Photos and story by Jay Carlisle
After a couple of weeks of fund-raising and other office work, I happily jumped at a chance to get out for a couple days of woodpecker surveys on the Boise National Forest. I needed to stretch my legs, I hadn’t heard or seen a Black-backed Woodpecker in about a year, and – this is important – there were no World Cup games on the schedule for 2 straight days so I had a perfect window in which to get out!
I waited until after the US-Belgium game ended on Tuesday afternoon so I got a late start heading out and arrived to camp around 11pm. I was awake a little after 5am the next AM to start a steep hike along the Riordan Lake trail to reach my first survey point around sunrise. Surveying for birds in a new area is always exciting for me and of course there’s always the hope of seeing other wildlife on the trail. The partly burned forest surrounding the creek and Hennessey Meadow made for a great backdrop and the meadow itself supported a diverse riparian bird community, including Fox, Lincoln’s, and Song Sparrows; Dusky and Willow Flycatchers; and more.
On my 5th survey point I had an almost immediate response from a Black-backed Woodpecker and soon there were 2 individuals – a good start! I ended up detecting one more Black-backed and also observed four other woodpecker species (Downy, Hairy, Northern Flicker, and Red-naped Sapsucker) and other fun birds like Olive-sided Flycatchers.
After my long hike down, I drove back towards Warm Lake in order to get lunch and find some WiFi access so I could finish work on submitting a proposal before heading back out to my next site. As I got alongside the lake, I saw an adult Red-necked Grebe carrying a chick on its back – how cool!
Thus, I was already fully content with my trip sightings before heading to my second site. My drive that evening took me through miles of burnt trees and it was daunting to think about how large of a fire this was … but also how much habitat this had created for species like Black-backed Woodpeckers, Olive-sided Flycatchers, Mountain Bluebirds, and even American Robins – all of which reach higher densities in burns.
As I drove up the final road, the wind picked up because of a nearby thunderstorm and I hoped no trees would blow down to block my passage in or out! Fortunately, the storm and wind soon subsided. I arrived around 830pm and was more than a little dismayed to find a large and hungry greeting party of mosquitoes! After psyching myself up, I started walking around in search of a good flat place to set up my tent and was swatting mosquitoes constantly – not thinking about birds at all and not carrying binoculars. Then I looked up and saw a bird-like shape on the side of a snag – my heart jumped a bit because of the apparent shape but then I reasoned it had to be one of those thousands of pieces of loose bark hanging off the trees in the area. Then I saw its head turn and I said to myself, “No way!” before stumbling/sprinting my way back to my car to get binoculars, scope, and camera/phone attachment for the scope. A Northern Hawk Owl! I’d been so preoccupied with biting insects that I hadn’t really noticed that the habitat had a boreal nature to it and was similar to other places where I’d seen Hawk Owls … it’s just that I was 250+ miles from the nearest known breeding area. I hurried to snap a few documentation pictures before the sun disappeared. While I was observing the bird, I noticed that it was hanging around the same area and even gave a couple of quiet vocalizations. It made me curious about how long this bird had been here and was it possibly occupying a territory? But, the mosquitoes soon drove me to set up my tent and seek refuge.
Thus, I hurriedly set up my tent and crawled inside – and basked in the excitement of an unexpected sighting of such a charismatic bird! I’d only just started to relax when I heard a high-pitched screeching – I knew I’d heard this sound before and it was when I’d seen fledgling Northern Hawk Owls in Glacier National Park (closest known breeding area) a few summers ago! I knew I wouldn’t have much time to look in the morning as I had woodpecker survey duties so I raced out of my tent. I soon saw an adult in a different area and it flew over me towards the main activity area – this bird was noticeably bigger than the other adult so I must have originally been seeing the male and this was the female! I soon confirmed a view of at least a single fledgling and thought I heard another – but I didn’t want to intrude any closer to pursue the other bird. I had just confirmed breeding Northern Hawk Owls well over 250 miles from where they’ve been documented to breed previously!
I was too excited to sleep for a while so it was another short night and I was awake again before sunrise for woodpecker surveys. After my first point, I took 15 minutes to try for a few more pictures before I continued on my woodpecker transect. I was quickly rewarded with seeing the male capture, kill, then cache a songbird (I’m pretty sure it was a Yellow-rumped Warbler but hard to tell in the low light)! I heard a juvenile beg once but apparently dad didn’t think junior was hungry enough :-) The lighting was still terrible but I tried for a few more pics before moving on and was lucky enough to get this video of a juvenile playing with a branch (!) and a couple other pictures.
