What Good is a Sister (Bird Club)? - Re-learning Everything You Thought You Knew About Bird Behavior

          Those of us who grew up with sisters know that they are smart -- really smart.  Even if you think you know a lot, you can always learn something from your sisters.  I know this is true because my two brothers and I have five sisters.  Growing up, we boys had to learn, re-learn, and re-re-learn things over and over again -- mostly things like not taking advantage of their fear of snakes or not forgetting their propensity to stab first and ask "who's there" later.  All kidding aside, I am still learning so much from my sisters, and I hope to for a long, long time to come.

          I think the same can be true for the idea of sister bird clubs.  I recently returned from an extended visit to Honduras where I was exploring the idea of establishing sister bird clubs between the U.S. and that Central American country.  When I came back, some of my birder friends asked, "what good is it to develop a network of sister bird clubs?" I think the simple answer is that we can learn a lot from each other about the birds we think we know pretty well, but maybe don't know as much as we think we do.

          Consider the Neotropical migratory birds that we northerners wait all winter to see in spring.  When migration starts, we don't just go looking for these birds in random places.  We know where to look for them because we know their habitat preferences and their behaviors.  Want to find migrating Bay-breasted Warblers or

Look in the forest canopy if you want to find one of

these Bay-breasted Warbler in breeding plumage

during spring migration.  Photo credit: Bill Majoros.

Black-throated Green Warblers in central New York?  Check out the forest canopy.  Looking for Common Yellowthroats or Gray Catbirds?  Head to brushy areas and edge habitats.  What about Golden-winged or Blue-winged Warblers?  Early-successional habitats and brushy habitats are the places to look. 

          Most of these birds are fairly specific in their habitat use and foraging behaviors when migrating through our area and when staking out breeding territories.  The authoritative website All About Birds hosted by the Cornell Lab of Ornithology provides useful summary icons to help birders know what habitats to look in (e.g., forest, scrub) and foraging habits to look for (e.g., foliage gleaner, ground forager) to help searching birders encounter specific birds.     

          Indeed, at the northern end of the migratory pathways, these Neotropical migrants are such creatures of habit that one can generalize about the particular part of a tree in which they are mostly likely to be found!  In an article in the summer 2016 issue of Living Bird magazine (also produced by the Cornell Lab of Ornithology), distinguished ornithologist Irby Lovette penned an article about how a young graduate student named Robert MacArthur discovered in the 1950s that some warblers nesting in the spruce forests of Maine partitioned individual spruce trees as a way of dealing with stiff competition from other species with similar food requirements and foraging strategies.  Dr. Lovette wrote that nearly 70 years later, another young graduate student found that some of the species of bird had changed from the 1950s, but that birds still generally spent most of their time foraging in particular parts of trees.  You can read about that on Cornell Lab of Ornithology website. 

 

Drawing from the summer issue of the Cornell Lab of

Ornithology's Living Bird magazine showing how

some warbler species generally forage in certain parts

of spruce trees to reduce inter-specific competition.

Drawing was done by: Deborah Kaspari.

         Bay-breasted and Black-throated Green Warblers are mentioned in that article as two of these tree-partitioning species.  In general, these two species tend to forage much lower in the branches of spruce trees than Yellow-rumped or Blackburnian Warblers (mid-tree foragers) or Cape May Warblers (tree-top foragers).  Knowledge of such specific behavior can be especially useful for birders who may only get partial glimpses of quickly moving birds trying to gorge themselves on insects.

          What does any of this have to do with sister bird clubs?  Well, like any smart sister, our sister bird clubs in Honduras could help us learn that almost none of this specificity applies to habitat use or foraging habits of these very same species in Central America.  I had this lesson driven home time and time again on my trip to Honduras.  Yeah, everything I thought I knew about the behavior of these birds that could help me locate and identify these species had to be re-calibrated on the migration and wintering grounds. 

          I'll never forget the rapid-fire birding late on the fourth day of competition during the Honduras Birding for Conservation Tour.  Our team of 10 birders, which we named The Ant Swarm, was led by Jeff Gordon, president of the American Birding Association, and Esdras Lopez, a highly-skilled, Honduran bird guide.  We had just returned via a several-hour bus ride from the dry Aguan Valley to the north coast after successfully tallying dry forest species such as the endemic Honduran Emerald, Lesser Roadrunner, White-bellied Wren, and Lesser Ground-Cuckoo.  In La Ceiba, we were birding around some sewage lagoons close by where the Cangrejal River empties into the Caribbean Sea. 

          After spending hours on a bus, we were in serious need of adding more bird species to our tally during the fading hour of daylight.  Between the lagoons and a few small houses of some

Members of The Ant Swarm birding along waste water lagoons

in La Ceiba, Honduras.  Does this look like Bay-breasted

Warbler habitat?  We found them feeding on the ground here.

