| some analyses and recommendations on diet formulation for conservation breeding of the galapagos rice rat of isla santiago, nesoryzomys swarthi. | nesoryzomys swarthi, the most endangered of the three surviving, endemic galapagos "rice rats," was only discovered in the early 20th century and was considered extinct until its rediscovery in 1997 at a north-central coastal location on isla santiago. potential threats to the entire genus include invasive rodent species, feral cats, new diseases, and climate change. these threats have been the basis for conservation breeding recommendations (as yet unmet) by several observers during the last se ... | 2012 | 22553176 |
| prickly coexistence or blunt competition? opuntia refugia in an invaded rodent community. | endemic nesoryzomys swarthi and invasive rattus rattus exist in unlikely sympatry in galápagos as female n. swarthi suffer from competition with r. rattus. this study evaluates the role of feeding habits in facilitating their co-occurrence. spool-and-line tracking of 85 n. swarthi and 33 r. rattus was used to quantify their selected diets, foods of which were used in captive trials of 46 n. swarthi and 34 r. rattus to quantify their preferred diets. selected diets were compared between species a ... | 2009 | 18998171 |
| interference competition between introduced black rats and endemic galápagos rice rats. | replicated field experiments were used to quantify and to describe the mechanism of competition between the introduced black rat rattus rattus and the endemic santiago rice rat nesoryzomys swarthi on santiago island, galápagos islands, ecuador. the removal of r. rattus significantly slowed the rate of seasonal population decline in n. swarthi. this effect was particularly evident for female, relative to male, n. swarthi and appeared to be driven solely by enhanced immigration; no other fitness o ... | 2007 | 17918410 |
| space invaders? a search for patterns underlying the coexistence of alien black rats and galápagos rice rats. | the introduction and spread of the black rat rattus rattus is believed to have caused the worst decline of any vertebrate taxon in galápagos. however, the "extinct" santiago rice rat nesoryzomys swarthi has recently been rediscovered in sympatry with r. rattus providing the first exception to this general pattern of displacement. we carried out an exploratory investigation of this novel system with the aim of identifying patterns that may facilitate the apparent coexistence of the two species. w ... | 2006 | 16761142 |