scholarly journals Assessing factors affecting adult female white-tailed deer survival in the Northern Great Plains

2018 ◽  
Vol 45 (8) ◽  
pp. 679 ◽  
Author(s):  
Katherine L. Moratz ◽  
Bailey S. Gullikson ◽  
Eric S. Michel ◽  
Jonathan A. Jenks ◽  
Daniel M. Grove ◽  
...  
Keyword(s):  
Great Plains ◽  
Adult Female ◽  
Survival Rates ◽  
Adult Survival ◽  
Northern Great Plains ◽  
Late Winter ◽  
High Survival ◽  
Factors Affecting ◽  
Time Period ◽  
Specific Mortality

Context Documenting cause-specific mortality and deriving survival estimates for a population are both vital to understanding potential restrictions to population growth. Survival varies among populations of the same species and depends on several factors, including climatic events, density-dependent and density-independent factors, observed predator composition and whether recreational hunting occurs. Therefore, understanding factors affecting adult survival and estimating survival rates at biologically important times will help refine management of these populations. Aims We aimed to assess cause-specific mortality, estimate survival rates, and determine at what part of the winter (January to April) most mortalities occurred for female white-tailed deer located in the Northern Great Plains region of the USA. Methods We captured 165 adult female white-tailed deer (Odocoileus virginianus) located in western North Dakota and north-western South Dakota, USA, during the winters of 2014 and 2015. We fitted individuals with Very High Frequency (VHF) radio-collars and located them 1–3 times per week to monitor survival. We investigated all mortalities to establish proximate cause of death. Key Results Survival was lowest during our Hunt time period (S=0.93), although hunter harvest was not the leading cause of mortality. Predation was the greatest source of mortality, particularly during our Post-hunt time period. Additionally, almost 90% of mortalities occurring during the Post-hunt time period happened during late winter before spring green up. Conclusions and Implications Predation was the main source of mortality for adult females in our study, with coyotes (Canis latrans) being the sole predator capable of depredation in our study area. Predation by coyotes may indicate that potential factors, including winter severity and nutritional restrictions, have decreased female body condition, making individuals more susceptible to predation. Although we report relatively high survival, managers should consider the possibility that coyotes may impact adult populations, particularly in regions where other large-sized predators occur, or in regions where coyotes are newly established. Managers should also acknowledge that overwinter density estimates may need to be adjusted during severe winters to account for mortalities that occur after population surveys are conducted.

scholarly journals Fitness of breeders in social Damaraland mole-rats is independent of group size

2021 ◽  
Author(s):  
Jack Thorley ◽  
Hanna Bensch ◽  
Kyle Finn ◽  
Tim Clutton-Brock ◽  
Markus Zöttl
Keyword(s):  
Reproductive Success ◽  
Group Size ◽  
Survival Rates ◽  
Group Living ◽  
Adult Survival ◽  
High Survival ◽  
Successful Reproduction ◽  
Related Group ◽  
Group Members ◽  
Using Data

Damaraland mole-rats (Fukomys damarensis) are usually viewed as an obligatorily group living eusocial species in which successful reproduction is dependent on reproductive altruism of closely related group members. However, the reproductive ecology of social mole-rats in their natural environment remains poorly understood and it is unclear to what extent successful reproduction is dependent on assistance from other group members. Using data from a 7-year field study of marked individuals, we show that, after dispersal from their natal group, individuals typically settled alone in new burrow systems where they enjoyed high survival rates, and often remained in good body condition for several years before finding a mate. Unlike most other eusocial or singular cooperative breeders, we found that Damaraland mole-rats reproduced successfully in pairs without helpers and experimentally formed pairs had the same reproductive success as larger established groups. Overall there was only a weak increase in reproductive success with increasing group size and no effect of group size on adult survival rates across the population. Juveniles in large groups grew faster early in life but their growth rates declined subsequently so that they eventually plateaued at a lower maximum body mass than juveniles from small groups. Taken together, our data suggest that the fitness benefits of group living to breeders are small and we suggest that extended philopatry in Damaraland mole-rats has evolved because of the high costs and constraints of dispersal rather than because of strong indirect benefits accrued through cooperative behaviour.

