Sunday, November 06, 2016

Mi Regreso a España

I recently had the opportunity to return to Spain to work with partners and friends of the Intermountain Bird Observatory, Fundación Migres. This was my third time over there working with the team during the fall migration. It was great to spend time working with old friends and colleagues. I have previous summaries of my 2-week-long 2013 trip (HERE, with links to more stories) and Karyn and my two-month-long 2014 trip (HERE, with links to more stories).

This year’s trip was a little bit different in that the two previous trips were always during the first half of the fall migration season, whereas this trip was scheduled toward the end of the season. This gave me the opportunity to experience different birds and different projects. Another big difference was the fact that the Migres group has a new center, where I was allowed to stay!

Sunrise at the southern-most tip of Europe, Africa is visible in the distance on the right.

The beginning of the trip was a little rough. The plane was delayed out of Boise, leaving me just enough time to run to my flight to Europe at the Seattle airport. I boarded the plane just 5 minutes before the doors closed. This is never a good scenario from a checked baggage perspective! Landed in Paris and then in Malaga Spain. My bags did not. It would be another two days before my bags would join me at the Centro Internacional de Migración de Aves. Two days later, the airline attempted to deliver the baggage, but could not find the center. They asked around and someone sent them to closest count site (not the one I was at). They walked up and asked one of the Spanish employees of Migres (Andres) if he was “Rob Miller”. No, but he knew who I was and the airline handed him the bag.

Twenty hours of airports and flying, then a train, and a three hour bus connection, and I was closing in on Tarifa Spain, my home for two weeks. I texted my friend Alejandro asking for a ride from the bus station. He replied and asked if I was going to go band swallows that night in Laguna de La Janda. Ha ha, absolutely! Alejandro and I have a long standing joke about not getting any sleep upon arrival during my previous trips. This must surely be a joke. “Indeed” I reply. Lola, Wioleta, and Javi pick me up at the bus station. I am excited to arrive at the center, take a shower, get some food, and then sleep. Lola drives out of Tarifa toward the center, but then takes a left turn…what…wait… are we really going to La Janda? Yes. No food, no water, seven more hours before sleep… Welcome to Spain.! (Actually, it was a great evening and I was glad that I went). We banded 55 Barn Swallows and then stopped for a mid-night pizza on the way back to the center. I did great until I ate the pizza, then I was ready to sleep right there.

My home and office for two weeks in Spain.
It was great to be back, even without clean clothes! Migres has opened their new center which has dormitory rooms, shared kitchen, office space for employees and for visitors, a library, conference room, is a 5 minute walk from the Mediterranean, and is only a 20 minute walk to downtown Tarifa. But the biggest thrill was to be back to see one of the largest raptor migrations on earth – a place where most of the raptors in western Europe travel to for the 10 mile cross to Africa.

Cigueña blanca (White Storks) approaching the Strait of Gibraltar.
All things in Tarifa are dictated by the wind – recreation, energy, bird migration, etc. As one example, people don’t use weather apps to get the weather forecasts, they use wind apps – WindGuru – being the most reliable source. The birds approach the Strait of Gibraltar for the crossing to Africa, but if conditions are not perfect, may turn back to wait days and sometimes more than a week for conditions to improve. It can make conditions for counting very difficult – we have to discern which birds are crossing and which birds are not.

Flock of over 300 Cigueña blanca (White Storks) and 4 Espátulas (Spoonbills) with wind turbines in the background. These birds did not cross on this day due to the string Levante (east) winds.

I joined three previous Boise State University graduate students (Michelle, Erin, and Tempe) who were each spending three months working in Spain with our Migres partners. I was there for their final two weeks on the project to help wrap up the research plan and begin the work toward manuscript publication. Through IBO's partnership with Fundación Migres, we have published two research manuscripts. My previous paper from my work in Spain was published earlier this year - Local and regional weather patterns influencing post-breeding migration counts of soaring birds at the Strait of Gibraltar, Spain.

But, most of my time was out in the field counting, and in some cases identifying the age and sex of, the migratory raptors.

Rob (me) trying to identify birds at Observatorio del Estrecho. The Strait of Gibraltar is roughly 50 meters behind me.
Inmaduro Águila Culebrera (inmature [2 –4 years old] Short-toed Snake Eagle).

