Estimating Population Parameters of Pterostichus cupreus and P. melanarius (Carabidae) in Arable Fields by Means of Capture-Recapture

Oikos ◽  
1977 ◽  
Vol 29 (3) ◽  
pp. 407 ◽  
Author(s):  
D. Ericson
2017 ◽  
Vol 67 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Rodica Plăiaşu ◽  
Arpat Ozgul ◽  
Benedikt R. Schmidt ◽  
Raluca I. Băncilă

Reliable estimates of population parameters are lacking for most cave-dwelling species. This lack of knowledge may hinder the appropriate management of caves and populations of cave-dwelling species. Using monthly capture-recapture data and Cormack-Jolly-Seber models, we (i) estimated the apparent survival of individuals in two cave populations of the harvestman Paranemastoma sillii sillii (Herman, 1871) from the Mehedinti Mountains in south-western Romania; (ii) investigated temporal variation in apparent survival; (iii) tested if surface weather conditions affect apparent survival of cave-dwelling harvestmen through their influence upon cave environmental conditions and (iv) tested for sex differences in apparent survival. Our results show that the apparent monthly survival estimates were high for both studied cave populations and there was a significant sex effect on survival. Males had lower survival than females, and the survival difference between caves was larger in males than in females. Temporal (i.e., monthly) variation in apparent survival was low and the weather conditions at the surface had little influence on apparent survival as the environment inside the caves is well buffered against weather fluctuations outside the caves. Our results indicate that caves stabilize survival of facultative cave-dwelling species and may serve as microrefugia for epigean species. We suggest that caves should be considered for conservation because they may serve as a refuge for some epigean species during harsh weather conditions.


1976 ◽  
Vol 54 (6) ◽  
pp. 1019-1024 ◽  
Author(s):  
Ray Hilborn ◽  
James A. Redfield ◽  
Charles J. Krebs

Some studies of populations in small rodents rely on enumeration of individuals to provide an estimate of population size. A computer simulation of the capture–recapture process was used to examine the influence of five population parameters on the reliability of enumeration. Enumeration is shown to be insensitive to population size, survival between sampling intervals, and individual variation in the probability of capture. Enumeration is sensitive to the probability of capture; if the probability of capture for the average individual falls below 0.5, the enumeration technique provides a poor estimate of population size. Enumeration is also extremely sensitive to reduced probabilities of capture for unmarked animals. Data from capture–recapture studies of five species of Microtus were used in the computer simulation, and it was concluded for these five species that enumerated populations are at least 10–20% smaller than the actual populations.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Varun R. Goswami ◽  
Mahendra K. Yadava ◽  
Divya Vasudev ◽  
Parvathi K. Prasad ◽  
Pragyan Sharma ◽  
...  

An amendment to this paper has been published and can be accessed via a link at the top of the paper.


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