Age-class influences on feeding choices of free-ranging wild boars (Sus scrofa)

1989 ◽  
Vol 67 (11) ◽  
pp. 2792-2796 ◽  
Author(s):  
Maryse Dardaillon
Keyword(s):  
Diet Composition ◽  
Dietary Diversity ◽  
Age Classes ◽  
Wild Boars ◽  
Adult Age ◽  
Plant Parts ◽  
Age Class ◽  
The Mean ◽  
Feeding Choices ◽  
Free Ranging

Diet composition and diversity were compared between juvenile, yearling, and adult wild boars living in the Camargue region (southern France). Despite close similarity, feeding choices differed in various respects. First, the mean stomach content included a greater proportion of animal matter in subadults (juveniles and yearlings combined) than in adults. Secondly, yearlings and adults ate larger proportions of rice, and larger quantities by weight of underground plant parts, than juveniles. These differences were attributed to differing nutritional requirements according to age-class. On the other hand, greater diversity of feeding choices was found in juveniles than within the yearling and adult age-classes. It is argued that early experience of a broad dietary diversity is an advantage for coping with fluctuations in food availability such as those encountered in the Camargue.

scholarly journals Covariation of diet and gut microbiome in African megafauna

2019 ◽  
Vol 116 (47) ◽  
pp. 23588-23593 ◽  
Author(s):  
Tyler R. Kartzinel ◽  
Julianna C. Hsing ◽  
Paul M. Musili ◽  
Bianca R. P. Brown ◽  
Robert M. Pringle
Keyword(s):  
Seasonal Variation ◽  
Gut Microbiome ◽  
Diet Composition ◽  
Dietary Diversity ◽  
Nutritional Ecology ◽  
East African ◽  
Large Herbivore ◽  
Environmental Pressures ◽  
Microbiome Composition ◽  
Free Ranging

A major challenge in biology is to understand how phylogeny, diet, and environment shape the mammalian gut microbiome. Yet most studies of nonhuman microbiomes have relied on relatively coarse dietary categorizations and have focused either on individual wild populations or on captive animals that are sheltered from environmental pressures, which may obscure the effects of dietary and environmental variation on microbiome composition in diverse natural communities. We analyzed plant and bacterial DNA in fecal samples from an assemblage of 33 sympatric large-herbivore species (27 native, 6 domesticated) in a semiarid East African savanna, which enabled high-resolution assessment of seasonal variation in both diet and microbiome composition. Phylogenetic relatedness strongly predicted microbiome composition (r = 0.91) and was weakly but significantly correlated with diet composition (r = 0.20). Dietary diversity did not significantly predict microbiome diversity across species or within any species except kudu; however, diet composition was significantly correlated with microbiome composition both across and within most species. We found a spectrum of seasonal sensitivity at the diet−microbiome nexus: Seasonal changes in diet composition explained 25% of seasonal variation in microbiome composition across species. Species’ positions on (and deviations from) this spectrum were not obviously driven by phylogeny, body size, digestive strategy, or diet composition; however, domesticated species tended to exhibit greater diet−microbiome turnover than wildlife. Our results reveal marked differences in the influence of environment on the degree of diet−microbiome covariation in free-ranging African megafauna, and this variation is not well explained by canonical predictors of nutritional ecology.

Life history, demography, diet and habitat associations in the southwestern earless lizard, Cophosaurus texanus scitulus from northern and southern limits of its geographical range

2007 ◽  
Vol 28 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Fred Punzo
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Diet Composition ◽  
Life History Traits ◽  
Geographic Range ◽  
Habitat Associations ◽  
Generalist Predators ◽  
Reproductive Condition ◽  
Age Classes ◽  
Adult Age

AbstractI studied life history traits, demography, diet composition and habitat associations in the southwestern earless lizard, Cophosaurus texanus scitulus. Individuals from various age classes were sampled from populations at the northern (FCM) and southern (CAS) boundaries of its geographic range (FCM, foothills of Chinati Mts., Texas, USA; CAS, Castonos, Coahuila, Mexico). Males had higher growth rates as compared to females between the juvenile-to-yearling stages at both sites. Significant differences were also found for yearlings, and between yearling-to-adult stages. Growth rates decreased as a function of increasing age and were lowest in adults, and highest during the juvenile-to-yearling and yearling age classes. Earliest date on which a female was found to contain oviductal eggs was 19 May and 10 June, for the CAS and FCM sites, respectively. No females with oviductal eggs were found between 01 March and mid-May. Most females in reproductive condition had a SVL of 53-61 mm, and 57-64 mm, at the CAS and FCM sites, respectively, indicating that most females attain maturity at an age of 10-11 months. Clutch sizes were significantly smaller for females from the FCM site. Sex ratio was significantly biased toward females Survivorship was highest between yearling and adult age classes. Most lizards were found in areas with creosote and mesquite. These lizards are generalist predators that feed on a wide variety of arthropods.

