scholarly journals Sexual dimorphism in morphology and plumage of endangered Yuma Ridgway’s Rails: a model for documenting sex

2021 ◽  
Author(s):  
Eamon Harrity ◽  
Lauren E. Michael ◽  
Courtney J. Conway
Keyword(s):  
Discriminant Function ◽  
Wildlife Management ◽  
Field Studies ◽  
Sexual Differences ◽  
Discriminant Functions ◽  
Missing Measurements ◽  
Morphometric Measurements ◽  
Marsh Bird ◽  
Practical Tool ◽  
Discriminant Function Analyses

Many applications in wildlife management require knowledge of the sex of individual animals. The Yuma Ridgway’s Rail Rallus obsoletus yumanensis is an endangered marsh bird with monomorphic plumage and secretive behaviors, thereby complicating sex determination in field studies. We collected morphometric measurements from 270 adult Yuma Ridgway’s Rails and quantified the plumage and mandible color of 91 of those individuals throughout their geographic range to evaluate inter-sexual differences in morphology and coloration. We genetically sexed a subset of adult Yuma Ridgway’s Rails ( N =101) and used these individuals to determine the optimal combination of measurements (based on discriminant function analyses) to distinguish between sexes. Males averaged significantly larger than females in all measurements and the optimal discriminant function contained whole-leg, culmen, and tail measurements and classified correctly 97.8% (95% CI: 92.5-100.0%) of genetically sexed individuals. We used two additional functions that correctly classified ≥95.5% of genetically sexed Yuma Ridgway’s Rails to assign sex to individuals with missing measurements. These simple models provide managers and researchers with a practical tool to determine the sex of Yuma Ridgway’s Rails based on morphometric measurements. Although color measurements were not in the most accurate discriminant functions, we quantified subtle inter-sexual differences in the color of mandibles and greater coverts of Yuma Ridgway’s Rails. These results document sex-specific patterns in coloration that allow future researchers to test hypotheses to determine the mechanisms underlying sex-based differences in plumage coloration.

Description and comparison of morphological structures of the eggs of Anopheles hyrcanus group and related species (Diptera: Culicidae) from the Republic of Korea

Zootaxa ◽  
2009 ◽  
Vol 2268 (1) ◽  
pp. 23-40 ◽  
Author(s):  
LEOPOLDO M. RUEDA ◽  
TRACY L. BROWN ◽  
HEUNG-CHUL KIM ◽  
TERRY A. KLEIN ◽  
AMPORN THONGKUKIATKUL ◽  
...  
Keyword(s):  
Electron Micrographs ◽  
Discriminant Function ◽  
Related Species ◽  
Republic Of Korea ◽  
Scanning Electron Micrographs ◽  
Morphometric Measurements ◽  
Interspecific Differences ◽  
The Republic ◽  
Scanning Electron ◽  
Discriminant Function Analyses

The eggs of six Anopheles Hyrcanus Group (An. sinensis Wiedemann, An. kleini Rueda, An. belenrae Rueda, An. pullus M. Yamada, An. lesteri Baisas and Hu, An. sineroides S. Yamada) and related species (An. koreicus S. Yamada and Watanabe, An. lindesayi japonicus S. Yamada), were described from scanning electron micrographs of specimens collected from different localities of the Republic of Korea. Morphometric measurements of egg samples of the eight species were compared and relationships analyzed by multivariate statistics. About 27 characters were selected and used as a basis for principal and discriminant function analyses. Scanning electron micrographs of various parts of the eggs were selected to illustrate interspecific differences for particular morphological features (e.g. anterior and posterior tubercles, decks, plastron, micropyles, floats).

Niche separation in coprophagous beetles: a comparison of two multivariate approaches

1997 ◽  
Vol 87 (6) ◽  
pp. 625-631 ◽  
Author(s):  
P. Sowig
Keyword(s):  
Discriminant Function ◽  
Discriminant Function Analysis ◽  
Function Analysis ◽  
Niche Overlap ◽  
Niche Separation ◽  
Discriminant Functions ◽  
Niche Space ◽  
Advantages And Disadvantages ◽  
Southwest Germany ◽  
Discriminant Function Analyses

AbstractCoprophagous beetles (endocoprid and paracoprid Scarabaeidae, Hydrophilidae, and Staphylinidae) were extracted from 698 sheep droppings from a pasture in southwest Germany. To quantify the pairwise niche overlap of these species, pairwise discriminant function analysis was used to calculate the overlap of the discriminant distributions in a four-dimensional niche space. Niche separation was studied considering the following four factors: season (month) and macrohabitat when and where the dropping was deposited, dropping size, and water content of the dropping. Multiple discriminant function analysis was used to describe the distribution of species in a space defined by four discriminant functions. The first discriminant function was mostly influenced by the factor ‘season’. The importance of different factors for niche separation in different functional groupings of dung beetles is compared with results from the literature. Advantages and disadvantages of pairwise and multiple discriminant function analysis, and univariate evaluation methods are compared. The following problems and restrictions of discriminant function analyses are emphasized: (i) the usage of non-numerical variables; (ii) the calculation of niche breadths; (iii) failures, when bimodally distributed variables are considered; and (iv) the ecological interpretation of statistical significances.