The following evening, Larry & Missy Arnold “chased” these birds and confirmed 2 fledglings; thus, 2 adults and at least 2 fledglings! The story gets even better … on the way back home, they stopped to move a fallen tree out of the way and Missy looked up to see another Hawk Owl miles away and a little exploration turned up a total of 2 adults and 3 fledglings. I was excited at seeing one bird and blown away to have documented nesting … but 2 nesting pairs a few miles from each other is mind boggling! It’s such a remote area with relatively few biologists and birders so it’s hard to know what to make of this. Have they been there in prior years, just unnoticed? Or is this a relatively recent colonization event? One Hawk Owl came to Moscow, ID this past winter and we wondered then if that was an isolated event or if others had possibly arrived to more remote areas of Idaho. I don’t think we’ll ever know for sure but future study of this phenomenon might be worthwhile going forward.
*Because of the rarity of the species (especially rare is evidence of breeding in the state – I know of only one other breeding record in Idaho), their confiding nature, and the potential for foul play, I’m reluctant to post the exact location or directions on a public forum. I trust all birders but just don’t want to inadvertently mess up a good thing by letting the info get into the wrong hands. I don’t know all details but >10 years ago there was a pair w/ fledglings in N Idaho and some birders worried they ended up shot & I don’t want the same result.
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.
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!
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.
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.
by Jay Carlisle
Late last week I started to notice that something was amiss with Borah’s transmitter – in technical terms, the activity counter data was “stuck” which suggests the transmitter wasn’t moving. My heart sunk – in the 3 prior times this had happened, we found a dead curlew (one in which we strongly suspected foul play, 1 predator kill, and 1 unknown cause). Of course I care about all of these curlews but Borah had migrated to Mexico and back last winter and we’d just recently captured his mate (“Goldie”) so I feel a little extra for Borah and really didn’t want this to be the same result.
On Tuesday I made the 5+ hour drive from Boise to his breeding area on Big Creek Ranch, decidedly nervous about what I would find. I had texted with ranch co-owners, Molly & Tom Page, the night before and they were going to be there at the same time and generously offered to help me search – a relief for me b/c finding a small transmitter in a vast grassland can be tough even with the tracking gear! I thought I might have 4 helpers (Molly & Tom and their children, Lilia & Henry) but I ended up with 7 because Molly’s sister Ann Fuell was visiting with her 2 children, Kate & Ted, and they were excited for an outing. What a bonus!
Once we met up, they enthusiastically asked, “what do we do?” I suggested we walk straight towards their nesting territory because if Borah was alive and their nest was still active, he’d surely appear.
As we neared the nest, I could see a female (longer bill) standing in the vicinity of where the nest was and as I looked closer I could see, but not read, the plastic leg band (“alpha flag”) and suspected it was Goldie. Not long afterwards a screaming curlew appeared – as it flew towards us I could see it was a male by bill shape/length and then I saw the leg band and was hopeful. There was no antenna from a satellite transmitter which could suggest Borah was alive and had shed his transmitter – I just needed to read the alpha flag with certainty. On his next fly-by I could clearly read the letters “AU” and I breathed a huge sigh of relief – this was Borah and he must have dropped the transmitter. Likewise, once the female flew towards us I could see her antenna and read her 2-letter code.
Adding to my excitement is that both Borah and Goldie were exhibiting the aggressive and defensive behavior that happens when they are protecting chicks! I was dive-bombed several times and I think Lilia & Henry were wondering if Goldie might actually hit one of us :-) Needless to say, I’m pretty sure these 2 curlews don’t share the same affection for me!
We then turned our attention to finding the transmitter. This consisted of waiting for once-a-minute messages from the receiver to deduce direction & distance. It took a while but we eventually got “warm” as we neared the headwaters of the creek (which flows into the Pahsimeroi River).
The family had previously agreed that extra s’mores would be the reward for whoever found the transmitter while I would just be happy to find it in one piece and try to figure out why it had fallen off. Before long, Kate said, “hey, what’s this?” and I was relieved once again – an intact transmitter on which the Teflon harness material had worn down so it fell off the bird.
