Squirrels (Sciuridae)

Maurice Chen

Sciurus carolinensis. Photo credit to Maurice Chen.

Sciurus carolinensis. Photo credit to Maurice Chen.

I was walking through Madison Square Park earlier this week when I was stopped in my path by a rather outgoing bushy-tailed rodent. We stared at each other for several seconds, neither one of us willing to turn back down the road we traveled. After a short time time, I decided to circle around and continue along my path, the whole time being barraged with disgruntled chittering noises as I didn't pay the proper toll in nuts or whatever food I had on me. Because of my encounter, I decided that this month we honor the squirrelly members of the Sciuridae famly.

There are 286 known species within the Sciuridae family (Waldheim 1817) which can be further categorized into three groups. They are tree squirrels, ground squirrels, and flying squirrels.(Bradford 2014) The squirrels that we most commonly see in New York City are the tree squirrels, Sciurus carolinensis, or Eastern Gray Squirrels. Squirrels can be found throughout the world except in Australia. Squirrels primarily eat non-cellulose plant matter, such as seeds, fruits, and conifer cones, however they are also known to eat fungi and occasionally insects (Thorington & Ferrel 2006).

If you decide to enjoy your lunch in Madison Square Park, don’t be surprised if a squirrel casually walks up to you and patiently waits for a portion of your meal. It’s not uncommon to see squirrels in Madison Square Park perched on benches sharing french fries with a recent Shake Shack customer. However, you might notice that there is a particularly high population of squirrels running around compared to most years. This is the result of the 2016 mast year. A mast year is a period where oaks produce a much higher volume of acorns. Oaks can yield up to 10 times the amount they produce in an average year. Scientists hypothesize that masting developed as a way to guarantee propagation in the presence of high predation (Savage 2016). If acorns are produced in high quantities during certain years, some of the acorns will survive unscathed since the level of predators cannot consume the excess amount. This concept is called predator satiation. Mast years seem to occur irregularly and predicting when they might occur have eluded the best scientists. What makes squirrels special is that they can somehow predict when a mast year is about to occur and will also change their mating behaviors accordingly (Boutin et al. 2006). Before a mast year, female squirrels will produce a second litter of offspring since food sources will be plentiful in the upcoming mast. This allows squirrel to have an advantage over many of the other organisms that forage acorns.

Squirrels play an important role in genetic composition of oak forests due to their foraging behaviors. Squirrels are more likely to bury, or “cache” acorns from red oaks while immediately eating acorns from white oaks. Red oak acorns tend to have a higher fat content and will last the winter before germinating in the spring. White oak acorns tend to germinate soon after falling from their parent tree and are sweeter, thus making them more ideal for immediate consumption. Squirrels will therefore cache red oak acorns up to 150 feet away from its parent tree resulting in expansive red oak forests with tight clusters of white oaks (Line 1999).

While acorns are the preferred food source for storing for the winter, squirrels will resort to other sources when acorn yields are low. Interestingly, squirrels will actually harvest fungi and dry them out into a jerky (Bittel 2014). Squirrels will also tap maple trees for their sap, eating the sugary syrup once the water content has evaporated (Roach 2005).

References

Bittel, J. 2014. 5 surprising facts about squirrels (hint: they make jerky). National Geographic

Boutin, S., L.A. Waters, A.G. McAdam, M. M. Humphries, G. Tosi & A. A. Dhondt. 2006. Anticipatory reproduction and population growth in seed predators. Science 314: 1928-1930

Bradford, A. 2014. Squirrels: diet, habits & other facts. Live Science

Line, L. 1999. When nature goes nuts: an astonishing array of animals is linked in some surprising ways to the mighty oak and its bounty. National Wildlife Federation

Roach, J. 2005. No nuts, no problem: squirrels harvest maple syrup. National Geographic

Savage, J. 2016. When is a tree smarter than a squirrel? Society for the Protection of New Hampshire Forests

Thorington, R. W. & K. Ferrell. 2006. Squirrels: the animal answer guide. John Hopkins University Press 75

Waldheim, F. 1817. Scuridae. Integrated Taxonomic Information System

Mountain Gorilla (Gorilla beringei beringei)

Harald Parzer

Dominant Silverback with wound due to a fight with a lone male. Photo credit to Harald Parzer.

