Photo by Corey Husic


Showing posts with label nature. Show all posts
Showing posts with label nature. Show all posts

Saturday, April 27, 2013

What do the bird watchers know and a lot of other questions

A bit on citizen science and some other interesting tidbits of information can be found in this opinion piece from the New York Times:

http://www.nytimes.com/2013/04/21/opinion/sunday/what-do-the-bird-watchers-know.html?smid=fb-share

Phenology data, from Pennsylvania and from other locations in more northern latitudes, tell us that many bird species are arriving earlier in the spring than they did 40 or 50 years ago.  The results are the same regardless if trained scientists or citizens are reporting their observations over the long term.  The difference is that scientists typically publish their data in peer-reviewed journals; citizen scientists publish (or crowd source) their data in public databases such as e-Bird maintained by the Cornell Lab of Ornithology (see http://ebird.org/content/ebird/about).

What we don't yet know is how this early arrival impacts the ability of birds to find food after a long migration.  Are their spring food sources -- mainly insects -- hatching earlier?  We know that the fuel reserves of birds can be largely depleted after their long flight; we don't know if they are able to sufficiently replenish their energy needs.  If not, how is this impacting the health and survival of neotropical migrants -- our long-distance athletes? 

And if spring arrival of birds and the emergence of insects are no longer in sync, what is happening to the population of insects?  The trend has been for milder winters.  Bats are in decline.  And both of these two observations lead to more bugs.

Do the birds find shelter if the leaves on trees and shrubs aren't unfurling earlier?  The earliest plants to leaf-out are typically woody invasive plants.  Are the birds o.k. with these new types of temporary shelter?  Birders create list of the birds they see on a given day at a given location.  But they typically don't report the habitat conditions, so we don't really know.

Is there a competitive advantage for the "early bird"?  Perhaps, but we don't know if the worms are available.  These squiggly animals also migrate, but do so vertically through the soil.  (This migration was described by Edwin Way Teale in his 1951 book North With the Spring.)  Contributors to Journey North can track spring observations of earthworms (see http://www.learner.org/jnorth/worm/index.html), but I don't know of anyone linking these data with that of the timing of bird arrivals. 

Do the birds build nests and lay eggs earlier?  If so, is there a greater risk that a cold snap will diminish their reproductive success in a given season?

So many questions.  So many birders and nature lovers/observers are needed to help us find out more information in our changing environment.

Thursday, August 11, 2011

The First Signs of Fall?

It is not even mid-August, but I have already noticed a murmuration of starlings (actually I have seen a few).  Witnessing these roving bands is to me one of the earliest signs that summer is beginning to wane.  I suspect that this is, in part, because the observation coincides with the time that I begin working on (or at least thinking about) the syllabi for my fall courses.  Fall is my favorite season, but I always experience a touch of melancholy when I notice signs of summer’s end.

Meteorological summer ends with the month of August, although many people associate the season's passing with Labor Day weekend since beaches and pools typically close.  Our days have been getting shorter for some time now, and the third week of July that is typically the hottest in eastern PA is long gone.  You can feel the fresher, cooler air if you are an early riser and it is refreshing to open the windows in the evening.  And there are other signs that things in nature are starting to change. The complementary colors of fall-blooming flowers—purple and gold—are already visible in the Joe Pye Weed, Ironweed, and the species of Goldenrod that are already blooming.  And any birders out there know that the hawk watch seasons at Bake Oven Knob (http://lgnc.org/research/bok-hawk-watch) and Hawk Mountain (http://www.hawkmountain.org/Raptor_Migration.php) commence in just a few days on August 15th.

What do all of these seasonal notes tell us?  That it is time to think about fall phenology and to contribute new data to the Eastern PA Phenology Project (http://lgnc.org/research/phenology)! 
 
There are a number of raptors that will begin to migrate early including Bald Eagles and Ospreys.  Songbirds that are early fall migrants include Louisiana Waterthrush, Yellow-billed Cuckoos, and flycatchers--especially Eastern Kingbird, Olive-sided Flycatcher, and Empidonax species (the ones I can’t typically distinguish without hearing their spring songs).  In fact, late this afternoon, a Least Flycatcher was spotted by my son in an apple tree by our house.

You should begin to see Monarch caterpillars and chrysalises soon.  This past week, I have been seeing more Monarchs nectaring on plants, but, as of yet, they aren’t showing migration behavior.  These butterflies will likely lay eggs and you may soon begin to see the caterpillars munching on milkweed.

Yesterday we began seeing the dark form of the female Eastern Tiger Swallowtail that mimics the Pipevine Swallowtail—both being late season butterflies in this region.

Below is a list of some other fall seasonal signs to be looking for.  Don’t forget to report your observations of seasonal changes to the Eastern PA Phenology Project at phenology@lgnc.org.

Goldenrod (Solidago sp.; photo by D. Husic)

Aromatic Aster (Symphyotrichum oblongifolius; photo by D. Husic)
-         First blooms on goldenrod (Solidago sp.) and asters (typically Symphyotrichum sp. in this region);

-         Chipmunks collecting and storing food;

-         Milkweed seed pods opening and dispersal of the seeds;

-         Last sightings of Barn and Tree Swallows (see fact sheets on project website for identification);

-         First sightings of Dark-eyed Juncos returning – often at feeders;

-         Loss of bright yellow color on male American Goldfinches or of the brilliant blue of Indigo Buntings;

-         The date of the first frost;

-         Tree leaves beginning to change color (note species, first color changes, timing of tree at peak color).  The Red Maple is one of our species of particular interest, but we will take reports on any and all trees that are common to eastern PA (see fact sheet on project website);

-         The timing of when leaves begin to fall and when a tree is completely bare; 

-         The timing of sumac leaves changing color and loosing leaves; 

-         Starting this fall, we are particularly interested comparing the timing of when native vs. invasive shrubs lose all of their leaves.  Some examples include native viburnums, dogwoods, and blueberries, vs. the invasive Autumn Olive, Multiflora Rose, Japanese Honeysuckle, and Japanese Barberry.
-         Last sightings of Bumblebee, Cabbage Whites or Ruby-throated Hummingbird (see fact sheets on project website for identification); 

-         First sighting of a Milbert’s Tortoiseshell butterfly; 

Milbert's Tortoiseshell (Aglais milberti; photo by Corey Husic)
-         The timing of the emergence of the yellow flowers on Witch-hazel (picture on fact sheet on project website). 

These are just some of the fall seasonal signs.  If you observe other phenological events, we would love to know about your observations.  Remember that you can report your observations at phenology@lgnc.org.  Periodic summaries of what our project contributors are observing will be posted on this blog.