A spatially explicit optimal foraging model of Black-legged Kittiwake behavior based on prey density, travel distances, and colony size

2007 ◽  
Vol 204 (3-4) ◽  
pp. 335-348 ◽  
Author(s):  
R. Glenn Ford ◽  
David G. Ainley ◽  
Evelyn D. Brown ◽  
Robert M. Suryan ◽  
David B. Irons
2012 ◽  
Vol 90 (2) ◽  
pp. 222-236 ◽  
Author(s):  
C.E. Rizkalla ◽  
R.K. Swihart

Measuring connectivity in fragmented landscapes remains a central problem in ecology. Connectivity metrics range from descriptors of landscape structure to direct observations of a species’ ability to move to and colonize a forest patch. We constructed individual-based spatially explicit population models for a guild of forest rodents in Indiana to test the ability of structural and actual, or behavioral, measures of connectivity to predict patch and landscape occupancy and abundance. Model accuracy was assessed using comparisons with data from trapping studies. Predicted abundances within patches correlated with empirical data for five out of six species, but predicted patterns of patch occupancy corresponded with observations for only one species. Discrepancies may be due to inaccurate parameter values or the absence from the models of ecological processes such as conspecific attraction and competition. Nonetheless, the models demonstrated the utility of patch immigration as a measure of connectivity in explaining population abundance in fragmented landscapes. We discuss potential methods of collecting these behavior-based data.


2021 ◽  
Author(s):  
Julie Serena Miller ◽  
Emma Wan ◽  
Noa Pinter-Wollman

Large body sizes have evolved structures to facilitate resource transport. Like unitary organisms, social insect colonies must transport information and resources, and colonies with more individuals may experience transport challenges similar to large-bodied organisms. In ant colonies, transport occurs in the nest, which may consist of structures that facilitate movement. We examine three attributes of nest structures that could mitigate transport challenges related to colony size: (1) subdivision: nests of species with large colonies are more subdivided to reduce viscosity of large crowds; (2) branching: nest tunnels increase branching in species with large colonies to reduce travel distances; and (3) short-cuts: nests of species with large colonies have cross-linking tunnels to connect distant parts of the nest and create alternative routes. We test these hypotheses by comparing nest structures of species with different colony sizes in phylogenetically controlled meta-analyses. Our findings support the subdivision and branching hypotheses. The nests of species with large colonies contain more, but not larger, chambers and reduce travel distances by increasing branching frequency. The similarity in how ant nests and the bodies of unitary organisms respond to increasing size suggests structural solutions that are common across levels of biological organization.


2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Edward V. Farley ◽  
Marc Trudel

A spatially explicit bioenergetics model was used to predict juvenile sockeye salmonOncorhynchus nerkagrowth rate potential (GRP) on the eastern Bering Sea shelf during years with cooler and warmer spring sea surface temperatures (SSTs). Annual averages of juvenile sockeye salmon GRP were generally lower among years with cooler SSTs and generally higher in offshore than nearshore regions of the eastern Bering Sea shelf during years with warmer SSTs. Juvenile sockeye salmon distribution was significantly (P<.05) related to GRP and their prey densities were positively related to spring SST (P<.05). Juvenile sockeye salmon GRP was more sensitive to changes in prey density and observed SSTs during years when spring SSTs were warmer (2002, 2003, and 2005). Our results suggest that the pelagic productivity on the eastern Bering Sea shelf was higher during years with warmer spring SSTs and highlight the importance of bottom-up control on the eastern Bering Sea ecosystem.


CICTP 2020 ◽  
2020 ◽  
Author(s):  
Jiewen Xiao ◽  
Ji Hu ◽  
Zhancun Yan ◽  
Gang Wang ◽  
Weixin Chen

2017 ◽  
Vol 24 (1) ◽  
pp. 71-86
Author(s):  
Amin Wibowo

Up to now, organizational buying is still interesting topic discussed. There are divergences among the findings in organizational buying researches. Different perspectives, fenomena observed, research domains and methods caused the divergences. This paper will discusse organizational buying behavior based on literature review, focused on behavior of decision making unit mainly on equipment buying. From this review literatures, it would be theoritical foundation that is valid and reliable to develop propositions in organizational buying behavior. Based on review literature refferences, variables are classified into: purchase situation, member of decision making unit perception, conflict among the members, information search, influences among members of decision making unit. Integrated approach is used to develop propositions relating to: purchasing complexity, sharing responsibility among the members, conflict in decision making unit, information search, time pressure as moderating variable between sharing responsibility and conflict in decision making unit, the influence among the members inside decision making unit and decision making outcome


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