Dominant Silverback with wound due to a fight with a lone male. Photo credit to Harald Parzer.

Mountain gorillas (Gorilla beringei beringei) are a subspecies of the Eastern Lowland Gorilla (Gorilla beringei) and are endemic to (or only found in) the mountainous region of the Albertine Rift in East Africa at an altitude from around 2200m to 4000m. They are found in two disjunct areas: the Virunga mountains, Rwanda and in Bwindi Impenetrable Forest, Uganda. Interestingly, these two populations behave quite differently. Bwindi Mountain Gorillas tend to climb much more and eat plenty of fruits, while the Virunga gorillas mostly stay on the ground and replace fruits with herbaceous stems. In fact, because of this, and morphological and genetic differences, some scientists argue that these populations represent two species, or at least two subspecies. Unfortunately, due to poaching and habitat destruction, only 880 individuals of this critically endangered species are left on this planet.

Mountain gorillas are incredibly powerful specimens to behold. They can grow to be as tall as an average man, with the same muscle and fat distribution, and weigh up to 430 lbs. Bodybuilders could only dream of such numbers. And yet, the mountain gorilla diet consist solely of plant matter! To maintain such weight, male mountain gorillas eat up to 34 kg of plants. Although they do not consume animal protein, about 18% of their overall food intake is protein from plant matter they select. Thus, an adult mountain gorilla can eat of up to 612 grams of protein every day far surpassing that of a bodybuilder's diet. Higher ranking females tend to have a higher caloric intake, not because they get nutrient richer plants, but because they tend to eat faster and are less active than their male counterparts.

Female mountain gorilla with her offspring. Photo credit to Harald Parzer.

Female mountain gorilla with her offspring. Photo credit to Harald Parzer.

Research shows that the home range of mountain gorillas changes with the seasons. In the dry season, mountain gorillas may increase their home ranges to 18 square miles in order to find their favorite plants (in Bwindi they have been observed to eat 107 species of plants). During the rainy season, the home ranges of mountain gorillas shrink dramatically as plants are more abundant and foraging doesn't require them to travel as far.

Mountain gorillas, which are either left or right handed in about the same proportions, live in small groups of around 10 individuals. The groups are composed of one to a few adult males, as well as females and juveniles of either sex. The dominant male, or silverback (named after his grey short hair on his back, which develops as a teenager), is almost twice as heavy as an adult female, and sires about 85% of the offspring if a second ranking silverback is in the group (who sires the remaining 15%). Thus, a silverback benefits from a large harem, as this means a lot of offspring. At times, like the group visited by the author in Bwindi Impenetrable Forest, older silverbacks are still hanging onto their group (and regularly get lost due to their slower pace...) and can be observed at the edge of it, old men observing the youth.

Infant mountain gorilla (about half a year old). Photo credit to Harald Parzer.

Infant mountain gorilla (about half a year old). Photo credit to Harald Parzer.

On average, a female produces 2.1–3.6 surviving offspring in her lifetime. Dominant females, which have higher lifespans, are producing more than lower ranking females. Infant mortality is high (21% of all infants won't make it to adulthood), mostly because of infanticide - yes, the ugly side of the mountain gorilla. When a new male takes over the group, after a vicious fights (see picture above) or natural death of the dominant silverback, the newcomer tends to kill all offspring to make sure that his harem is receptive for his own offspring. Thus, females prefer strong dominant males, which can protect their group as long as possible. Young males leave their groups when they are about 11 years old, and wander through the forest, mostly as lone males, to fight for a new group for themselves and that can take time.

