The Rodent Situation (Not Your Grandfather’s Mouse)

Spawned from undersea volcanoes and thousands of miles from any continent, the Hawaiian Islands harbor very few indigenous land animals. Once in a while a bird or insect made its way here – perhaps blown in by a storm – and over the eons a few survived and were able survive. From these the entire Hawaiian terrestrial fauna evolved. Most mammals don’t do overseas travel very well, as evidenced by the fact that the only native mammal in the entire Hawaiian archipelago is the reclusive Hawaiian Hoary Bat (‘ope‘ape‘a). After human technology developed to the point where people could travel long distances by boat, the situation changed.  Some of the earliest Polynesian explorers that made their way the shores of these islands in seagoing canoes unwittingly carried with them the Polynesian rat (Rattus exulans). When Europeans began to visit the islands they brought along their own rat:  black rat (Rattus rattus; sometimes called the “ship rat”). Also onboard were mice (Mus musculus).

Non-native rodents often found on oceanic islands. Top: House mouse (Mus musculus). Photo courtesy of JN Stuart (Flickr / Non-commercial Creative commons license). Bottom: Black rat (Rattus rattus). Photo courtesy Hermann Falkner (Flickr / Non-commercial Creative commons license)

Rats and mice have followed humans around for millennia, inhabiting our homes, barns, fields, roaming the streets and back alleys of cities and towns. They are well known thieves of food and have a catholic diet. Sure, they like cheese and peanut butter, but contrary to Walt Disney, they are not vegetarians and are known to a variety of animal prey and will even resort to cannibalism when the situation demands. People have battled with rats and mice for centuries and the success of the otherwise ornery and not always appreciated house-cat can probably be better attributed to our distaste for rodents than for our love of felines.

The immediate effects of rodents are pretty obvious: spilled rice grains on the shelf of the pantry reveal, on closer inspection, a hole chewed through the bag; small brown droppings foul the silverware drawer. Rats and mice are also notorious for their role in spreading diseases such as hantavirus,rabies, and bubonic plague. But because of their sheer number, rodents affect the world in ways that can be difficult to fully appreciate. In the 1980s James Brown (the ecologist, not the soul singer) of the University of Arizona conducted a series of experiments which showed that certain seed-eating rodents could transform a grassland into to a shrubland. Once Polynesian rats established themselves in Hawaii, they took to eating the seeds of native fan palms eventually wiping out forests in places like Ewa Beach on Oahu.

The uninhabited Northwestern Hawaiian Islands remained rodent-free until fairly recently.  Lisianski Island may have been the first to have been colonized when in 1844 a ship visiting from Honolulu deposited some mice onshore. Lacking natural predators, introduced rodents can increase in number at astonishing rates. Five decades after their first introduction, John Cameron, captain of the ship Ebon, made shore at Lisianski and found the island overrun.

We settled ourselves in for an appetizing supper of fresh food when myriads of mice attacked our meal ravenously and utterly without fear. Drive them away we could not; we slaughtered them by the hundreds, yet they would not be denied (quote taken from M Rauzon, Isles of Refuge)

Rodents didn’t find their way to Midway until decades later. Despite the establishment of the Pacific Commercial Cable Company Station on Sand Island in 1903 and the frequent supply ships that brought provisions to its residents, it was not until after WWII that rats and mice arrived, more or less at the same time, presumably on a Navy ship. By 1943 the black rat and the house mouse were noted as present. While the black rat eventually become established on all three of the atoll’s islands, mice were limited to just one, Sand Island.

The effects of rats on Midway’s wildlife were noticed pretty quickly.  Harvey Fisher and Paul Baldwin of the University of Hawaii visited the atoll in 1945 to see how birds were faring after the war. They were especially interested in two species: the Laysan rail and Laysan finch. Not indigenous to Midway, these birds had been brought there decades earlier from their native Laysan Island, where an overpopulation of rabbits had transformed their lush habitat into a barren wasteland, in what must have been one of the earliest wildlife translocation efforts ever attempted. Fisher and Baldwin were extremely disappointed to find that neither the finch nor the rail, which had thrived after their introductions, had made it through the war. The cause of the bird’s demise, they concluded, wasn’t bombs or bullets, nor could it be attributed to the habitat that had been lost to buildings, roads, and runways but rather it was due to a major infestation of rats. Sadly for the Laysan rail – and for us – its disappearance from Midway was tantamount to extinction; if you want to see one you’ll have to settle for an old grainy photo or a stuffed specimen in a museum. Laysan finches were able to pull through the tough times; rabbits were exterminated on Laysan Island in 1923 after which populations rebounded.

The Laysan Rail (Porzana palmeri) was introduced to Midway in the late 1800s and thrived until rats were introduced in 1943 after which it quickly went extinct. Top:  Illustration by John Gerrard Keulemans. Bottom: 1913 photograph by Alfred M. Bailey.

Rats had taken their toll on other bird species as well especially burrow-nesting species such as Bonin petrel, Bulwer’s petrel, wedge-tailed shearwater which are especially vulnerable. Numbers of Bonin petrels had been estimated at about half a million prior to the arrival of rats on Midway; Fisher and Baldwin counted only about 25,000, a 95% reduction. Rats not only preyed on the birds’ eggs but also attacked chicks and adults. Capable climbers, rats also impacted tree-nesting like the brown noddy.

