House Sparrows-a Social Species
- I continue to have a smaller group of this species visiting my yard. (However, they continue to avoid the oil sunflower feeder with the 'halo'.) Typically, these arrive suddenly as a group to drink from my heated water source plus to snack very briefly at my raw suet feeders. They appear and depart quickly and sporadically from a neighbouring yard where they are being fed their preferred millet and whole seed mix. House Sparrow arrivals here are apparently coincidental with the arrival of another species particularly one of the other regulars- Red-breasted Nuthatches, Black-capped Chickadees and Downy Woodpeckers.
My sense is that the movement and vocalizations of these birds are in part a 'trigger' which quickly translates into often a displacement of those species as the HOSP fly as a group directly to the water source or suet. After a few minutes perhaps because of the apparently unattractive nature of my food sources, these depart 'en mass' shortly. At this point, the displaced birds typically return to have access again. If I am in the yard the wary HOSP do not fly in and the regulars continue to forage at the feeders or arrive. Sometimes, I think the birds know that if I am present the HOSP's will not.
These typical HOSP social behaviours -moving as a group, has its costs and benefits. In winter, House Sparrows spent a great deal of energy moving back and forth particularly if there is much disturbance at the location..They are typically very nervous reacting to any nearby sounds or movement. Travelling as a group though obviously has benefits as for example predators may be confused by numbers and being less able to single out a victim.However, in addition to the higher energy costs (Native sparrows have more of a tendency to often freeze at the arrival of a predator and utilise their cryptic markings as camouflage rather than fly and draw attention to themselves.) this strategy may have costs for the birds that were unable to quickly locate a food source while the others who may have obtained some food can munch away in cover while the others have nothing. These less fortunate birds typically remain with the group awaiting another move to the food source rather than risk returning alone.
In other words, if the food source is: 1) not readily/quickly available to all. 2) is not relatively free from disturbance, perhaps survival issues may beset the group..Eventually, if enough individuals will not thrive perhaps the group viability will suffer at some point. Certainly,within any specific group of any species there will losers and winners as the environment and chance always sorts out survival. With a social species the basic unit is more the group and although there are apparently acceptable losses there perhaps is a tipping point.The group requires the survival of a sufficient core numbers to sustain itself. This may in part explain why this species may exist/thrive in certain locations while curiously being absent in others.
These of course are my theories based upon my limited observations and may not be scientifically valid or useful. Observing bird behaviour is part of what I enjoy in addition to learning more about the challenges of basic identification.Attempting to draw conclusions based upon a perhaps smaller sample while risky is at least a starting point and can be fun.
On another note, I observed several White-winged Crossbills nearby in some mature spruce trees. To hear the males uttering their typical courting trills in this weather is special. I have noted this song previously during the last several weeks when I have encountered them mostly at Douglas Park. WWCR apparently will nest in any month when the cone seed conditions are suitable. Somehow, I think their breeding viability going into late December and January here seems on the surface rather dubious.I have already noted numbers of striped hatch year birds among the groups at Douglas Park. My sense is that these have moved here from breeding elsewhere based upon the larger numbers of birds in these groups..
[Non-text portions of this message have been removed]