Wednesday, August 18, 2010

That was fast...

After completing my Flammulated Owl surveys early in the summer and taking a little time off, I have spent the last 4 weeks banding songbirds at the Idaho Bird Observatory's Lucky Peak site. The time flew by and that assignment is now complete, although the team will be banding until October 15. This week I am at school orientating for my new masters program in Raptor Biology and my teaching assignment which begins next week.
It hasn't been all fun and games. In addition to banding songbirds I have been completing the data entry for the owl surveys (completed this morning), updating the final report on our owl season (still work in progress), updating my undergraduate research manuscript for resubmission to The Condor (ornithology journal, completed on Monday and distributed to my reviewers), and performing background research on my potential master thesis projects. Wedged in between we have been mountain bike riding, camping in the woods to pick huckleberries (good season), etc. It has definitely been a busy 4 weeks!
The masters thesis work is progressing. My lead project would be working on the breeding ecology of Northern Goshawks within the Sawtooth National Forest. It would be an excellent project, but I need to find some money to fund it. My second choice, requiring fewer funds, would be to study predator prey relationships during autumn migration. This would be a continuation of my undergraduate research. I am meeting with my thesis committee next week to flesh out more of the details of both options.
In a previous post about songbird banding, I covered the process and some of the work involved. I thought I should share some other interesting experiences. When cold weather first arrives in Idaho it is often a shock to these small bird species, especially the juveniles. When we are processing a cold bird we will occasionally put them in our shirt to warm them up. Last year, I had a juvenile Ruby-crowned Kinglet that didn't want to leave. A few weeks back, on our first really cold morning of the season, I had another Ruby-crowned Kinglet friend. I first should say that the Ruby-crowned Kinglet is one of the smallest birds, other than hummingbirds, that we process. They weight roughly the same as 1 US quarter. After processing a juvenile bird, I released it in my hand. The bird did not fly away but instead climbed my jacket up to my shoulder. I walked over and sat down. The bird remained. Everyone went to get their cameras and returned to take a picture. It was a good 5-10 minutes before he/she flew off.
Juvenile Ruby-crowned Kinglet on my shoulder.
Speaking of small birds, we occasionally process hummingbirds as well. We do not have a banders permit for hummingbirds, but we do take basic measurements before releasing the bird. We just don't catch enough of them to focus on banding. The Calliope Hummingbird is the smallest bird we catch at 2.5 grams (1/2 weight of US quarter), but we also catch Rufous and Black-chinned Hummingbirds which are about 50% larger.
Me processing a juvenile female Black-chinned Hummingbird.
Since juvenile Rufous and Black-chinned Hummingbirds are difficult to distinguish, especially females, we often have to consult the reference books to be sure we have a correct identification. The books also help on other species in identification, aging, and sexing.
Checking in reference book for positive ID.
Hummingbird feathers are so thin you can actually see right through them. It is amazing that these birds can fly 10's of thousands of miles.
Juvenile female Black-chinned Hummingbird.
I will still spend more time up at the bird observatory, but on a less regular basis and on a mixture of activities. For example, I will probably train the new hawkwatch crew next week (counting migrating raptors overhead as they migrate) and I look forward to spending time in the hawk trapping blind after we begin hawk banding next week. I still encourage people to go up and visit. It is a great experience.