As rats were a nuisance to people as well as wildlife, the Navy made some efforts to control their populations, but impacts to many seabird species persisted. Albatrosses, may have been less affected by rats than were other species, perhaps because their chicks are large and are guarded by a parent for some time after hatching. Which is not to say that it was smooth sailing for them during those times. Roadbuilding, mowing of lawns, overhead power lines, collision with aircraft, harassment by people and dogs, and the deliberate destruction of nests in areas where they were not convenient resulted in steep declines in their numbers, especially for Laysan albatross which inhabits the central portions of the islands. Although no reports of rats killing albatrosses had been made on Midway, there were highly credible accounts of rat attacks on Laysan albatross similar islands.  While visiting Kure Atoll in the late 1960s, Cameron Kepler of Cornell University observed Polynesian rats attacking and sometimes killing adult Laysan albatross.

[We] frequently  encountered  injured  Laysan  Albatrosses  and  noticed  dying  and  dead  adults  with  large  gaping  wounds  in  their  backs;  12  such  birds  were  found  in  the  1963-64  breeding  season… The  open  wounds  were  always  found  on  the  birds'  backs,  either  slightly  anterior  to  the  uropygial  gland,  or  forward  between  the  scapulae.  Small  holes,  one  to  two  inches  in  diameter,  were  occasionally  found.  At  this  stage,  wounds  were  sometimes  obscured  by  feathers,  and  the  injury  did  not  cripple  the  bird …  More  often,  sores  five  to  seven  inches  in  diameter  were  seen.  The  thoracic  cavity  was  often  exposed,  and  ribs  and  scapulae,  or  even  lungs,  were  visible  through  the  gaping  hole.  The  wings  drooped  when  the  bird  stood  or  walked,  as  a  result  of  severed  muscles.  Birds  that  had  wounds  on  their  rumps  often  limped  or  were  unable  to  walk.  The  injuries  were  often  infested  with  the  eggs  of  flies,  and  occasionally  harbored  maggots.  The  feathers  surrounding  the  hole  were  caked  with  blood,  and  the  birds'  bills  were  stained  from  probing  into  the  wound.  Birds  in  these  advanced  stages  rarely  survived  the  night  following  their  discovery (Kempler, 1967)

Could it be that the Polynesian rat is more likely to attack albatrosses than the black rat?  Or, perhaps, control of rats on Midway kept them numbers low enough such that they could subsist on other prey? I’m not sure we’ll ever know, but the rodent situation at Midway continued to harm seabird populations until the mid-1990s when, in anticipation of transfer of the atoll to the US Fish and Wildlife Service, rats were eradicated through a massive trapping and poisoning campaign. The last rat to be seen at Midway was in October of 1997.

The birds approved.  Bonin petrels, which had nearly been wiped out during the age of rats, returned to the atoll to nest once again.  While numbers are hard to come by, it is thought that over one million of these birds now breed on Sand Island alone. Rats on Midway may have been exerting strong effects on vegetation as well. After their eradication, the native shrub naupaka appeared to greatly increase in abundance. Rats, apparently, were eating more than just seabirds and as naupaka plays an important role in stabilizing dunes, rats may even, indirectly, have been accelerating coastal erosion on the atoll.

With rats out of the picture one might think Midway’s rodent problems had finally been solved. And so it seemed for a couple of decades. Though Sand Island still hosted a significant mouse population, they were thought to be primarily a nuisance to the human residents. During my first few days at Midway last spring, I was a bit surprised at how many mice scurried across my headlight beam as I rode my bike at night. It was also hard not notice the dozens of little black bait boxes placed outside of buildings. While there were certainly lots of conservation challenges to be addressed regarding the birds of Midway – ingestion of plastic, lead poisoning, invasive species, and entrapment hazards just to name a few – rodents weren’t high on the list.

During the fall and winter of 2015-6, exceptionally warm water in the Pacific created a particularly strong El Niño which, for this part of the world, means below average rainfall.  Black-footed and Laysan albatrosses arrived from the northern Pacific Ocean around Halloween to begin their long breeding cycle.  Things were going along pretty much as usual when the team of bird counters arrived in mid-December to do their annual albatross census. Then, two days before Christmas, several of the bird counters reported finding five adult Laysan albatrosses with bloody wounds on their necks and heads.  The cause of the wounds was a mystery. Albatross sometimes engage in fights that leave them bloodied and occasionally a peregrine falcon or other avian predator finds its way to the atoll and these possibilities were considered. Fish and Wildlife Service staff investigated the situation through a variety of avenues. On January 5^th, motion-sensing cameras set up alongside nests captured images that many had a hard time believing. Photos clearly showed mice crawling onto the heads and backs of albatrosses while they were sitting on their nests disappearing under their feathers. When those birds were examined, it was revealed that the mice were chewing through the feathers and skin and then eating their victim’s flesh. Both Laysan and black-footed albatross were affected though the former made up the vast majority of the casualties.

Some of the birds succumbed to infection while others abandoned their nests. Video footage revealed that albatross appeared to be annoyed by the presence of the mice but did not seem to know how to respond to the attacks. Perhaps this is not that surprising as animals such as albatrosses that have evolved for millions of years in the absence of mammalian predators may behavioral adaptations that would allow them to defend themselves. It is for this same reason that the island avifauna here and in places like the Galapagos Islands show little or no fear of humans. Watching the videos is painful. You want the albatross to do something, turn its head around and snap the mouse in half with its powerful, sharp bill. Instead the bird is agitated and confused and the mouse returns again and again, seemingly bolder each time, slowing chipping away at the life of a magnificent bird that might otherwise have thrived for decades in some of the harshest environments that our planet offers. It just seems so wrong.

Mouse attacks on albatrosses were first observed on Midway Atoll in 2015 during the early part of the nesting season.  Upper left: A motion-sensing camera captures a mouse crawling on the head of an albtross  sitting on its nest;. Lower left: An obvious and severe mouse-inflicted wound. Right: Sometimes wounds can be hard to detect; in this case wet, ruffled feathers hide a bite on the bird’s right shoulder. Photos  on left courtesy of US Fish and Wildlife Service. Right photo by RV Taylor.