It was only a few feet from the creek so maybe Borah was bathing at the time? Lucky it hadn’t fallen in the stream because my understanding is that if the antenna is underwater, the unit won’t transmit and we wouldn’t have been able to find it at all!
The bad news is that we won’t be able to track both Borah and Goldie in the same migration but I’m thankful that Borah survives and will cross my fingers that they raise the chicks to fledging and that Goldie goes somewhere exciting this winter! Thanks a ton to the Pages and Fuells for assisting with the search and for helping make my trip that much more worthwhile.
Sometime soon Jay and I will post the full story from our time at MPG Ranch in Montana, but in the mean time we wanted to share this crazy story.
The second week of May we traveled to MPG Ranch to place 4 transmitters on curlews there. The plan had been to do 5, but one transmitter had been sent off to be refurbished and didn’t get back to us in time.
So we put on 4 transmitters and finished up at MPG. The next week we made a loop to the Pahsimeroi Valley in Idaho, the National Elk Refuge in Wyoming, and The Nature Conservancy’s Flat Ranch near Island Park, putting on 3 other transmitters (more on that later too!).
While we were traveling, we continued to get location uploads from our 4 MPG transmitters, and updates from the MPG biologists…things weren’t looking good. The last female we transmittered, who we nicknamed “The Beast” (she was really huge, and super feisty!) had stopped transmitting. The MPG folks were still seeing a bird on the nest during the day when females usually incubate, so we deduced that her transmitter must be malfunctioning. We decided that we should capture her and take her transmitter off.
So Kate from MPG organized a trapping mission and headed out mid-day. They successfully trapped the incubating bird, but to their surprise it did not have a transmitter, band, or leg flag….they had caught the wrong bird! This was the MALE incubating during the day! (Male curlews are supposed to switch incubation with their mates in the evening and take the night shift). Things weren’t looking good for “The Beast”. If she was not on her nest during the day when she was supposed to be, it was very possible that she was dead (cause unknown but many predators in the area).
The MPG team watched the male over the next few days and never saw his mate. He diligently incubated the eggs during the day, only hopping off the nest for short stints to feed every few hours. With him doing double-duty we were worried that the nest wouldn’t make it. How could a male curlew raise the eggs on his own? Our only encouragement was that we knew the pair had started their nest about 3 weeks prior, so with an incubation period of about 28 days he didn’t have much longer to go….could he hold out another week until they hatched??
We were getting all this news during our travels and realizing we were going to have to change our plans. The 5th transmitter was shipped back to us and we had to make a decision…do we make the long run back up to MPG to put it on? We decided that with “Beast” likely dead, leaving only 3 transmitters remaining on MPG, we had to make a go for it. We left Island Park in the morning and made it up to MPG by dinner time. We tried in vain to find a new nest in order to transmitter a different bird.
This lone male was our last resort since we were hesitant to add an extra 40 minutes of stress to what was already probably a pretty stressful spring for him. In the end, we decided to go for it – we’d catch him, and if he seemed too thin to handle the transmitter we’d just band him and let him go. We figured that if he was successful it would be really good to have location data on him to learn more about this odd single-parent behavior. As it turned out, his muscle condition seemed right and he weighed a healthy 486 grams so we went for it.
We attached the transmitter, wished him luck, and left for Boise. On our drive home the next day we were brainstorming names and texting with Kate the biologist. We were trying to think of a good name, maybe of a heroic character or a famous single dad. The first character that popped into both our minds was Atticus Finch. So we decided that’s what we had to call him: “Atticus”, after the heroic single father from the novel To Kill a Mockingbird.
That was last week. And here’s where the story gets better. With a predicted hatch date any day (but possibly delayed if he wasn’t able to incubate as much as 2 parents could), we were anxiously awaiting news from the biologists at MPG. Finally, on Wednesday we heard the news we’d been waiting for. Debbie of MPG Ranch checked on Atticus and found that the eggs had hatched. He was now the proud parent of three fuzzy chicks!
With the hard incubation work over, we hope that Atticus can successfully raise the chicks on his own. We’re sure he’s very happy to have mobile babies that can feed right alongside him, instead of fragile eggs to tend to. That said, let’s cross our fingers that the chicks find good cover and can survive to fledging … go Atticus!