Neonatal survival: an overview

1992 ◽  
Vol 15 ◽  
pp. 1-7 ◽  
Author(s):  
M. A. Varley
Keyword(s):  
Medical Profession ◽  
Survival Rates ◽  
Farm Animals ◽  
Physical Factors ◽  
High Survival ◽  
Animal Agriculture ◽  
Factors Affecting ◽  
Neonatal Deaths ◽  
Probability Of Survival ◽  
Use Of Resources

AbstractMortality in neonates has always represented significant economic wastage and slow progress has been made in the understanding of the factors influencing the probability of survival or death. There is also increasing pressure in the animal agriculture sphere to pursue improved welfare and in the situation where neonatal deaths are a high proportion of the liveborn offspring, then this becomes not only an economic concern but also a welfare issue. This paper highlights principal problems within the neonatal area in order to introduce the ensuing text dealing with specific technical challenges.The magnitude of loss for different species including humans is given and the factors affecting mortalities are discussed. The major components include: human factors, pathogenic agents, immunological factors, temperature and thermoregulation, nutrition, behaviour and physical factors.Although single factors are often ascribed as the cause of death, the reality is that there are usually multifactorial components involved which interact and contribute to the final mortality of the individual.The approach to the practical management of neonates varies widely between the different animal industries and the techniques deployed depend on relative economic values. In human health care every available resource is used to ensure very high survival rates because of the incalculable value of each individual delivered. With farm animals the use of resources is at a much lower level and survival rates are lower. It ought to be possible in animal agriculture to adopt some of the methods used in the medical profession to assess high risk situations and to divert resources appropriately.

scholarly journals Survival of a long-lived single island endemic, the Raso lark Alauda razae, in relation to age, fluctuating population and rainfall

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
E. G. Dierickx ◽  
R. A. Robinson ◽  
M. de L. Brooke
Keyword(s):  
Strong Evidence ◽  
Survival Rates ◽  
Adult Survival ◽  
Tropical Species ◽  
High Survival ◽  
Cape Verdean ◽  
Island Endemic ◽  
The Face ◽  
Dry Conditions ◽  
Population Sizes

AbstractEstimating and understanding variation in survival rates is crucial for the management of threatened species, especially those with limited population sizes and/or restricted ranges. Using a capture-resighting dataset covering 2004–2017, we estimate adult survival in the Raso lark Alauda razae, a Critically Endangered single-island Cape Verdean endemic, whose population varied 25-fold during the study. Average annual adult survival was similar for males (0.813 ± 0.011) and females (0.826 ± 0.011) over the period. These values are high for a temperate passerine but not unusual for an insular tropical species like the lark. The oldest bird was recorded 13 years after first ringing. There was strong evidence that survival varied among years (between 0.57 and 0.95), being generally higher in wetter years. Survival, especially of males, was lower when the population was large, but only in drier years. Survival declined with age but there was no evidence that this decline was other than linear. High survival, even in the face of dry conditions, at least when the population is depressed, has probably contributed to the persistence of the species on its 7 km2 island home over several centuries.

scholarly journals Juvenile and Adult Survival in the Sociable Weaver (Philetairus Socius), A Southern-Temperate Colonial Cooperative Breeder in Africa

The Auk ◽  
2004 ◽  
Vol 121 (4) ◽  
pp. 1199-1207
Author(s):  
Rita Covas ◽  
Charles R. Brown ◽  
Mark D. Anderson ◽  
Mary Bomberger Brown
Keyword(s):  
Survival Rates ◽  
Adult Survival ◽  
Easy Access ◽  
High Survival ◽  
Capture Recapture ◽  
Sociable Weavers ◽  
Philetairus Socius ◽  
Similar Survival ◽  
Survival Patterns ◽  
Access To Food