Tuesday, August 03, 2010

Summer is "flying" by

Here it is the beginning of August. School starts back up in just a couple of weeks!
After completing the owl surveys earlier in the summer, Karyn and I took a much needed vacation to the Stanley Idaho area. There we hiked, mountain biked, and admired wildlife. Upon our return I started working up at Lucky Peak banding songbirds for the Idaho Bird Observatory. I call it work, it is really volunteering. Karyn refers to it as my summer camp! This activity continues their 15 year work in studying avian migration. It was the basis for my undergraduate research into the weather effects on avian migration and supports many other important studies as well. This is the second summer I have worked there. Its hard to believe that its already week three in my four week assignment there. After that I return to school for a week of teaching assistantship orientation and then the fall semester begins! Wow, where did the summer go?
Banding songbirds is a great way to learn a lot about birds. Not only does it help with identification, but also the birds life history and ecological requirements. Songbird banding at Idaho Bird Observatory begins in mid-July and continues through mid October. Hawk banding begin in late August and continues through the end of October. The songbird nets operate for the first 5 hours after sunrise every day. We currently have 4-6 people working each morning.
The focus of the banding activities is on avian migration. Early in the season we mostly catch local birds which are dispersing through the area, but there are a few migrants coming through. To catch these few migrants we must start as early as mid-July. The Lucky Peak banding site is considered a stopover site. Migratory birds stop there to refuel before continuing their long journey south. Just before migration begins, they experience a hormone change which causes them to enter hyper-phagy (eating a lot). Their body also shifts to load up on fat to fuel their journey. We can tell that a bird is migrating or getting ready to migrate by examining its fat stores, one of the many attributes we measure on each bird banded. The first "loaded" bird I banded this year was a beautiful male Bullock's Oriole heading south. We only delayed his journey for a few minutes...
Bullock's Oriole heading south!
Many people talk about how hard it is to identify birds in the wild. This is illustrated very well when it becomes difficult to identify birds in your hand! Some of the most confusing that we handle are the flycatchers. The difference between a Dusky Flycatcher and a Hammond's Flycatcher is very subtle. Sure, there is the primary projection rule, but what if the bird is a juvenile that is still growing its tail feathers? Bill size? There are differences, but they too are subtle. Then its gets down into the details ... such as primary feather #10 in a Dusky is longer than feather #5, about the same in a Hammond's. Now memorize these rules for the 100+ species we catch at Lucky Peak and there is always lots to learn. A while back the "Western" Flycatcher was split into the Pacific Slope Flycatcher and the Cordilleran Flycatcher. We do catch a number of westerns, but which species is a quandary. The reference guides say we only have Cordillerans here in Idaho, but all that we catch measure up to be Pacific Slope. Hmm. For now we just call them Westerns...
Hammond's Flycatcher (l) and Western Flycatcher (r).
Some species just make it easy. There are no mistakes with the male Lazuli Bunting. I love these birds.
Male Lazuli Bunting.
Once past the identification of species, we measure wing chord (length), tail length, fat score, muscle score, feather molt and wear, try to identify the sex, and the age. Sex is easy in some birds and just not possible in other species. Age is also a very tricky determination. Its usually easier to tell hatch year from after hatch year, but determining second year from after second year can be a challenge. In most species the birds don't molt all of their feathers during the second year, but in the third year they will replace all flight feathers within a very short period. Thus, to age the bird we try to analyze the flight feathers to determine if they are of different ages. If they are of different ages, then the bird is likely a second year, if the feathers are all the same age, the bird is likely an after second year (can't age beyond this). Making this more difficult is that different species will have different approaches to feather replacement. Lazuli Buntings are unique in that they replace their outermost primaries and innermost secondaries, but not the ones in the middle during their second year. This is illustrated in the photo below (it is rarely this obvious!).
Molt limit in male Lazuli Bunting.
You can see the outermost 6 feathers are darker (newer) than the next 5 feathers, then the next inner feathers are also newer. The primary coverts (small, short feathers "covering" the outermost flight feathers) are also old. These wear slowly so it makes sense to use them as long as possible. Growing new feathers is a very expensive process.
We often catch juvenile birds which might still be fed by their parents. Under these circumstances, we quickly process and return the birds to where they were caught. We often get to watch as the parent immediately feeds them. Its pretty cool. If we catch birds of the same species together, then we process them and then release them together. Yesterday, I extracted 4 juvenile Black-capped Chickadees from the net. We processed them and then delivered them back to the area where they were caught to regroup with any others they might be marauding with.
Juvenile Black-capped Chickadees.
The Idaho Bird Observatory is located east of Boise Idaho on top of Lucky Peak. We welcome visitors. Come by and check us out.