Mountain gorillas, like all other gorillas, have not been observed to use tools in the wild, and have so far not been kept in zoos. Thus, if you want to meet this gentle giants, you will have to travel to Uganda or Rwanda, and join a gorilla trekking tour. The prices for such tours are steep ($600 for Bwindi National Park and $1500 for the Virunga Mountains), but they allow you to stay very close to one of the habituated groups for one hour. And you may even be hugged by a juvenile, as it happened to the trekking group of the author! These tours are well worth it and at least some of the money goes into protecting the habitat of the gorillas and to protecting other national parks, which are less frequently visited. So start saving money (cancel your TV subscription and write an essay for our upcoming competition to gain a few extra bucks), and get ready for a fantastic adventure! 

References

Bradley, B. J., M. M. Robbins, E. A. Williamson, H. D. Steklis, N. G. Steklis, N. Eckhardt, C. Boesch & L. Vigilant. 2005. Mountain gorilla tug-of-war: silverbacks have limited control over reproduction in multimale groups. Proceedings of the National Academy of Sciences of the United States of America 102: 9418–9423.

Robbins, M. M., A. M. Robbins, N. Gerald-Steklis & H. D. Steklis. 2007. Socioecological influences on the reproductive success of female mountain gorillas (Gorilla beringei beringei). Behavioral Ecology and Sociobiology 61: 919–931.

Rothman, J. M., A. J. Plumptre, E. S. Dierenfeld, & A. N. Pell. 2007. Nutritional composition of the diet of the gorilla (Gorilla beringei): a comparison between two montane habitats. Journal of Tropical Ecology 23: 673–682.

Zihlman, A. L., & R. K. McFarland. 2000. Body mass in lowland gorillas: a quantitative analysis. American Journal of Physical Anthropology 113: 61–78.

The Sea Robin (genus Prionotus)

Allison Bronson

This month, while counting horseshoe crabs as part of the event, Monitoring Horseshoe Crab Breeding with NYC Audubon, the MSNH spotted a distinctive fish abandoned by fisherman along the shore - the sea robin (genus Prionotus). Part of the family Triglidae, sea robins are scorpaeniforms (scorpion fishes) that feed along the sea floor, and are quite common on the East Coast of the United States.

Part of the sea robin’s odd appearance is due to its little ‘legs’ – these are modified pectoral (chest) fin rays. Though it appears to walk on these spines, they are actually utilized for chemoreception, allowing the sea robin to ‘smell’ food hidden in the sand. The rest of the pectoral fin is probably how the sea robin got its common name – it fans out to make a beautiful ‘wing,’ visible in the photos that accompany this post. The sea robin can also produce a deep thumping sound, by using its swim bladder (a gas-filled internal sac) to amplify vibrations.

Most common sea robins (P. carolinus) only reach about a foot in length, though some have been noted at 16 inches. They are found near shore much more frequently in the summertime. In winter, they head for deeper waters. They are indiscriminate predators, consuming a remarkably wide range of invertebrates, as well as small fishes and algae.

Here in New York, sea robins are often sold as a fairly inexpensive fillet. Although the sea robin found by the MSNH had been rejected by some local fisherman, however, far from being ‘trash fish’ they are favored worldwide for traditional dishes like bouillabaisse (French fish soup). A simple sea robin recipe can be found at the On The Water article, Praise for Sea Robins. They’re a species of Least Concern (i.e. fairly abundant) and harmless to humans, so picking up a sea robin at the farmers market (or better yet, catching one yourself!) is a good way to sample our local New York City seafood.

References

Fishes of the Gulf of Maine: Sea Robin

FishBase.org: Northern Searobin

 

Eastern Tiger Swallowtail (Papilio glaucus)

Harald Parzer

Male. North Carolina, 2010. Photo Credit: Stephanie Loria.

Male. North Carolina, 2010. Photo Credit: Stephanie Loria.