Abstract We used capture-recapture analyses to describe juvenile and adult survival from 1993 to 2001 in a population of Sociable Weavers (Philetairus socius), a colonial, cooperatively breeding passerine of southern Africa. We examined temporal variation in survival and the role that the breeding season's length and environmental factors play in determining survival patterns in the population. Annual survival probability (mean ± SE) was 0.66 ± 0.02. In contrast to most passerines, juveniles and adults had similar survival probabilities; survival rates did not vary significantly between years. We found no relationship among temperature, rainfall, and survival. Relatively high survival rates in Sociable Weavers probably result from a benign climate and easy access to food in winter. Juvenile survival may also be enhanced by prolonged parental care and delayed dispersal.

scholarly journals Demographic drivers of decline and recovery in an Afro-Palaearctic migratory bird population

2016 ◽  
Vol 283 (1842) ◽  
pp. 20161387 ◽  
Author(s):  
Catriona A. Morrison ◽  
Robert A. Robinson ◽  
Simon J. Butler ◽  
Jacquie A. Clark ◽  
Jennifer A. Gill
Keyword(s):  
Population Growth ◽  
Survival Rates ◽  
Bird Species ◽  
Migratory Bird ◽  
Adult Survival ◽  
High Survival ◽  
Population Declines ◽  
High Productivity ◽  
Population Growth Rates ◽  
Sub Saharan

Across Europe, rapid population declines are ongoing in many Afro-Palaearctic migratory bird species, but the development of appropriate conservation actions across such large migratory ranges is severely constrained by lack of understanding of the demographic drivers of these declines. By constructing regional integrated population models (IPMs) for one of the suite of migratory species that is declining in the southeast of Britain but increasing in the northwest, we show that, while annual population growth rates in both regions vary with adult survival, the divergent regional trajectories are primarily a consequence of differences in productivity. Between 1994 and 2012, annual survival and productivity rates ranged over similar levels in both regions, but high productivity rates were rarer in the declining southeast population and never coincided with high survival rates. By contrast, population growth in the northwest was fuelled by several years in which higher productivity coincided with high survival rates. Simulated population trajectories suggest that realistic improvements in productivity could have reversed the decline (i.e. recovery of the population index to more than or equal to 1) in the southeast. Consequently, actions to improve productivity on European breeding grounds are likely to be a more fruitful and achievable means of reversing migrant declines than actions to improve survival on breeding, passage or sub-Saharan wintering grounds.

scholarly journals Unraveling Factors Affecting Micropropagation of Four Persian Walnut Varieties

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1417
Author(s):  
Togzhan Kadylbekovna Yegizbayeva ◽  
Silvia García-García ◽  
Tatyana Viktorovna Yausheva ◽  
Markhabat Kairova ◽  
Amangeldy Kairbekovich Apushev ◽  
...  
Keyword(s):  
Culture Medium ◽  
Juglans Regia ◽  
Survival Rates ◽  
Great Influence ◽  
Holistic Approach ◽  
High Survival ◽  
Factors Affecting ◽  
Persian Walnut ◽  
In Vitro Establishment

Walnuts are considered recalcitrant to tissue culture, with a great genetic determinism on all stages of micropropagation; while other factors, also with great impact, become more complicated with the reproduction of newly realized varieties. In this research, a holistic approach aimed to determine the influence of genotype and the nutritive formulation throughout the whole cycle of micropropagation of four Persian walnut varieties (Juglans regia L.) was presented. During the in vitro establishment it was determined that besides genotype and culture medium, the effect of collection season and the likely interaction amongst factors had a great influence on the successful introduction of all four genotypes. However, all cultures were affected by a deep decay, being necessary the introduction of ethylenediamine di-2-hydroxyphenyl acetate ferric, as iron source, and Phloroglucinol in both Murashige and Skoog (1962) and the corrected Driver and Kuniyuki (1987) formulations. These modifications allowed the stabilization of cultures, maintaining thereafter a steady quality. Either proliferation, rooting and ex vitro survival of four clones were affected by the culture medium, obtaining the best results with the corrected Driver and Kuniyuki (1987) formulation. Finally, in vitro plants produced from all clones were acclimated with high survival rates (75.9–91.1% for the best culture medium), depending of clone and the culture medium used. Microsatellite analysis showed that micropropagated plants maintained the same genetic profiles of their corresponding donor trees. These results might contribute to deepening of the understanding of factors that determine the success of micropropagation of walnuts, and the extents of its influence; whereas, it sets the basis for the commercial micropropagation of all four clones.

