Advancing Terrestrial Salamander Population Ecology: The Central Role of Imperfect Detection

2015 ◽  
Vol 49 (4) ◽  
pp. 533-540 ◽  
Author(s):  
Katherine M. O'Donnell ◽  
Raymond D. Semlitsch
Keyword(s):  
Population Ecology ◽  
Imperfect Detection

scholarly journals Population dynamics of Cosmoclopius nigroannulatus Stal (Hemiptera, Reduviidae) in tobacco culture

2002 ◽  
Vol 62 (4b) ◽  
pp. 819-826 ◽  
Author(s):  
S. M. JAHNKE ◽  
L. R. REDAELLI ◽  
L. M. G. DIEFENBACH
Keyword(s):  
Population Dynamics ◽  
Population Ecology ◽  
Population Estimates ◽  
Daily Survival Rate ◽  
Porto Alegre ◽  
Individual Number ◽  
Mark Release Recapture ◽  
Culture Cycle ◽  
The Individual

The role of predators influencing populations of insects considered as pests is extremely important for agroecosystems. The population ecology of Cosmoclopius nigroannulatus, a predatory reduvid associated with the tobacco culture was investigated aiming to study the population dynamics of adults, along the culture cycle. In an experimental plot of approximately 300 m², in Porto Alegre (30°0'S; 51°13'W), RS, Brazil, 270 tobacco plants were grown; each plant identified by alphanumeric coordinates. Using the mark-release-recapture method, daily samplings were done from August to December 1999, and three times a week from this date until April 2000. The adults were captured by hand, marked, sexed and released on the same plant they were captured. The individual number and plant coordinate were registered. Population estimates were analyzed by the Fisher-Ford method. In 107 sampling occasions, 604 individuals were marked, 273 males and 331 females. Three generations of C. nigroannulatus were registered during the culture cycle. The colonizing generation was represented by 14 males and 15 females (a sex ratio of 0.48), the first by 109 males and 137 females (0.44) and the second by 150 males and 179 females (0.46). The estimated daily survival rate varied between generations decreasing from 98% in the colonizing generation to 87% in the second. The observed longevity or permanence time in the experimental area varied significantly among generations, being at about 40 days in the colonizing generation, 13 days in the first and 5 days in the second. It was observed that as the population increases, the survival and/or permanence time in the area decreases, suggesting a relation between this and a decline in the available resources probably with an associated increase in intra-specific competition.

Role of Seed Reproduction in the Population Ecology of Sorghum halepense in Maize Crops

1988 ◽  
Vol 25 (3) ◽  
pp. 951 ◽  
Author(s):  
Ana L. Scopel ◽  
C. L. Ballare ◽  
C. M. Ghersa
Keyword(s):  
Population Ecology ◽  
Sorghum Halepense ◽  
Seed Reproduction

Wild Bird Populations in the Face of Disease

2021 ◽  
pp. 121-144
Author(s):  
Kathryn P. Huyvaert
Keyword(s):  
Population Dynamics ◽  
Disease Ecology ◽  
Population Level ◽  
Host Population ◽  
Infection Prevalence ◽  
Imperfect Detection ◽  
Statistical Parameters ◽  
Bird Populations ◽  
The Face

Parasites and pathogens typically have detectable negative fitness impacts on individual avian hosts, but the role of parasites in driving population dynamics is less straightforward. Questions about whether and under what conditions parasites influence host population dynamics have been long-standing in infectious disease ecology for many years. Understanding the role of parasites in host population dynamics requires estimating statistical parameters such as infection prevalence and host abundance at population scales. Mathematical approaches such as process-based models are also often used to simulate population-level dynamics of host and parasite interactions over time. This chapter first describes tools commonly used in disease ecology to estimate these key parameters, with a focus on accounting for imperfect detection of individual animals or their disease or infection status and mark-recapture approaches. Some of the mathematical approaches, including SIR models, network approaches, and agent-based models, that are commonly used to simulate and predict the population dynamics of host–parasite interactions are presented. Through a series of case studies, the chapter finishes by considering whether and under what conditions parasites affect the overall growth of populations, whether parasites have a tendency to cause cycles or to regulate populations of wild birds, and some examples of parasite-induced local extinctions.

Population Ecology (Organizational Ecology): An Experiential Exercise Demonstrating How Organizations in an Industry Are Born, Change, and Die

2017 ◽  
Vol 42 (3) ◽  
pp. 375-397
Author(s):  
Karen MacMillan ◽  
Jennifer Komar
Keyword(s):  
Environmental Factors ◽  
Decision Maker ◽  
Systems Thinking ◽  
Population Ecology ◽  
Organizational Ecology ◽  
Organizational Size ◽  
Present Evidence ◽  
Random Chance ◽  
Longitudinal Approach

This article describes a classroom exercise that is designed to help students understand the basic tenets of population ecology (also known as organizational ecology). The macro-level, longitudinal approach to understanding organizations can be difficult for students to conceptualize as it involves systems thinking. This exercise makes the theory come alive by asking students to put themselves directly into the role of an organizational decision maker in an evolving industry. Over the course of one class, students get to experience how organizational size/age, environmental factors, and even random chance can affect organizational success and the makeup of an industry. Simulating up to a decade or more, students learn that populations of organizations change in predictable ways. We have tested this exercise with hundreds of students and we present evidence that it is effective in teaching the principles of population ecology (postexercise testing average of 92%) and also engaging and enjoyable for students.

