Age-related patterns of antler development in free-ranging white-tailed deer

2014 ◽  
Vol 78 (6) ◽  
pp. 976-984 ◽  
Author(s):  
David G. Hewitt ◽  
Mickey W. Hellickson ◽  
John S. Lewis ◽  
David B. Wester ◽  
Fred C. Bryant
Keyword(s):  
Age Related ◽  
Free Ranging ◽  
Antler Development

Reproductive senescence in free-ranging North American elk Cervus elaphus Cervidae

Mammalia ◽  
2019 ◽  
Vol 83 (6) ◽  
pp. 593-600 ◽  
Author(s):  
Louis C. Bender ◽  
Jessica R. Piasecke
Keyword(s):  
Age Structure ◽  
Cervus Elaphus ◽  
North American ◽  
Reproductive Senescence ◽  
Female Age ◽  
North American Elk ◽  
Age Related ◽  
Consistent Manner ◽  
Multiple Species ◽  
Free Ranging

Abstract Successful production of calves is necessary for growth of North American elk (Cervus elaphus Linnaeus 1758) populations, but few studies have evaluated age-related effects on both the conception and survival of a calf to weaning in multiple free-ranging populations. Conception and survival of calves to weaning were both affected by maternal age, with old (age 9 and older) females showing reproductive senescence as compared to prime-aged (ages 2–8) females despite achieving similar or greater size and condition. Reproductive senescence in our free-ranging populations ultimately resulted in old females weaning fewer calves (0.42 calves/female) than did prime-aged females (0.64 calves/female). Other factors, especially maternal size, also influenced conception and survival to weaning, and these interacted with age in a consistent manner, i.e. larger females or females in better condition were more likely to conceive and successfully wean calves within each age class. Female age structure receives less consideration in ungulate management than does male age structure, despite demonstrated impacts on population productivity of multiple species because of reproductive senescence. Because of the large proportion of individuals in senesced age classes in elk populations, low productivity in populations may simply reflect female age structure, rather than other frequently hypothesized factors.

Rutting Behavior in African Elephants: the Phenomenon of Musth

Behaviour ◽  
1987 ◽  
Vol 102 (3-4) ◽  
pp. 283-316 ◽  
Author(s):  
Joyce H. Poole
Keyword(s):  
Behavioral Characteristics ◽  
African Elephants ◽  
Temporal Patterning ◽  
Age Related ◽  
Time Of Year ◽  
One Year ◽  
Rutting Behavior ◽  
Free Ranging ◽  
Number Of Males ◽  
Older Males

Abstract1. The physical and behavioral characteristics and the temporal patterning of musth were studied over a ten-year period in a free-ranging population of African elephants. 2. Males spent more time in association with females during musth than during non-musth periods. 3. Males were more aggressive during their musth periods than during non-musth. 4. The occurrence and duration of musth were age-related: no male under 24 years was seen in musth; bouts of must among younger individuals were short and sporadic, while older males experienced longer more predictable periods of musth on an annual basis. 5. Although males in musth were observed year-round, the frequency of musth males was highest during and following the two rainy seasons and, in general, good rainfall years had higher frequencies of males in musth than did poor rainfall years. 6. The number of males in musth per month correlated closely with the number of females observed in estrus. However, since the period of estrus lasts only four to six days (Moss, 1983), while musth may last several months, the onset of musth was not necessarily triggered by the onset of estrus in a particular female. 7. The musth periods of different males were asynchronous and each male came into musth at a specific time of year. This period was relatively consistent from one year to the next, particularly among the older males. 8. Males in musth advertised their heightened sexual and aggressive state through visual and olfactory signals and by vocalizing. It is suggested that these signals function to announce identity, condition and location to both rival males and to potentially receptive females. 9. The physical and behavioral characteristics and temporal patterning of musth in African and Asian elephants are compared and found to be remarkably similar. 10. The physical and behavioral manifestations of musth in elephants are similar to those described for other male mammals during rut. Since estrus in female elephants is less clumped relative to most ungulates, male elephants have a different temporal pattern of rutting. Although the musth periods of male elephants are asynchronous the phenomenon can functionally be considered a rutting period.

