Wednesday, July 02, 2014

Surveys, Nests, Nestlings, and Adults–All Things Goshawk!

Wow! Two more weeks in the field studying the Northern Goshawk with fantastic friends, findings and results. Here’s a follow up to my previous posts (My Project of the Year – The Northern Goshawk and The Northern Goshawk in Biogeographical Context), with new updates, photos and stories.

Old Acquaintances

I have stated in previous posts that one of the objectives the Intermountain Bird Observatory’s 2014 goshawk season is to establish the degree of linkage between the more “island-like” forests of the northern Great Basin and the more contiguous forests of the Rocky Mountains. We expect to do that using genetic techniques. Our area of focus for this first year of genetic work is the Minidoka Ranger District of the Sawtooth National Forest. However, our past work of banding and color banding individuals continues to pay off as we relocate these birds.

While surveying for goshawk territories in the Albion mountains, I came upon this female bird with the familiar purple color band. Our team is the only group assigned to use purple color bands on goshawks, so I knew that it was a “friend” of ours. Upon closer inspection, I could read the two digit color band code and identify the bird. This female (Purple Z3) was hatched in the South Hills in 2012 and banded by our team as part of that effort. She now has offspring of her own, likely her first, although some females do breed as sub-adults. 

Female Purple Z3 nesting in the Albion Mountains, Idaho.

Purple color band Z3 clearly visible on her right leg. This is a “Type 1” band with two digit code oriented vertically.

Female Purple Z3 as nestling in 2012 in the South Hills, Idaho.

Female Purple Z3’s 2014 nest with a single nestling, approximately 15 days old, Albion Mountains, Idaho.

Learning the Basics

This year my field partner is an undergraduate student from Oberlin College in Ohio, Steph Szarmach. She is in the NSF-funded Research for Undergraduates (REU) program at Boise State University. She has now completed her four weeks in the field and will transition into the lab for the remainder of her time in Boise to work on the genetic analysis of the Northern Goshawk. She plans to measure the genetic diversity of the goshawk within the Minidoka Ranger District and to relate these genetics to the biogeography of other populations. In more simple terms, how related are the northern Great Basin goshawks to the Rocky Mountain populations?

As part of Steph’s field experience, she learned to survey, find nests, age young, trap birds, climb trees, band birds, and draw blood samples from birds, not to mention all of the new laboratory and analysis techniques. Wow, what an experience. Some activities took quite a bit of practice. During our first practice, it took Steph and I nearly two hours to “shoot a line” through a high Aspen tree.

Steph practicing with the throwline used to pull a rope into the tree.

Other activities came more easily. After only 4 practice climbs, Steph successfully climbed into her first raptor nest. This one was into a 40’ Douglas Fir tree in the Sublett Mountains. She would complete two more flawless climbs before our fieldwork was complete.

Steph’s first climb into a real goshawk nest, Sublett Mountains, Idaho.

Steph retrieving nestlings from nest for banding and genetic sampling, Sublett Mountains, Idaho.

In other nest stands Steph learned to band both adult and nestling birds, measure and record morphometric attributes and complete the collection of genetic samples.

Steph checking the band size of an adult goshawk, South Hills, Idaho.

Steph applying USGS band to adult goshawk, South Hills, Idaho.

Steph measuring the Hallux of an adult goshawk, South Hills, Idaho.

Steph now transitions into lab to continue processing the 26 blood samples that team goshawk collected in 2012 along with the 24 new samples we collected this past week. Additional samples are being sent in from forest service teams across the state. Steph will process the samples, analyze the results and then present those results at an undergraduate research conference at the end of July. Her and I have also received a joint NSF grant to travel to the Raptor Research Foundation annual conference in Corpus Christi, Texas in Late September. Steph will present her results to an international audience of raptor researchers at that conference. Very exciting stuff!

Unique Adults

Whenever we handle individual birds, we often witness unique aspects which differentiate individuals within the population. Our field guides like to suggest that there is one reference model individual with all others being similar, but variation is very high, just as it is in humans. We had a female bird whose legs were so big, the “standard” band would barely fit. On the final individual we processed, an adult male from the Albion Mountains, Greg noticed that the tail lacked the barring which is common on goshawks.

Rob (me) and Greg with adult male goshawk with all grey tail, Albion Mountains, Idaho.

Rob (me) with adult male goshawk with all grey tail, Albion Mountains, Idaho.

Unfortunately, not everything we find is as exciting. Most of the adult female birds we processed showed signs of Leucocytozoon infection. Leucocytozoons  are blood parasites related to malaria (Apicomplexans). The IBO team (Michelle Jeffries, Michelle Laskowski, Jay Carlisle, and myself) have a research manuscript in review on this matter. We know the disease pervasive in the area, but these skin lesions suggest that the impact on individuals is far from minimal.

Skin lesions on adult female goshawk indicative of Leucocytozoon infection, South Hills, Idaho.

The Birds

You just can’t have too many goshawk photos!

Steph and Rob (me) with an adult specimen of one of the greatest birds on the planet, the Northern Goshawk, South Hills, Idaho.

Two recent goshawk fledglings, approximately 40-42 days old in the Sublett Mountains, Idaho.

Adult goshawk, Sublett Mountains, Idaho.

Northern Goshawk weapons of flesh destruction, South Hills, Idaho.

Adult Goshawk, South Hills, Idaho. Dark red eyes suggestive of an older bird.

Adult Goshawk, Albion Mountains, Idaho. Orange eyes suggestive of a younger bird, but at least two years old (adult plumage instead of juvenile plumage).

Rob (me) with the final bird banded in the 2014 season, an adult male, Albion Mountains, Idaho.

Team Goshawk 2014

Here I am, the fearless leader of Team Goshawk, ready for action! South Hills, Idaho.

Steph Szarmach, Field Technician and Genetic Analyst displaying a hole in her climbing jacket resulting from an adult goshawk attack! Yes, the bird penetrated her skin as well! Sublett Mountains, Idaho.

Greg Kaltenecker, IBO Executive Director applying a hood to an adult goshawk, South Hills, Idaho.

Dusty Perkins, volunteer, genetics mentor, and tree climbing mentor preparing to climb, Sublett Mountains, Idaho.

Austin Young, volunteer, with Northern Goshawk nestling, Sublett Mountains, Idaho.

Michelle Jeffries, volunteer and fellow goshawk researcher with adult female goshawk, South Hills, Idaho.

Michelle Jeffries with four other visiting Boise State REU students – Patrick (studies Northern Harriers), Rachel (studies Harpy Eagles), Sara (studies Burrowing Owls), and Jarod (studies Burrowing Owls).

Skyler, another visiting Boise State REU student (studies Burrowing Owls).

Leroy, raptor expert, one of my mentors and project volunteer, along with Steph and Greg, Albion Mountains, Idaho.

It’s not a bird, but come on, that’s cute!

Steph and I would each see more than 10 Moose!

Moose calf, Albion Mountains, Idaho.

Cow and calf Moose, Albion Mountains, Idaho.

1 comment:

Rachel said...

Thanks Rob for having us out there. I had a great time banding nestlings!