Effects of selection harvesting on bark invertebrates and nest provisioning rate in an old forest specialist, the brown creeper (Certhia americana)

Ecoscience ◽  
2012 ◽  
Vol 19 (2) ◽  
pp. 106-112 ◽  
Author(s):  
Émilie D'Astous ◽  
Marc-André Villard
2019 ◽  
Author(s):  
Joel L Pick ◽  
Nyil Khwaja ◽  
Michael A. Spence ◽  
Malika Ihle ◽  
Shinichi Nakagawa

We often quantify a behaviour by counting the number of times it occurs within a specific, short observation period. Measuring behaviour in such a way is typically unavoidable but induces error. This error acts to systematically reduce effect sizes, including metrics of particular interest to behavioural and evolutionary ecologists such as R2, repeatability (intra-class correlation, ICC) and heritability. Through introducing a null model, the Poisson process, for modelling the frequency of behaviour, we give a mechanistic explanation of how this problem arises and demonstrate how it makes comparisons between studies and species problematic, because the magnitude of the error depends on how frequently the behaviour has been observed (e.g. as a function of the observation period) as well as how biologically variable the behaviour is. Importantly, the degree of error is predictable and so can be corrected for. Using the example of parental provisioning rate in birds, we assess the applicability of our null model for modelling the frequency of behaviour. We then review recent literature and demonstrate that the error is rarely accounted for in current analyses. We highlight the problems that arise from this and provide solutions. We further discuss the biological implications of deviations from our null model, and highlight the new avenues of research that they may provide. Adopting our recommendations into analyses of behavioural counts will improve the accuracy of estimated effect sizes and allow meaningful comparisons to be made between studies.


Polar Biology ◽  
2021 ◽  
Author(s):  
Carola Rackete ◽  
Sally Poncet ◽  
Stephanie D. Good ◽  
Richard A. Phillips ◽  
Ken Passfield ◽  
...  

AbstractThe wandering albatross, Diomedea exulans, is a globally threatened species breeding at a number of sites within the Southern Ocean. Across the South Georgia archipelago, there are differences in population trends even at closely located colonies. Between 1999 and 2018 the largest colony, at Bird Island, declined at 3.01% per annum, while in the Bay of Isles, the decline was 1.44% per annum. Using mean demographic rates from a 31-year study at Bird Island and an 11-year study of breeding success at Prion Island in the Bay of Isles in a VORTEX model, we show that differences in breeding success do not fully explain observed differences in population trends. Other potential contributing factors are differential use of foraging areas, with possible knock-on effects on adult body condition, provisioning rate and breeding success, or on bycatch rates of adults or immatures.


2002 ◽  
Author(s):  
Sallie J. Hejl ◽  
Karen R. Newlon ◽  
Jock S. Young ◽  
Mary E. McFadzen ◽  
Cameron K. Ghalambor
Keyword(s):  

2018 ◽  
Vol 285 (1892) ◽  
pp. 20182141 ◽  
Author(s):  
Stefania Casagrande ◽  
Michaela Hau

The trade-off between reproductive investment and survival is central to life-history theory, but the relative importance and the complex interactions among the physiological mechanisms mediating it are still debated. Here we experimentally tested whether baseline glucocorticoid hormones, the redox system or their interaction mediate reproductive investment–survival trade-offs in wild great tits ( Parus major ). We increased the workload of parental males by clipping three feathers on each wing, and 5 days later determined effects on baseline corticosterone concentrations (Cort), redox state (reactive oxygen metabolites, protein carbonyls, glutathione peroxidase [GPx], total non-enzymatic antioxidants), body mass, body condition, reproductive success and survival. Feather-clipping did not affect fledgling numbers, chick body condition, nest provisioning rates or survival compared with controls. However, feather-clipped males lost mass and increased both Cort and GPx concentrations. Within feather-clipped individuals, GPx increases were positively associated with reproductive investment (i.e. male nest provisioning). Furthermore, within all individuals, males that increased GPx suffered reduced survival rates. Baseline Cort increases were related to mass loss but not to redox state, nest provisioning or male survival. Our findings provide experimental evidence that changes in the redox system are associated with the trade-off between reproductive investment and survival, while baseline Cort may support this trade-off indirectly through a link with body condition. These results also emphasize that plastic changes in individuals, rather than static levels of physiological signals, may mediate life-history trade-offs.