The world’s largest colony of Laysan Albatross was under attack the Fish and Wildlife Service worked diligently with wildlife experts from other agencies and organizations to formulate an appropriate response.  The plan eventually hatched (OK, I know that’s a blatant and not very clever pun but I thought you might need a little levity at this point) was to try to reduce the mouse population in the areas where the attacks were occurring using a combination of traps and rodenticide. The strategy appeared to work and mouse numbers declined in the treated areas and fewer new albatross casualties (birds bitten/injured, dead birds, and abandoned nests) were reported by the field surveyors. Would the mice attack the chicks once they hatched?  No one knew, so it was with great relief in late January when after checking hundreds of nests with newborn chicks that no evidence of mice predation was revealed. When all was said and done though, the impacts were significant: 480 albatross were injured, 57 abandoned their nests, and 52 died. In areas where albatross were seen attacking mice, nests failed at twice the normal rate.

Scientists were dumbfounded as nothing like this had ever been observed in any of the Pacific Islands. What had precipitated the sudden change in the relations between albatrosses and mice on Midway? Maybe the El Niño-caused drought had caused severe food limitations? Or maybe it was a consequence of successful efforts in reducing the invasive weed golden crownbeard, which produces abundant seeds? And most importantly of all, would the situation repeat itself the following winter? There were many questions but few answers.

It turns out, though, that there was some precedent for mice attacking albatrosses, but you had to go to the other side of the world to find it. Gough Island, in the South Atlantic Ocean, is a globally significant seabird colony and hosts the largest colony of Tristan albatross in the world.  During the nesting season of 2000/2001 a substantial portion of albatross chicks died of unknown causes.  Ross Wanless and colleagues from the University of Capetown and the Royal Society for the Protection of Birds set out to find the source of the nest failures. As islands go, Gough Island is unusual in never having had populations of rats, cats, goats, or sheep.  The only introduced mammal there is the house mouse but few believed that they might be the cause. How could a tiny mouse take down an albatross chick that weighs over 8 kg (17 lb)? Using a combination of field surveys and motion-sensing cameras they discovered the cause. Mice!  In this case, however, the rodents were not attacking the adult albatrosses but the chicks. Mice attacked Predation on chicks by mice reduced halved the breeding success rate of these albatross during that season. Subsequent monitoring of the Tristan albatross population on Gough Island painted an even bleaker picture as attacks of mice on albatross seemed to be increasing over time. A team led by Delia Davies from the University of Capetown conducted a follow up study during the 2013/2014 breeding season and found that only 5 of 20 chicks they monitored fledged and of the 15 failures, 14 were due to mice.

"All attacks happened at night and the initial attack was always by a single mouse, which repeatedly targeted the same site, usually on the chick’s rump, clinging to its down and biting until the skin was penetrated. When displaced by the irritated chick nuzzling its wound, or vigorously shaking its body, the mouse would return to the wound within seconds. Chicks were seldom attacked by more than 1-2 mice at a time, although one chick had up to 9 mice attacking at once (Table 1). The behavior of the mice suggested that this was a well-practiced technique, as they generally climbed directly onto the nest mound and the chick without hesitation (Davies et al. 2015)"

The situation on Midway remains unique. On Gough Island, mice never were observed attacking adult albatrosses, only chicks. And at Midway the reverse is true. Putting these two facts together probably makes everyone a little nervous as it suggests that the situation at both of these seabird colonies could probably substantially worse should mice at either location discover there might be yet another source of food.

Given that mice and albatross had seemingly coexisted for over half a century on Midway, no one was sure what the 2016/2017 nesting season would bring. After the albatrosses arrived in the fall and began nesting, we waited and watched anxiously, hoping that the events of the previous year would prove to be an anomaly. On December 4, while out checking birds in areas where mice had attacked the previous year, Fish and Wildlife Service biologist Meg Duhr-Schultz found several bitten birds, removing any possibility that the events of 2015/2016 were some kind of El Niño-driven anomaly. Staff and volunteers were deployed over the next few days to survey other parts of the island and more attacks were discovered. In less than a week the area impacted by mouse attacks had exceeded the total area affected during all of the previous year. And the fact that the mouse attacks were noticed several weeks earlier was of real concern.  Again, the Fish and Wildlife Service had to quickly figure out what to do and the decision was made to take steps to reduce the mice populations in the affected areas. The large area that had already been affected meant that staff and volunteers had to log a lot of extra hours and additional resources were sent from Honolulu. The bird counters pitched in too with some remaining an extra couple of weeks to assist with surveys and treatment. So far the actions that the Fish and Wildlife have taken seem to be having a positive effect. The abundance of mice in the impacted area dropped sharply in areas where rodenticide was applied.

My primary role has been information gathering and analysis, including mapping out the areas affected, and the design of treatments using geographic information systems. This latter part is critical as the rodenticide that is being needs to be broadcast by hand within a predefined grid and must be done in strict accordance with procedures.

Caption: A dead albatross found during the attacks of 2016/2017 next to an abandoned nest (Photo: RV Taylor).

As of today, 48 areas totaling 10.5 ha (26 acres) of mouse affected area has been mapped and over 1,200 bitten birds have been discovered, 211 of which have died. Nearly one thousand abandoned nests have been documented. Mice may also be having impacts on other seabirds here but it would be more difficult to detect, especially for the burrow-nesting species.  Sounds kind of depressing, huh?  It is, but at least we’re not just sitting back and letting it happen. And although the numbers may seem large they need to be put into context. This year, the bird counters tallied nearly a million breeding Laysan albatross across the atoll, so there are still hundreds of thousands of birds going about their business, more or less, as usual. Add to that all the non-breeders who liven up the atmosphere here nearly 24 hours a day with their crazy dancing and “singing” and a group of tight-knit community of good people who recognize how important it is to laugh in the face of adversity.

