scholarly journals Pairing functional connectivity with population dynamics to prioritize corridors for Southern California spotted owls

2021 ◽  
Vol 27 (5) ◽  
pp. 844-856
Author(s):  
Erin Conlisk ◽  
Emily Haeuser ◽  
Alan Flint ◽  
Rebecca L. Lewison ◽  
Megan K. Jennings
Keyword(s):  
Population Dynamics ◽  
Functional Connectivity ◽  
Southern California ◽  
Spotted Owls

scholarly journals Sixty-five years of northern anchovy population studies in the southern California Current: a review and suggestion for sensible management

2020 ◽  
Vol 77 (2) ◽  
pp. 486-499 ◽  
Author(s):  
William J Sydeman ◽  
Simon Dedman ◽  
Marisol García-Reyes ◽  
Sarah Ann Thompson ◽  
Julie A Thayer ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Southern California ◽  
Stock Assessment ◽  
California Current ◽  
Ecosystem Functions ◽  
Abundance Estimate ◽  
Harvest Control Rule ◽  
Northern Anchovy ◽  
Upwelling Intensity ◽  
Recovery Dynamics

Abstract The central stock of northern anchovy (CSNA; Engraulis mordax), the most abundant small pelagic fish in the southern California Current, is key to ecosystem functions. We review drivers of its population dynamics in relation to management. Springtime upwelling intensity lagged by 2 years co-varied positively with CSNA biomass, as did the abundance of Pacific sardine (Sardinops sagax; weakly negative). CSNA population dynamics indicate the need for a multi-species stock assessment, but given serious challenges with modelling population collapse and recovery dynamics, and its moderate fisheries, we suggest that sensible management could be a simple 2-tier harvest control rule designed to emphasize the key trophic role of CSNA in the ecosystem while maintaining moderate socio-economic services. We recommend a monitoring fishery of no more than 5 KMT year−1 split between central and southern California when the stock falls below the long-term median abundance estimate of 380 KMT across the California portion of its range, and a catch limit of 25 KMT year−1 when the stock is above this reference point. This rule would be precautionary, serving to maintain the most important small pelagic forage in the ecosystem, various fisheries interests, and information streams when the population is in a collapsed state.

scholarly journals Larval Population Dynamics of Culicoides variipennis (Diptera: Ceratopogonidae) in Southern California

1987 ◽  
Vol 24 (5) ◽  
pp. 566-574 ◽  
Author(s):  
Bradley A. Mullens ◽  
Keh-Shin Lip
Keyword(s):  
Population Dynamics ◽  
Southern California ◽  
Larval Population ◽  
Culicoides Variipennis

scholarly journals Invader removal triggers competitive release in a threatened avian predator

2021 ◽  
Vol 118 (31) ◽  
pp. e2102859118
Author(s):  
J. David Wiens ◽  
Katie M. Dugger ◽  
J. Mark Higley ◽  
Damon B. Lesmeister ◽  
Alan B. Franklin ◽  
...  
Keyword(s):  
Invasive Species ◽  
Population Dynamics ◽  
Large Scale ◽  
Trophic Levels ◽  
Spotted Owl ◽  
Avian Predator ◽  
Competitive Release ◽  
Spotted Owls ◽  
Barred Owls ◽  
Positive Effect

Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before–after control–impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl (Strix occidentalis caurina). Removal of barred owls had a strong, positive effect on survival of sympatric spotted owls and a weaker but positive effect on spotted owl dispersal and recruitment. After removals, the estimated mean annual rate of population change for spotted owls stabilized in areas with removals (0.2% decline per year), but continued to decline sharply in areas without removals (12.1% decline per year). The results demonstrated that the most substantial changes in population dynamics of northern spotted owls over the past two decades were associated with the invasion, population expansion, and subsequent removal of barred owls. Our study provides experimental evidence of the demographic consequences of competitive release, where a threatened avian predator was freed from restrictions imposed on its population dynamics with the removal of a competitively dominant invasive species.

Investigating the population dynamics of California spotted owls without marked individuals

2010 ◽  
Vol 152 (S2) ◽  
pp. 597-604 ◽  
Author(s):  
D. I. MacKenzie ◽  
M. E. Seamans ◽  
R. J. Gutiérrez ◽  
J. D. Nichols
Keyword(s):  
Population Dynamics ◽  
Spotted Owls

Influence of fire and salvage logging on site occupancy of spotted owls in the San Bernardino and San Jacinto Mountains of Southern California

2013 ◽  
Vol 77 (7) ◽  
pp. 1327-1341 ◽  
Author(s):  
Derek E. Lee ◽  
Monica L. Bond ◽  
Mark I. Borchert ◽  
Richard Tanner
Keyword(s):  
Southern California ◽  
Site Occupancy ◽  
Salvage Logging ◽  
San Bernardino ◽  
Spotted Owls
Sign in / Sign up

Export Citation Format

Share Document