We’re used to seeing curlews defend their nests from aerial predators while we’re out doing surveys, but yesterday Ben, one of our all-star curlew technicians, witnessed some behavior we’ve never seen before when a ground predator showed up:
Story by Ben Wright
While out nest searching today, I watched a pair of curlews land next to each other in the distance. At this point in the season we get excited anytime we find a female, because they are very hard to locate once the incubation period begins and they sit nearly invisible on the nest for virtually all the daylight hours.
Right after the pair landed, a coyote ran toward them from the west. As the coyote came over the hill, the male curlew took off and flew across the draw to the east of him. The coyote stopped a few feet from the female but watched where the male flew to. The male landed near the bottom of the east side of the draw, seemingly trying to lure the predator away.
After landing he began making an unusual chirping call I had never heard before, but one that sounded very similar to the call curlews use when they are with their chicks. As soon as the male began to call, the coyote immediately ran in his direction. It seemed that the coyote knew that that noise should mean there would be some curlew chicks nearby! The coyote disappeared in what seemed like a pursuit of some chicks and the male successfully distracted the predator from discovering the nest. Shortly after the coyote left, the female made her way over the hill to her nest, revealing its location to me. What really amazed me was to realize that the coyote had passed within meters of their nest! This pair’s nest makes the 6th for the 2014 season so far so stay tuned for more curlew updates in the next few weeks!
By Rob Miller
This week is the official launch of the Intermountain Bird Observatory’s woodpecker survey projects. Of the three woodpecker survey projects we will complete this year, two kick off this week. It is an exciting time to get out in the woods, as many resident species are claiming their territories and the long distance migrants are inbound to compete as well. Most of our areas are still buried in snow, so it provides a great contrast to the summer heat that is soon to arrive.
The first project to launch is the Management Indicator Species project with the Boise National Forest. The forest service is required by their rules to identify management indicator species, or species whose status is tied to the health of the forest. The idea is if the indicator species is doing well, the forest is doing well, and vice versa. It is much more cost efficient to monitor a few indicator species, than to survey for all species. The challenge is to choose species which are truly representative of forest health. Each forest has the latitude to choose their own species based upon their management goals. The Boise National Forest has identified three species, all woodpeckers – Pileated Woodpecker, White-headed Woodpecker, and the Black-backed Woodpecker. The Pileated and White-headed surveys are performed in April and May, whereas the Black-backed surveys will be launched in June.
The surveys begin 30 minutes before sunrise. Each transect includes ten points, spaced 250 meter apart. We must finish all points by 10am. At each point we will perform a 10-minute point count. This is split between five minutes of silent listening and, new this year based upon our recommendations from last year, five minutes of White-headed Woodpecker call broadcasts. We added the calls this year to try and increase detection of this rare species. This project was designed by the forest service and they have responsibility to analyze the results. However, as noted, we have influenced the approach by adding the call broadcasts for White-headed Woodpeckers.
The second project kicking off this week is also a management indicator species project. The Caribou-Targhee National Forest has contracted with IBO to survey for eight woodpecker species across the northern section of the forest. IBO designed the project and will execute, analyze, and report the results. This complex project will involve surveying four points per morning, each separated by 500 meters. The points are located “off trail” so access and navigation will be more difficult. The presence of deep snow, rough terrain, and grizzly bears, further complicate the logistics. The surveys also begin 30 minutes before sunrise and must finish by 10am. At each point there will be a six minute silent listening period followed by broadcasts of each of the eight species. Yes, that is 22 minutes in total! This project will continue daily for six weeks.
In June we will kick off the Black-backed Woodpecker project for the Boise National Forest. This project was new last year and was designed, implemented, analyzed, and reported by IBO. We have made a few modifications this year to improve the project. The Black-backed Woodpecker is a fire specialist, so we are excited to see how their population and distribution have changed after two seasons with large fires.
The forest service does choose other management indicator species besides woodpeckers. The Sawtooth National Forest has chosen the Northern Goshawk. IBO will kick off our goshawk project in partnership with the Sawtooth National Forest in June.
Check back for updates on each of these projects!
In 2014, I have the honor to lead a team for the 4th straight year to study the breeding ecology of the Northern Goshawk within the Minidoka Ranger District of the Sawtooth National Forest. This work continues IBO’s focus on this species and fits into a multiple-year research plan to assess the importance of this possibly isolated population of goshawks with respect to the broader biogeographical context of the species.
