Alabama hunting trip

On a chilly overcast afternoon I climbed a metal latter extending about 25 feet up an oak tree to a padded camouflaged seat.  I slung my bolt action Remington rifle off my back and lower a padded metal bar across my chest.  The tree stand on private land  in the transition zone between the Alabamian upland Piedmont and the east gulf coastal plain provided me a commanding view of an elongated food plot with a field of planted loblolly pines to my left, and a relatively young hardwood forest to my right.  I was covered, virtually, head to toe with with high tech, real tree, HD, hardwoods camouflage, and I suspect that once I made it my goal to sit as still as possible, whitetail deer would not be able see me.  However, I came across an article published by the Quality Deer Management Association that indicates that all this high tech cammo may be all for naught if treated with UV enhancing dyes used to make garments slightly brighter to the human eye in the hopes of more sales.   Deer lack UV filters that we humans have which allow them to see the tail end of the UV spectrum.  Therefore, my new cammo pants could literally appear to be glowing to a vigilant whitetail.  Interesting, but I didn't know this at the time, so there I sat as still as possible. 

Before I left for this trip, it was mentioned to me by a friend of mine who just returned from his first hunting trip that deer hunting was "boring until you hear leaves rustling, but then you realize that it's a squirrel, then it's boring again."  Having been hunting a few times before this current trip, I could not disagree more.  After I nestled into my perch, the woods were quite.  This was most likely the result of me scaring everything off by my boisterous tromping up to the stand which sounded like the Macy's day parade compared to the noise that evolved prey animals make while conducting their daily business of trying to find food without being food.  But soon the soft fluttering of wings altered me to the presence of unknown avian critters.  Soft knocking against wood told me that woodpeckers were out looking for breakfast.  And a piercing squeal told me that Northern Flickers were the ones looking to grub out.  Later, a Red-shouldered Hawk lit in a hickory next to my stand.  A  2-year old Wild Turkey quietly crept onto the plot fed for a moment and moved back into cover.  I even saw a older looking doe, but a fawn was still with her, so I watched the mother take her time browsing on the plot while the hyperactive kid bounced around.

This is what I enjoy most about my few hunting experiences.  I love getting out in the woods at a time when it seems most folks are either sleeping or indoors by a heater.  I love seeing the woods with its vulnerable trees with branches that exhibit the juxtaposition of chaos and order in a display of fractal geometry that inspired Pollock.  I love sitting so quietly that rapid, sporadic, wing beats of a Carolina Wren are the loudest sound in the woods, and when he flips fallen leaves in search of meal, the sound becomes defining.  I love being invisible to the gray squirrels that bound from tree trunk to tree trunk frantically searching for hidden nuts and seeds in a ritual that goes unnoticed by most.  Boring indeed!  This is what I love, and if an old buck or doe happens walk by my cross hairs, I will thank God for the opportunity to put meat in the freezer and take the shot; I haven't done so yet.

Lost nests

I returned from Tall timbers Research Station to check up on some Athens area shrikes to find two shrike nests we have been monitoring on the ground with no sign of eggs or young.

One site had no sign of shrikes at all, but at the other site, just as I was about to leave thinking those birds were gone too, I saw a shrike light on telephone wire where I have seen the adults hunt. I quickly got out my spotting scope to see if it was the adult bird I had tagged for the purpose of monitoring its movements, but was happy to see that it was one of the juveniles from the adult pair's previous clutch.

No doubt this bird was one of the two that I have seen begging for food from the adults in some of my previous visits to this spot. When I left for Tall Timbers last week, this bird was not hunting for itself and relied on the good graces of it's parents for nourishment to keep it alive, but now it was actively hunting on it's own, snatching grasshoppers out of the air; curiously eyeballing deft barn swallows as they swooped in to investigate the tiny raptor.

I watched this hatch-year bird for an hour in the hopes that it's parents or sibling would join him/her, but to no avail. Since their second nests failed, did the adults disperse to another location? What about the juvenile? Did he relocate as well?

I'd like to think that is all that happened; the birds just moved to greener pastures, but the pessimist in me tells me they are dead. This, realistically, could be the case. This would mean that this lone juvenile is the survivor.

Part of me wants me to trap this juvenile, put a radio tag on him, and see where it goes. Will it stay in this area since the parents are gone? I mean, at least one successful brood was raised in this habitat.

As I watched the once incapable and now lonely bird hunt, I think that I will opt to not harass him. What if he injures himself in the trap? What if the color bands I put on him attracts a predator? What if his band get tangled in a mess of thorns? It hasn't happened to any birds I have banded to my knowledge, but what if it happens to him? I started to think of a million things that could go wrong and soon I became overwhelmed.

At that point I could never think of touching that bird. I began to think that just by watching him he might erupt in a burst of flames and it would, of course, be my fault.

No, I will not mess with this bird, but I will come back to see if he's still around knowing that some time soon, I will arrive at the site and he will be gone. Then, I will silence the pessimist and imagine this bird raising a next generation of shrikes.
Shrike nest with eggs

Same nest abandoned (bottle cap for scale)
I didn't get a picture of the juvenile bird... but here's some nestlings from Tall Timbers!

Shrike Radio tagging

Sorry I haven't updated in a while. Things have been pretty busy. I have officially begun my field season and I have not had a spare moment.