2020 ◽  
Vol 80 ◽  
pp. 177-191
Author(s):  
Joseph R. Coelho ◽  
Jon M. Hastings ◽  
Charles W. Holliday

Factors affecting the ecology of a large population of Pacific cicada killers (Sphecius convallis) occupying a field of mine tailings in Ruby, AZ, were examined. Burrows were quite dense in certain areas around the periphery of the mine tailings, but were dispersed randomly within these areas. Approximately 1600 females (based on burrow counts) and 2500 males (based on mark-recapture) were recorded, yielding a total population estimate of 5000–6000 adults. Female wasps were able to dig much more rapidly in the mine tailings than their congeners S. speciosus in soils from PA, suggesting that the habitat suitability was a large factor in this robust population. Provisioning rate was comparatively slow, however, suggesting that cicada abundance in that year was not a contributor to the high population density. The presence of a sap-producing tree may have eased the energetic and thermoregulatory demands of the wasps. Although excavations revealed that the number of burrows and cells could easily maintain the population size, the lack of cicadas probably resulted instead in a population crash the following season.


2016 ◽  
Vol 46 (4) ◽  
pp. 499-507 ◽  
Author(s):  
Daniel M. Geleynse ◽  
Erica Nol ◽  
Dawn M. Burke ◽  
Ken A. Elliott

The Brown Creeper (Certhia americana Bonaparte, 1838) has been identified as one of the most sensitive passerines to partial forest harvest in North America. The effect of selection logging on Brown Creeper density, nest timing, nest survival, and nest and foraging site selection was examined in five silviculture treatments (intensive group selection, typical group selection, old single-tree selection, recent single-tree selection, and control forests) of Algonquin Provincial Park, Canada. As Brown Creeper nests under the bark of large, decaying trees, we hypothesized that Brown Creeper density, timing of breeding, nest survival, and nest and foraging site selection would be negatively affected by silviculture through the removal of large, decaying trees as part of providing safe conditions for loggers. We monitored 101 nests of Brown Creeper during the 2010 and 2011 breeding seasons, mapped territories to estimate density, and conducted foraging surveys. Brown Creeper density was reduced by about 42% in logged stands compared with control stands. Despite that, silviculture did not significantly alter timing of breeding or nest survival. However, the loss of large trees through partial harvesting meant that Brown Creeper nested closer to adjacent, small forested wetlands and often in balsam fir (Abies balsamea (L.) Mill.) in treated stands. In control stands, Brown Creeper nested further from forested wetlands, disproportionately in greater numbers in upland hardwoods, and preferentially in the bark of snags of yellow birch (Betula alleghaniensis Britton). The change in the species of tree used for nesting and the general forest type as a result of logging also resulted in consequences for the selection of foraging substrates. To maintain higher densities of Brown Creeper in logged stands in Algonquin Park, we recommend retaining larger diameter yellow birch, both snags and live trees, preferably within strategically located uncut reserves based on habitat supply planning, that maintains patches roughly the size of Brown Creeper territories (10 ha).


1996 ◽  
Vol 11 (3) ◽  
pp. 90-96 ◽  
Author(s):  
Loren D. Kellogg ◽  
Pete Bettinger ◽  
Richard M. Edwards

Abstract Logging planning, felling, and cable yarding costs were determined for five group-selection treatments and a clearcut in a 90 yr old Douglas-fir (Pseudotsuga menziesii) stand in western Oregon. The harvesting system included manual felling and a yarder rigged in a standing skyline configuration with a mechanical slackpulling carriage. The clearcut treatment had the lowest total harvest cost; costs of the group-selection treatments were 7.3 to 31.5% higher than the clearcut. Yarding cost associated with road and landing changes, plus the cost of equipment moving, set up, and tear down allocated over different treatment volumes removed had the biggest influence on total cost for each silvicultural treatment. West. J. Appl. For. 11(3):90-96.


2007 ◽  
Vol 83 (1) ◽  
pp. 36-40 ◽  
Author(s):  
L A Venier ◽  
J L Pearce ◽  
B A Wintle ◽  
S A Bekessy

In this paper, we provide an overview of a project that we initiated to explore the utility of spatially-explicit metapopulation models linked to dynamic landscape models as a way of incorporating biological indicators into sustainable forest management. We developed models for three indicator species as case studies; brown creeper (Certhis americana), redbacked vole (Clethrionomys gapperi) and red-backed salamander (Plethodon cinereus) in a northern Ontario landscape. Results from the project to date suggest that there are significant advantages to models that are spatially-explicit and dynamic in their treatment of both populations and landscapes. Dynamic landscape metapopulation (DLMP) models allow a manager to track population change through time in response to a changing landscape and a fluctuating environment. These DLMP models may be used to predict the impact of current and alternative forest management strategies on population sizes of a suite of species chosen to indicate the health of forest ecosystems. Key words: biological indicators, population viability analysis, population modeling, dynamic landscape modeling, sustainable forest management, brown creeper, red-backed salamander, red-backed vole


The Auk ◽  
2017 ◽  
Vol 134 (1) ◽  
pp. 229-239 ◽  
Author(s):  
Lesley P. Bulluck ◽  
Miran J. Foster ◽  
Samantha Kay ◽  
Donald E. Cox ◽  
Catherine Viverette ◽  
...  

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