... J. BLOHM, US Fish and Wildlife Service, Office of Migratory Bird Management, Laurel, MD 20708... more ... J. BLOHM, US Fish and Wildlife Service, Office of Migratory Bird Management, Laurel, MD 20708 RONALD E. REYNOLDS, US Fish ... It seems reasonable, therefore, that individuals entering 'Present address: Savannah River Ecology Labo-ratory, Drawer E, Aiken, SC 29801. ...
... PDF (181 KB). Masami Fujiwara, Hal Caswell. (2002) ESTIMATING POPULATION PROJECTION MATRICES ... more ... PDF (181 KB). Masami Fujiwara, Hal Caswell. (2002) ESTIMATING POPULATION PROJECTION MATRICES FROM MULTI-STAGE MARKRECAPTURE DATA. Ecology 83:12, 3257-3265 Online publication date: 1-Dec-2002. Abstract . Full Text . PDF (169 KB). William L ...
ABSTRACT Range performance is often the key requirement around which electro-optical and infrared... more ABSTRACT Range performance is often the key requirement around which electro-optical and infrared camera systems are designed. This work presents an objective framework for evaluating competing range performance models. Model selection based on the Akaike's Information Criterion (AIC) is presented for the type of data collected during a typical human observer and target identification experiment. These methods are then demonstrated on observer responses to both visible and infrared imagery in which one of three maritime targets was placed at various ranges. We compare the performance of a number of different models, including those appearing previously in the literature. We conclude that our model-based approach offers substantial improvements over the traditional approach to inference, including increased precision and the ability to make predictions for some distances other than the specific set for which experimental trials were conducted. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
We randomly partitioned mallard (Anas platyrhynchos) bandings and recoveries from each of a numbe... more We randomly partitioned mallard (Anas platyrhynchos) bandings and recoveries from each of a number of selected reference areas into 2 groups and estimated survival and harvest rates for each area and group. This procedure produced independent vectors of survivaland harvest-rate estimates, which were used to test the general hypothesis that mallard survival and harvest rates were inversely related. We used Spearman rank correlation analysis and z-test contrasts between survival rates from years of high vs. low harvest rates. We also conducted computer simulation experiments to gain insight into the ability of these analyses to detect the relationship of interest. The data analyses suggested that survival and harvest rates of young females were inversely related, at least for the 5 areas included in the analysis. However, for young males and adults of both sexes, the analyses provided no evidence of an inverse relationship between survival and harvest rates, except possibly in a few specific areas. J. WILDL. MANAGE. 47(2):334-348 The manner in which different sources of mortality operate to produce the total probability of death within a specific time period is a matter of considerable importance. In most animal population models, different sources of mortality operating over a period of interest are treated as representing independent, competing risks, the magnitudes of which do not depend on the magnitudes of other concurrently operating risks. However, evidence from a number of empirical studies (reviewed in Anderson and Burnham 1976: 7-8) suggests that different sources of mortality act in a compensatory manner with increases in 1 source of mortality resulting in corresponding decreases in another. Anderson and Burnham (1976) studied the effect of sport hunting on mallards and rejected the hypothesis that hunting mortality represented a completely additive form of mortality. Their results corroborated the hypothesis that increases in hunting mortality below some unknown threshold level were compensated by corresponding decreases in nonhunting mortality. Anderson and Burnham (1976) used 3 basic analyses or sets of hypothesis tests. One approach involved a complicated components-of-variance procedure for estimating the slope of the linear relationship between hunting and nonhunting mortality rates. Another approach involved contrasts of mallard survival rates during years of restrictive and liberal regulations. The 3rd approach used simple correlation analysis to examine the relationship between pooled continental survival-rate estimates and independent harvest-rate indices. The latter 2 procedures are straightforward and readily understood. Because of the importance of the conclusions of Anderson and Burnham (1976) to North American waterfowl management, Rogers et al. (1979) repeated these latter 2 analyses on mallard data from more recent years characterized by higher harvest rates and reached similar conclusions. Despite the appealing simplicity of these 334 J. Wildl. Manage. 