When zookeepers discovered that flamingos need a large flock in order to breed, it led to all kinds of crazy approaches to fool the birds – mirrors, plastic yard ornaments, speakers playing bird-crowd sounds (now, zoos generally just keep more birds). I think of habitat loss and fragmentation like a flock of flamingos. There’s a certain amount required for the habitat to function properly. If the size is too small or divided, it will fail.
The Atlantic Longleaf Pine Ecosystem (a.k.a. pine barrens – a deceptive name considering the high amount of biodiversity) spanned over 35 million hectares (about the size of Germany) around the year 1500; today, only ~1 million hectares of pocket forests remain. (1)
Good news though! If habitat is restored, amphibians (including our friend, Mabee’s salamander), among many other species, come back too. (2)
- D.H. Van Lear et al. 2005. History and restoration of the longleaf pine-grassland
ecosystem. Forest Ecology and Management 211:150–165
- J. C. Mitchell. 2016. Restored Wetlands in Mid-Atlantic Agricultural Landscapes Enhance Species Richness of Amphibian Assemblages. Journal of Fish and Wildlife Management. 7(2) 490-498
When a predator approaches, options are limited – especially if you’re a tadpole. The woodfrog tadpole (Rana sylvatica) is known to stop swimming and sink to the pond bottom, an action called “freezing behavior.”
In one study, researchers exposed woodfrog embryos to some water from a predator’s tank with or without an injured tadpole (1). When the embryos hatched, the ones that had smelled both the predator and injured relative showed very reduced activity (freezing behavior) if re-exposed to just predator-water.
In mice, freezing behavior is affected by the size and speed of an object. Video showing lab mice exposed to various dots indicates that small, slow objects trigger mice to freeze. When exposed to terrifying large dots, mice take off.
- Mathis, A., M.C.O. Ferrari, N. Windel, F. Messier, and D.P. Chivers. 2008. Learning by embryos and the ghost of predation future. Proc Biol Sci. 275(1651): 2603-2607.
The boreal forest, or taiga, extends across Canada and Russia. Conifers dominate this cold ecosystem. The evergreen needles allow the trees to photosynthesize all year.
While conifers grow well in the frigid taiga, they don’t decompose very quickly when a tree falls. In other habitats, trees that die release their carbon as they decay. The pines, firs, spruce, and larches of the taiga soak in carbon from the atmosphere, add that carbon to their mass, and hold it in their bodies even after they die. One study suggests that the boreal forest sequesters twice as much carbon as tropical forests and six times the amount held in temperate forests (1).
For now, the taiga is helping us combat climate change. As temperatures warm, though, stored carbon can break down and release into the atmosphere as carbon dioxide, exacerbating the issue. The more we limit carbon emissions now, the more the boreal forest can help us into the future.
The nuthatch (Sitta carolinensis) has a lot of friends. It often teams up with chickadees and titmice. While larger flocks give greater protection from predators, more species diversity within the flock improves problem solving (1). Birds in diverse groups were able to get food from a new feeder faster.
- Freeberg, T.M., S.K. Eppert, K.E. Sieving, and J.R. Lucas. 2017. Diversity in mixed species groups improves success in a novel feeder test in a wild songbird community. Scientific Reports. Volume 7, Article number: 43014.
Trout Lilies (Erythronium americanum) pop up from the forest floor, tiny harbingers of warm weather to come. This little lily is a spring ephemeral – a flowering plant that takes advantage of that tiny window of time between the last frozen days of winter and the heyday of spring, when the forest canopy selfishly soaks up all the sun’s rays. During those few weeks, the Trout Lily breaks through a ceiling of dead leaves, and slurps up sun and nutrients to store for the rest of the year in its underground bulb. If that’s not enough, that brief time is also used to flower, produce seeds, and make sure the next generation is safely on its way. No wonder this little plant needs a rest for the remainder of the year!
Given the time limitation, the Trout Lily can’t mess around with seed distribution. It has to be done right and done quickly. Call in the ants.
