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Atlas of wintering north american birds: An analysis of christmas bird count data
TREE vol. 4, no. 8, August
7989
Ruttner does an excellent job of reviewing the available information on the morphology, behavior and ecology of the species and geographic variants. What is most striking about his treatment is the poor state of knowledge on the nonEuropean bees. In particular, there is little or no information concerning the ecological and behavioral differentiation of the African races of A. mellifera. This will be fertile ground for future biogeographic studies.
On the whole, this is a good book which should be of interest to bee biologists and to biogeographers. The reader should keep in mind that the species-level taxonomy is open to reinterpretation, but this does not diminish the value of the biogeographic information. Detailed studies, for which this book is a quite useful background, of widely distributed ‘species’ such as those found in Apis will tell us much about the evolution of variation.
Michael D. Breed Deptof Environmental, Population, andOrganismic Biology,TheUniversityof Colorado, Boulder, CO80309-0334, USA References 1 Maa, T.C. (1953) Treubia 21,525-640 2 Tingek, S., Rinderer, T.E., Koeniger, N. and Koeniger, G. (1988) Apidologie 19, 97-l 02 3 Smith, D.R., Taylor, O.R. and Brown, W.M. (1989) /Vature339,213-215
ComputingChristmasCounts Atlas of Wintering North American Birds: An Analysis of ChristmasBird Count Data
by Terry Root, The University of Chicago Press, 7988. f47.95/$60.00 hbk, f27.95G35.00 pbk (xxiv + 372pages) ISBN 0 226 72540 5 There has been a rash of atlases in recent years, depicting the ranges of birds in different parts of the world, mainly Europe and some North American States. This volume is a departure in a number of respects. First, it is devoted to winter distributions - which only a few atlases it have attempted; secondly, attempts to show these distributions in a quantitative way. Since the beginning of the century, bird-watchers have been making Christmas Bird Counts. Over the years, ‘rules’ for these counts developed, and they have changed little with time. The results are open to a lot of statistical noise, but so many counts are made that, for the commoner species at least, a mass of fairly reliable data has been banked, usually translated into ‘birds per hour’. Although these data have been laboriously published each year, rather little has been done with them because they are so extensive and difficult to analyse. Arlas of Wintering North American Birds is truly a child of the computer: it could not have been done without one. The results cover the ten-year period 1962-1971, for which there are 1282 observation sites and just over 600 bird species, all of which have been computerized and analysed. Rare, irruptive, local or nomadic species have not been easy to analyse and are mostly not mapped or given a special map in Appendix B. The computer programmes used have in some cases led to small errors (mostly of a rounding nature), such
as showing small numbers of birds occurring beyond the actual limit of their range. The main part of the text relates to the 250 species that it was thought could be analysed with the greatest confidence. Each of these gets a page to itself. This page is about half text, explaining habitat, range and species’ limits. The other half is the two maps for each species. One of these is essentially a contour map, showing the winter distribution in terms of differences in abundance. I found these a little difficult to read; the edge of the range is shown, together with contours showing 20%, 40%, 60% and 80% of the maximum abundance. Each species has a different maximum abundance so these contours must be read in relation to this figure. The second map is a three-dimensional one, showing the results in a form that is slightly easier to visualize. There is also a useful series
of transparent overlays showing, amongst other things, rainfall, humidity, winter temperature, vegetation and altitude. The book’s quantitative basis will make it especially valuable as a reference point in the future when looking for changes in status. With this in mind, it is perhaps unfortunate that more of the older data could not have been analysed, for these must show that some interesting changes have already taken place. All in all, this is a useful reference work. I have one slight niggle, which concerns its shape: the book is 21.5 cm high by 28 cm wide and, with its soft cover, will not fit easily onto many bookshelves.
C.M. Perrins Dept of Zoology, Edward Grey Institute of Field Ornithology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
253
7989
Ruttner does an excellent job of reviewing the available information on the morphology, behavior and ecology of the species and geographic variants. What is most striking about his treatment is the poor state of knowledge on the nonEuropean bees. In particular, there is little or no information concerning the ecological and behavioral differentiation of the African races of A. mellifera. This will be fertile ground for future biogeographic studies.
On the whole, this is a good book which should be of interest to bee biologists and to biogeographers. The reader should keep in mind that the species-level taxonomy is open to reinterpretation, but this does not diminish the value of the biogeographic information. Detailed studies, for which this book is a quite useful background, of widely distributed ‘species’ such as those found in Apis will tell us much about the evolution of variation.
Michael D. Breed Deptof Environmental, Population, andOrganismic Biology,TheUniversityof Colorado, Boulder, CO80309-0334, USA References 1 Maa, T.C. (1953) Treubia 21,525-640 2 Tingek, S., Rinderer, T.E., Koeniger, N. and Koeniger, G. (1988) Apidologie 19, 97-l 02 3 Smith, D.R., Taylor, O.R. and Brown, W.M. (1989) /Vature339,213-215
ComputingChristmasCounts Atlas of Wintering North American Birds: An Analysis of ChristmasBird Count Data
by Terry Root, The University of Chicago Press, 7988. f47.95/$60.00 hbk, f27.95G35.00 pbk (xxiv + 372pages) ISBN 0 226 72540 5 There has been a rash of atlases in recent years, depicting the ranges of birds in different parts of the world, mainly Europe and some North American States. This volume is a departure in a number of respects. First, it is devoted to winter distributions - which only a few atlases it have attempted; secondly, attempts to show these distributions in a quantitative way. Since the beginning of the century, bird-watchers have been making Christmas Bird Counts. Over the years, ‘rules’ for these counts developed, and they have changed little with time. The results are open to a lot of statistical noise, but so many counts are made that, for the commoner species at least, a mass of fairly reliable data has been banked, usually translated into ‘birds per hour’. Although these data have been laboriously published each year, rather little has been done with them because they are so extensive and difficult to analyse. Arlas of Wintering North American Birds is truly a child of the computer: it could not have been done without one. The results cover the ten-year period 1962-1971, for which there are 1282 observation sites and just over 600 bird species, all of which have been computerized and analysed. Rare, irruptive, local or nomadic species have not been easy to analyse and are mostly not mapped or given a special map in Appendix B. The computer programmes used have in some cases led to small errors (mostly of a rounding nature), such
as showing small numbers of birds occurring beyond the actual limit of their range. The main part of the text relates to the 250 species that it was thought could be analysed with the greatest confidence. Each of these gets a page to itself. This page is about half text, explaining habitat, range and species’ limits. The other half is the two maps for each species. One of these is essentially a contour map, showing the winter distribution in terms of differences in abundance. I found these a little difficult to read; the edge of the range is shown, together with contours showing 20%, 40%, 60% and 80% of the maximum abundance. Each species has a different maximum abundance so these contours must be read in relation to this figure. The second map is a three-dimensional one, showing the results in a form that is slightly easier to visualize. There is also a useful series
of transparent overlays showing, amongst other things, rainfall, humidity, winter temperature, vegetation and altitude. The book’s quantitative basis will make it especially valuable as a reference point in the future when looking for changes in status. With this in mind, it is perhaps unfortunate that more of the older data could not have been analysed, for these must show that some interesting changes have already taken place. All in all, this is a useful reference work. I have one slight niggle, which concerns its shape: the book is 21.5 cm high by 28 cm wide and, with its soft cover, will not fit easily onto many bookshelves.
C.M. Perrins Dept of Zoology, Edward Grey Institute of Field Ornithology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
253