Population Ecology of the Brook Trout, Salvelinus fontinalis, in Matamek Lake, Quebec

1970 ◽  
Vol 27 (3) ◽  
pp. 413-424 ◽  
Author(s):  
Lloyd H. Saunders ◽  
G. Power
Keyword(s):  
Brook Trout ◽  
Total Population ◽  
Survival Rates ◽  
Standing Stock ◽  
Age Groups ◽  
Population Estimates ◽  
Lake Ecosystem ◽  
High Survival ◽  
Factors Affecting ◽  
Trout Population

Population estimates of an unexploited brook trout population at Matamek Lake, Quebec, indicated that more than 86% of the total population inhabited the tributaries of the lake during the summer of 1968. As opposed to the stream habitat, the combination stream–lake ecosystem moderated the mortality rates of the intermediate age-groups and allowed survival to higher ages in the population. Estimates of standing stock and production in the lake were 3.1 and 2.2 kg/ha respectively during 1968.The population was characterized by a slower growth rate, higher age at maturity, higher survival rate in the intermediate age-groups, and longer life span when compared with an exploited population in Wisconsin. Increased numbers of trout in higher age-groups at Matamek Lake were attributed to high survival rates in the intermediate age-groups in the absence of exploitation. Low estimates of standing stock and production were attributed to environmental factors affecting growth.

scholarly journals A Teleconnection between Forced Great Plains Snow Cover and European Winter Climate

2008 ◽  
Vol 21 (11) ◽  
pp. 2466-2483 ◽  
Author(s):  
Nicholas P. Klingaman ◽  
Brian Hanson ◽  
Daniel J. Leathers
Keyword(s):  
Snow Cover ◽  
Great Plains ◽  
North American ◽  
The United States ◽  
Northern Great Plains ◽  
Late Winter ◽  
Winter Climate ◽  
Early Season ◽  
Late Season ◽  
The North

Abstract Anomalies in Siberian snow cover have been shown to affect Eurasian winter climate through the North Atlantic Oscillation (NAO). The existence of a teleconnection between North American snow cover and the NAO is far less certain, particularly for limited, regional snow cover anomalies. Using three ensembles of the Community Atmosphere Model, version 2 (CAM2), the authors examined teleconnections between persistent, forced snow cover in the northern Great Plains of the United States and western Eurasian winters. One ensemble allowed the model to freely determine global snow cover, while the other two forced a 72-cm snowpack centered over Nebraska. Of the forced ensembles, the “early-season” (“late season”) simulations initiated the snowpack on 1 November (1 January). The additional snow cover generated lower (higher) sea level pressures and geopotential heights over Iceland (the Azores) and warmer (cooler) temperatures over northern and western (eastern and southeastern) Europe, which suggests the positive NAO phase. Differences between the free-snow-cover and early-season ensembles were never significant until January, which implied either that the atmospheric response required a long lag or that the late-winter atmosphere was particularly sensitive to Great Plains snow. The authors rejected the former hypothesis and supported the latter by noting similarities between the early- and late-season ensembles in late winter for European 2-m temperatures, transatlantic circulation, and an NAO index. Therefore, a regional North American snow cover anomaly in an area of high inter- and intra-annual snow cover variability can show a stronger teleconnection to European winter climate than previously reported for broader snow cover anomalies. In particular, anomalous late-season snow in the Great Plains may shift the NAO toward the positive phase.