Age-Related Reproductive Effort and Senescence in Free-Ranging Moose, Alces alces

Ecology ◽  
2001 ◽  
Vol 82 (6) ◽  
pp. 1613 ◽  
Author(s):  
Goran Ericsson ◽  
Kjell Wallin ◽  
John P. Ball ◽  
Martin Broberg
Keyword(s):  
Reproductive Effort ◽  
Alces Alces ◽  
Age Related ◽  
Free Ranging

scholarly journals Antler development in reindeer in relation to age and sex

Rangifer ◽  
2002 ◽  
Vol 22 (1) ◽  
pp. 75 ◽  
Author(s):  
Amund Høymork ◽  
Eigil Reimers
Keyword(s):  
Field Study ◽  
Rangifer Tarandus ◽  
Sex Discrimination ◽  
Male And Female ◽  
Adult Females ◽  
Antler Size ◽  
Free Ranging ◽  
Suggested Classification ◽  
Age And Sex ◽  
Antler Development

Yearling male and adult female reindeer (Rangifer tarandus tarandus) are similar in size and shape. If sexual clues are hidden, it can be difficult to distinguish between them. Antlers can be a useful aid in classifying yearling males and adult females, depending on whether specific antler characteristics are identifiable for these two groups. We recorded antler characteristics in a domestic reindeer herd (Vågå) and found considerable overlap in antler height, width and circumference between the different age and sex groups. Total tines and number of tine split-offs are use¬ful for the field biologist when discriminating among adult females, yearling males and 2.5 year-old males. For example, when using the tine split-offs with the suggested classification, 79% of the observed adult females and 76% of the yearling males were classified correctly. The antler height, width and circumference provide other biological dif¬ferences between groups, but are not easy to use to identify free ranging reindeer. This is due to the great overlap in antler size between the groups and measuring difficulties in a field study situation. Male and female calves have very similar antlers, and only the antler width is possible for sex discrimination, giving 67% accuracy of discriminating between these two groups.

scholarly journals Age and sex-associated variation in the multi-site microbiome of an entire social group of free-ranging rhesus macaques

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Mareike C. Janiak ◽  
Michael J. Montague ◽  
Catalina I. Villamil ◽  
Michala K. Stock ◽  
Amber E. Trujillo ◽  
...  
Keyword(s):  
Social Group ◽  
Beta Diversity ◽  
Rhesus Macaques ◽  
Age Groups ◽  
Taxonomic Composition ◽  
Oral Microbiome ◽  
Body Regions ◽  
Age Related ◽  
Free Ranging ◽  
Age And Sex

Abstract Background An individual’s microbiome changes over the course of its lifetime, especially during infancy, and again in old age. Confounding factors such as diet and healthcare make it difficult to disentangle the interactions between age, health, and microbial changes in humans. Animal models present an excellent opportunity to study age- and sex-linked variation in the microbiome, but captivity is known to influence animal microbial abundance and composition, while studies of free-ranging animals are typically limited to studies of the fecal microbiome using samples collected non-invasively. Here, we analyze a large dataset of oral, rectal, and genital swabs collected from 105 free-ranging rhesus macaques (Macaca mulatta, aged 1 month-26 years), comprising one entire social group, from the island of Cayo Santiago, Puerto Rico. We sequenced 16S V4 rRNA amplicons for all samples. Results Infant gut microbial communities had significantly higher relative abundances of Bifidobacterium and Bacteroides and lower abundances of Ruminococcus, Fibrobacter, and Treponema compared to older age groups, consistent with a diet high in milk rather than solid foods. The genital microbiome varied widely between males and females in beta-diversity, taxonomic composition, and predicted functional profiles. Interestingly, only penile, but not vaginal, microbiomes exhibited distinct age-related changes in microbial beta-diversity, taxonomic composition, and predicted functions. Oral microbiome composition was associated with age, and was most distinctive between infants and other age classes. Conclusions Across all three body regions, with notable exceptions in the penile microbiome, while infants were distinctly different from other age groups, microbiomes of adults were relatively invariant, even in advanced age. While vaginal microbiomes were exceptionally stable, penile microbiomes were quite variable, especially at the onset of reproductive age. Relative invariance among adults, including elderly individuals, is contrary to findings in humans and mice. We discuss potential explanations for this observation, including that age-related microbiome variation seen in humans may be related to changes in diet and lifestyle.

Age-related feeding site selection in urban pigeons (Columba livia): experimental evidence of the competition hypothesis

2000 ◽  
Vol 78 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Daniel Sol ◽  
David M Santos ◽  
Mariano Cuadrado
Keyword(s):  
Site Selection ◽  
Columba Livia ◽  
Age Classes ◽  
Feeding Site ◽  
Feeding Sites ◽  
Age Related ◽  
Competition Hypothesis ◽  
Ecological Mechanism ◽  
Free Ranging ◽  
Feeding Site Selection

Although age-specific habitat use has received much attention in recent years, the mechanisms that underlie ecological separation are not well known. This study examined the age-specific feeding site selection and its ecological mechanism in free-ranging Rock doves (Columba livia; referred to as pigeons). The distribution of age-classes at the feeding sites adjusted to a partially truncated distribution as follows: adults were consistently found more often than expected in the most rewarding feeding site, while juveniles were more often found in suboptimal sites. A removal experiment was conducted to determine whether competition accounted for the niche segregation between juvenile and adult pigeons. The reduction in intraspecific competition following removal was accompanied by an increased use of the preferred feeding site by juveniles. However, when the population recovered its initial size through immigration, juveniles were once again more frequently found in the suboptimal site. The proportion of juveniles feeding in each site was related to the total number of birds present; the higher the total number of birds, the higher the percentage of juveniles feeding in the less preferred site. These results support the idea that segregation between age-classes is due to competition by which adults displace juveniles from the richer foraging sites.