Map of areas where albatross have been attacked by mice on Sand Island, Midway Atoll National Wildlife Refuge as of 15 January 2017.Areas with green borders indicate areas where only abandoned nests found but no bitten or dead birds. Red triangles represent individual dead or bitten birds.

Another bright spot is that there are plans underway to address the underlying cause of the mouse problems here at Midway.  As the only atoll within the Papahānaumokuākea Marine National Monument that still harbors lingering populations of invasive rodents, there have been plans to eradicate mice from Midway Atoll for some time. The discovery that mice are harming the albatrosses should only strengthen the case for their removal and expedite the project’s implementation. First steps were, in fact, taken just last November when a team of biologists and invasive species experts from the Fish and Wildlife Service and the non-profit organization Island Conservation visited Midway begin a study of the project’s feasibility.  Although eradicating mice from a place as big and complicated as Midway is challenging, similar projects have been successfully completed on other, and in some cases even larger, islands. With the first-hand knowledge I’ve gained on how damaging mice can be to wildlife, I think it would be great to be able to play a role in the eradication effort here.  Who knows, maybe there will be an opportunity? What I am sure of is that after this experience I’ll never look at Mickey Mouse the same way again.

Further reading

Brown, JH, and EJ Heske. 1990. Control of a desert-grassland transition by a keystone rodent guild. Science 250:1705-1707.

Davies, D., B. J. Dilley, A. L. Bond, R. J. Cuthbert, and P. G. Ryan. 2015. Trends and tactics of mouse predation on Tristan Albatross Diomedea dabbenena chicks at Gough Island, South Atlantic Ocean. Avian Conservation and Ecology 10(1):5.

Fisher, HI and PH Baldwin. 1946. War and the birds of Midway Atoll. The Condor 48:3-15.

Hess, SC and J D Jacobi. 2011. The history of mammal eradications in Hawai ‘i and the United States associated islands of the central Pacific.  Pp. 67-73 in Veitch et al. Island invasives: eradication and management. IUCN, Gland, Switzerland.         

Kepler, CB. 1967. Polynesian rat predation on nesting Laysan Albatrosses and other Pacific seabirds. The Auk 84: 426-430.               

Rauzon, MJ. 2001. Isles of Refuge: Wildlife and history of the Northwestern Hawaiian Islands. University of Hawaii Press. Honolulu, HI.

Wanless, R. M., A. Angel, R. J. Cuthbert, G. M. Hilton, and P. G. Ryan. 2007. Can predation by invasive mice drive seabird extinctions? Biology Letters 3:241-244.

               

Savage Love (“Midway Style”)

After a couple of months of relative quiet, the albatrosses started arriving in the middle of October. The first sighting, a lone black-footed albatross in a field behind the “Fuel Farm” spotted by Chugach employee Suriya Hemphumee on October was met with much excitement, not just by the geeky biologists with the Fish and Wildlife Service, but also by other island residents. After going to check out the birds, I remember telling “Jack” (Phosri Kriengsak), one of the power plant operators, that the albatross were back and he replied with a big smile “Really???”. Most everyone I spoke to seemed to think the albatross were a little early this year.The first Laysan albatross arrived about a week later (typical, as black-footed albatross always constitute the vanguard); a single individual that appeared one sunny, breezy day near the old water tower. Slowly but steadily more birds arrived until eventually – over the course of a week or so – it seemed like there were birds nearly everywhere. 

Arrival of the albatross as illustrated by repeat photography in a field north of Charlie Barracks on Sand Island, Midway Atoll (one photo taken each day during the period of November 3-22, 2016).

This being my first time experiencing “albatross welcome week” I was not sure what to expect but will admit that I was not prepared for what I would witness. Postcards of snuggling albatross couples with captions touting their long lifespan and monogamous lifestyle had led me astray. Imagine if your only knowledge of organized crime was a Broadway production of West Side Story prior to finding yourself in the middle of gang shootout in Compton?

The first albatrosses appeared lonely, tired, and somewhat disoriented. Given that many of these birds had been out in the ocean for months and had travelled thousands of miles to get here, perhaps, that is to be expected. It didn’t take them long, though, to recoup their energy. As more birds arrived, disputes over spacing and territory quickly arose. Albatross don’t require a lot of space on their breeding grounds but do have preferences as to where to build their nests and do try to maintain a little space from neighbors (according to a study by Earl Meseth conducted on midway in the early 1960s, nests are always separated by at least 32 inches). As it is males that arrive first, it is among them that disputes over nesting locations seem most common. These can range from, in their mildest form, two birds sitting low and thrusting their bills out towards one another while holding their ground, to full-on brawls that occur when a bird “trespasses” into an area where others have already settled into their territories. As tensions escalate, one bird often locks down on the bill of the other and shake it violently, leaving one or both bloodied. It is also common for the aggressor in one of these encounters to wrap its neck around another bird and attempt to wrestle it to the ground. Fights are accompanied by loud screams that you would think signal mortal wounding, though, it seems, they rarely lead to serious injury.

Squabbles erupt among Laysan albatross as they attempt to claim potential nest sites. 