A GEFA Assessment of Observed Global Ocean Influence on U.S. Precipitation Variability: Attribution to Regional SST Variability Modes

2011 ◽  
Vol 24 (3) ◽  
pp. 693-707 ◽  
Author(s):  
Yafang Zhong ◽  
Zhengyu Liu ◽  
Michael Notaro
Keyword(s):  
Great Plains ◽  
Tropical Indian Ocean ◽  
Precipitation Variability ◽  
Global Ocean ◽  
Northern Great Plains ◽  
Late Winter ◽  
Unified Framework ◽  
Southern Great Plains ◽  
Sst Variability ◽  
The Impact

Abstract This paper presents a comprehensive assessment of the observed influence of the global ocean on U.S. precipitation variability using the method of Generalized Equilibrium Feedback Assessment (GEFA), which enables an unambiguous attribution of the influence from multiple ocean basins within a unified framework. The GEFA assessment based on observations for 1950–99 suggests that the tropical Pacific SST variability has the greatest consequence for U.S. precipitation, as both ENSO and meridional modes are associated with notable responses in seasonal mean precipitation. The anomalously cold tropical Indian Ocean is a good indicator for U.S. dry conditions during spring and late winter. The impact of North Pacific SST variability is detected in springtime precipitation, yet it is overshadowed by that of the tropical Indo-Pacific on seasonal-to-interannual time scales. Tropical Atlantic forcing of U.S. precipitation appears to be most effective in winter, whereas the northern Atlantic forcing is likely more important during spring and summer. Global ocean influence on U.S. precipitation is found to be most significant in winter, explaining over 20% of the precipitation variability in the Southwest and southern Great Plains throughout the cold seasons and in the northern Great Plains and northeast United States during late winter. The Southwest and southern Great Plains is likely the region that is most susceptible to oceanic influence, primarily to the forcing of the tropical Indo-Pacific. The Pacific Northwest is among the regions that may experience the least oceanic influence as far as precipitation variability is concerned.

Persistence of giants: population dynamics of the limpet Scutellastra laticostata on rocky shores in Western Australia

2020 ◽  
Vol 646 ◽  
pp. 79-92
Author(s):  
RE Scheibling ◽  
R Black
Keyword(s):  
Population Dynamics ◽  
Western Australia ◽  
Size Structure ◽  
Survival Rates ◽  
Maximum Size ◽  
High Rate ◽  
Adult Survival ◽  
Rocky Shores ◽  
Adult Size ◽  
Decadal Time Scale

Population dynamics and life history traits of the ‘giant’ limpet Scutellastra laticostata on intertidal limestone platforms at Rottnest Island, Western Australia, were recorded by interannual (January/February) monitoring of limpet density and size structure, and relocation of marked individuals, at 3 locations over periods of 13-16 yr between 1993 and 2020. Limpet densities ranged from 4 to 9 ind. m-2 on wave-swept seaward margins of platforms at 2 locations and on a rocky notch at the landward margin of the platform at a third. Juvenile recruits (25-55 mm shell length) were present each year, usually at low densities (<1 m-2), but localized pulses of recruitment occurred in some years. Annual survival rates of marked limpets varied among sites and cohorts, ranging from 0.42 yr-1 at the notch to 0.79 and 0.87 yr-1 on the platforms. A mass mortality of limpets on the platforms occurred in 2003, likely mediated by thermal stress during daytime low tides, coincident with high air temperatures and calm seas. Juveniles grew rapidly to adult size within 2 yr. Asymptotic size (L∞, von Bertalanffy growth model) ranged from 89 to 97 mm, and maximum size from 100 to 113 mm, on platforms. Growth rate and maximum size were lower on the notch. Our empirical observations and simulation models suggest that these populations are relatively stable on a decadal time scale. The frequency and magnitude of recruitment pulses and high rate of adult survival provide considerable inertia, enabling persistence of these populations in the face of sporadic climatic extremes.

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