Milano Real (Red Kite).
One day at the Cazalla count site, we observed a very interesting bird. Carlos was very excitedly shouting in Spanish too fast for me to understand. I understood Águila (“Eagle”). It was an eagle. It was a rare eagle. It was an extremely rare eagle! Águila Esteparia – what is that?!? I am challenged enough with Spanish names for the birds I do know, but I was not prepared for a very rare sighting. Luckily the bird was flying toward us. Carlos had originally spotted it miles away. I grabbed the book and found what he was talking about – a Steppe Eagle from Africa. Woah! Spectacular. It was flying closer and closer.

It had a snake in its talons… no… it has falconry jesses on its legs… This bird is an escaped falconry bird. We don’t get to count it… We later received the owners name and was asked to call him if we encountered the bird again, which we did. I haven’t heard if he was able to recapture the bird or if it is still flying wild.

Águila Esteparia (Steppe Eagle), this one is an escaped falconry bird.
But I would get my rare bird after all. On my final half day of work before catching the bus to Malaga, a rare Águila pomarena (Lesser-spotted Eagle) would fly over the Cazalla count site, close enough for photos.

Águila pomarena (Lesser-spotted Eagle).
Another highlight of my final day at the Cazalla count site was the Griffon Vulture migration. Griffon Vultures are very large birds. Late in the season we would count hundreds of Griffon Vultures flying around the count site, but none were crossing to Africa. On my final morning there, that all changed. The wind was right and it was time to move. We could sense the change in behavior. They climbed up the ridgeline, soaring higher and higher and then streamed across the Strait. Ten, hundreds, thousands! In all, 5000 Griffon were counted migrating to Africa that day. What a great finish!

Buitre Leonado (Griffon Vulture) migrating to Africa.
But my trip was not all about raptors. The week that I arrived the team started counting the seabird migration at the very tip of Europe. I would spend two days out there counting Gannets, Cory Shearwaters, Balearic Shearwaters, Sandwich Terns, Lesser-crested Terns, Storm-petrals, etc. Being seabirds, these guys were not migrating from one continent to another, but instead from one ocean to one sea (or vice versa). The Gannets were migrating from the Atlantic Ocean into the Mediterranean Sea, as were the Balearic Shearwaters. The Cory Shearwaters were headed in the other direction. Presumably their food sources were also migrating. Tuna migrate through the Strait, which is why there are Orca at the Strait. We also observed dolphins migrating, one pod of more than 100!

The counts begin at sunrise on the Isle de Tarifa, the southern-most tip of Europe.

Michelle and Carlos counting for this round. We count for ten minutes and then rest your eyes for five minutes, with a longer break after three rounds, hence counting 30 minutes per hour. 
Adult Gannets migrating from Atlantic Ocean into the Mediterranean Sea. Their white feathers are more iridescent and reflective than most white birds. Spectacular.

We get to see other birds too, such as these Sanderlings and Mediterranean Gull.
And this Northern Wheatear perched on the very tip of Europe, possibly contemplating a crossing.
I also got to spend two nights banding swallows and one morning banding songbirds in Laguna de La Janda. Here are some of my favorites.

Male Blackcap.
Male Bluethroad, my favorite!

Pied Flycatcher. A new bird for me, but one I have read many papers on. This species is a model example of how climate change has negatively affected long-distant migrants when their food source changes its phenology (timing), but they do not.
We had a few days of spotty weather which closed some of the observatories. What do bird biologists do in these scenarios – they go birding. Alejandro took us on a birding trip up through and around Laguna de La Janda, where the weather was surprisingly good. We enjoyed three sightings of Spanish Imperial Eagles and the critically endangered Bald Ibis. Both species are benefiting from reintroduction efforts in the area.

Águia Imperial Ibérica (Spanish Imperial Eagle) in Laguna de La Janda.
The Bald Ibis was completely extirpated from Europe. Just a few years ago the estimated global population was around 500 birds! After numerous attempts at reintroduction in Europe, one colony just north of Tarifa has been successful. This colony has grown since my last visit, just two years ago.
Critically Endangered Bald Ibis.
Critically Endangered Bald Ibis allopreening.
Here is a short video I took of the Allopreening behavior. These are truly fantastic creatures.

As expected it was a fantastic trip that I got to spend with great friends from the past and new friends I made on this trip. I look forward to my next visit!

I will close with a fun video that the Migres team put together featuring some of the volunteers and collaborators including team America (myself and the three women from Boise State).

Sunday, July 03, 2016

Nature, Nurture, Environment, or All of the Above?