If the bro’ fights weren’t bad enough there is the raping. Is the, perhaps, anthropomorphic term “raping” really the right word? I don’t know, but honestly, I can’t think of a reasonable alternative. Although authoritative sources state that the “male rarely copulates with female other than his mate"² what one observes on the breeding grounds strongly suggests otherwise, unless there are a lot of single dudes out there. During the first few weeks, as females are returning to the atoll, they seem to be constantly harassed by males (you can tell the difference as males have larger bills relative to the size of their heads). When a female lands, it is instantly recognized by nearby males which begin chasing her and trying to climb on top of her. The female often senses danger and tries to escape with its wings held high but what often ensues are ridiculous pile-ups consisting of three or more males with a terrified female crushed underneath. Whether or not, given the anatomy of these birds the male attackers can actually affect insemination during these non-consensual encounters isn’t clear as males don’t have a penis but instead just an opening (a "cloaca" in technical jargon) very similar to that of the females. After watching albatross have sex several times it would seem to me that the female would have to cooperate for sperm to enter, however scientific studies that might shed light on this question, apparently, have yet to be conducted. Females typically try to defend themselves by biting the attacker but what often ends up saving them are the males themselves, as sexual assault devolves into a testosterone-fueled brawl among the aggressors giving the female the opportunity to escape.

A female Laysan albatross is forcibly mounted by two competing males.

As the sex-ratio on the atoll becomes more balanced things calm down a bit and more socially-acceptable (to humans, that is), oxytocin-inspired, pair-bond behaviors gradually supplant the testosterone frenzy. Once mates arrive, male birds spend more time cuddling with their long-departed lovers and less attacking their neighbors. Preening each other seems to be a very popular form of love amongst the paired birds with attention paid especially to the neck and head (makes sense since these are parts of the body that are not easily reached by an individual). Albatross also just have a way of assuming very cute postures. Consensual sex is also observed in all of its clumsy, web-footed seabird glory as males clamber atop willing females to get the essential business done. This is often followed by dancing and other courtship behaviors. During this early stage of the breeding season an amazingly rich collection of behaviors unfolds. In Meseth’s study of Laysan albatross he detailed at least 26 behavioral elements including the air snap, headshake and whine, head flick, rapid bill clapper, eh-eh bow, scapular action, sky moo, stare and whinny, bob-strut, bill touch, bow clapper, nest threat, bill thrust, charge, glare, victory cry, escape run, and mutual preen. Even though, after six months here at Midway, I have seen these things hundreds of times, I am still fascinated by them and in my reading about the history of Midway it seems that I am not unique in this regard. Beginning in 1904 when employees of the Pacific Commercial Cable Company came to Midway and continuing through the Navy years and into the present, watching the albatross has always been an important form of entertainment for island residents.

Albatross courtship and mating. Clockwise from upper left: A pair of Laysan albatross dance on the breeding grounds; mutual preening; a pair of black-footed albatross enjoy each other's company; Laysan albatross copulating (consensual).

Before you know it there are eggs! The first egg seen on the atoll this year was on November 9^th which just happened to be my birthday. Quite the gift! Before laying an egg the female builds a nest, often with the help of her mate. Some of the nests seem fairly minimal while others are are much more substantial and well-constructed. Nests are built using just the bill and have a foundation of sand or soil sometimes lined with dried leaves or grass. Excavation of material surrounding the nest often results in their being a kind of moat around it. I have only seen one bird actually lay and egg but it seemed like an arduous and uncomfortable. Not surprising since they are quite large, averaging 11 x 7 cm (4.2 x 2.7 inches) in size and constitute nearly 10% of the females body mass!

Laysan albatross female with brand new egg.

As I write this post the albatrosses seem to be incredibly busy. Fights are few as most birds are either courting and mating or have already settled onto their nests and begun the marathon that is reproduction for these species. If all goes well, male and female, in nearly equal turns, will incubate the egg for just over 2 months and then care for and feed their chick for about five months before it is big enough to fly off on its own. For some birds things already have not gone well. Heavy rain fell on the atoll this week which resulted in the inundation of some nests and more storms are sure to come. The waves that overwashed the atoll during the tsunami of March 10, 2011 killed an estimated 110,000 albatross chicks (Laysan and black-footed combined). Albatross will stick tight to their nests with the most incredible tenacity but if the egg is lost they have no choice but to put off breeding until the next year as they lack sufficient reserves to lay a second egg. Knowing that many of the nests will not succeed can be a bit saddening, but the energy and enthusiasm that albatross possess imbue the atoll with a feeling of vitality and inspiration.

Postscript

The title of this blog post was inspired by the refreshingly candid and honest newspaper column Savage Love by Dan Savage. If you have never read it, check it out!

References

1 - Meseth, E. H. (1975). The dance of the Laysan Albatross, Diomedea immutabilis. Behaviour 54(3): 217-257.

2 - Awkerman, Jill A., David J. Anderson and G. Causey Whittow. (2009). Laysan Albatross (Phoebastria immutabilis), The Birds of North America (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America: DOI: 10.2173/bna.66

Pseudo-Post Apocalyptic

In previous posts I’ve given you stories about dancing seabirds, fascinating flowers, endangered seals, and charming men from Thailand. Today though I want to share with you a darker view of Midway. If you’re the kind of person that has bad dreams after reading disturbing things, this might not be the blog post for you. And if there are children in the room, this might be a good time to lock them in the coal closet (well, at least that’s what my parents used to do when they wanted to get rid of us for a spell).

Upon arriving at Midway I was struck by the incredible abundance of seabirds which, coupled with the remoteness of the island and the lack of fear exhibited by wildlife, give the island a surreal flavor for sure. Visitors to the Galapagos or other remote islands would likely have similar impressions and feelings. But the strangeness didn’t stop there. Riding my bicycle across pot-holed roads, among derelict buildings, passing by rusty heaps of scrap metal and old guns, with not another human soul in sight, I have often found myself thinking about what it would be like to one of a handful of survivors of some kind of apocalypse. Some of these buildings are impressive hulks that can even be entered to consummate the feeling of post-nuclear near-annihilation. The seaplane hangar, which suffered great damage during a Japanese bombing raid during World War II, is a great place to do some thinking about the fragility of human societies.

