Red Winged Blackbird. Photo by Connor Charchuk
Dark Eyed Junco. Photo by Scott Martin
Canyon Towee. Courtesy/Mike’s Birds
By ROBERT DRYJA
Los Alamos
Bird populations are reported as decreasing when considered on a continental or world wide scale. However this is something like the statistical joke about what average means.
You feel fine on the average if your foot is in a bucket of ice water and your hand is on a stove. There actually is considerable variation when group counts for specific bird species and their geographic location are considered. The challenge is in how to define the characteristics of a large scale pattern when there is much variation on a smaller scale.
The following charts show group counts for three different species of birds seen in Los Alamos County and New Mexico. Group counts are based on the average number of birds seen repeatedly together in a group throughout a year. The trend over several years can vary depending upon the species considered. There are upward and downward trends or remaining relatively constant.
Chart A shows that the average group size has increased over the past eight years has Red Winged Blackbirds. None were seen in 2015/16 but increased to groups of 30 to 50 in recent years. The group size at the state level has remained approximately the same in contrast.
Chart B shows a general downtrend for Dark Eyed Juncos. The group counts have decreased from an early peak in 2016/17of about 12 in a group to become similar to the state counts. The state counts have remained approximately at 4 to 6 birds in a group.
Chart C shows that their average group size for Canyon Towees has remained approximately the same for both the county and the state. There has not been a clear upward or downward trend. The annual average group counts have been in the range of 1 to 2 birds in a group.
Long term changes in seasonal temperature and moisture for an area may encourage or discourage bird species to live there. Red Winged Blackbirds may be finding more favorable conditions if the seasonal temperature is increasing in the mountains around Los Alamos.
Conditions in contrast may have been highly favorable for Dark Eyed Juncos in prior years. Conditions now may becoming more like the state as a whole and so the Los Alamos population also is becoming similar to the state. Canyon Towees may be highly adaptable species for a range of conditions. There is no clear trend for them as a result.
