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Life history theory predicts that individuals should maximize their fitness by balancing current investment in offspring versus future prospects for reproduction. Faced with reduction of their current clutch, birds should desert if the prospective opportunity would increase inclusive fitness more than continued investment in the reduced clutch. I studied nest desertion in response to clutch reduction by house sparrows (Passer domesticus) to determine if continuing investment in a reduced clutch differs based on proportion of original clutch remaining, stage in incubation, and ordinal date. Nests were reduced to two eggs early or late in incubation over two complete breeding seasons. Of 150 nests manipulated, 36 were deserted. Nests were more likely to be deserted when reduction occurred earlier in incubation, earlier in the season, and with a smaller proportion of original clutch remaining. This suggests that both time and brood size are used to assess the tradeoffs between current and future investment. However, near the end of the breeding season, the proportion of original clutch remaining and stage in incubation were less important, and low desertion was likely associated with a lack of re-nesting opportunities in the current season. Therefore, whether to desert or continue investing in a reduced clutch is a function of offspring reproductive value (RV) when there is opportunity for re-nesting in the same season. However, near the end of the season the decision is based on the residual reproductive value (RRV) of parents.

High-precision land-cover-land-use GIS mapping was performed in four major townships in Maine's Aroostook River Valley, using on-screen digitization and direct interpretation of very high spatial resolution satellite multispectral imagery (15-60 cm) and high spatial resolution LiDAR data (2 m) and the field mapping method. The project not only provides the first-ever high-precision land-use maps for northern Maine, but it also yields accurate hectarage estimates of different land-use types, in particular grassland, defined as fallow land, pasture, and hay field. This enables analysis of potential land availability and suitability for grass biomass production and other sustainable land uses. The results show that the total area of fallow land in the four towns is 7594 hectares, which accounts for 25% of total open land, and that fallow plots equal to or over four hectares in size total 4870, or 16% of open land. Union overlay analysis, using the Natural Resources Conservation Service (NRCS) soil data, indicates that only a very small percentage of grassland (4.9%) is on "poorly-drained" or "very-poorly-drained" soils, and that most grassland (85%) falls into the "farmland of state importance" or "prime farmland" categories, as determined by NRCS. It is concluded that Maine's Aroostook River Valley has an ample base of suitable, underutilized land for producing grass biomass. OPEN ACCESSLand 2015, 4 232