Predicting the Birds at Our Feeders

PREDICTING THE BIRDS AT OUR FEEDERS  

December, 2014/January, 2015 issue  
Having  pursued the study of birds as a hobby for close to 60 years now, it  is  always fun to reflect on how much we have learned about bird behaviour  in  that time. A lot, mind you, but we still have much more to learn. 
  
 The  late Toronto Daily Star birding columnist from the 1960s, Hugh   Halliday, once wrote that the irregular appearances at our feeders of  boreal  species of finches that typically nest and stay in the far  northern regions of  Ontario, “might” be linked to food shortages in  their normal breeding range.  Food, or the lack of it, he felt, was more  of a driving force behind these  unexplained movements of northern  birds, then any programmed instinct to  migrate, just for the sake of  migrating. After all, this explanation was already  pretty much accepted  for snowy owls whose appearance in winter was linked to  shortages of  lemmings, their favourite food. Made sense that the same might be  true  for other species.
  
 Today,  it seems to be generally accepted that food is indeed the directive   which determines the comings and goings of our birds. This is especially  so with  boreal species.
  
 What  are boreal species? They are species of finches – crossbills,   grosbeaks, siskins, redpolls, along with a few others, that typically  call the  far northern forests of Ontario, and sometimes beyond, their  home. They don’t  migrate in the general sense of the word, like our  warblers do without fail  every fall, but only move out of their normal  areas when their favourite foods  become scarce. While this movement  usually is south, until they find something  they like, it also can be  east or west, wherever the dangling carrot leads them.  Birds will go  where the food supply takes them, then once they exhaust that  supply,  they will move on. Some nomads like crossbills don’t really have a   permanent home, but just follow a baited highway through the coniferous  forests  across the continent, nesting as they go.
  
 In  recent years, friend Ron Pittaway of Minden, has made it a special   interest to study the food habits of these northern residents, and make  note of  each species’ food preferences. From his own observations, and  the input from  many other knowledgeable contributors, he assesses the  successes and failures of  these crops throughout the region, then  brings it all together in an effort to  forecast what species may remain  right where they are due to an abundant food  crop, and what species  will move out seeking greener pastures, and in what  direction.
  
 Ron  began his interest in birds at about the same time that I did. He spent   a decade as a Park Naturalist at Algonquin Park and worked for 23  years teaching  conservation and resource management at the Leslie M.  Frost Natural Resources  Centre near Minden where he lives.  His  involvement in birding though goes far  beyond just a keen interest; he  is a founding life member of the Ontario Field  Ornithologists (OFO),  was co-editor of Ontario Birds from 1991 to 2006, and  technical editor  of OFO News from 1994 to 2007. He has authored over 130  articles on  birds. He was a member of the Ontario Bird Records Committee for 12   years between 1984 and 2003, including three years as Chair and one as   Secretary. Ten years ago, Ron received the Distinguished Ornithologists  Award.  
  
 After  receiving input from numerous sources and from observers  in the   field, Ron predicts what we might have at our feeders every winter in  the way of  boreal finches. He summarizes this winter as a “mixed bag”  of finch movements.  He says some species like purple finches will  travel south, and we have already  witnessed this flight this past fall.  Good cone crops, he says, will keep  white-winged crossbills in the  northern forests wherever spruces are laden with  cones. 
  
 Ron  says to expect a moderate to good flight of redpolls south this winter   because their favourite food, birch seeds, is in short supply. Look for  them at  a feeder near you.  Once they arrive this winter, if they do,  they will  gravitate to niger seed in silo feeders. Among the most  unpredictable are the  pine siskins. In the Bay of Quinte region, they  arrived in October in droves  seeking out spruce cone crops. If they  find anything worthwhile on these  sojourns, they will stay; more times  than not, however, they just keep on moving  until they all but  disappear from the area.
  
 Five  pine grosbeaks seen in Prince Edward County in late October may be a   good omen for this species. This sighting was unexpected since  mountain-ash  berries, their favourite food, are generally excellent. In  theory, pine  grosbeaks should stay put.  So, the science of predicting  isn’t cut and dried;  individuals within a species that are not  expected to move out of home territory  will sometimes drift our way,  but not in the numbers that we see other winters  when there is an  irruption and our area is bombarded with a certain species,  like it was  one winter when visiting Bohemian waxwings outnumbered cedar   waxwings.  Speaking of which, Bohemian waxwings (not a finch species, of   course)  are expected to stay where they are because they are also a   mountain-ash specialist, but if a few do appear, they will be attracted  to  buckthorn berries and crabapples while they are here. 
  
 Evening  grosbeaks that once dominated feeders in the 1970s may move south  in  small numbers. Their population was high in the 1970s and 1980s due to  major  outbreaks of spruce budworm, the larvae of which they feed their  young. Since we  haven’t had a major outbreak of budworm since the  1970s, their numbers never  really recovered from the days when feeder  operators routinely raked up massive  amounts of spent sunflower seed  hulls from beneath their feeders. Birds, like  other animals, regulate  their populations in accordance to the amount of their  favourite food  that’s readily available. When a particular food is plentiful,  numbers  will be high, and when a favourite food is in short supply, the overall   population will drop. 
  
 The  above predictions just scrape the surface. For a more detailed account,   you need to access my website at www.naturestuff.net and click on  BIRDING from  the Main Menu. Then scroll down the selections until you  reach ‘Winter Finch  Forecast’. Here, you will find other species  listed, including irruptive species  like the blue jay and red-breasted  nuthatch, and lots of information on the  boreal finches and what they  may be up to this winter. Included are several  links to previous  forecasts and some informative facts on finches. If some of  these  boreal species have not yet arrived as you read this, they may very well   trickle in later this winter.
  
 For more information on birding and nature, check out the NatureStuff  website at www.naturestuff.net  .           
  
 Terry Sprague lives in Prince Edward County and is self-employed as a  professional interpretive naturalist.