Many spring ephemerals, like the Trout Lily, produce an incentive for ants to take their seeds, move them a distance away, and plant them in a safe, nutrient-rich location. Each seed has a dollop of yumminess on its outer surface, like icing on a seed-shaped cupcake (officially the “icing” is called an elaiosome, a mixture of fats and protein). Ants carry the seeds back to their nests, feed the yumminess to their larvae, and dispose of the seeds in a waste area which just happens to be a wonderfully fertile location for young seedlings to begin their lives.
Not only do ants spread seeds to new locations and give them a fertile spot to grow, they also protect the seeds from predators like mice. Ruhren and Dudash (1) placed seeds in four scenarios on the forest floor: (a) accessible to both ants and mice, (b & c) accessible to either mice or ants, and (d) inaccessible to mice and ants. The researchers found that ants secured the seeds before the mice, saving the little plants’ lives. In locales where these superhero ants have vanished, spring ephemeral populations drop 70% (2).
Want to learn more about the superhero ants (a.k.a. winnow ants)? Visit School of Ants.
- Ruhren, S. and M. R. Dudash. 1996. Consequences of the Timing of seed release of Erythronium americanum (Liliaceae), a deciduous forest myrmecochore. American Journal of Botany 83(5):633-640.
- Rodriguez-Cabal, M., K.L. Stuble, B. Guenard, R.R. Dunn, N.J. Sanders. 2012. Disruption of ant-seed dispersal mutualisms by the invasive Asian needle and (Pachycondyla chinensis). Biol. Invasions 14:557-565.
“One of the costliest substances ever produced by man” was actually produced by sea snails (Hexaplex and Haustellum sp.). The Phoenicians (in modern-day Lebanon and Syria) harvested whelks and manufactured a reddish-purple dye called Tyrian Purple. Processing just one pound of the dye required millions of snails and cost almost $100,000 in today’s dollar. The color was prized by the Romans, who used the rare and expensive cloth to designate nobility. Romans named the land that produced the dye “Land of Purple,” or Phoenicia. (1)
As you can probably imagine, destroying millions of whelks for one pound of dye is pretty unsustainable. Over time, populations of the Mediterranean snail declined and were eventually extirpated from the region. The dye industry also collapsed. Even though other sources of purple dyes were found, they paled in comparison to Tyrian purple – literally, since Tyrian purple doesn’t fade in sunlight.
Today, many more species in the Mediterranean are facing extirpation. Almost every sea resource (like snails and other mollusks, turtles, crustaceans) in the area has plummeted to less than half its past population size. (2)
Nature can be an amazing provider, if respectfully and responsibly utilized. Populations of plants and animals produce more than could ever survive, so harvesting a certain number of individuals can actually help many species. But that “certain number” is important. Harvest too much, and the populations we rely upon decline. In harming other species, we ultimately harm our own – a lesson we could learn from the Phoenicians and the snails.
- McCord, C.P. 1969. The Lowly Whelk and the Lofty Royal Purple Dye. Archives of Environmental Health: An International Journal 18(3) 379-385.
- Lotze, H.K., M. Coll, and J.A. Dunne. 2011. Historical Changes in Marine Resources, Food-web Structure and Ecosystem Functioning in the Adriatic Sea, Mediterranean. Ecosystems. 14(2): 198-222.
Deep inside the corpse flower are its developing fruits (painted in the sketch above). After 6-9 months, they’ll look like a column full of beautiful ripe tomatoes, tempting birds to eat them and distribute the seeds inside.
Unfortunately, both the corpse flower (Amorphophalus titanium) and its major seed distributor, the rhinoceros hornbill, are threatened by deforestation. Populations of the rhinoceros hornbill bird (Buceros rhinoceros) have declined by 72%. Other species, such as the orangutan and Sumatran tiger, are also suffering from this habitat loss.
What’s driving the deforestation? Many old growth forests in Sumatra have been cut to make way for palm oil plantations. Are the Sumatrans really eating that much palm oil? Nope. It’s you and me. So check your food labels – sometimes palm oil is listed under “vegetable oil” (if so, it must describe which plants). Look up eateries and food brands by using the Union of Concerned Scientists’ Palm Oil Scorecard – thankfully, Ben & Jerry’s has a good score!