47(2):1983 This content downloaded from 157.55.39.221 on Mon, 03 Oct 2016 05:17:19 UTC All use subject to http://about.jstor.org/terms MALLARD HARVEST AND SURVIVAL RATES * Nichols and Hines 335 2 types of analyses, they are subject to some potential criticism. For example, the years of contrasted survival rates were chosen based on continental hunting regulations rather than on direct estimates of harvest rate. Although continental summary test statistics indicated that bandrecovery rates (indices of harvest rates [Henny and Burnham 1976]) did indeed generally differ between the 2 sets of contrasted years (Martin et al. 1979, Rogers et al. 1979), it could be argued that this type of test is insensitive to geographic variation. Despite relatively liberal continental hunting regulations in a particular year, for example, it would be possible for groups of birds to experience low harvest rates because of weather-related shifts in the timing of migration, reducing exposure to heavily hunted areas along migration pathways. The existence of some banded samples that did not experience harvest-rate extremes in the contrasted years would reduce the ability of the test to detect the relationship of interest. The continental correlation analysis uses mean continental survival estimates and could also suffer from the same insensitivity to geographic variation. In addition, it is possible to criticize the harvest-rate indices used. We randomly partitioned mallard bandings from each of a number of specific reference areas into 2 groups and estimated survival and harvest rates from both groups in each reference area. This procedure provided independent vectors of harvestand survival-rate estimates that were then used in correlation analyses and contrasts between survival rates for years of high vs. low harvest rates. This methodology avoided the potential criticisms for the 2 analogous continental tests of Anderson and Burnham (1976) and Rogers…
Summary 1 We used up to 35 years of capture–recapture data from nearly 3300 individual female duc... more Summary 1 We used up to 35 years of capture–recapture data from nearly 3300 individual female ducks nesting on Engure Marsh, Latvia, and multistate modelling to test predictions about the influence of environmental, habitat and management factors on breeding dispersal probability within the marsh. 2 Analyses based on observed dispersal distances of common pochards and tufted ducks provided no evidence that breeding success in year t influenced dispersal distance between t and t+ 1. 3 Breeding dispersal distances (year t to t+ 1) of pochards and tufted ducks were associated with a delay in relative nest initiation dates in year t+ 1. The delay was greater for pochards (c. 4 days) than for tufted ducks (c. 2 days) when females dispersed > 0·8 km. 4 Northern shovelers and tufted ducks moved from a large island to small islands at low water levels and from small islands to the large island at high water levels before the construction of elevated small islands (1960–82). Following this habitat management (1983–94), breeding fidelity was extremely high and not influenced by water level in the marsh for either species. 5 Because pochard nesting habitats in black-headed gull colonies were saturated during the entire study period, nesting females moved into and out of colonies with similar probabilities. Local survival probabilities and incubation body masses were higher for both yearlings (SY) and adults (ASY) nesting within gull colonies, suggesting that these females were of better quality than females nesting outside of the colonies. 6 Tufted ducks showed higher probabilities of moving from islands to emergent marshes when water levels were higher both before and after habitat management. However, rates of movement for a given water level were higher during the period before management than after. 7 Both pochards and tufted ducks exhibited asymmetric movement with respect to proximity to water, with higher movement probabilities to near-water nesting locations than away from these locations. 8 Multistate capture–recapture models provided analyses that were useful in investigating sources of variation in breeding dispersal probabilities.
... JAMES D. NICHOLS, US Fish and Wildlife Service, Migratory Bird and Habitat Research Laborator... more ... JAMES D. NICHOLS, US Fish and Wildlife Service, Migratory Bird and Habitat Research Laboratory, Laurel, MD 20811 RICHARD S ... Abstract: The relationship between habitat conditions in prairie breeding areas of North America and mallard (Anas platyrhynchos) survival rates ...
Capture-recapture models provide a statistical framework for estimating population parameters fro... more Capture-recapture models provide a statistical framework for estimating population parameters from mist-net data. Although Cormack-Jolly-Seber and related models have recently been used to estimate survival rates of birds sampled with mist nets, we believe that the full potential for use of capture-recapture models has not been realized by many researchers involved in mist-net studies. We present a brief discussion of the overall framework for estimation using capture-recapture methods, and review several areas in which recent statistical methods can be, but generally have not yet been, applied to mist-net studies. These areas include estimation of (1) rates of movement among areas; (2) survival rates in the presence of transients; (3) population sizes of migrating birds; (4) proportion of birds alive but not present at a breeding site (one definition of proportion of nonbreeding birds in a population); (5) population change and recruitment; and (6) species richness. Using these models will avoid the possible bias associated with use of indices, and provide statistically valid variance estimates and inference.