The Seaplane Hangar, an enormous steel framed building  was bombed
on December 7^th, 1941 and nearly destroyed. Though never repaired, it's still used for storage.

Many aspects of life on Midway add to the impression that we live in some sort of post-apocalyptic world. It is a motley crew out here: a dozen or so Americans that for whatever reason decided to station themselves thousands of miles from anywhere. Add to this a couple dozen men from Thailand that certainly must be escaping something, if only perhaps pitiful wages in their home country. When away from my desk and computer, it’s not hard to imagine that this we are the only ones in the world remaining.  Although writers and filmmakers have imagined many variations on what the world might be like should catastrophe come to pass, most agree that motorized modes of transportation would be scarce as the facilities used in the production of oil and gasoline would be the first targets hit. So if we forget about the birds for minute we can easily imagine a more sinister reason why Midway’s residents travel about the island on old rusty bicycles and golf carts.

Midway's only ambulance seems to be a relic passed on from another, more prosperous time and is an example of the island's tradition of keeping old equipment in service as long as possible.

Folks on the island seem to be pretty much oblivious to things happening in the outside world, including even major US elections¹. I remember an occasion last summer when a group of a dozen or so of us argued back and forth on the topic of when and where the Olympic Games were to be held that summer. After five minutes of back and forth – in both English and Thai – no one could offer a definitive answer we weren't even sure if they had already happened or not. It was almost like we were discussing something hypothetical or imaginary. In the so-called civilized world, this kind of ridiculous conversation, unlikely as it might be, would quickly be settled with someone pulling out a smartphone to look it up, but given the lack of connectivity here at Midway that is not something that ever happens. It’s not that people don’t have smartphones, most do, but in proper post-apocalyptic fashion, they seem more like souvenirs from a more technologically-advanced world that was left behind.

Derelict and dilapidated: a few of Midway's pseudo-post-apocalyptic treasures. Clockwise from upper left: The old power plant where WWII hero George Cannon suffered fatal injuries yet refused to leave his post; abandoned office in old Naval Air Facilities (NAF) hangar; massive generators of the old power plant; mysterious cross and refrigerator in room in NAF hangar.

Nothing speaks post-apocalypse better than Midway’s “boneyard”, an assortment of junk piles that covers several acres by the harbor. It is here – not Wal-Mart – that residents of the atoll go when they find themselves in need of something. In fact, on Midway, when you say you’re going “shopping”, it means you’re heading over to the boneyard to find something (wear sturdy shoes and be sure you're up to date on your tetanus vaccinations). Here I’ve found old, but serviceable, aluminum poles, cricket bats, a functional cooler, a giant bolt that I use as a stake, snowshoes, and a table and chair. You could also find wrecked cars, boats heavy equipment (there is, I think, a giant asphalt-grinding machine), washing machines, refrigerators, satellite dishes and nearly anything else you might desire. Common household trash judged to have no value is taken to a giant burn pile on the edge of the island an on certain days when the wind is right the acrid smoke burns your nostrils as it blows by. But anything that could even possibly find purpose in the future is hoarded. There are small piles of possibly valuable things cached nearly everywhere on the island. Closets are crammed with surplus clothing, spare rooms in houses piled high with old furniture and nick knacks, and a drawer in the kitchen of my with dozens of MREs (the famous “meals, ready to eat” which have caused nearly as many cases of post-traumatic stress disorder as shell shock). Should materials be needed for the set of the next Mad Max sequel, the boneyard would be a profitable place to seek them.

There's something for everyone in the Boneyard. At first glance it looks somewhat
random but closer inspection reveals considerable organization.

The hydroponic garden, located next the abandoned, former dining hall, provides fresh vegetables to supplement the island exile’s diet of canned and deep-frozen foods, and could also be envisioned in a post-apocalyptic outpost. But as soon as my stomach's rumbling sends me to the Clipper House for lunch, the illusion falls apart. Whereas my fantasy had me living disconnected from the outside world and post-civilization, life here on Midway is in reality completely the opposite. Food grown in various parts of the world is hauled in by ship and by jet. Thousands of gallons of fuel are burned each month to keep the lights on and the air conditioners humming. And even if most island residents ignore the news, they maintain close communication with family and friends back home and frequently share photos and stories through social media thanks to our satellite communications system. Maybe what we have here is more like pseudo-post apocalyptic?

Midway has played a key role throughout US military history including as a surveillance outpost
during the Cold War years.

While it is true that many of the things that lend Midway a post-apocalyptic feel are simply a consequence of its remoteness and decaying infrastructure, it is hard to escape the historical importance it's held during times when it seemed not too far fetched that the most world's most powerful nations might just bomb each other into oblivion. The Battle of Midway is famously recognized as a pivotal victory for the US against the Japanese. Less well known is the role that Midway played during the Cold War. Shortly after the Korean War the Soviet Union began military maneuvers in the Pacific prompting the US to deploy the “Airborne Early Warning Barrier”, a system to keep track of Soviet planes. Midway was a key resource with over 30 flight crews stationed on the atoll and flights departing the island's airfield every four hours to conduct surveillance across the Pacific all the way to Adak Island in the Aleutians. Midway also served an important function during the Vietnam war, as a fueling station for ships and aircraft and also as a base for the Missile Impact Locating System and other weapons programs. Should things have gone a little differently in this small corner of the globe, it is hard to say how things would have turned out but it would probably be fair to say that there were times when apocalypse was a very real possibility.

