Demographic indications of decline in the spectacled flying fox (Pteropus conspicillatus) on the Atherton Tablelands of northern Queensland

2008 ◽  
Vol 35 (5) ◽  
pp. 417 ◽  
Author(s):  
Samantha Fox ◽  
Jon Luly ◽  
Catlin Mitchell ◽  
Jenny Maclean ◽  
David A. Westcott
Keyword(s):  
Life History ◽  
Life Table ◽  
Life History Traits ◽  
Mortality Rates ◽  
Mammal Species ◽  
Lack Of Information ◽  
Extended Longevity ◽  
Management And Conservation ◽  
Age Estimates ◽  
Flying Fox

A lack of information about the spectacled flying fox (Pteropus conspicillatus) makes management and conservation of this vulnerable species difficult. The analysis of population dynamics using life-history traits and life tables is widely used in planning for the conservation and management of wildlife. In the present study, the first life table for any species of bat is provided and age estimates derived from counts of annual increments in tooth cementum rings are used to assess population trends and life-history traits in the spectacled flying fox on the Atherton Tablelands in north Queensland. As a result of high mortality, longevity was much shorter than expected from a theoretical basis. Life-table analyses suggest that the population experienced a 16% decrease during the 2 years of study. Absence of extended longevity to compensate for low reproductive output and delayed sexual maturity in ‘slow end’ mammal species such as P. conspicillatus reduces the window of opportunity for females to reproduce and adapt to changes in mortality rates. This study suggests that spectacled flying fox populations are sensitive to increased mortality and that reducing mortality rates should be the primary goal in conservation planning for P. conspicillatus.

scholarly journals Density Dependence, Evolutionary Optimization, and the Diversification of Avian Life Histories

The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Robert E. Ricklefs
Keyword(s):  
Life History ◽  
Life Table ◽  
Life Histories ◽  
Life History Traits ◽  
Evolutionary Ecology ◽  
Reproductive Rate ◽  
Empirical Modeling ◽  
Adult Survival ◽  
Life History Variation ◽  
Evolutionary Response

Abstract Although we have learned much about avian life histories during the 50 years since the seminal publications of David Lack, Alexander Skutch, and Reginald Moreau, we still do not have adequate explanations for some of the basic patterns of variation in life-history traits among birds. In part, this reflects two consequences of the predominance of evolutionary ecology thinking during the past three decades. First, by blurring the distinction between life-history traits and life-table variables, we have tended to divorce life histories from their environmental context, which forms the link between the life history and the life table. Second, by emphasizing constrained evolutionary responses to selective factors, we have set aside alternative explanations for observed correlations among life-history traits and life-table variables. Density-dependent feedback and independent evolutionary response to correlated aspects of the environment also may link traits through different mechanisms. Additionally, in some cases we have failed to evaluate quantitatively ideas that are compelling qualitatively, ignored or explained away relevant empirical data, and neglected logical implications of certain compelling ideas. Comparative analysis of avian life histories shows that species are distributed along a dominant slow-fast axis. Furthermore, among birds, annual reproductive rate and adult mortality are directly proportional to each other, requiring that pre-reproductive survival is approximately constant. This further implies that age at maturity increases dramatically with increasing adult survival rate. The significance of these correlations is obscure, particularly because survival and reproductive rates at each age include the effects of many life-history traits. For example, reproductive rate is determined by clutch size, nesting success, season length, and nest-cycle length, each of which represents the outcome of many different interactions of an individual's life-history traits with its environment. Resolution of the most basic issues raised by patterns of life histories clearly will require innovative empirical, modeling, and experimental approaches. However, the most fundamental change required at this time is a broadening of the evolutionary ecology paradigm to include a variety of alternative mechanisms for generating patterns of life-history variation.

scholarly journals Subterranean Invasion by Gapped Ringed Crayfish: Effectiveness of a Removal Effort and Barrier Installation

Diversity ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 3 ◽  
Author(s):  
Joshua Mouser ◽  
David Ashley ◽  
Tom Aley ◽  
Shannon Brewer
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Major Threat ◽  
Males And Females ◽  
Native Crayfish ◽  
Age Estimates