Paternal ages below or above 35 years old are associated with a different risk of schizophrenia in the offspring

2007 ◽  
Vol 22 (1) ◽  
pp. 22-26 ◽  
Author(s):  
M. Wohl ◽  
P. Gorwood
Keyword(s):  
Meta Analysis ◽  
Paternal Age ◽  
Age Classes ◽  
Future Studies ◽  
Age Class ◽  
Increased Risk ◽  
The Mean ◽  
The Difference ◽  
Class Reference ◽  
Different Origins

AbstractBackgroundA link between older age of fatherhood and an increased risk of schizophrenia was detected in 1958. Since then, 10 studies attempted to replicate this result with different methods, on samples with different origins, using different age classes. Defining a cut-off at which the risk is significantly increased in the offspring could have an important impact on public health.MethodsA meta-analysis (Meta Win®) was performed, assessing the mean effect size for each age class, taking into account the difference in age class references, and the study design.ResultsAn increased risk is detected when paternal age is below 20 (compared to 20–24), over 35 (compared to below 35), 39 (compared to less than 30), and 54 years old (compared to less than 25). Interestingly, 35 years appears nevertheless to be the lowest cut-off where the OR is always above 1, whatever the age class reference, and the smallest value where offspring of fathers below or above this age have a significantly different risk of schizophrenia.ConclusionNo threshold can be precisely defined, but convergent elements indicate ages below or above 35 years. Using homogeneous age ranges in future studies could help to clarify a precise threshold.

scholarly journals Studi Kelompok Siamang (Hylobates Syndactylus) Di Repong Damar Pahmungan Pesisir Barat

2015 ◽  
Vol 3 (3) ◽  
pp. 85 ◽  
Author(s):  
Erna Maya Sari ◽  
Sugeng P. Harianto
Keyword(s):  
Sex Ratio ◽  
National Park ◽  
Local Community ◽  
Agroforestry Systems ◽  
Age Classes ◽  
Adult Age ◽  
Age Class ◽  
Hylobates Syndactylus ◽  
The Individual ◽  
Coastal District

Repong Damar in Pahmungan, West Coastal District is a buffer of Bukit Barisan Selatan National Park (TNBBS).  Repong Damar is one example of the success of agroforestry systems managed by local community that is still very traditional.  This area was identified as a component of siamang (Hylobates syndactylus) habitat.  The absence of data and the latest information about the siamang groups in Pekon Pahmungan were reasons of this research.  The purpose of this research was to determine the siamang groups in Repong Damar, used concentrated area methode.  The research was done on April 2015.  The results showed that the existence of siamang group in Repong Damar Pahmungan were 4 individuals/group.  The distribution of age classes in the individual phases of adult siamang were 2 individuals and the individual of adolescent phase were 2 individuals.  The sex ratio in the adult age class phase was 1:1 and at adolescent age class phase was 1:1.  Keywords: siamang, groups, repong damar

Comparative hunting abilities of polar bear cubs of different ages

1978 ◽  
Vol 56 (8) ◽  
pp. 1768-1772 ◽  
Author(s):  
Ian Stirling ◽  
Paul B. Latour
Keyword(s):  
Polar Bear ◽  
Canadian Arctic ◽  
Ursus Maritimus ◽  
Adult Males ◽  
Age Classes ◽  
Adult Age ◽  
Probability Of Survival ◽  
Age Class ◽  
Management Concept ◽  
Kill Rate

In most areas of the Canadian Arctic polar bear (Ursus maritimus) cubs apparently remain with their mothers until they are 2.5 years of age. The degree to which cubs of each age-class participate in the hunting of seals while with their mothers is examined in this paper in order to evaluate the degree to which they might be capable of independent hunting, should they be orphaned prior to the completion of the normal weaning period. Cubs of all age-classes did almost no hunting during the spring. The proportions of time spent hunting by yearling and 2-year-old cubs, and the durations of their lying 'still hunts' were not significantly different from each other but they were significantly shorter than their mothers' and than adult males' during the summer. However, the frequency of the lying 'still hunts' of 2-year-old cubs was double that of yearling cubs and the kill rate of 2-year-old cubs was comparable with that of adult age-classes, despite the fact they hunted for a significantly lesser proportion of their time. These results suggest that cubs which remain with their mothers until they are weaned have a higher probability of survival than those that do not and this interpretation lends support lo the management concept of total protection of family groups and the harvesting of independent bears only.

