Why counting population numbers alone is not informing of population health: this population cannot sustain itself numbers are increasing due to immigration. Invertebrate biomass: yellow robins sit and wait for prey on the ground and pounce from above, used 10 pitfall traps per territory and 6 territories per fragment to assess surface-dwelling invertebrates. Sampled three times between october 6 and november 24. Incubation feeding: while the female incubates the eggs, the male brings food to her. Measure limiting factors: food: the food supply is lower in smaller fragments than large fragments, *appears* to have effects on reproductive success but correlation causation. Very possible, but would require experimentation: ultimate conclusion from this study and preceding literature: food shortage in small fragments may be a common problem faced by songbirds in fragmented landscapes. Measure limiting factors: predators: different approaches to indicate nest predator threat, measure the predators directly, density of predators, types of predators.