Photo caption: Jody Enck.

local residents was an open, dirt-and-grass area backed by some brushy habitat.  We found a number of species using this general area.  Some birds were on the ground.  Members of The Ant Swarm sorted through the birds and called out the species.  I recall seeing a Bay-breasted warbler in that dirt-and-grass area, and calling out its name.  "No way!" barked Jeff Gordon.  "I've never seen a Bay-breasted Warbler foraging on the ground."  But, there it was in all its glory acting more like a sparrow than a forest warbler.  We found numerous other individuals on the open ground during the Tour, too.

          Oh, but we also found them deep in the forest.  Early in my travels in Honduras, I was fortunate enough to spend a couple days on the north coast at the Lodge and Spa at Pico Bonito.  The lodge property abuts the largely inaccessible Pico Bonito National Park. 

Another habitat where we found Bay-breasted

Warblers, this time feeding high in the canopy.

Photo credit: Jody Enck.  

One morning, Katinka Domen from Beaks and Peaks Birding and Adventure Tours and I trekked off in the dark for an hour of hiking uphill just so we could access a sort-of trail into the National Park at daylight.  As we hiked our way through an amazingly pristine Rainforest on the lower slopes of the namesake mountain, we came across a number of deep-forest species.  These included Plain Antvireo, Tawny-crowned Greenlet, Nightingale Wren, and Ruddy-tailed Flycatcher.  We also repeated saw these birds that for all the world acted like some deep-woods Oriole, gleaning for insects high in the canopy of Rainforest.  You guessed it -- Bay-breasted Warblers were really quite common in the deep Rainforest.

          This very idea was raised by birders from a couple of the bird clubs with whom I met in Honduras.  Their experiences with Neotropical migratory birds as well as resident Central American species let them to realize that these species seem to use habitat differently and that their foraging habitats likely differ as well.  The Honduran birders pointed out that they would like to know more from us about habitat use and behaviors of migrant birds when they are here on their breeding grounds, and that they could help us learn more about habitat use and behaviors of those birds on their wintering grounds.

          Sharing information about the bird species we share is a great idea.  It goes well beyond just helping birders know where to look for these species, however.  A big part of what we can learn from our sister bird clubs has to do with long-term conservation of bird species. 

Non-breeding plumaged Bay-breasted Warbler.  When foraging

high in the canopy of the Rainforest, these relatively large

warblers can be confused with female or immature orioles.

Photo Credit: Jame Hurt.

          Data from the Canadian breeding grounds for both Bay-breasted Warbler and Black-throated Green Warbler show that these species have been experiencing slow, but long-term declines in population size.  Habitat loss on breeding grounds, along migration routes, and on wintering grounds is a key factor influencing population trends for both species.  Consider, however, that these species seem to be able to use a great variety of habitat types during migration and on their wintering grounds than some of the more habitat-specific resident birds in Central and South America. 

          Loss of habitat for those resident species has an even great

In the buffer zone of Santa Barbara National Park, Honduras,

clearing for small-scale agriculture negatively impacts habitat

availability for birds.  Photo Credit: Jody Enck.

impact because they are unable to utilize as wide of a range of habitats.  I witnessed loss of forest habitat on a frequent basis when I was in Honduras.  Each day, more forest was lost to wood cutting and clearing for agriculture.  Loss of mature forest is having a devastating effect on populations of resident birds in Central America.

          Even week-to-week changes in habitat structure in areas cleared for agriculture affect distribution, and ultimately, abundance of Neotropical migratory species.  In mid-October, I

A farmer using a machete to cut weeds and remnants of

agricultural plants to prepare the hillside for the next crop.

Even small-scale farmers can have large-scale impacts on

habitat for both resident and Neotropical migratory birds.

Photo Credit: Jody Enck.

observed many species of Neotropical migratory species and some resident birds that utilize weedy and early-successional woody habitats in areas where small-scale farmers recently had harvested corn and other crops.  When I was back in the same area four weeks later, agricultural habitats where I had encountered Mourning and McGillivray's Warblers, Variable Seedeater, Prevost's Ground-Sparrow, Green-throated Mountain-Gem, and Rufous-capped Warbler had been hacked to the ground in preparation for planting a new crop of corn and beans. 

          These are the kinds of things that our sister bird clubs can help us learn: habitat use and habits of birds with which we are familiar in North America are not the same farther south in migration or on the wintering grounds.  Habitat types and short-term changes to those habitats are not the same as what we are used to in North America.  At the very least, our sister bird clubs can share these stories, pictures, videos, and bird population information with us to help us re-learn what we might have thought that we know.  We also might engage in exchange visits to learn some of these things firsthand. 

          Yes, our sister bird clubs can help us learn and re-learn a lot.  Gaining that kind of knowledge is important.  Even more important is connecting the dots between the various pieces of knowledge to increase our understanding about the world around us, especially the conservation implications.  Most important then will be to work with our sister bird clubs to use that understanding to achieve conservation outcomes for the birds we share and that we love so much.