scholarly journals Evidence of breeding activity of subadult Turdus thrushes in Argentina

2019 ◽  
Vol 27 (3) ◽  
pp. 149-152
Author(s):  
Exequiel Barboza ◽  
Patricia Capllonch ◽  
Fernando Diego Ortiz ◽  
Alex E. Jahn
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Bird Species ◽  
Life History Strategies ◽  
Brood Patch ◽  
Breeding Condition ◽  
Different Populations ◽  
Males And Females ◽  
Breeding Seasons ◽  
Subadult Female

AbstractLittle is known about the age at which many Neotropical bird species first attempt to breed. We evaluated the breeding condition of 515 adult and subadult males and females among four species of Turdus thrushes (T. nigriceps, T. chiguanco, T. amaurochalinus and T. rufiventris) in Tucumán, Argentina during three breeding seasons (2015 to 2018). We registered a total of 126 individuals with brood patches and cloacal protuberances, which accounted for 24.5% of thrushes in breeding condition that we sampled. Forty thrushes had a brood patch (31.7% of those in breeding condition), of which 11 were subadults (8.7%). Eighty-six thrushes (68.3%) had a swollen cloacal protuberance, 18 of which were subadults (14.3%). Only a few of the subadults in breeding condition built nests, incubated eggs or raised nestlings. Of 130 nests we found, only 3 belonged to a subadult thrush (in all cases, a subadult female with an adult social mate), one of which was successful. Further research on these patterns among various Neotropical bird species could lead to important insights into the life history strategies that characterize different populations, and how these ultimately affect their population dynamics.

The sensitivity of Australian animals to 1080 poison. I. Intraspecific variation and factors affecting acute toxicity

1981 ◽  
Vol 8 (2) ◽  
pp. 369 ◽  
Author(s):  
J. C. Mcilroy
Keyword(s):  
Acute Toxicity ◽  
Intraspecific Variation ◽  
Factors Affecting ◽  
Eastern Australia ◽  
Vertebrate Pests ◽  
Breeding Condition ◽  
Different Populations ◽  
Males And Females

The calculated sensitivity (LD50) of a species to 1080 poison (sodium fluoroacetate), used for control of vertebrate pests, is affected by the experimental procedures employed. Variation can be minimized if the most obvious sources are avoided, as described in this paper. Very young mammals and female waterfowl in breeding condition may be more sensitive to 1080 than other members of their populations. No other substantial differences in sensitivity were found between males and females, immatures and adults, or within and between different populations of six species of birds and mammals in eastern Australia.

scholarly journals Contrasting effects of climate change on seasonal survival of a hibernating mammal

2020 ◽  
Vol 117 (30) ◽  
pp. 18119-18126 ◽  
Author(s):  
Line S. Cordes ◽  
Daniel T. Blumstein ◽  
Kenneth B. Armitage ◽  
Paul J. CaraDonna ◽  
Dylan Z. Childs ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Life History ◽  
Environmental Conditions ◽  
Temporal Trends ◽  
Life History Strategies ◽  
Environmental Drivers ◽  
Age Classes ◽  
History Of ◽  
Colorado Rocky Mountains

Seasonal environmental conditions shape the behavior and life history of virtually all organisms. Climate change is modifying these seasonal environmental conditions, which threatens to disrupt population dynamics. It is conceivable that climatic changes may be beneficial in one season but result in detrimental conditions in another because life-history strategies vary between these time periods. We analyzed the temporal trends in seasonal survival of yellow-bellied marmots (Marmota flaviventer) and explored the environmental drivers using a 40-y dataset from the Colorado Rocky Mountains (USA). Trends in survival revealed divergent seasonal patterns, which were similar across age-classes. Marmot survival declined during winter but generally increased during summer. Interestingly, different environmental factors appeared to drive survival trends across age-classes. Winter survival was largely driven by conditions during the preceding summer and the effect of continued climate change was likely to be mainly negative, whereas the likely outcome of continued climate change on summer survival was generally positive. This study illustrates that seasonal demographic responses need disentangling to accurately forecast the impacts of climate change on animal population dynamics.