1 - A notable exception was the recent death of Thai King Bhumibol Adulyadej which was was met by island residents with deep sadness.

Postscript: Popular culture has conjured many visions for a post-apocalyptic world but none for me has been more compelling than The Road  by Cormac MacCarthy. In this dark novel, the protagonists, an unnamed father and his son (the boy), wander through a world so ruined that nature as we know it no longer exists. A recommended, though very dark, read!

Meet the Natives

In an earlier post (Floral Inflation), I described how Midway Atoll went from having just a dozen or so species of plants to over 200 over the course of about 100 years (the botanical equivalent to the acceleration of a Lamborghini). And although I included the names and photos of a few native plant species, I didn’t really do them justice. I thought I should revisit to topic and introduce you to some of the beautiful and interesting native plants we have out here and so I began the task of researching the plants and taking some photos. Little did I know that I would be pulled, in an ironically-metaphorical sense, “into the weeds”. What once seemed like a neatly circumscribed topic became muddied with complications. What is native to this place? And how do we know?  What to do about the fact that the very physical environment of Midway has changed so radically over the decades? It has taken me some time to extract myself from the thicket but I hope that you will find what I have to share with you worth the wait.

Every ecologist is well-versed in concepts of “native” versus “exotic” and uses this as a way to separate the “good species” from the troublesome. Back in New Mexico and Oregon it was a pretty straightforward task to take the list of plants found at a site and split them into these two categories. Generally speaking, if a plant existed in the area prior to the arrival of white people it was considered native and if it wasn’t it was exotic (the exact word used changed over time as folks struggled to find something politically acceptable and included “non-native”, “alien”, and “invasive”). It wasn’t that the indigenous peoples of North America didn’t move plants around (for example, bringing corn from Mexico to the Mississippi basin), but the changes that ensued after Columbus’ “discovery” were so profound in comparison that dividing things into “pre-“ and “post-Columbus” has typically proven very useful (check out this book by Charles C. Mann for more on that topic). Ecosystems that still retained their native species were judged to be more pristine while those dominated by exotics were thought of as degraded.

So my original plan was to do a little research into the dozen or so plants I had been told were native to Midway and write about them. Early on I had noticed a few things that seemed really cool. Even though there weren’t many native species, they seemed diverse in terms of their growth forms – which included bunchgrasses, sedges, sprawling vines with showy flowers, big shrubs that enable the formation of dunes, and delicate wildflowers – as well as in their life histories – a mix of opportunistic short-lived plants that produced a lot of seed and long-lived plants with more complicated ecological relationships. One thing most of them had in common was the ability to grow from cuttings or to produce large, durable, seeds worthy of sea voyages – traits essential for establishing themselves remote islands far from their source populations.

As I was putting together that post though I also took on the task – as part of my work responsibilities – of compiling a list of plant species for the atoll. In doing so I relied heavily on the work of Forest and Kim Starr, botanists based out of Maui who have for decades catalogued and researched Midway’s flora. They listed not a dozen but 39 native species encountered here over the years. Digging deeper, I found that while the term native could be applied to species discovered here during the very first botanical surveys, it might also include those found on nearby islands or even on one of the main Hawaiian islands (Oahu, the Big Island, Maui, etc.) but encountered here at a later date. And what about species that might have been missed on those earlier surveys or those that were native to the region but only showed up once the island had extensively modified during “military occupation” or where purposefully introduced? What did it really mean to be a native plant species on Midway? This was a question without a simple answer and required that I examine each species individually using whatever evidence I could acquire which included research into published journal articles and unpublished works (the “gray literature”) as well as herbarium records and online databases.

In the end I reckoned 22 of the 39 species to be truly native to Midway atoll, meaning, they were had a very good chance of being here before the Pacific Commercial Cable Company set up operations here in 1903.  The remaining 17 species were those that were native to somewhere in Hawaiian archipelago but probably had made it to Midway with the help of people – either by them acting as their couriers or by the changes wrought by them as a consequence of their presence here. My research also revealed what had been lost. Of the 22 native species, about half had their entire populations eliminated from Midway as a consequence of the environmental perturbations that resulted from the island’s occupation (one of these was subsequently reintroduced and still struggles to survive). Three are now extinct – that is, vanished entirely from the planet.  The 12 survivors are clearly a hardy bunch and play important roles in the US Fish and Wildlife Service’s efforts to restore the islands ecosystems.

The first botanical surveys of Midway Atoll were conducted by ornithologist William A. Bryan who visited these remote islands for just a few hours in 1902 (a side trip taken while en route from Marcus Island back to Honolulu). Until that time, Midway had been visited primarily by bird hunters and a few unfortunates who found themselves shipwrecked here.  Little had been done to modify the environment at the time and Bryan described Sand Island as a “barren, blinding, heap of sand” noting also that nearby Eastern Island was much greener, covered in low shrubs, and more hospitable despite its smaller size and simpler topography. In his very short time at Midway, Bryan recorded a mere 13 species of plants consisting of three shrubs, four wildflowers, four grasses, and two vines but admitted that that he would likely have encountered more species if he’d been there longer. Eight of these plants are still present on the atoll and are critical players in restoration efforts here, including alena (Boerhavia repens), emaloa (Eragrostis variabilis), koali awa (Ipomoea indica), and popolo (Solanum nelsonii). Unlike some of the northwestern Hawaiian Islands, there are no plant species endemic to Midway (that is species that occur here but nowhere else in the world). Of the 13 true natives, five no longer occur on Midway and of these, two are extinct. One of these is the grass Kamanomano (Cenchrus agrimonioides var. laysanensis) which was once abundant on several of the Northwestern Hawaiian Islands but was last seen in 1961 on nearby Kure Island.  The other, ʻahinahina (Achyranthes atollensis) was a shrub in the amaranth family with hairy leaves that grew up to four feet high on sand mounds and was never seen again on Midway after 1902!