Validity and Clinical Scale Comparisons between the MMPI and MMPI-2 with Psychiatric Inpatients

1992 ◽  
Vol 70 (1) ◽  
pp. 323-332 ◽  
Author(s):  
Dudley David Blake ◽  
Phillip M. Kleespies ◽  
Walter E. Penk ◽  
Suellen S. Walsh ◽  
DeAnna L. Mori ◽  
...  
Keyword(s):  
Discriminant Function ◽  
Relative Stability ◽  
Patient Population ◽  
Psychiatric Patients ◽  
Special Populations ◽  
Clinical Scale ◽  
Acute Psychiatry ◽  
Highly Correlated ◽  
Discriminant Function Analyses

This study was designed to investigate the comparability of the original MMPI (1950) and the MMPI-2 (1989) with a psychiatric patient population. 34 male and 3 female patients, shortly after admission to one of two acute psychiatry units, completed the old and revised versions of the MMPI. Paired t tests indicated but scant differences for raw scores, while many more differences were found among T scores for validity, clinical, and supplemental scales. Analyses, however, showed all scales on the two forms to be highly correlated. Analysis of the high-point and two-point codes across the two administrations also showed relative stability, although the proportion of Scales 2 (Depression) and 8 (Schizophrenia) decreased, while those for Scales 6 (Paranoia) and 7 (Psychasthenia) increased markedly in the MMPI-2 protocols. Examination of each version's discriminability among mood- and thought-disordered subsamples suggested that the MMPI provides slightly better delineation between diagnostic classes. Discriminant function analyses showed that there were essentially no differences between the two forms in the accurate classification of clinical and nonclinical groups. The findings reported here provide support for the MMPI-2; despite modification, the newer form retains the advantages of the original MMPI. Differences found here may be unique to psychiatric patients and their patterns of MMPI/MMPI-2 equivalence and may not generalize to other special populations.

scholarly journals Preserving Wildlife: An International Perspective

2001 ◽  
Vol 7 (2) ◽  
pp. 146
Author(s):  
Nadia Elizabeth Tapp
Keyword(s):  
Wildlife Management ◽  
Native Species ◽  
Captive Breeding ◽  
Management Strategies ◽  
Field Studies ◽  
Moral Values ◽  
International Perspective ◽  
Management Approaches ◽  
Sport Hunting ◽  
Selection Of

PRESERVING Wildlife: An International Perspective is an anthology of twenty papers exploring the issues related to the preservation of wildlife, with an emphasis on related management approaches. This topic is introduced philosophically with a discussion of moral values associated with human activities. Sport hunting, the medical aid of injured wild animals and the manipulation of wildlife during ecological field studies are discussed within this context. The focus then shifts to a selection of wildlife management strategies including habitat protection, captive breeding, culling of non-native species, eco-tourism and marketing of wildlife products.

scholarly journals Truss network based morphometric and meristic variations among south-western populations of Macrognathus aculeatus in Bangladesh

2021 ◽  
Vol 42 (3(SI)) ◽  
pp. 887-894
Author(s):  
M. Sarower-E-Mahfuj ◽  
◽  
S.K. Das ◽  
K.N. Azad ◽  
A.K. Paul ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Discriminant Function ◽  
Network System ◽  
Meristic Characters ◽  
Morphometric Characters ◽  
Baseline Information ◽  
Macrognathus Aculeatus ◽  
Post Hoc ◽  
Separation Results ◽  
Discriminant Function Analyses