... J. BLOHM, US Fish and Wildlife Service, Office of Migratory Bird Management, Laurel, MD 20708... more ... J. BLOHM, US Fish and Wildlife Service, Office of Migratory Bird Management, Laurel, MD 20708 RONALD E. REYNOLDS, US Fish ... It seems reasonable, therefore, that individuals entering 'Present address: Savannah River Ecology Labo-ratory, Drawer E, Aiken, SC 29801. ...
... PDF (181 KB). Masami Fujiwara, Hal Caswell. (2002) ESTIMATING POPULATION PROJECTION MATRICES ... more ... PDF (181 KB). Masami Fujiwara, Hal Caswell. (2002) ESTIMATING POPULATION PROJECTION MATRICES FROM MULTI-STAGE MARKRECAPTURE DATA. Ecology 83:12, 3257-3265 Online publication date: 1-Dec-2002. Abstract . Full Text . PDF (169 KB). William L ...
ABSTRACT Range performance is often the key requirement around which electro-optical and infrared... more ABSTRACT Range performance is often the key requirement around which electro-optical and infrared camera systems are designed. This work presents an objective framework for evaluating competing range performance models. Model selection based on the Akaike's Information Criterion (AIC) is presented for the type of data collected during a typical human observer and target identification experiment. These methods are then demonstrated on observer responses to both visible and infrared imagery in which one of three maritime targets was placed at various ranges. We compare the performance of a number of different models, including those appearing previously in the literature. We conclude that our model-based approach offers substantial improvements over the traditional approach to inference, including increased precision and the ability to make predictions for some distances other than the specific set for which experimental trials were conducted. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
We randomly partitioned mallard (Anas platyrhynchos) bandings and recoveries from each of a numbe... more We randomly partitioned mallard (Anas platyrhynchos) bandings and recoveries from each of a number of selected reference areas into 2 groups and estimated survival and harvest rates for each area and group. This procedure produced independent vectors of survivaland harvest-rate estimates, which were used to test the general hypothesis that mallard survival and harvest rates were inversely related. We used Spearman rank correlation analysis and z-test contrasts between survival rates from years of high vs. low harvest rates. We also conducted computer simulation experiments to gain insight into the ability of these analyses to detect the relationship of interest. The data analyses suggested that survival and harvest rates of young females were inversely related, at least for the 5 areas included in the analysis. However, for young males and adults of both sexes, the analyses provided no evidence of an inverse relationship between survival and harvest rates, except possibly in a few specific areas. J. WILDL. MANAGE. 47(2):334-348 The manner in which different sources of mortality operate to produce the total probability of death within a specific time period is a matter of considerable importance. In most animal population models, different sources of mortality operating over a period of interest are treated as representing independent, competing risks, the magnitudes of which do not depend on the magnitudes of other concurrently operating risks. However, evidence from a number of empirical studies (reviewed in Anderson and Burnham 1976: 7-8) suggests that different sources of mortality act in a compensatory manner with increases in 1 source of mortality resulting in corresponding decreases in another. Anderson and Burnham (1976) studied the effect of sport hunting on mallards and rejected the hypothesis that hunting mortality represented a completely additive form of mortality. Their results corroborated the hypothesis that increases in hunting mortality below some unknown threshold level were compensated by corresponding decreases in nonhunting mortality. Anderson and Burnham (1976) used 3 basic analyses or sets of hypothesis tests. One approach involved a complicated components-of-variance procedure for estimating the slope of the linear relationship between hunting and nonhunting mortality rates. Another approach involved contrasts of mallard survival rates during years of restrictive and liberal regulations. The 3rd approach used simple correlation analysis to examine the relationship between pooled continental survival-rate estimates and independent harvest-rate indices. The latter 2 procedures are straightforward and readily understood. Because of the importance of the conclusions of Anderson and Burnham (1976) to North American waterfowl management, Rogers et al. (1979) repeated these latter 2 analyses on mallard data from more recent years characterized by higher harvest rates and reached similar conclusions. Despite the appealing simplicity of these 334 J. Wildl. Manage. 