Spring arrived, and along with it Papilio glaucus or the Eastern Tiger Swallowtail, one of our most spectacular butterflies. While adults feed on nectar of a wide variety of flowers, their caterpillars feed on leaves of Tulip trees (Liriodendron tulipifera), Black Cheeries (Prunus serotina), among many others. Choosy they are not!

The common name tells it all: this large butterfly, with a wingspan of up to 5.5 inches, belongs to the family of Swallowtails or Papilionidae (with over 570 species worldwide), and can be found in Eastern North America from Vermont to Florida, and show bold black stripes on their yellow wings (“tiger”), along with elegantly elongated tips at the end of their hindwings (“swallowtail”). They can be observed in a variety of habitats, including woodlands, fields, and in your garden, assuming you planted some butterfly-friendly (and hopefully native) flowers! For more information on how to do that, please see at the reference list.

After emergence from tiny green eggs, which the butterfly mom conveniently placed on their host trees, the caterpillars get right to business: first, they eat their egg shell (no waste in nature!), and then they use their large mandibles to chew up the leafs of their host tree. The caterpillar, which eventually will become about 1 ¼ inches before it pupates, is, unlike so many other swallowtail caterpillars, dull and green in appearance. The head itself has two rows of simple eyes, short antenna, and mandibles. The body has 13 segments, of which the first three form the thorax with a pair of true legs on each of them. Five of the other ten remaining segments have fleshy outgrowths which function as legs, keeping them stable on stems and leaves.

Given the essentially unlimited food supply, caterpillars get bigger by the minute. Like all arthropods, Eastern Tiger Swallowtails have their skeleton outside (“exoskeleton”), and thus have to replace this sturdy shell with an even bigger one, if they want to continue to grow. They do this by shedding their outer skin (“cuticula”) through a process called molting. Molting is orchestrated by a variety of insect hormones, including ecdysone and juvenile hormone. Once a caterpillar reaches a certain size, ecdysone is released, and in the presence of juvenile hormone it molts into another, larger caterpillar. However, with each molt, less and less juvenile hormone is released. And if the caterpillar was a good baby, and ate everything Mother Nature provided, the levels of juvenile hormone will eventually drop to such low levels, that when ecdysone rises once again, the caterpillar starts to pupate, instead of becoming another, even larger caterpillar.

And so it goes: the caterpillar, with lots of ecdysone, but little juvenile hormone, has one more bit of a tulip tree leaf, ejects whatever was not digested, and wanders to a safe spot where it molts into a pupa (“chrysalis”). Depending on the season, the pupa will metamorphose into our beloved Eastern Tiger Swallowtail within a few weeks (this species has up to three broods per year), or it overwinters, until spring returns.

Upon emergence, the careful observer can easily distinguish between males and females. While the hindwing of the male (figure above) has a dark black band along the edges, females have the same band with elegant blue spots, and usually also carry a slightly thicker “tail”. Interestingly, females come in two forms (“morphs”), depending on the region. In addition to the morph described above, females also have a dark morph in certain regions of the USA, and are thought to mimic the toxic Spicebush Swallowtail (Battus philenor), which is avoided by avian predators. As females refuse to mate with males who try get away with the same disguise, males are stuck with the conspicuous tiger pattern, attractive to female Tiger Swallowtails, humans, and birds alike.

You might also be able to observe (young) males congregating at puddles, mud, and even dung and carrion, a behavior which is called “puddling”. They do this to extract additional sodium ions and amino acids, as nectar is full of sugar, but not much else. And, like good gentlemen, they present this gift to their lady to give their offspring a head start. In fact, it has been shown that males who are able to provide more sodium, will allow the female to have more offspring.

Next time you see one, ask yourself: is it a male or female? Which morph? And if you have a little garden available, why not welcome them with a native flower bouquet!

References

Belth, J. E. 2013. Butterflies of Indiana – A Field Guide. Indiana University Press, Bloomington.