scholarly journals Seed ingestion and germination in rattlesnakes: overlooked agents of rescue and secondary dispersal

2018 ◽  
Vol 285 (1872) ◽  
pp. 20172755 ◽  
Author(s):  
Randall S. Reiserer ◽  
Gordon W. Schuett ◽  
Harry W. Greene
Keyword(s):  
Seed Dispersal ◽  
Population Ecology ◽  
Empirical Studies ◽  
Evolutionary Process ◽  
Terrestrial Plants ◽  
Frugivorous Birds ◽  
Secondary Dispersal ◽  
Cheek Pouches ◽  
Primary Dispersal

Seed dispersal is a key evolutionary process and a central theme in the population ecology of terrestrial plants. The primary producers of most land-based ecosystems are propagated by and maintained through various mechanisms of seed dispersal that involve both abiotic and biotic modes of transportation. By far the most common biotic seed transport mechanism is zoochory, whereby seeds, or fruits containing them, are dispersed through the activities of animals. Rodents are one group of mammals that commonly prey on seeds (granivores) and play a critical, often destructive, role in primary dispersal and the dynamics of plant communities. In North America, geomyid, heteromyid and some sciurid rodents have specialized cheek pouches for transporting seeds from plant source to larder, where they are often eliminated from the pool of plant propagules by consumption. These seed-laden rodents are commonly consumed by snakes as they forage, but unlike raptors, coyotes, bobcats, and other endothermic predators which eat rodents and are known or implicated to be secondary seed dispersers, the role of snakes in seed dispersal remains unexplored. Here, using museum-preserved specimens, we show that in nature three desert-dwelling rattlesnake species consumed heteromyids with seeds in their cheek pouches. By examining the entire gut we discovered, furthermore, that secondarily ingested seeds can germinate in rattlesnake colons. In terms of secondary dispersal, rattlesnakes are best described as diplochorous. Because seed rescue and secondary dispersal in snakes has yet to be investigated, and because numerous other snake species consume granivorous and frugivorous birds and mammals, our observations offer direction for further empirical studies of this unusual but potentially important channel for seed dispersal.

The feeding and consequent role of Eulalia viridis (O. F. Müller) (Polychaeta) in intertidal communities

1977 ◽  
Vol 57 (1) ◽  
pp. 93-96 ◽  
Author(s):  
R. H. Emson
Keyword(s):  
Population Ecology ◽  
Feeding Behaviour ◽  
Soft Tissues ◽  
Feeding Habits ◽  
The Other ◽  
Sufficient Evidence ◽  
Intertidal Communities ◽  
Other Hand

The intertidal phyllodocid polychaete Eulalia viridis (O. F. Müller) is widely regarded as a predator as stated, for example, by Newell (1970). This assertion is based on statements made by several authors, e.g. Moore & Kitching (1939), Glynne-Williams & Hobart (1952), Connell (1961), and Kensler (1964, 1967), who have reported E. viridis foraging over rocky substrates at low tide in daylight and in some cases have observed the insertion of the proboscis between the opercular plates of a barnacle and the subsequent ingestion of the soft tissues. The capture of a large chironomid by E. viridis has been recorded by Connell (1961). This was considered sufficient evidence for stating that E. viridis is a predator attacking living barnacles and other intertidal animals. Moore & Kitching (1939) further suggested that E. viridis might be as important a predator on barnacles as Thais lapillus (L). On the other hand Michel (1970) regarded E. viridis as a scavenger feeding on dead and decaying animals. There is evident disagreement about the feeding habits of E. viridis and consequently of its role in the population ecology of the community of which it forms a part. Examination of its feeding behaviour has been undertaken to clarify the situation.

scholarly journals Accounting for imperfect detection reveals role of host traits in structuring viral diversity of a wild bat community

2020 ◽  
Author(s):  
Anna R. Sjodin ◽  
Simon J. Anthony ◽  
Michael R. Willig ◽  
Morgan W. Tingley
Keyword(s):  
Detection Methods ◽  
Viral Diversity ◽  
Imperfect Detection ◽  
Species Identity ◽  
Viral Ecology ◽  
Individual Level ◽  
Multi Scale ◽  
Host Sex ◽  
Bat Conservation

AbstractUnderstanding how multi-scale host heterogeneity affects viral community assembly can illuminate ecological drivers of infection and host-switching. Yet, such studies are hindered by imperfect viral detection. To address this issue, we used a community occupancy model – refashioned for the hierarchical nature of molecular-detection methods – to account for failed detection when examining how individual-level host traits affect herpesvirus richness in eight species of wild bats. We then used model predictions to examine the role of host sex and species identity on viral diversity at the levels of host individual, population, and community. Results demonstrate that cPCR and viral sequencing failed to perfectly detect viral presence. Nevertheless, model estimates correcting for imperfect detection show that reproductively active bats, especially reproductively active females, have significantly higher viral richness, and host sex and species identity interact to affect viral richness. Further, host sex significantly affects viral turnover across host populations, as females host more heterogeneous viral communities than do males. Results suggest models of viral ecology benefit from integration of multi-scale host factors, with implications for bat conservation and epidemiology. Furthermore, by accounting for imperfect detection in laboratory assays, we demonstrate how statistical models developed for other purposes hold promising possibilities for molecular and epidemiological applications.

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