Aim: Landmark-based truss network system was applied to examine the morphometric and meristic differences among four different populaces of Macrognathus aculeatus namely; Dhakuriabeel, Jashore (DBJ); Arial Kha River, Madaripur (AKRM); Nabaganga River, Jhenaidah (NRJ); Kopotakkha River, Jashore (KRJ) in Bangladesh. Methodology: Completely 80 samples of M. aculeatus were collected (20 individuals from each population) for this study. Six meristic characters, 6 morphometric characters and 15 truss-based morphometric characters were measured for one-way analysis of variance (ANOVA) and Tukey-HSD post hoc test. Discriminant function analyses were also performed by using morphometric and truss-based morphometric characters to detect potential characters responsible for population separation. Results: Completely 80 samples of M. aculeatus were collected (20 individuals from each population) for this study. Six meristic characters, 6 morphometric characters and 15 truss-based morphometric characters were measured for one-way analysis of variance (ANOVA) and Tukey-HSD post hoc test. Discriminant function analyses were also performed by using morphometric and truss-based morphometric characters to detect potential characters responsible for population separation. Interpretation: The baseline information derived from the present study would be useful for appropriate conservation of M. aculeatus populations as well as for the researchers for further investigation.

Morphometric Sex Identification of Nestling and Free-Flying Tasmanian Wedge-Tailed Eagles (Aquila audax fleayi)

2021 ◽  
Author(s):  
James M. Pay ◽  
Todd E. Katzner ◽  
Jason M. Wiersma ◽  
William E. Brown ◽  
Clare E. Hawkins ◽  
...  
Keyword(s):  
Late Stage ◽  
Sex Identification ◽  
Age Classes ◽  
Single Measurement ◽  
Morphometric Measurements ◽  
Molecular Analyses ◽  
Linear Discriminant ◽  
Causes Of Mortality ◽  
Forearm Length ◽  
Discriminant Function Analyses

ABSTRACT The endangered Tasmanian Wedge-tailed Eagle (Aquila audax fleayi) is the focus of continued research and conservation efforts. A tool for accurate and efficient identification of the sex of individuals would be a valuable aid to research and management. However, plumages are monomorphic between the sexes, making sex identification difficult without molecular analyses. Our aim was to assess whether Tasmanian Wedge-tailed Eagles of different age classes could be sexed accurately using morphological measurements. We took measurements of 25 live late-stage eagle nestlings and 108 carcasses of free-flying birds found opportunistically throughout Tasmania. Sex of all individuals was confirmed via genetic analyses. Free-flying birds were larger than nestlings; thus, we used age-specific statistical tools to distinguish the sexes. For both nestlings and free-flying birds, females were significantly larger than males, but overlap between the sexes prevented accurate sex identification using any single measurement. We used stepwise linear discriminant function analyses to select morphometric measurements necessary for accurate sex identification. Free-flying birds could be sexed with 97.6% accuracy using a combination of measurements of the forearm length, tarsus width (i.e., lateromedial width), and hallux length. Late-stage nestlings (9–10 wk old) could be sexed with 95.4% accuracy using measurements of the hallux width (i.e., lateromedial width), hallux breadth (i.e., anteroposterior width of hallux), and tarsus breadth (i.e., anteroposterior width of the tarsometatarsus at the narrowest point). The discriminate functions we present also allow the identification of sex in cases where morphological sex identification may be in doubt and molecular analyses should be prioritized. These equations provide a valuable research tool for studies of sexual differences in behavior and causes of mortality of this endangered subspecies.

Obsidian Blades from La Blanca, a Changing Lithic Industry on the South Coast of Guatemala

1991 ◽  
Vol 2 (4) ◽  
pp. 371-383 ◽  
Author(s):  
C. Roger Nance ◽  
Katharine A. Kirk
Keyword(s):  
Low Power ◽  
Discriminant Function ◽  
Linear Discriminant Function ◽  
South Coast ◽  
Linear Discriminant ◽  
Bipolar Technology ◽  
Lithic Industry ◽  
Edge Wear ◽  
Middle Preclassic ◽  
Discriminant Function Analyses

In a study of Middle Preclassic (Conchas phase) ceramics from the site of La Blanca, Love (1989) derived a sequence of four subphases. Here, the focus is on 431 prismatic obsidian blades excavated from the same deposits in order to discern if patterns of change can be discovered in this lithic industry. For each blade, recorded attributes describe blade dimensions and edge wear, as observed through low-power microscopy. Chronological controls were set by ceramic associations. Through the sequence, blades became smaller and more fragmentary, due, we hypothesized, to an increasing scarcity of obsidian. As predicted from these trends, we found that wear patterns became more pronounced through time, and use of a bipolar technology became increasingly important for removing (rejuvenating) worn lateral edges. A definite obsidian-blade sequence emerged, which was investigated through linear discriminant-function analyses.