NABA-North Jersey Butterfly Club. 2017. New Jersey Butterflies – Eastern Tiger Swallowtail (http://www.naba.org/chapters/nabanj/butterflies/eastern_tiger_swallowtail.html)

NABA-North Jersey Butterfly Club. 2017. Creating a butterfly garden (www.naba.org/chapters/nabanj/gardening.html)

Atlantic Horseshoe Crab (Limulus polyphemus)

Stephanie F. Loria

This month we honor an organism which will soon begin its breeding season in NYC - the Atlantic horseshoe crab, Limulus polyphemus. Despite their name and superficial resemblance, horseshoe crabs are not crabs. They actually belong to their own class Xiphosura in Chelicerata, an arthropod group that also includes the classes Arachnida (spiders, scorpions, ticks, etc), Eurypterida (the extinct sea scorpions and also MSNH's logo taxon), and Pycnogonida (sea spiders). The placement of Xiphosura within Chelicerata has been debated and recent research has even placed Xiphosura within Arachnida (Sharma et al. 2014). Worldwide only four extant species of horseshoe crabs exist and all species except L. polyphemus are found in the Indo-Pacific Ocean (Xia 2000). Extinct horseshoe crab species have also been described and the oldest fossil, found in Canada, dates to the Upper Ordovician, 445 million years ago (Rudkin et al. 2008)! Despite their remarkably old age, horseshoe crabs have changed little morphologically since their first appearance and are therefore often referred to as 'living fossils' in the scientific literature (Avise et al. 1994). 

The breeding season of L. polyphemus runs from March to July with peak season occurring in May and June (Rudloe 1980; Rutecki et al. 2004). During the breeding season, male and female L. polyphemus arrive on the shores of eastern North America in droves with most breeding happening at high tide on new and full moon nights (Rudloe 1980). Males typically mount females using special claspers and eggs are fertilized externally (Brockmann 1990). However, eggs may also be fertilized by satellite males which are not attached to females and surround the mating couple (Sasson et al. 2015). Eggs develop in the sand, hatching 3 to 4 weeks later and larvae disperse into the ocean (Bakker et al. 2016; Botton and Loveland, 2003; Rudloe, 1979). Horseshoe crabs live longer than dogs typically reaching 19 years of age (Rutecki et al. 2004).

During the breeding season, red knots (Calidris canutus rufa) feast on horseshoe crab eggs, an important food source for these birds (Niles et al. 2009). Horseshoe crabs are also harvested by humans for biomedical use as their blood contains amoebocyte lysate (ACL), a compound that can be used to detect bacterial endotoxins (Rutecki et al. 2004). Although biomedically harvested individuals are typically released once blood has been taken, mortality does occur among released individuals (Rutecki et al. 2004). Horseshoe crabs are also harvested for fishing bait and overharvesting from fishing and the biomedical industry and shoreline destruction has led to population declines (Land et al. 2015). In order to help track the health of horseshoe crab populations, nonprofit organizations such as NYC Audobon, and researchers survey horseshoe crabs populations each year during the breeding season. This year, the MSNH will team up again with NYC Audubon on Friday, June 9 to participate in the survey so that we can interact and help protect this fascinating and ancient species.

Horseshoe crabs (L. polyphemus) at Jamaica Bay. Courtesy of Maurice Chen.

Horseshoe crabs (L. polyphemus) at Jamaica Bay. Courtesy of Maurice Chen.

References

Avise, J. C., W. S. Nelson, and H. Sugita. 1994. A speciational history of" living fossils": molecular evolutionary patterns in horseshoe crabs. Evolution: 1986-2001.

Bakker, A. K., J. Dutton, M.  Sclafani and N. Santangelo. 2016. Environmental exposure of Atlantic horseshoe crab (Limulus polyphemus) early life stages to essential trace elements. Science of The Total Environment 572: 804-812.

Botton, M. L. and R. E. Loveland. 2003. Abundance and dispersal potential of horseshoe crab (Limulus polyphemus) larvae in the Delaware estuary. Estuaries 26: 1472-1479.

