphibians; recording frog calls; specimen preparation; collecting tissue for biochemical analysis; vendors; and random number table. -S.R.Harris