AGE-RELATED REPRODUCTIVE EFFORT AND SENESCENCE IN FREE-RANGING MOOSE,ALCES ALCES

Ecology ◽  
2001 ◽  
Vol 82 (6) ◽  
pp. 1613-1620 ◽  
Author(s):  
Göran Ericsson ◽  
Kjell Wallin ◽  
John P. Ball ◽  
Martin Broberg
Keyword(s):  
Reproductive Effort ◽  
Alces Alces ◽  
Age Related ◽  
Free Ranging

scholarly journals Free-ranging dogs show age related plasticity in their ability to follow human pointing

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0180643 ◽  
Author(s):  
Debottam Bhattacharjee ◽  
Nikhil Dev N. ◽  
Shreya Gupta ◽  
Shubhra Sau ◽  
Rohan Sarkar ◽  
...  
Keyword(s):  
Age Related ◽  
Free Ranging ◽  
Human Pointing

Spindle shaped bodies in foveolar cones of the baboon retina

1989 ◽  
Vol 47 ◽  
pp. 960-961
Author(s):  
W. Krebs ◽  
I. Krebs
Keyword(s):  
Cross Sections ◽  
Inclusion Bodies ◽  
Photoreceptor Cells ◽  
Papio Anubis ◽  
Retinal Photoreceptor ◽  
Age Related ◽  
Cone Cells ◽  
Membrane Bound ◽  
Oriented Parallel ◽  
Shaped Inclusion

Various inclusion bodies occur in vertebrate retinal photoreceptor cells. Most of them are membrane bound and associated with phagocytosis or they are age related residual bodies. We found an additional inclusion body in foveal cone cells of the baboon (Papio anubis) retina.The eyes of a 15 year old baboon were fixed by immersion in cacodylate buffered glutaraldehyde (2%)/formaldehyde (2%) as described in detail elsewhere . Pieces of retina from various locations, including the fovea, were embedded in epoxy resin such that radial or tangential sections could be cut.Spindle shaped inclusion bodies were found in the cytoplasm of only foveal cones. They were abundant in the inner segments, close to the external limiting membrane (Fig. 1). But they also occurred in the outer fibers, the perikarya, and the inner fibers (Henle’s fibers) of the cone cells. The bodies were between 0.5 and 2 μm long. Their central diameter was 0.2 to 0. 3 μm. They always were oriented parallel to the long axis of the cone cells. In longitudinal sections (Figs. 2,3) they seemed to have a fibrous skeleton that, in cross sections, turned out to consist of plate-like (Fig.4) and tubular profiles (Fig. 5).

Autophagy and ageing: implications for age-related neurodegenerative diseases

2013 ◽  
Vol 55 ◽  
pp. 119-131 ◽  
Author(s):  
Bernadette Carroll ◽  
Graeme Hewitt ◽  
Viktor I. Korolchuk
Keyword(s):  
Neurodegenerative Diseases ◽  
Energy Availability ◽  
Future Studies ◽  
Intracellular Degradation ◽  
Age Related ◽  
Autophagy Induction ◽  
Social Importance ◽  
Cellular Dysfunction ◽  
Autophagy Activity ◽  
Intense Research

Autophagy is a process of lysosome-dependent intracellular degradation that participates in the liberation of resources including amino acids and energy to maintain homoeostasis. Autophagy is particularly important in stress conditions such as nutrient starvation and any perturbation in the ability of the cell to activate or regulate autophagy can lead to cellular dysfunction and disease. An area of intense research interest is the role and indeed the fate of autophagy during cellular and organismal ageing. Age-related disorders are associated with increased cellular stress and assault including DNA damage, reduced energy availability, protein aggregation and accumulation of damaged organelles. A reduction in autophagy activity has been observed in a number of ageing models and its up-regulation via pharmacological and genetic methods can alleviate age-related pathologies. In particular, autophagy induction can enhance clearance of toxic intracellular waste associated with neurodegenerative diseases and has been comprehensively demonstrated to improve lifespan in yeast, worms, flies, rodents and primates. The situation, however, has been complicated by the identification that autophagy up-regulation can also occur during ageing. Indeed, in certain situations, reduced autophagosome induction may actually provide benefits to ageing cells. Future studies will undoubtedly improve our understanding of exactly how the multiple signals that are integrated to control appropriate autophagy activity change during ageing, what affect this has on autophagy and to what extent autophagy contributes to age-associated pathologies. Identification of mechanisms that influence a healthy lifespan is of economic, medical and social importance in our ‘ageing’ world.

Sign in / Sign up

Export Citation Format

Share Document