Brockmann, H. J. 1990. Mating behavior of horseshoe crabs, Limulus polyphemusBehaviour 114: 206-220.

Landi, A. A., J. C. Vokoun, P. Howell, and P. Auster. 2015. Predicting use of habitat patches by spawning horseshoe crabs (Limulus polyphemus) along a complex coastline with field surveys and geospatial analyses. Aquatic Conservation: Marine and Freshwater Ecosystems. 25: 380-395.

Niles, L. J ., J. Bart, H. P. Sitters, A. D. Dey, K. E. Clark, P. W. Atkinson, A. J. Baker, K. A. Bennett, K. S. Kalasz, N. A. Clark, and J. Clark. 2009. Effects of horseshoe crab harvest in Delaware Bay on Red Knots: are harvest restrictions working? Bioscience59: 153-164.

Rudkin, D. M., G. A.  Young, and G. S. Nowlan. 2008. The oldest horseshoe crab: a new Xiphosurid from Late Ordovician Konservat‐Lagerstätten Deposits, Manitoba, Canada. Palaeontology 51: 1-9.

Rudloe, A. 1979. Locomotor and light responses of larvae of the horseshoe crab, Limulus polyphemus (L.). The Biological Bulletin 157: 494-505.

Rudloe, A. 1980. The breeding behavior and patterns of movement of horseshoe crabs, Limulus polyphemus, in the vicinity of breeding beaches in Apalachee Bay, Florida. Estuaries and Coasts 3: 177-183.

Rutecki, D., R. H. Carmichael, and I. Valiela. 2004. Magnitude of harvest of Atlantic horseshoe crabs, Limulus polyphemus, in Pleasant Bay, Massachusetts. Estuaries and Coasts 27: 179-187.

Sasson, D. A., S. L. Johnson, and H. J. Brockmann. 2015. Reproductive tactics and mating contexts affect sperm traits in horseshoe crabs (Limulus polyphemus). Behavioral ecology and sociobiology 69: 1769-1778.

Sharma, P. P., S. T. Kaluziak, A. R. Pérez-Porro, V. L. González, G. Hormiga, W. C. Wheeler, and G. Giribet. 2014. Phylogenomic interrogation of Arachnida reveals systemic conflicts in phylogenetic signal. Molecular Biology and Evolution, p.msu235.

Xia, X. 2000. Phylogenetic relationship among horseshoe crab species: effect of substitution models on phylogenetic analyses. Systematic Biology 49: 87-100.

Cannonball Jellyfish (Stomolophus meleagris)

Stephanie F. Loria

With the diversity of life in the ocean still largely unknown, this month we honor a marine organism, the cannonball jellyfish (Stomolophus meleagris). Cannonball jellies, like other jellyfish belong to the phylum Cnidaria, one of the oldest animal lineages originating approximately 740 million years ago (Park et al. 2012). During their life cycle, most cnidarians exhibit two different morphological forms: the motile medusa stage (aka the typical jellyfish form) and the sessile polyp stage (like sea anemones). For jellyfish, the medusa is the sexually reproducing form and most jellyfish species are dioecious meaning that each medusa is either male or female and not hermaphroditic. Male medusae release sperm into the water which fertilize eggs externally or internally in female medusae. Fertilized eggs hatch to form larvae that can then travel long distances to find a substrate to attach to and metamorphosize into the polyp form. Polyps later transform into medusae and the life cycle repeats.

To feed, cnidarians use nematocysts (stinging cells which look like they have tiny barbs) on their tentacles to paralyze prey and then digest the prey using enzymes in a gastrovascular cavity. As jellyfish have no anus, all food must enter and leave through the same opening. Cannonball jellyfish, although found across the world's oceans are most common on the southeastern coast of North America (Wikipedia). If you find yourself walking along the beaches in South Carolina, a state where these jellyfish are quite common, you might see some washed-up cannonball jellies with tiny crabs on them as depicted in the image below. These juvenile spiders crabs (Libinia dubia) are not eating the dead jellyfish but are rather cast away in a catastrophic jellyfish shipwreck. The juvenile spider crabs have a symbiotic relationship with the cannonball jellyfish, sharing its food and using it for protection (Afford & Patel). 