Non-native crayfish invasion is a major threat to many stream fauna; however, invasions in subterranean habitats are rarely documented. Our study objectives were to examine demographics and morphological and life-history traits of a gapped ringed crayfish Faxonius neglectus chaenodactylus population that invaded Tumbling Creek Cave and determine the effects of removal on the population. Crayfish were found throughout the cave though fewer individuals were observed upstream of an installed weir. Fecund females were collected in nearly all months, but were prevalent during spring (February–June). Males and females were of similar sizes. Males had larger chelae and chelae that were regenerated slightly more often than females. Removal of >4000 crayfish since 2011 resulted in reduced abundances, but the population persisted. Age estimates from counting bands on gastric mills indicated crayfish within the cave lived longer than populations in nearby Big Creek (6 vs. 4 years). Recent efforts to prevent upstream cave migrations included a barrier installation and since installation, few crayfish have been located upstream. We show that exploitation of new environments may lead to trait changes (i.e., reproduction and longevity). We also demonstrate that barriers reduce the spread of invasion at a comparable cost to removal. We hypothesize that increased reservoir elevation inundates springs hydrologically connected to the cave and this may be the invasion source.

scholarly journals Life history traits and fishing mortality estimations of Caspian vimba, Vimba vimba (L.), in southwestern coastal regions of the Caspian Sea

2017 ◽  
Vol 25 (3) ◽  
pp. 145-155
Author(s):  
Fateme Taridashti ◽  
Javid Imanpour ◽  
Shahram Abdolmalaki ◽  
Mahvash Hadavi
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Caspian Sea ◽  
Life History Traits ◽  
Mortality Rates ◽  
Fishing Mortality ◽  
Coastal Regions ◽  
The Caspian Sea ◽  
Males And Females ◽  
Existing Data

Abstract This study was conducted to complement existing data about the life cycle of Caspian vimba, Vimba vimba (L.), with estimations of age, growth, and mortality rates. To achieve this, 811 specimens were collected between May 2012 and June 2013 at three fisheries catch stations in southwestern regions of the Caspian Sea including Talesh, Bandar Anzali, and Kiashahr. The growth rate in vimba is relatively high at approximately 0.29 year−1 for females and 0.32 year−1 for males. Asymptotic lengths are 245 mm and 233 mm for females and males, respectively. The growth pattern was isometric for both males and females. The overall sex ratio was balanced (1: 0.92). The instantaneous coefficients of total, natural, and fishing mortality were 1.27, 0.4, and 0.8 year, respectively, and the current exploitation ratio was 0.63 year−1. Results showed that the growth rate of males is higher than that of females. Considering the exploitation ratio, it is apparent that the vimba population is experiencing significant legal and illegal exploitation pressure.

scholarly journals Evidence of infanticide in the Cape mountain zebra (Equus zebra zebra)

Behaviour ◽  
2021 ◽  
pp. 1-13
Author(s):  
J.A. Britnell ◽  
L. Vorster ◽  
S. Shultz
Keyword(s):  
Life History ◽  
Birth Interval ◽  
Life History Traits ◽  
Conclusive Evidence ◽  
Reproductive Skew ◽  
Family Group ◽  
Mammal Species ◽  
Parent Group ◽  
Local Resources ◽  
Captive Populations

Abstract Infanticide has been described across mammal species. Infanticide is thought to be a tactic which increases reproductive opportunities or reduces competition over local resources. Species of the genus Equus exhibit life history traits such as expensive young, long gestation, lactation and dependency, extended inter-birth interval when there is a foal at foot and strong male reproductive skew. These traits suggest infanticide may be present throughout the genus. However, most documented cases of infanticide attempts come from captive populations and rely heavily on indirect accounts in free-roaming populations. Here, we report an infanticide attempt in Cape mountain zebra (Equus zebra zebra). The aggression was perpetrated by multiple bachelor males on two foals belonging to the same family group. The foals were separated from the parent group, chased and harried for a total of 45 minutes before the mothers and herd stallion were able to regain their offspring. We also report three cases of infanticide from necropsy. The injuries sustained by the foals are consistent with infanticide-based injuries documented in other equids species. The timing of these deaths occurs after a stallion turnover. These two cases provide the most conclusive evidence to date that infanticide takes place within mountain zebra.

scholarly journals What do we know about the life-history traits of widely hunted tropical mammals?

