@article {41666, title = {Ranking the hazard level of wildlife species to aviation}, journal = {Wildlife Society Bulletin}, volume = {28}, year = {2000}, month = {2000}, pages = {372}, author = {Dolbeer, R. A. and Wright, S. E. and Cleary, E. C.} } @article {41643, title = {The impacts of non-native species on UK biodiversity and the effectiveness of control}, journal = {Journal of Applied Ecology}, volume = {37}, year = {2000}, pages = {845{\textendash}864}, author = {Manchester, Sarah J and Bullock, James M} } @article {41641, title = {Stimulus enhancement in greylag geese: socially mediated learning of an operant task}, journal = {Animal Behaviour}, volume = {59}, year = {2000}, pages = {1119{\textendash}1125}, abstract = {

We recently observed the spreading of a novel tradition in a flock of semiferal greylag geese, Anser anser:
an increasing number of individuals began to bite and chew the stems of butterbur, Petasites hybridus.
Because this behaviour spread particularly fast within families, social learning seemed to be involved. We
therefore designed an experiment with hand-reared goslings, which were socially imprinted on humans,
to investigate whether and how the observation of an experienced tutor affects the acquisition of a novel
skill. Goslings had to open the gliding lid of a box to get at a food reward. To each of seven hand-reared
observers a human tutor demonstrated where and how to open the lid, whereas seven controls remained
untutored. All observers learned to perform the task but only one of the controls succeeded. The observers
explored more often at the position shown by the tutor than elsewhere and seemingly learned by trial
and error. In contrast, control birds explored primarily at positions that did not allow them to open the
box. These results indicate that in greylag goslings the observation of an experienced model facilitates the
learning of an operant task. We conclude that stimulus enhancement followed by operant conditioning
were the mechanisms involved, which may have accounted for the fast spread of the stem-chewing
tradition between family members.

}, doi = {10.1006/anbe.2000.1424}, author = {Fritz, Johannes and Bisenberger, Agnes and Kotrschal, Kurt} } @book {41632, title = {Managing Canada geese in urban environments}, year = {2000}, publisher = {Cornell Cooperative Extension}, organization = {Cornell Cooperative Extension}, author = {Smith, Arthur E and Craven, Scott R and Curtis, Paul D} } @article {41616, title = {Do moulting Greylag Geese Anser anser forage in proximity to water in response to food availability and/or quality?}, year = {2000}, abstract = {

Flightless moulting Greylag Geese on the Danish island of Saltholm fed on Puccinellia maritima almost exclusively within 150 m of the coastline, despite abundant equivalent food further away. This distribution pattern could theoretically be explained by two alternative (but not necessarily mutually exclusive) explanations: predation risk (since birds take to open water when disturbed) or variation in food quantity/quality. Above ground green parts of this plant showed consistently higher protein and lower fibre content inland than on the coast, hence differences in food quality could not account for the difference in foraging distribution. However, in grazed plots, shoot density was greater at the coast than inland, resulting in an increase of 1.2\–2.8 times the available green above-ground biomass. Hence, the greater abundance of Puccinellia at the coast may contribute to the explanation. However, within exclosures at the coast, Puccinellia shoot density was no different to inland areas, suggesting that some function of goose grazing at the coast was involved in enhancing biomass there. It therefore seems likely that the greater food biomass at the coast is a consequence of geese feeding to within 150 m of the coast, though not necessarily the cause. The fact that the Greylag Geese fed throughout the island whilst able to fly but fed exclusively on the coast during flightlessness suggests that a predator escape mechanism could be the most important factor constraining the feeding distribution of moulting geese.

}, keywords = {Anser, Puccinellia}, doi = {10.1080/00063650009461186}, url = {http://www.tandfonline.com/doi/abs/10.1080/00063650009461186}, author = {Fox, A.D. and Kahlert, J} } @article {Therkildsen2000, title = {Energetics of feeding on winter wheat versus pasture grasses: a window of opportunity for winter range expansion in the pink-footed goose Anser brachyrhynchus}, journal = {Wildlife Biology}, volume = {2}, year = {2000}, month = {06/2000}, pages = {65{\textendash}74}, abstract = {

Traditionally, pink-footed geese Anser brachyrhynchus wintering in Denmark, the Netherlands and Belgium have used the Danish sites only during mild winters, rapidly moving southwards in case of cold spells. Since the 1980s, an increasing number of geese have remained on the Danish wintering grounds despite cold spells, foraging on pastures and winter wheat Triticum aestivum fields. We compare the daily time and energy budgets and the food quality in the two habitats during winter. Winter wheat fields were increasingly used by the geese as temperatures dropped. At temperatures around 0{\textcelsius}, the geese foraged in both habitats, spending on average 83.8\% and 74.9\% of the daytime foraging in pastures and winter wheat, respectively. The estimated daily energy expenditure was slightly higher on pastures than on winter wheat fields (1,076 vs 1,057 kJ). The estimated daily food intake determined using the \&$\#$39;marker substance\&$\#$39; method was 148 and 157 g ash free dry weight (AFDW) in geese feeding on pastures and winter wheat fields, respectively, equivalent to a daily net energy intake of 1,109 kJ and 1,145 kJ. Daily food intake, estimated on the basis of oesophagus contents of collected birds, was 170 g AFDW in pasture feeding geese and varied within 159-229 g AFDW in winter wheat feeding geese. In the mild winter, the protein content in winter wheat and Poa did not differ, whereas in the severe winter the protein content remained high in winter wheat but decreased in Poa. During the winters of 1994-1996, the abdominal profile index, API, in individually neck-banded geese observed repeatedly, only changed significantly during late January 1996. Neither during cold spells was there any change in API. Since the 1980s, the area covered by winter wheat has increased markedly in Denmark. Because winter wheat represents a reliable and profitable food source even in severe winters, the recent change in agricultural practice has enhanced the development of a new wintering strategy of pink-footed geese, allowing a northward expansion of their winter range. Potentially, this will increase the crop damage conflict and may lead to further population growth.

}, keywords = {8410 r{\o} nde, body mass, denmark - e-mail, department of coastal zone, dk, dk-, dmu, ecology, feeding ecology, grenaavej 12, habitat selection, institute, jesper madsen, jm, kal{\o}, national environmental research, ole r, therkildsen, wintering ecology}, url = {http://www.wildlifebiology.com/Downloads/Article/274/en/oldpath.pdf}, author = {Therkildsen, OR and Madsen, Jesper} } @article {Taylor2010, title = {Do moulting Greylag Geese Anser anser forage in proximity to water in response to food availability and/or quality?}, journal = {Bird Study}, volume = {47}, number = {3}, year = {2000}, pages = {266{\textendash}274}, isbn = {0006365000}, issn = {0006-3657}, doi = {10.1080/00063650009461186}, url = {http://www.tandfonline.com/doi/abs/10.1080/00063650009461186}, author = {Fox, A.D. and Kahlert, J} }