The future of cannonball jellyfish populations is uncertain as this North American species has become a delicacy in Asia and business has been booming (Narula 2014). Carolinan fishing companies are harvesting these jellyfish via trawling and shipping them to the other side of the world to be sold in fish markets (Narula 2014). The profits from harvesting jellyfish are enormous, with some fisherman making 10000 USD per day (Narula 2014). However, the ecological impacts of harvesting cannonball jellyfish may soon be realized as environmental groups warn that excessive trawling and pollution from jellyfish processing plants may outweigh the monetary benefits to local communities (Narula 2014). 

Cannonball jellyfish with juvenile spider crab. Hilton Head Island, S.C. Photo Credit: Stephanie Loria.

Cannonball jellyfish with juvenile spider crab. Hilton Head Island, S.C. Photo Credit: Stephanie Loria.

References

Afford, H. & T. Patel. Stomolophus meleagris, cannonball jellyfish. Animal Diversity Web. University of Michigan, Museum of Zoology.

Narula, S. K. 2014. 'Jellyballs' are serious business. The Atlantic.

Park, E., D. S. Hwang, J. S. Lee, J. I. Song, T. K. Seo & Y. J. Won. 2012. Estimation of divergence times in cnidarian evolution based on mitochondrial protein-coding genes and the fossil record. Molecular phylogenetics and evolution. 62: 329-345.

Cannonball Jellyfish. Wikipedia.

 

Snowy Owl (Bubo scandiacus)

Harald Parzer

Male snowy owl. By Michael Gäbler, CC BY-SA 3.0, from Wikimedia Commons.

Male snowy owl. By Michael Gäbler, CC BY-SA 3.0, from Wikimedia Commons.

Ever since the arrival of Harry Potter, children, teenagers, and even adults (you know who you are!), inquire at pet stores on how to adopt a snowy owl (Bubo scandiacus). What books and movies forgot to mention is that keeping a snowy owl is not an easy task.

First, snowy owls are adapted to the bitter dry-cold environment of the North American and Eurasian Arctic. You better have a well air conditioned aviary for your new pet! Second, snowy owls are nomads and can mass migrate – quite unpredictably – as far south as Florida and Texas. So, do not leave your aviary open! Thirdly, snowy owls are fierce predators, which require plenty of bird and mammal meat to feed themselves and their young (7-12 small rodents/day). Like other owls, they swallow their prey as a whole, allowing strong stomach juices to digest the flesh, only to regurgitate the remnants as ugly pellets. And who will clean that?

But pretty they are: males develop an almost snow-white plumage, while females are primarily white with some black spots. These owls see the world through mesmerizing yellow eyes, and have a sharp black beak, both of which are important adaptations to their predatory life style. Among the 164 species of owls, Bubo scandiacus is one of the largest, with a wingspan of up to 59 inches (52 inches average) and a weight of up to 6.6 lbs (4 lbs average). Like many raptors, females are usually larger than males, possibly to maximize egg production. As a rare exception among owls (which mostly use either tree cavities or abandoned nests of other species to breed), the snowy owl is building its own nest in the Arctic tundra. Usually, one can find such nests at elevated spots with little vegetation, which this fierce animal uses to defend its 5 – 10 eggs whenever a predator approaches. Be aware!

