6.15.2009

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!

6.09.2009

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