Wow, another Northern Goshawk field season is beginning to wrap up. How does it go so fast? The Intermountain Bird Observatory’s Team Goshawk 2016, led by me, has been busy with many expected and unexpected discoveries. As with the past two years, I am once again hosting a National Science Foundation funded intern. My 2016 intern is Lauren Whitenack. She has been a great team player, putting up with me for the past month in the field. Be sure to check out her blog for her personal view of these adventures: Wild Life.

2016 Team Goshawk intern Lauren releasing newly banded adult goshawk Female Z5

One of the reasons I like fieldwork, is that it presents many mental challenges to try and figure out. While walking through the woods, I like to think about the roles of various plants and animals, how they evolved to be who they are, and why they are so different from each other. In some cases, these mental challenges may lead to formal research questions. In other cases, it may just be an interesting thought exercise. For example, one that I have been bouncing around in my head for years, is why are Common Ravens, that sometimes nest in similar habitats as goshawks, able to be so loquacious or noisy in the nest, whereas, goshawks which seem better able to defend themselves, have evolved to generally remain silent. Is anyone interested in a behavioral evolution study?

Newly banded nestling goshawk Female AM (right) amidst jackrabbit prey remains in the nest. The first evidence I have of breeding season use of jackrabbits. The nestling on the left remained out of reach for banding.

Another one of my age-old questions rolling around in my noodle pertains to the intensity of defense behavior exhibited by different goshawks when an intruder, typically me, enters their domain. Some goshawks are prepared to give their life in defense of their young while I may still be 50m from the nest. Others simply sit silently, or even more passively, fly out of the area leaving the nest behind. What factors influence these decisions and why the different approaches?

A great deal of research, of which I am not an expert, has focused on aggressive behavior in various organisms, including humans. Is aggressive behavior dictated by nature (i.e., encoded in our genes), influenced by nurture (i.e., parental up-bringing), or by environment (i.e., events and conditions around the organism throughout its life). If only it were that simple... We biologists like to put things into simple little categories, but it rarely works out. Well, I say the answer is - all of the above!

Here I will tell the tale of three different goshawks or family of goshawks, with differing levels of aggression, that may support my hypothesis for all of the above. Furthermore, it is generally agreed that goshawks in North America are on average more aggressive than their European counterparts. This, in and of itself, is not well understood, although a number of hypotheses exist.

Part of my research involves color marking goshawks (with 2-digit purple color bands) to keep better track of breeding bird turnover and recruitment. However, like humans and other animals, these birds have unique personalities that in many cases allow me to be reasonably confident in the continued persistence of individual breeding birds, without having to read the bands. In my opinion, anyone who does not believe that birds have emotions and personalities has not spent much time getting to know them. Confirmation of identification via the color band definitely increases our confidence.

Photos of color bands I took while resighting previously banded birds during the 2016 field season.

Case #1: Female 9Z and her offspring Female Z3.

Female 9Z sitting on the nest in the campground (May 16, 2011).

Female 9Z occupied a nest within 50m of the busiest campsite within the busiest campground within my study area. She nested in the same tree for years. Clearly she was well adapted to disturbance as the summer brings non-stop ATV and motorcycle noise from dusk until dawn. We know from other studies that even birds that are well adapted to disturbance, still suffer lower productivity as a result (Strasser and Heath 2013), yet she returned year after year. I don’t know her productivity over time, but her final two years in the area did result in below-average success. There are many interesting questions that this raises? What was the advantage she saw in the area? In a world of increasing noise and disturbance, is there an evolved adaptation to be more tolerant? Was she tolerant of disturbance upon arrival, or did she grow accustomed over time?

Female Z3, daughter of Female 9Z, as a nestling in the campground (July 10, 2012).

Female 9Z was very calm. She never attacked and never flew out of the area when we visited. I twice climbed her nest tree to band her nestlings (in 2011 an 2012). On one occasion, she didn’t even issue an alarm call until I was 10 feet off the ground. She never left her perch. In 2012, I banded her single nestling Female Z3 within this nest. I have later found Z3 breeding (2014, 2015, and 2016) in a neighboring mountain range. She is just as calm and collected as her mother was, yet she is nesting in an area very isolated from human disturbance. Is her calm demeanor the result of nature (i.e., genetics - calm mother = calm daughter) or the result of nurturing (Z3 observed the calm demeanor of 9Z in the nest and learned or not over-react)? Their two environments could not have been more different, so probably not a string influence in this case. Very cool questions indeed!