As I write, the sun is beginning to set here at Tall Timbers Research station. The purpose of my trip down here is to track previously radio tagged birds that inhabit these beautiful Longleaf pine forests in order to see how much open pine habitat Loggerhead Shrikes need.

My other study site is in the rural areas surrounding Athens, GA. I have radio tagged birds there as well and am driving back and forth between Tall Timbers and Athens every other week to track birds.

With the help of Hutch, a Tall Timbers summer intern. We are starting to get enough data at Tall Timbers to really start to see how much space these birds need. Similarly, with the help of Brady, Bobby, Lindsay, Brent, and Kathryn (all of which are volunteers) we have gathered similar data for the Athens area.

Already, we are starting to see some interesting results. For instance, all the pairs we are monitoring around Athens, are provisioning 2 or less juveniles, while on Tall Timbers, all pairs with young have 4 or 5 juveniles that they are tending to. While the sample size is still small, this will be something worth exploring later on.

More information can be found by following this link to the latest Tall Timbers e-news bird notes:

http://www.talltimbers.org/ttnews/news.cfm?news_id=121

What is the reason for this? Do the pine "barrens" truly offer better quality habitat than agricultural fields? Hopefully, when all is said and done, we will have an idea....
Radio tagged bird in Athens


Impaled Carolina Wren


Radio tagged shrike on the Wade Tract

Cammo-clad Shrike ninja, aka Hutch

Stable Isotopes and Shrikes

Sorry I haven't posted in a while. Some new developments have come up in my research. What started out as a peripheral interest to my project is quickly taking more precedent.

Stable isotope analysis is an ever-changing and ever-growing technique that combines basic ecological concepts with relatively simple chemistry. Before I completely confuse whoever may read this, you may want to check out this site (http://www.uga.edu/~sisbl/stable.html) for a brief introduction to what stable isotope analysis is all about.

The first, and most basic concept that stable isotope analysis draws upon is that everything is interconnected in an ecosystem (and in a larger sense: the entire planet). One may think of a large web in which each strand is connected to adjacent strands. Remove or distort one of these strands, and the structural integrity of the whole web is effected. Moving on.

Every living thing has some atoms in common, i.e. every living thing incorporates carbon and nitrogen atoms into their living tissues. These atoms exist in different forms, called isotopes. What differentiates these forms of the same atom is not their function, but their weight. For example, most carbon has 6 neutrons, 6 protons, and 6 electrons. Since electrons do not contribute to the atomic weight of an atom, this typical carbon molecule can be said to have an atomic weight of the 6 protons plus the 6 neutrons, which sums to 12. But if you were to look up the atomic weight of a carbon atom in the periodic table, you would see that the listed atomic weight was 12.011. This is because carbon can exist as heavier and lighter isotopes. For example, there is one carbon isotope that consists of 7 neutrons, 6 protons, and 6 electrons, giving that atom the atomic weight of 13, but it still retains all the properties of a carbon atom. Therefore we call this isotope C13. The 12.011 atomic weight that you see in the periodic table is a function of the natural abundance of not just the 'normal' carbon with the atomic weight of 12, but also of all the carbon in the environment that exists in heavier (or lighter) isotopes. Whew.

Now, when any living thing (the predator) eats something else (the prey), the isotopes in the prey move up the food chain into that predators living tissue. The interesting thing is that the lighter isotopes are selected to run that predators various metabolic processes, while the heavier isotopes, like C13, remain sequestered in the predators living tissues. If this predator is consumed by something else, then these heavier isotopes bioaccumulate up the food chain. So if C13 concentrations increase as they move higher up in the food chain, then by analyzing this concentration of C13 of various organisms in an ecosystem, someone could see who was on top of the food chain, who was on the bottom, and any organism in between.

Lucky for us, there is a machine that can analyze these heavy isotopes! These measurements of the relative amount of heavy isotopes in an organisms living tissue are called isotopic signatures.

But wait! That's not all! Depending on how the plants photosynthesize in an ecosystem, the concentration of heavy isotopes, thus the isotopic signatures, differentiates. For example, marsh plants photosynthesize differently than most other plants (which is another topic for a another time). Thus all the organisms that use the mash will have a unique 'marsh' isotopic signature while organisms inland will have a different isotopic signature and so forth.

So what does this have to do with shrikes? Well, it may help answer the question on whether or not we have the endangered migratory subspecies L. l. migrans wintering here in Georgia. In Georgia, shrikes live in many habitats including agricultural fields, open pine forests, and even on the coast. If you were to collect a feather from a shrike that was grown in each of these ecosystems, you would presumably get different isotopic signatures for each habitat type. Now feathers are neat because they 'freeze' the isotopic signature of wherever that feather was grown. So if a feather was grown in an inland breeding ground, but then that bird moved and grew more feathers on a coastal wintering ground then those two feather types grown in different habitats should have different isotopic signatures. If you get two distinct isotopic signatures from two different feathers from ONE bird, then that bird must have migrated between its breeding and wintering grounds, i.e. there is a strong chance that this bird may be L. l. migrans!

This is just one application of stable isotope analysis in ecological research, but I figured I have bored you enough already (if you have managed to stay with me for this long).... So here are some pictures of Loggerhead Shrikes from my latest outing around Athens, GA! Special thanks to Vanessa and DeeAnne for helping on that frigid day!