47(2):1983 This content downloaded from 157.55.39.221 on Mon, 03 Oct 2016 05:17:19 UTC All use subject to http://about.jstor.org/terms MALLARD HARVEST AND SURVIVAL RATES * Nichols and Hines 335 2 types of analyses, they are subject to some potential criticism. For example, the years of contrasted survival rates were chosen based on continental hunting regulations rather than on direct estimates of harvest rate. Although continental summary test statistics indicated that bandrecovery rates (indices of harvest rates [Henny and Burnham 1976]) did indeed generally differ between the 2 sets of contrasted years (Martin et al. 1979, Rogers et al. 1979), it could be argued that this type of test is insensitive to geographic variation. Despite relatively liberal continental hunting regulations in a particular year, for example, it would be possible for groups of birds to experience low harvest rates because of weather-related shifts in the timing of migration, reducing exposure to heavily hunted areas along migration pathways. The existence of some banded samples that did not experience harvest-rate extremes in the contrasted years would reduce the ability of the test to detect the relationship of interest. The continental correlation analysis uses mean continental survival estimates and could also suffer from the same insensitivity to geographic variation. In addition, it is possible to criticize the harvest-rate indices used. We randomly partitioned mallard bandings from each of a number of specific reference areas into 2 groups and estimated survival and harvest rates from both groups in each reference area. This procedure provided independent vectors of harvestand survival-rate estimates that were then used in correlation analyses and contrasts between survival rates for years of high vs. low harvest rates. This methodology avoided the potential criticisms for the 2 analogous continental tests of Anderson and Burnham (1976) and Rogers…
Summary 1 We used up to 35 years of capture–recapture data from nearly 3300 individual female duc... more Summary 1 We used up to 35 years of capture–recapture data from nearly 3300 individual female ducks nesting on Engure Marsh, Latvia, and multistate modelling to test predictions about the influence of environmental, habitat and management factors on breeding dispersal probability within the marsh. 2 Analyses based on observed dispersal distances of common pochards and tufted ducks provided no evidence that breeding success in year t influenced dispersal distance between t and t+ 1. 3 Breeding dispersal distances (year t to t+ 1) of pochards and tufted ducks were associated with a delay in relative nest initiation dates in year t+ 1. The delay was greater for pochards (c. 4 days) than for tufted ducks (c. 2 days) when females dispersed > 0·8 km. 4 Northern shovelers and tufted ducks moved from a large island to small islands at low water levels and from small islands to the large island at high water levels before the construction of elevated small islands (1960–82). Following this habitat management (1983–94), breeding fidelity was extremely high and not influenced by water level in the marsh for either species. 5 Because pochard nesting habitats in black-headed gull colonies were saturated during the entire study period, nesting females moved into and out of colonies with similar probabilities. Local survival probabilities and incubation body masses were higher for both yearlings (SY) and adults (ASY) nesting within gull colonies, suggesting that these females were of better quality than females nesting outside of the colonies. 6 Tufted ducks showed higher probabilities of moving from islands to emergent marshes when water levels were higher both before and after habitat management. However, rates of movement for a given water level were higher during the period before management than after. 7 Both pochards and tufted ducks exhibited asymmetric movement with respect to proximity to water, with higher movement probabilities to near-water nesting locations than away from these locations. 8 Multistate capture–recapture models provided analyses that were useful in investigating sources of variation in breeding dispersal probabilities.
... JAMES D. NICHOLS, US Fish and Wildlife Service, Migratory Bird and Habitat Research Laborator... more ... JAMES D. NICHOLS, US Fish and Wildlife Service, Migratory Bird and Habitat Research Laboratory, Laurel, MD 20811 RICHARD S ... Abstract: The relationship between habitat conditions in prairie breeding areas of North America and mallard (Anas platyrhynchos) survival rates ...
Capture-recapture models provide a statistical framework for estimating population parameters fro... more Capture-recapture models provide a statistical framework for estimating population parameters from mist-net data. Although Cormack-Jolly-Seber and related models have recently been used to estimate survival rates of birds sampled with mist nets, we believe that the full potential for use of capture-recapture models has not been realized by many researchers involved in mist-net studies. We present a brief discussion of the overall framework for estimation using capture-recapture methods, and review several areas in which recent statistical methods can be, but generally have not yet been, applied to mist-net studies. These areas include estimation of (1) rates of movement among areas; (2) survival rates in the presence of transients; (3) population sizes of migrating birds; (4) proportion of birds alive but not present at a breeding site (one definition of proportion of nonbreeding birds in a population); (5) population change and recruitment; and (6) species richness. Using these models will avoid the possible bias associated with use of indices, and provide statistically valid variance estimates and inference.
Uploads
Papers by James Hines