Not all of the Sawtooth National Forest is near the Sawtooth Mountains. The five sections of the Minidoka Ranger District of the Sawtooth National Forest in south-central Idaho/northern Utah, USA.
It is probably worth pointing out that not all of the Sawtooth National Forest is near the Sawtooth Mountains. It is a common and understandable misconception. There are three ranger districts in central Idaho encompassing the Sawtooth Mountains (SNRA, Ketchum, and Fairfield), but there is one district south of the Snake River, spread across five “forest islands” (Fig. 1). This later district, known as the Minidoka district, is where our recent work was performed. This district includes four sections in Idaho and one in northern Utah.
The Northern Goshawk (Accipiter gentilis; hereafter “goshawk”) is of interest to many resource management agencies. It is considered a “sensitive species” by the USDA Forest Service and a “regional/state imperiled species” by the BLM. The goshawk has twice been petitioned as an endangered species under the Endangered Species Act, but the petition was rejected on both occasions. The Sawtooth National Forest has identified the goshawk as a local Management Indicator Species. As such they must monitor the health of the population and make forest management decisions based upon the results. The species has received a lot of monitoring attention within the South Hills off and on over the past 20 years, but much less attention has been applied in the other sections.
The Minidoka Ranger District is located in the northern portion of the Great Basin. The Great Basin consists largely of shrub-steppe habitat with forested landscapes only at higher elevations. Even at these higher elevations the forest is still fragmented with most of the trees on northern facing slopes and in drainages. The result is an island-like landscape where the space between the “islands” consists largely of shrubland and native grassland. In the modern era, the matrix between fragments is also distinguished by agriculture, increasing development, and an increasing transformation to invasive grasslands. The size and isolation of these “islands” influences the species diversity which is able to survive within each fragment. The theory of Island Biogeography predicts that species diversity is related to the size of the island (larger islands have more species) and the distance to the next population (islands closer to mainlands have more species). In general, this theory applies to forest fragments as well, but the degree is determined by what occupies the matrix land between fragments and whether the matrix is easily traversed by dispersing individuals. Birds can easily fly to the next island, but mammalian dispersal is much more limited. The South Hills and nearby Albion Mountains present a unique prey assemblage for goshawks as their most common diet of tree squirrels are naturally absent, although tree squirrels do exist in the Sublett and Black Pines Mountains.
Tree Squirrels, a common part of most goshawks’ diets, are naturally absent from the South Hills.
American Red Squirrel (Tamiasciurus hudsonicus)
The lack of tree squirrels has led to the rise of the South Hills Crossbill as a sub-species of the Red Crossbill, but that is a whole other story with many ecological lessons as well.
South Hills Crossbill, “South Hills”, Sawtooth National Forest.
During the 2011 and 2012 breeding seasons, the focus of our research, and my thesis, was on the diet of the goshawk in this unusual prey landscape (Miller et al. 2014), the habitat use of the goshawks in this landscape (Miller et al. 2013), and the influence of prey abundance on nest occupancy and productivity (Miller et al. In review). This effort was focused on the Cassia section of the forest, also known as, the South Hills.
One of the most significant results from this recent work in the South Hills was a habitat suitability model, or statistical model which predicts areas with appropriate characteristics for goshawk nesting. In 2012, the model helped us find a number of new territories. In 2013, we applied this model to the Black Pines and Sublett sections of the forest and then spent a few weeks surveying the highest priority areas, discovering a half dozen previously unknown goshawk territories.
In 2014, we will cross the border outside of Idaho into northern Utah and the Raft River range. This will be the first time the area has been formally surveyed. The model predicts some, but not a lot, of suitable habitat. We will also survey the Albion mountains where we expect to discover a number of new nesting structures, hopefully occupied by goshawks. To finish the survey effort, we plan to check all historical nesting structures in the other three sections of the forest to determine which are occupied this year. It may sound easy, but we have documented over 110 nesting structures across a broad geographic area which were likely built by goshawks!