scholarly journals Variation in Demography and Life-History Strategies Across the Range of a Declining Mountain Bird Species

2021 ◽  
Vol 9 ◽  
Author(s):  
Arnaud G. Barras ◽  
Sébastien Blache ◽  
Michael Schaub ◽  
Raphaël Arlettaz
Keyword(s):  
Life History ◽  
Environmental Change ◽  
Life History Traits ◽  
Local Population ◽  
Bird Species ◽  
Life History Strategies ◽  
Adult Survival ◽  
Northwestern Part ◽  
European Alps ◽  
Demographic Processes

Species- and population-specific responses to their environment may depend to a large extent on the spatial variation in life-history traits and in demographic processes of local population dynamics. Yet, those parameters and their variability remain largely unknown for many cold-adapted species, which are exposed to particularly rapid rates of environmental change. Here, we compared the demographic traits and dynamics for an emblematic bird species of European mountain ecosystems, the ring ouzel (Turdus torquatus). Using integrated population models fitted in a Bayesian framework, we estimated the survival probability, productivity and immigration of two populations from the Western European Alps, in France (over 11 years) and Switzerland (over 6 years). Juvenile apparent survival was lower and immigration rate higher in the Swiss compared to the French population, with the temporal variation in population growth rate driven by different demographic processes. Yet, when compared to populations in the northwestern part of the range, in Scotland, these two Alpine populations both showed a much lower productivity and higher adult survival, indicating a slower life-history strategy. Our results suggest that demographic characteristics can substantially vary across the discontinuous range of this passerine species, essentially due to contrasted, possibly locally evolved life-history strategies. This study therefore raises the question of whether flexibility in life-history traits is widespread among boreo-alpine species and if it might provide adaptive potential for coping with current environmental change.

scholarly journals Breeding Biology of Passerines in a Subtropical Montane Forest in Northwestern Argentina

The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 321-333 ◽  
Author(s):  
Sonya K. Auer ◽  
Ronald D. Bassar ◽  
Joseph J. Fontaine ◽  
Thomas E. Martin
Keyword(s):  
Life History ◽  
Predation Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Life History Strategies ◽  
Temperate Species ◽  
Egg Mass ◽  
Breeding Ecology ◽  
Feeding Rates ◽  
Northwestern Argentina

Abstract The breeding ecology of south temperate bird species is less widely known than that of north temperate species, yet because they comprise a large portion of the world's avian diversity, knowledge of their breeding ecology can contribute to a more comprehensive understanding of the geographic diversity of avian reproductive traits and life history strategies. We provide the first detailed examination of the reproductive strategies of 18 forest passerines of subtropical, northwestern Argentina. Mean clutch sizes were smaller and egg mass was greater than for north temperate birds, but differed among species and nest types, with cavity-nesters having larger clutches than species with open-cup and enclosed nests. Across all species, the average breeding season duration was 50 days; thus, the common perception that southern species have smaller clutch sizes because of longer breeding seasons is not supported in this community. Daily nest predation rates were influenced by nest type, cavity nests suffering the least from predation, as found in north temperate systems. Only females incubated eggs in all but one species, whereas both parents fed and cared for nestlings in all species. Mean nest attentiveness was low compared to north temperate passerines. Mean hourly nestling feeding rates differed among species and were negatively related to nest predation risk. In short, coexisting species in this subtropical forest varied in their life history strategies, in part correlated with variation in nest predation risk, but also differing from north temperate species.

scholarly journals Life History Strategies of the Montane Vole, Microtus montanus

1987 ◽  
Vol 11 ◽  
pp. 75-78
Author(s):  
Frederick Jannett, Jr.
Keyword(s):  
Life History ◽  
Sympatric Species ◽  
Life History Strategies ◽  
Population Cycle ◽  
Scent Gland ◽  
Microtus Montanus ◽  
Microtine Rodents ◽  
Microtine Rodent ◽  
Different Populations ◽  
Gland Development