While snowy owls can be found year round in the Arctic Circle, even during polar nights, some of them may abruptly leave their wintering grounds to the more pleasant South, waiting there to return until the harsh Arctic winter is receding. During such southern vacations, snowy owls also choose the Big Apple as their winter destination. Like so many humans, these owls do not want to miss the comfort of their home, and thus are settling primarily in areas which resemble the Arctic tundra. As such, snowy owls can be found every winter at open areas with little vegetation on beaches, like Rhiis Beach, Floyd Bennett Field, or even JFK airport. While the winter of 2017 has not yet been proven to be an exceptional snow-owly year for NYC, many sighting have been made in 2014, when more than 20 different owls have been confirmed. But watch out - time to clean your binoculars, prepare yourself to see a rare visitor from the North: in January birdwatchers reported a sighting at the tip of Breezy Point, and several sightings of an individual have been made at Sandy Hook in February.

References

Holt, D.W., M. D. Larson, N. Smith, D. L. Evans and D. F. Parmalee. 2015. Snowy Owl (Bubo scandiacus), The Birds of North America (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America

Leonard, P. 2014. A Season of Snowy Owls. Living Bird Magazine.

Tuft, D. 2015. Amid Urban Debris, the Snowy Owl Is a Wintertime Ghost. The New York Times.

 

Critically Endangered Cabbage on a Stick (Brighamia insignis)

Allison Bronson

Take one look at Brighamia insignis, and you’ll see how it got the nicknames “cabbage on a stick” and “cabbage on a baseball bat.” Its quirky appearance aside, this member of the family Campanulaceae is an emblem of conservation in the face of extreme adversity on the islands of Kauaʻi and Niʻihau.

Photo Credit: Wikimedia commons. By C.T. Johansson.

Photo Credit: Wikimedia commons. By C.T. Johansson.

Brighamia is commonly known as the Hawaiian or Vulcan palm, despite having no relation to the palm family (Arecaceae). The ‘palm’ can grow to be 16 feet tall, but usually stands about three to six feet, and makes its home on rocky cliffs of volcanic soil. The plant is endemic to Hawaii – that is, it grows nowhere else on earth, and co-evolved with its pollinator, a species of endemic Hawaiian hawk moth. The hawk moth’s long proboscis was just the right length to reach into the plant’s long, tube-like flowers. In the last century, this hawk moth went extinct (for unknown reasons) and Brighamia was left with no way to distribute its pollen and produce offspring.

The loss of its pollinator only compounded the challenges faced by Brighamia. Like many native Hawaiian species, introduced taxa took a significant toll on the plant’s populations. While feral pigs and goats ate the plants, invasive plants colonized areas barren from fire and competed with Brighamia for space and resources. Perhaps most devastating were introduced spider mites (Tetranychus cinnabarinus), to which Brighamia is particularly susceptible. 
Despite conservation efforts to mitigate these problems, two hurricanes (1982 and 1992) blew many of the surviving plants off their cliffs. In previous years, five populations of this plant were recorded in the wild, each between 45 and 65 individuals. Sadly, as of last year, workers observing these populations believe there may be only a single plant left on the island of Kauaʻi.

Fortunately for Brighamia, its weird appearance has charmed conservationists and horticulturists alike, and extraordinary steps have been taken to bring this plant back from the brink. Scientists and volunteers even rappel down cliffs in order to hand-pollinate the plants, and to retrieve seeds to grow in greenhouses. The cabbage-on-a-stick is commonly bred as an ornamental plant and has become popular among plant enthusiasts worldwide, but despite its success in ‘captivity,’ the plant will never succeed in the wild without a pollinator. So Brighamia is a particular type of oddity: a unique morphology honed over millions of years of isolated island evolution, toppled by a changing environment, and preserved as a relict curiosity among human collections, hopefully to inspire fierce protection of the environment and preservation of endemic species.

References
Lewis, R. 2016. Down to the last plant: The painstaking work of extinction preventionFusion.

Wong, J. 2016. 2016. All Hail the Vulcan Palm. The Guardian.

University of Hawaii. Brighamia insignisNative Plants Hawaii.

Botanist works to save Hawaii’s rare plants. 2014. VOA News.