Female Z3 as a breeding “Third-Year” bird in a nearby mountain range (June 23, 2014).
Also observed in the same territory in 2015 and 2016.

Case #2:  Unbanded Female.

I have an unbanded female in one of the territories I monitored that I am fairly certain was the same female for four years in a row. During 2011, I visited this nest once a week to check on the nest status. In each case the female carefully watched me enter the territory, do my status check, and then leave. She never protested, she never flew off, she never attacked.

Unbanded female in nest stand (June 18, 2012).

In 2012, I once again returned to the area on a weekly basis to the same general response. That was until I decided to climb her nest tree to install a video camera as part of my diet study on this species. This action apparently crossed a trust barrier that we had in place. A trust that I had broken. She would never forgive the intrusion. This female transformed from one of the most calm individuals to the most defensive goshawk I have ever met. My intrusion had changed her world view. This aggressive behavior lasted for the two additional years with which she was breeding in the area. She may have had a predisposition to aggressive behavior (via nature or nurture), but it took a trigger to engage (environment). This environmental trigger had a long-term affect on the individual. I think about this bird, and my impacts upon her, before I initiate any action within my goshawk studies. Knowing that we have a long-term impact on individuals is not something I am completely comfortable with. I also use the knowledge of this situation to better interpret other behaviors. For example, I now know that environmental conditions can change behaviors. When I find an aggressive bird, I often think about what kind of other triggers that the bird may have experienced.

Case #3: Female N4

In contrast to case #2, Female N4 is another bird I have grown to know well. I, or one of my field technicians, have climbed her nest tree on three occasions over the past six years to band her young. We have also captured her for banding in 2014. This is a very high amount of intrusive behavior. However, in contrast to case #2, this female has not grown more aggressive. If anything she has become more accepting. This year I found her perched on the rim of her nest. I spent ten minutes walking around within the stand gathering habitat data for a new study that Lauren is leading. She never took her eye off me, but also never flew, protested, or attacked me. I spoke to her with admiration and respect, apologized for the inconvenience, wished her well, and left the area as soon as possible. Clearly the same environmental factors applied to two different birds, produced different results. Nature? Nurture, Environment, or all of the above? Yes!

Female N4 on her nest in 2016 (June 21, 2016).

Yes, I talk to birds. I believe that birds are capable of reading our emotions, at least to some extent. When handling birds, if you are calm and confident, the bird will be more likely to be calm. Sure, they do want to get out of your grip. However, the same bird will be more calm with an experienced bander than with a nervous bander. I talk to most of the birds I handle in the off chance that speaking calmly and slowly somehow reduces their stress, if just a little.

We may never know what really goes on in the heads of these birds, but I will continue to admire them for their grace, calm beauty and for the ferocity. I will also continue to believe that they, like ourselves, are influenced by many factors including nature, nurture, and their environment.

#GoshawksRule #TeamGoshawk2016 #LongLiveN4

Sunday, March 06, 2016

Early Spring Visit to City of Rocks National Reserve

Karyn and I just returned from a few fabulous days exploring the City of Rocks National Reserve. It is a great time of year to visit as we were essentially the only people camping there. The first night there was one other campsite occupied, the second night – none.
The weather cooperated providing us with 60 degree, calm , sunny days.

The view from our campsite at sunrise
Our campsite was spectacular. Great views and great sounds. We watched the courtship flight displays of Northern Harriers (two males courting a female), listened to male solicitation calls of the nearby Northern Goshawks, and heard three owl species – Two Great Horned Owls courting all night, a Barn Owl, and on our last night there, a nearby Northern Saw-whet Owl calling for a mate. Love was definitely in the air!
The landscape is unique and spectacular.

The park superintendent, Wallace, is an avid birder and joined us for a morning hike as we explored the park.

Wallace and Rob (me) searching for Cassin’s Finches.

Male Spotted Towhee.

Western Scrub-jay
At one point Wallace, Karyn, and I were sitting on a rock when I spotted a Short-tailed Weasel (a.k.a, Ermine) still in winter fur passing under a rock. I was too slow to grab my camera. However, the animal turned and headed straight toward us providing excellent opportunities for photographs. It eventually passed under the rock we were sitting on.

Short-tailed Weasel (a.k.a., Ermine) in winter fur.

Don’t forget to visit nearby Castle Rocks State Park.

Yellow-bellied Marmots in Castle Rocks State Park.
We definitely plan to return!