A Test of the Relationship between Otolith Weight and Age for the Pilchard Sardinops neopilchardus

1991 ◽  
Vol 48 (1) ◽  
pp. 35-38 ◽  
Author(s):  
W. J. Fletcher
Keyword(s):  
Linear Relationship ◽  
Uniform Distribution ◽  
Frequency Distribution ◽  
Direct Relationship ◽  
Original Sample ◽  
Age Classes ◽  
Age Class ◽  
The Mean ◽  
The Relationship ◽  
Additional Sample

A sample of 60 fish revealed a near-linear relationship between otolith weight and the estimated age (determined from scale and otolith annuli) for the pilchard Sardinops neopilchardus, with little overlap of otolith weight values between age classes. In an additional sample of 612 fish where only otolith weight and length were measured, only two clear length modes were found, but five modes using an otolith weight frequency distribution could be distinguished. The means of the five modes were similar to that predicted from the mean weights for each age class in the original sample of 60 fish. These five modes were also present in a subsample of the 612 fish, chosen such that their lengths formed a uniform distribution (i.e. no modes). These results were consistent with a direct relationship between otolith weight and age, but further validation is required before this variable can be used as the sole determinant of age.

scholarly journals Studi Populasi Siamang (Simphalangus syndactylus) DI Hutan Lindung Register 25 Pematang Tanggang Kabupaten Tanggamus

2017 ◽  
Vol 5 (3) ◽  
pp. 66
Author(s):  
Nur Lutfiatuz Zahra ◽  
Gunardi Djoko Winarno
Keyword(s):  
Land Use ◽  
Sex Ratio ◽  
Government Regulation ◽  
Community Forest ◽  
Age Classes ◽  
Adult Age ◽  
Age Class ◽  
Adult Phase ◽  
The Individual ◽  
Individual Adult

Siamang (Simphalangus syndactylus Raffles, 1821) was the primates that protected by government regulation of Republic Indonesia number 7 in 1999. The existence of the siamang was important role in forest as pollinator and seed dispersers. Conversion land has increased into plantations and agriculture so that siamang population became descreased. Protected forest on Register 25 Pematang Tanggang Tanggamus Regency was bordered by community forest, thus vulnerable to land use that siamang population became descreased. The aimed of the research was to find the size of the group, the composition of age, the sexual ratio and the habitat of siamang in protected forest Register 25 Pematang Tanggang. The method used an area concentrated in 3 areal observation. Observations were 30 days effective. The results of this research showed that the Group of siamang found about 3 groups/7 individuals. The distribution of age classes in the individual adult phase of siamang about 6 individuals, adolescent phase about 1 individual and baby phase not found in this group. The sex ratio value in the adult age class phase was 1:1 and at adolescent age class phase was 1:0. According to siamang society does not interfere with human activities so that  not harm for them and their habitat was quite adequate for a population of siamang. Keywords: protected forest, population, siamang

scholarly journals A Comparative Analysis of the Diets of a Genus of Freshwater Turtles across Africa

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 165
Author(s):  
Luca Luiselli ◽  
Gift Simon Demaya ◽  
John Sebit Benansio ◽  
Fabio Petrozzi ◽  
Godfrey C. Akani ◽  
...  
Keyword(s):  
Body Size ◽  
Vegetation Cover ◽  
Diet Composition ◽  
Linear Models ◽  
Dietary Diversity ◽  
Original Data ◽  
Animal Origin ◽  
Freshwater Turtles ◽  
Adult Age ◽  
Positive Effects

Pelusios (Testudines: Pleurodira) is an Afrotropical endemic genus of freshwater turtles that have adapted to a variety of habitats, with savannahs and forests being their two main habitat types. Although considered generally carnivorous, these turtles have rarely been subjected to detailed field surveys for determining their quantitative diet. In this paper, by using both the literature and original data, we analyze the diet of several Pelusios populations: three P. adansonii populations from South Sudan, one P. nanus from Zambia, seven P. castaneus from Nigeria, Benin and Togo, and four P. niger from Nigeria. All species were omnivorous but with a clear preponderance of the prey items being of animal origin (e.g., amphibians, fish, arthropods and annelids). Saturation curves revealed that the diet composition of all the surveyed populations was adequately assessed, and the diversity profiles indicated that all the populations were relatively similar in terms of overall dietary diversity. General Linear Models (GLM) showed a negative effect of vegetation cover on Anura adult consumption by turtles, and showed that the frequencies of Anura tadpoles, fish, reptiles and birds on Pelusios diets increased with the increase in vegetation cover. The GLM model also showed positive effects of individual body size on algae, Bivalvia, reptiles, birds and small mammal consumption by turtles, and underlined that the predation on Arachnida decreased with the increase in turtle body size. In all species, there were no significant intersexual dietary differences, whereas there were substantial ontogenetic dietary changes in three out of four species. Small-sized individuals of P. castaneus, P. niger and P. adansonii tended to feed mainly upon insects, with the adults also taking many fish and adult frogs, and in the case of P. niger, also birds and small mammals. Conversely, in P. nanus, the diet composition did not vary substantially from the juvenile to the adult age. All species appeared substantially generalist in terms of their diet composition, although the effects of season (wet versus dry) were not adequately assessed by our study.