Sensation Seeking among High and Low-Risk Male Athletes

1982 ◽  
Vol 4 (3) ◽  
pp. 246-253 ◽  
Author(s):  
William F. Straub
Keyword(s):  
High Risk ◽  
Sport Psychology ◽  
Discriminant Function ◽  
Sensation Seeking ◽  
Low Risk ◽  
Male Athletes ◽  
The Many ◽  
Sensation Seeking Scale ◽  
Discriminant Function Analyses

Many problems are associated with the measurement of athletes in contemporary sport psychology. There is, for example, a dearth of valid and reliable tests to assess the many and diverse behaviors of players. The purpose of this investigation was to attempt to validate Zuckerman's sensation seeking scale (SSS V) using high- and low-risk sport participants. The SSS (Form V) was administered to male hang gliders (n = 33), automobile racers (n = 22), and intercollegiate bowlers (n = 25). It was hypothesized that the high-risk athletes (hang gliders and auto racers) would score significantly higher (.05 level) than the low-risk sport participants (bowlers) in total sensation seeking score and on the four subscales of Zuckerman's test. Stepwise multiple discriminant function analyses found that except for thrill and adventure seeking and disinhibition subscales, the above hypotheses were tenable. Thus, it was concluded that support exists for Zuckerman's SSS (Form V) as a measure of sensation seeking among male athletes.

Dominance and geographic information contained within black-capped chickadee (Poecile atricapillus) song

Behaviour ◽  
2013 ◽  
Vol 150 (13) ◽  
pp. 1601-1622 ◽  
Author(s):  
Allison H. Hahn ◽  
Lauren M. Guillette ◽  
Marisa Hoeschele ◽  
Daniel J. Mennill ◽  
Ken A. Otter ◽  
...  
Keyword(s):  
British Columbia ◽  
Discriminant Function ◽  
Dominance Rank ◽  
Geographic Location ◽  
Relative Amplitude ◽  
Complex Signal ◽  
Acoustic Features ◽  
Song Variation ◽  
Eastern Ontario ◽  
Discriminant Function Analyses

In songbirds, male song is an acoustic signal used to attract mates and defend territories. Typically, song is an acoustically complex signal; however, the fee-bee song of the black-capped chickadee is relatively simple. Despite this relative simplicity, two previous studies (Christie et al., 2004b; Hoeschele et al., 2010) found acoustic features within the fee-bee song that contain information regarding an individual’s dominance rank; however each of these studies reported a different dominance-related acoustic cue. Specifically, the relative amplitude of the two notes differed between the songs of dominant and subordinate males from northern British Columbia, while the interval pitch ratio differed between the songs of dominant and subordinate males from eastern Ontario. In the current study, we examined six acoustic features within songs from both of the chickadee populations (northern British Columbia and eastern Ontario) examined in these previous studies and used bioacoustic analyses and discriminant function analyses to determine whether there is a consistent dominance-related acoustic cue across both, or in each of these populations. Consistent with the previous findings, the current results indicate that relative amplitude differs based on dominance status in the songs from British Columbia; however, our results failed to reach significance with songs from Ontario. These results suggest that acoustic cues that signal a male’s dominance in this species vary with geographic location. Furthermore, examining songs from these two locations and one additional location in northern British Columbia, we found that discriminant function analyses could correctly classify songs based on geographic location. Considering the broad extent of the species’ range, black-capped chickadee song is considered relatively invariant; however, our results suggest that there is geographic variation in songs, although the differences are subtle compared to geographic song variation in other species.

Differences in skeletal characters between the disjunct eastern and western populations of ring-billed gulls (Larus delawarensis)

1984 ◽  
Vol 62 (6) ◽  
pp. 1067-1074 ◽  
Author(s):  
Beatrice M. Termaat ◽  
John P. Ryder
Keyword(s):  
Discriminant Function ◽  
Multivariate Analyses ◽  
Correct Identification ◽  
Adult Males ◽  
Lake Of The Woods ◽  
Larus Delawarensis ◽  
Males And Females ◽  
Two Populations ◽  
Univariate Analyses ◽  
Discriminant Function Analyses

Univariate analyses of variance, multivariate analyses of variance (Manova), and discriminant function analyses were performed on measurements of 51 skeletal characters of adult males and females from the disjunct eastern and western populations of the ring-billed gull (Larus delawarensis) in Canada. The analyses established sufficient differences in skeletal characters to permit correct identification of the origin of 34 of 38 males (90%) and 40 of 42 females (95%). The populations are now expanding in range to the extent where new colonies are established in the Lake of the Woods, Ontario region, the historical hiatus between the two populations. Further expansion and contact may well erase the existing skeletal differences of individuals in these populations.

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