Effects of two grasshopper control insecticides on food resources and reproductive success of two species of grassland songbirds

2000 ◽  
Vol 19 (12) ◽  
pp. 2987-2996 ◽  
Author(s):  
Pamela A. Martin ◽  
Dan L. Johnson ◽  
Douglas J. Forsyth ◽  
Bernard D. Hill
Keyword(s):  
Reproductive Success ◽  
Food Resources ◽  
Grassland Songbirds

scholarly journals Pulsed food resources, but not forest cover, determine lifetime reproductive success in a forest-dwelling rodent

2017 ◽  
Vol 86 (5) ◽  
pp. 1235-1245 ◽  
Author(s):  
Katrine S. Hoset ◽  
Alexandre Villers ◽  
Ralf Wistbacka ◽  
Vesa Selonen
Keyword(s):  
Reproductive Success ◽  
Forest Cover ◽  
Food Resources ◽  
Lifetime Reproductive Success

scholarly journals Reproductive success of “herbivorous” zooplankton fed algal and nonalgal food resources

1996 ◽  
Vol 41 (6) ◽  
pp. 1295-1305 ◽  
Author(s):  
Robert W. Sanders ◽  
Craig E. Williamson ◽  
Paul L. Stutzman ◽  
Robert E. Moeller ◽  
Clyde E. Goulden ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Food Resources ◽  
Herbivorous Zooplankton

scholarly journals Reproductive Rates in Lesser Scaup (Aythya affinis) in Southwestern Manitoba: Another Look at the Data

2016 ◽  
Vol 130 (2) ◽  
pp. 110 ◽  
Author(s):  
Gord Hammell
Keyword(s):  
Reproductive Success ◽  
Population Decline ◽  
Food Resources ◽  
Egg Laying ◽  
Aythya Affinis ◽  
The Past ◽  
Age Class ◽  
Lesser Scaup ◽  
Continental Population ◽  
Reproductive Rates

Surveys indicate that Lesser Scaup (Aythya affinis) populations declined during the early 1980s and have since remained below conservation goals. Reasons suggested for the decline include chemical contamination, climate change, and reduced food resources. According to the latter theory, reproductive success of Lesser Scaup has declined because females now arrive on the breeding grounds with fewer nutrient reserves than in the past and this diminished body condition is the result of reduced food resources available at wintering and/or migration areas. To determine whether reproductive success has declined over time, I examined selected Lesser Scaup reproductive rates from 2008 to 2014 in southwestern Manitoba and compared them with those recorded before the continental population decline. Estimated productivity (age class IIa broods/pair), hatching date, Ia and IIa brood size, duckling survival rate (first sighting to age class IIa), and proportion of age class IIa broods with females in attendance were unchanged from values recorded in 1970–1972. Thus, if females are arriving on southern breeding areas with reduced body reserves, they may be recovering these losses before nesting, enabling them to attain reproductive rates similar to those in the past. In addition, these results are consistent with the hypothesis that reduced food resources at non-breeding areas could affect recruitment of southern prairie-parkland breeders to a lesser extent than northern breeders because of the longer time between arrival and egg-laying in the south.

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