Emphasis in microtine rodent biology has historically been placed on population regulation and the population cycle. Until recently, little attention has been directed to behavior and sociality in microtine rodents, but work on the sociobiology of the montane vole (Jannett, 1978, 1980, 1981, 1982, 1984) is serving to integrate various aspects of the biology of this species so that its life history characteristics can be interpreted in an evolutionary framework. Work undertaken in 1986 continues previously initiated surveys of various topics, such as synchrony of population events in different populations, survivorship, scent gland development, patterns of cranial and dental variation, population trends in a sympatric species of vole (M. longicaudus), and reproduction in a primary predator, the shorttail weasel (Mustela erminea).

scholarly journals Life History Strategies of the Montane Vole, Microtus montanus

1986 ◽  
Vol 10 ◽  
pp. 95-98
Author(s):  
Frederick Jannett, Jr.
Keyword(s):  
Life History ◽  
Sympatric Species ◽  
Life History Strategies ◽  
Population Cycle ◽  
Scent Gland ◽  
Microtus Montanus ◽  
Microtine Rodents ◽  
Microtine Rodent ◽  
Different Populations ◽  
Gland Development

Emphasis in microtine rodent biology has historically been placed on population regulation and the population cycle. Until recently, little attention has been directed to behavior and sociality in microtine rodents, but work on the sociobiology of the montane vole (Jannett, 1978, 1980, 1981, 1982, 1984) is serving to integrate various aspects of the biology of this species so that its life history characteristics can be interpreted in an evolutionary framework. Work undertaken in 1986 continues previously initiated surveys of various topics, such as synchrony of population events in different populations, survivorship, scent gland development, patterns of cranial and dental variation, population trends in a sympatric species of vole (M. longicaudus), and reproduction in a primary predator, the shorttail weasel (Mustela erminea).

scholarly journals Life History Strategies of the Montane Vole, Microtus montanus

1988 ◽  
Vol 12 ◽  
pp. 99-101
Author(s):  
Frederick Jannett, Jr.
Keyword(s):  
Life History ◽  
Life History Strategies ◽  
Population Cycle ◽  
Scent Gland ◽  
Development Patterns ◽  
Microtus Montanus ◽  
Microtine Rodents ◽  
Microtine Rodent ◽  
Different Populations ◽  
Gland Development

Emphasis in microtine rodent biology has historically been placed on population regulation and the population cycle. Until recently, little attention has been directed to behavior and sociality in microtine rodents, but work on the sociobiology of the montane vole (Jannett, 1978, 1980, 1981, 1982, 1984a) is serving to integrate various aspects of the biology of this species so that its life history characteristics can be interpreted in an evolutionary framework. Work undertaken in 1986 continues previously initiated surveys of various topics, such as synchrony of population events in different populations, survivorship, scent gland development, patterns of cranial and dental variation, population trends in a synpatric species of vole (M. logicaudus), and reproduction in a primary predator, the shorttail weasel (Mustela erminea).

scholarly journals Life History Strategies of the Montane Vole, Microtus montanus

1982 ◽  
Vol 6 ◽  
pp. 52-53
Author(s):  
Frederick Jannett, Jr.
Keyword(s):  
Life History ◽  
Sympatric Species ◽  
Life History Strategies ◽  
Population Cycle ◽  
Scent Gland ◽  
Microtus Montanus ◽  
Microtine Rodents ◽  
Demographic Correlates ◽  
Microtine Rodent ◽  
Different Populations

Emphasis in microtine rodent biology has historically been placed on population regulation and the population cycle. Until recently, little attention has been directed to behavior and sociality in microtine rodents, but work on the sociobiology of the montane vale (Jannett, 1978, 1980, 1981, 1982) is serving to integrate various aspects of the biology of this species so that its life history characteristics can be interpreted in an evolutionary framework. Work undertaken in 1982 continues previously initiated surveys of various topics, such as synchrony of population events in different populations, survivorship, scent gland development, patterns of cranial and dental variation, population trends in a sympatric species of vole (M. longicaudus), and reproduction in a primary predator, the shorttail weasel (Mustela erminea). It will also serve in preparation for more detailed studies of the social system and its demographic correlates to begin in 1983.

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