Oryx ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 670-676
Author(s):  
Nathalie van Vliet ◽  
Robert Nasi
Keyword(s):  
Life History ◽  
Species Distribution ◽  
Life History Traits ◽  
Local People ◽  
Mammal Species ◽  
Density Dependent ◽  
Distribution Ranges ◽  
Technical Innovations ◽  
Parameter Values

AbstractWe synthesize information on parameters useful for managing the hunting of two common mammal species that are important for local people in the Neotropics and Africa: Cuniculus paca and Philantomba monticola, respectively. We highlight the scarcity of data available on the parameters needed to manage these two species sustainably. As most of the studies were conducted > 40 years ago, we stress the need to supplement the information available using methodological and technical innovations. In particular, we call for new assessments covering the possible variations in parameter values across the species’ distribution ranges, and covering various anthropogenic contexts, to test density-dependent and compensatory processes that may explain the resilience of these species to hunting.

scholarly journals Life history traits and life table analysis of Lobiopa insularis (Coleoptera: Nitidulidae) fed on strawberry

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0180093 ◽  
Author(s):  
Nancy Greco ◽  
Nicolás Cluigt ◽  
Andrew Cline ◽  
Gerardo Liljesthröm
Keyword(s):  
Life History ◽  
Life Table ◽  
Life History Traits ◽  
Life Table Analysis ◽  
Table Analysis

The black flying-fox (Pteropus alecto) in north Australia: juvenile mortality and longevity

2000 ◽  
Vol 48 (1) ◽  
pp. 91 ◽  
Author(s):  
Michael J. Vardon ◽  
Christopher R. Tidemann
Keyword(s):  
Population Size ◽  
Life Table ◽  
Small Mammals ◽  
Mortality Rates ◽  
Northern Territory ◽  
Adult Size ◽  
Juvenile Mortality ◽  
The Mean ◽  
Size Data ◽  
Flying Fox

Mortality rates for juvenile black flying-fox (Pteropus alecto) are presented from data collected in the Northern Territory of Australia (12˚24′–13˚03′S) between 1992 and 1998. Forearm size data were used to construct a two-stage life table for each sex. Mortality rates from birth to adult size (170 mm) varied between sexes, between camp-sites and between years, and ranged from 0.43 to 0.80. Overall, the mortality rates from birth to adult size were 0.70 for females (n = 846) and 0.63 for males (n = 990). These rates represent annual juvenile mortality rates of 0.57 for females and 0.47 for males, given that females reach adult size at 14.8 months of age and males at 16.3 months of age. The maximum age of P. alecto recorded in this study was 4.5 years. The mean lifespan of females reaching adulthood would need to be seven years for a stable population size to be maintained, but may be shorter given that the mortality rates may have been over-estimated. The mortality rates and lifespan of P. alecto are not unusual amongst Chiroptera or small mammals in general.

Geographical Variations in Life Histories of House Flies, Musca domestica (Diptera: Muscidae), in Punjab, Pakistan

2019 ◽  
Vol 56 (5) ◽  
pp. 1225-1230 ◽  
Author(s):  
Hafiz Azhar Ali Khan ◽  
Muhammad Umer Khan ◽  
Amara Nasiba ◽  
Saira Riaz ◽  
Maria Altaf
Keyword(s):  
Life History ◽  
Life Table ◽  
Musca Domestica ◽  
Life History Traits ◽  
Population Increase ◽  
Lower Latitude ◽  
Life Table Parameters ◽  
Net Reproductive Rate ◽  
Geographical Variations ◽  
Geographical Regions

Abstract Musca domestica Linnaeus is an important public health pest with the ability to adapt to diverse climates. Assessment of variations in biology and life-history traits of insects along geographical gradients is important for a successful management plan in different regions. We investigated life-history traits and life table parameters of M. domestica from six different geographical regions of Punjab, Pakistan: Rahim Yar Khan (RYK), Bahawalpur (BWP), Multan (MTN), Lahore (LHR), Gujrat (GJT), and Murree (MRE). Overall, M. domestica from localities of lower latitude and elevations with higher mean temperatures completed their development faster than those from localities of higher latitude and elevations with lower mean temperatures. The immature developmental time was the longest for the MRE population that was collected from higher latitude and elevation with cooler climate, whereas the shortest for the RYK population from lower latitude with warmer climate. Pupal weights were heavier for the RYK, BWP, and MTN populations, all were from the lowest latitude and elevations with warmer climate, compared with rest of the field populations. Similarly, rate of adult eclosion, fecundity, egg hatching, longevity, and life table parameters such as intrinsic rate of population increase, mean relative growth rate, net reproductive rate, and biotic potential were significantly higher for the RYK, BWP, and MTN populations compared with the GJT, LHR, and MRE populations of M. domestica. The current results will probably be of importance when planning management of M. domestica in different geographical regions of Pakistan.

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