Undisputed natives. Boerhavia repens (top) and Lepturus repens (bottom) were
noted during the very first botanical explorations of Midway. Both of these species have widespread distributions across the tropics and subtropics.

Erling Christophersen and Edward Caum, travelling with the Tanager Expedition in 1923-4, were the next to document the flora of Midway and turned up four additional native plant species. These included the beautiful morning-glory vine Pohuehue (Ipomoea pes-caprae ssp. brasiliensis), and the spectacular yellow-flowered ilima (Sida fallax). Ilima, which also occurs on the main Hawaiian Islands has great cultural significance and is the most desired flower when creating the traditional lei or flower wreath. Two of the four species are, however, now gone from Midway. Phyllostegia variabilis, appears to have disappeared from the planet so quickly that there is no common name for it and virtually no information about it (try finding anything about this species using Google and you will surely be disappointed!). Moa (Psilotum nudum), is a rootless fernlike plant that no longer occurs on the atoll but persists across a wide swath of sub-tropical and tropical areas of the globe and was used by native Hawaiian people to prevent chafing incurred in the wearing of loincloths!

Botanists travelling with the Tanager Expedition (1923-4) were able to make a more complete list of Midway's flora adding Sida fallax (top)  and Ipomoea pes-caprae ssp. brasiliensis (bottom) to the list of native species.

The 1930s and ‘40s were periods of profound change at Midway as the islands became a tourist destination with the establishment of a Pan American Airways Clipper station (which included a hotel and restaurant) and then, shortly after, drew the attention of the US military as global tensions rose and the atoll was recognized as a place of strategic significance. Buildings were erected, roads constructed, and runways paved. Occasional visits by botanists documented the effects that these changes had on Midway’s flora. Johnson Neff and Philip Du Mont spent a month on the atoll in 1954 to “study bird problems” but also found time to document the plant life as it existed at that time. Two native species, mau'u 'aki'aki (Fimbristylis cymosa) and ena'ena (Pseudognaphalium sandwicensium var. sandwicensium) were recorded for the first time. These are species that, though native to the Hawaiian islands, had never before had a place to grow on Midway but were now found to be growing along paved surfaces. Ena’ena, interestingly, mostly finds its home on lava flows on the Big Island but was thriving in this novel ecosystem. In 1980 Derryl Herbst added kaʻa, puʻukaʻa (Cyperus polystachyos) to the list of sort-of-native Midway plants. This widespread and hardy sedge found a niche at the end of a runway where water pooled during the wet-season and decades later became a foundational species in creating wetland habitat for the endangered Laysan duck. The discovery of the succulent akulikuli (Sesuvium portulacastrum) in 1995 by Marie Bruegmann is a bit of a mystery as habitat for this plant – areas close to the beach that receive salt spray and are occasionally washed over by storm-driven waves – would seem to have been some of the least disturbed areas on the atoll.

Extensive modification of Midway's environment created suitable habitat for "new native species"
such as Fimbristylis cymosa (top) which grows in cracks in the runways; Although it is likely that the hardy,
salt-tolerant mat-forming Sesuvium portulacastrum (bottom) existed on Midway for many centuries it was not discovered until the 1990s.

When management of Midway was turned over to the US Fish and Wildlife Service in 1996 (see Trading Guns for Goonies) restoration of native plants became a priority. Ten species of plants native to the Hawaiian islands were either introduced or just showed up in the years that followed. These included species that were in trouble elsewhere and needed new homes. Aweoweo (Chenopodium oahuense), a robust shrub in the goosefoot family, and and Bryan’s flatsedge (Cyperus pennatiformis var. bryanii) were brought to Midway from Laysan Island, the former becoming an important species used for restoration while the latter failed to establish. Efforts to secure the critically endangered loulu lelo (Pritchardia remota) compelled Fish and Wildlife Service staff to collect several hundred seeds from their source population on Nihoa island and grow them out in the nursery on Midway. Today, five of these plants survive adding a some security to the original population.

Though not native to Midway, the Nihoa fan palm (Pritchardia remota), originall found only on the
island of Nihoa in the Northwestern Hawaiian Islands is currently being grown on the atoll as
part of efforts to secure its global population.

Efforts to re-establish the native plants of Midway Atoll and to provide habitat for endangered plants native to other parts of the Hawaiian archipelago are more concerted now than ever. The US Fish and Wildlife Service has stepped up its efforts to restore degraded habitat on Midway atoll which now includes a native seed library, a greenhouse, and a brand-new, 6,600 sq ft shadehouse. Through its native plant propagation program Midway has become an important site for conservation of the popolo at a time when populations elsewhere continue to decline. Exact definitions of what is native or not no longer seem so important in a world of changing climate and rising seas. What seems imperative now is to do the most we can with this 2 square miles of sand and coral out here in the Pacific Ocean with respect to both the wildlife and the plant life. This will require boldness, creativity, but also humility. Of the 22 “original” native species, half had their entire populations eliminated from Midway as a consequence of the environmental changes wrought upon the island during the early part of the 20^th century and only one of these, akiaki (Sporobolus virginicus) has been successfully reestablished. We need to do better than that in the future and doing so will require utilizing sound science in guiding future actions. That and maybe a little luck!

Currently, 20 species of "native" plants are being propagated by the
US Fish and Wildlife Service at Midway Atoll.