In 2012, we also collected blood samples from nestling goshawks to analyze for parasite infection, which we found in large numbers (Jeffries et al. In review). This year we are excited to bring on an NSF-funded intern who will work with a visiting Fulbright Scholar to evaluate the genetic health and diversity of the goshawks using those existing blood samples. We will also be gathering additional samples in the field this year. Look forward to more publications from IBO in the future.
Emmy, Alexis, and Heidi with nestling goshawk, “South Hills”, Sawtooth National Forest.
We have a full agenda ahead to meet the forest service requirements for monitoring this species across the five sections. However, we are seeking additional funding from other sources to fund the work to help place the Great Basin population of birds into a broader geographical context. We know from past studies that some birds do disperse between islands within the Great Basin to breed (Independence Mountains in Nevada to the South Hills in Idaho). However, we don’t know to what degree the Great Basin individuals mix with birds in the more contiguous Rocky Mountains or even the Pacific coast populations. We have some great work ahead of us.
But in the short term, I can’t wait to get my feet back on the ground within the Sawtooth National Forest! It is a unique and fantastic place.
Female Northern Goshawk on nest, “South Hills”, Sawtooth National Forest.
Miller, R. A., J. D. Carlisle, M. J. Bechard, and D. Santini. 2013. Predicting nesting habitat of Northern Goshawks in mixed aspen-lodgepole pine forests in a high-elevation shrub-steppe dominated landscape. Open Journal of Ecology 3:109–115.
Miller, R. A., J. D. Carlisle, and M. J. Bechard. 2014. Effects of prey abundance on breeding season diet of Northern Goshawks (Accipiter gentilis) within an unusual prey landscape. Journal of Raptor Research 48 (1):In Press.
Miller, R. A., J. D. Carlisle, and M. J. Bechard. In Review. Prey abundance and forest structural influences on occupancy and productivity of Northern Goshawks within a mixed forest and shrub community in the Great Basin, USA.
Jeffries, M. I., R. A. Miller, M. D. Laskowski, and J. D. Carlisle. In Review. High prevalence of Leucocytozoon parasites in nestling Northern Goshawks (Accipiter gentilis) in the northern Great Basin USA.
Back in December I was presented with an opportunity to attend a January conference in San Diego and I was really torn. I knew I would have lots of deadlines this month and, while I very much enjoy the traveling, meeting new people, and seeing old friends that goes along with conferences, it’s become a bigger part of my work life and sometimes it’s nice to just stay home! But then I thought, “San Diego isn’t that far from the Salton Sea and ‘Borah’ (a curlew that breeds in the Pahsimeroi Valley of east-central Idaho) has been there for almost 2 months – if he stays and I could go look for him, that’d be worthwhile” and my decision was made. I could attend the conference – very worthwhile, by the way (the M. J. Murdock Charitable Trust’s Partners in Science program) – and then take advantage of the long weekend afterwards to go on a bit of a road trip. Of course, maybe I could fit in a little birding too :-).
Before leaving Boise last week I called the Sonny Bono Salton Sea National Wildlife Refuge and reached a very friendly Mark Stewart, an education specialist, who told me how many curlews he’d seen lately (A LOT!) and gave me contact information for the biologists. Fortunately for me, Katie Montgomery was willing to spend part of her day off on Sunday afternoon touring me around the refuge and nearby agricultural habitats.
I didn’t drive directly from San Diego to the Salton Sea, however. I noticed on eBird that 2 of the many Blue-footed Boobies that ventured north and inland last fall were still lingering at a place I’d never been called Lake Skinner County Park, roughly between San Diego and Riverside. So, I got up too early on Sunday and drove to the park and it was well worth it – the boobies were easy to find so I spent a little time exploring the park and found LOADS of birds (maybe the long-running drought is concentrating even more birds at this oasis?), including some wintering migrants like Lark & White-crowned Sparrows and Townsend’s, Orange-crowned, and Yellow-rumped Warblers. I was most excited to see a few species I rarely get a chance to, such as California Gnatcatcher, Red-breasted Sapsucker, Nuttall’s Woodpecker, and Oak Titmouse. I literally had to force myself to leave but I had some miles to cover across some beautiful southern California foothills to get to the Salton Sea.
I arrived at our meeting spot (the Circle K in Westmorland) a little early so I used my phone to check the latest transmission locations from Borah’s satellite transmitter – a bay with mudflats on the refuge and a couple locations from nearby farm fields. We started by heading out to the refuge and I was amazed at the bird numbers – a cloud of Snow & Ross’s Geese, many raptors, sparrows fleeing from the road edges, and then tremendous waterbird numbers once we arrived at ‘the sea’.