scholarly journals Development of Downy Birch (Betula pubescens Ehrh.) Coppice Stands during Nine Years

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 958
Author(s):  
Jyrki Hytönen
Keyword(s):  
Low Cost ◽  
Stand Age ◽  
Age Classes ◽  
Annual Increment ◽  
Class A ◽  
Age Class ◽  
Growing Seasons ◽  
Downy Birch ◽  
The Mean ◽  
Betula Pubescens Ehrh

Growing of dense, naturally regenerated downy birch stands using rotations of 24–26 years has been shown to be profitable. Coppicing would be a low-cost regeneration method, however, knowledge on the development of birch coppices is scarce. The height, stem number, and biomass development of sprouts originating from six clearcut stands in three age classes (A: 10–12 years, B: 15–16 years, C: 22–24 years) located in northern Finland was studied. Equations for estimating the aboveground biomass from height were developed for sprouts. The number of sprouts, and their height and biomass were measured annually during nine growing seasons. In addition, sprout damage was assessed. The number of sprouts per hectare was highest in the youngest age class (A) throughout the study period, even though the decrease in the number of stems due to self-thinning was also fastest (from 591,000 sprouts per ha to 105,000 sprouts per ha). The stand age class did not have an effect on either the mean (2.7 m) or dominant height (5.4 m) of birch sprouts. The total leafless above-ground biomass, the mean annual increment (MAI), and the current annual increment (CAI) were highest in the youngest stand age class (A) and lowest in the oldest age class (C). After 9 years, the biomass in the oldest age class was 15.1 Mg ha−1 and 31.1 Mg ha−1 in the youngest age class. During the first six years, the biomass of the sprouts correlated with the number of stumps. A higher number of stumps produced more sprouts and biomass in the first years. However, due to faster self-thinning in the densest stands and higher mass of average sprout in the oldest stands, the correlation between the number of stumps and biomass decreased with the increase of age so that it was no longer significant in years 7, 8, and 9. In the older stand age classes, the MAI increased with the increase of the age of sprouts. The CAI varied considerably between the study years. The study showed that due to coppice vigor, growth of the birch sprouts can be high.

scholarly journals Widespread Infection with Hemotropic Mycoplasmas in Free-Ranging Dogs and Wild Foxes Across Six Bioclimatic Regions of Chile

2021 ◽  
Vol 9 (5) ◽  
pp. 919
Author(s):  
Sophia Di Cataldo ◽  
Aitor Cevidanes ◽  
Claudia Ulloa-Contreras ◽  
Irene Sacristán ◽  
Diego Peñaloza-Madrid ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Mixed Models ◽  
Rhipicephalus Sanguineus ◽  
Species Group ◽  
South American ◽  
Adult Age ◽  
Network Analyses ◽  
Male Sex ◽  
Free Ranging ◽  
Sequence Types

Blood samples of 626 rural dogs, 140 Andean foxes (Lycalopex culpaeus), and 83 South American grey foxes (L. griseus) from six bioregions of Chile spanning 3000 km were screened for Mycoplasma DNA by conventional PCR and sequencing. Risk factors of infection were inferred using Generalized Linear Mixed Models and genetic structure by network analyses. Overall, Mycoplasma haemocanis/Mycoplasma haemofelis (Mhc/Mhf) and Candidatus Mycoplasma haematoparvum (CMhp) observed prevalence was 23.8% and 12.8% in dogs, 20.1% and 7.2% in Andean foxes, and 26.5% and 8.4% in grey foxes, respectively. Both hemoplasmas were confirmed in all the bioregions, with higher prevalence in those where ticks from the Rhipicephalus sanguineus species group were absent. Candidatus M. haematominutum and a Mycoplasma sp. previously found in South American carnivores were detected in one fox each. Although the most prevalent Mhc/Mhf and CMhp sequence types were shared between dogs and foxes, network analysis revealed genetic structure of Mhc/Mhf between hosts in some regions. Male sex was associated with a higher risk of Mhc/Mhf and CMhp infection in dogs, and adult age with CMhp infection, suggesting that direct transmission is relevant. No risk factor was identified in foxes. Our study provides novel information about canine hemoplasmas with relevance in distribution, transmission routes, and cross-species transmission.

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