The birds were very distant and many of the curlews (I estimated about 180 in view) were either behind ducks or roosting with their bill tucked and one leg pulled up into their belly feathers. Thus, it would have been hard to see Borah’s color band or the antenna from his transmitter but I still gave it a shot! Katie, probably thinking ‘this guy is crazy if he thinks he’s going to see a color band from this distance’, was very patient with me and we enjoyed the birding in general, including a Sora that called once from the nearby marsh. Once I’d had my fill, we moved on to a few farm fields where recent transmissions had come from. A couple places with taller crops were likely areas where the bird had been flying over but we finally found a recently-irrigated field with loads of ibis and gulls and Katie said, “this is the type of situation I usually see curlews in when they’re in agriculture”.
We couldn’t see any curlews at first but we figured it was worth bringing out our scopes since Borah had been here just hours before … While first scanning through the ibis horde, I briefly thought I saw something brown but then it vanished and I wondered if I just really wanted to see a curlew so badly after coming this far! But, I scanned further left and found some curlews (about 18) – and there were also about 10 Black-bellied Plovers here (we’d seen over 100 of these back at ‘the sea’).
I tried in vain to find Borah but to no avail. I have to imagine he’d either been in view but hard to distinguish, flying over, or at least within a mile of us during our search. I knew it was a longshot to actually find one curlew among all these birds and at day’s end I was happy to have seen a few of the places where this curlew, whom I’d first seen and captured in late May near the historic settlement of Goldburg, Idaho, had been in the days and hours before our search. And, after studying White-faced Ibis for the first time in the summer of 2012, I really enjoyed getting to see similar concentrations using flood-irrigated agriculture on the wintering grounds as well.
Thanks to Borah for willingly carrying the lightweight burden of the satellite transmitter, teaching us about the rest of your life outside of Idaho, and for inspiring a fun road trip! Likewise, thanks to Katie Montgomery for giving up her off-day to show me some of the places that Borah has called home recently. Here’s to hoping I’ll see Borah back in the Pahsimeroi this May!
Since all our transmittered curlews left Idaho, I’ve watched their movements with excitement as it seems that every week or two something unexpected happens. It’s already been an eventful non-breeding season in terms of challenges faced by our curlews:
- Ada met her end soon after arriving to the Merced area of California in late July (story here)
- Curley, the first curlew to migrate (early June) then passed away in late September (her remains were found in an alfalfa field and we were unable to determine cause of death). She had spent her first 1.5 months in California (mid-June to late July) bouncing around agricultural lands between Fresno and Bakersfield before jumping to an area south of Bakersfield in late July (see below).
Thus, since late September we’ve been following the two remaining birds, Borah and Emmett, both males, and hoping they’d survive and keep teaching us. Watching Borah hadn’t been too exciting because he was staying put in a big way – in 4 months he hardly moved 500 meters since arriving at the mouth of the Colorado River in the Gulf of California. Specifically, he was spending time on Isla Montague, a rich delta environment that, according to a few Mexican colleagues I’ve been able to communicate with, supports HUGE numbers of shorebirds.
Meanwhile, Emmett had been exhibiting a little more wanderlust – spending a lot of time south of Fresno before moving up to the Los Banos area and undergoing more short-distance movements in each area (see below)
Then, almost simultaneously, both males made relatively long flights to the northwest:
On November 6th, Emmett started with a short hop and then gradually made his way to an area west of Sacramento – over 200km from where he’d been.
On November 8th, Borah started moving northwest and has seemingly settled at the southern end of the Salton Sea – about 175km from where he’d been.
So, why did both birds suddenly shift wintering areas in early November? We don’t expect them back in Idaho until mid-March at the earliest. Did something change in terms of food availability simultaneously in both areas (seems unlikely given that Borah’s been in an estuarine environment and Emmett in grasslands and agriculture) or is there some internal clock that causes both birds, and presumably the flocks they are wintering with, to move around the same time? Only time will tell … and hopefully more transmitters attached next breeding season will help us learn more. In the meantime, I’ll keep crossing my fingers that our transmittered males can survive the winter and return to breed in 2014!