Australian Water Dragons (Intellagama lasueurii) lounge and bask around pond edges at the University of Queensland, where I saw this handsome fellow. The colorful markings under his chin advertise his masculinity to the local lizard ladies… and to rival males too.
Researchers painted a model Water Dragon (actually a plastic iguana with a few glued-on additions) with either brown markings or red markings. (1) The toy was then introduced among resident Water Dragons to record their response to the intruder. When the toy had brown markings, the real Dragons attacked faster and more often.
Those fancy red and yellow stripes attract mates, but also deter rivals.
Baird, TA, TD Baird, and R Shine. 2013. Showing Red: Male Coloration Signals Sam-Sex Rivals in an Australian Water Dragon. Herpetologica 69(4) 436-444
Five years ago, this blog was born. In 2013, I wrote a grand total of two posts and received 21 visitors – not stellar for promoting conservation and an appreciation of biodiversity. But the number of posts and visitors have grown over the years… this site has now been viewed over 15,000 times! I can’t thank you enough.
Here’s a brief look back at the “top” posts:
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.
Birds nest in trees, on the ground, on water, among cliffs, and in caves. They build their nurseries from plant materials, mud, dung, saliva, spider silk, pebbles, and animal hair. Some nests have roofs or multiple rooms. Some are simple scraped depressions in the earth or natural cavities in trees.
Most songbirds construct cup-shaped nests which require about 1000 trips to bring in building materials (1). The birds use their feet to scrape, chests to push, and beaks to manipulate twigs and grasses as they rotate. Exhausting! Why go to such an extreme effort? Predators. Birds living on predator-free islands nest on the ground.
Some ground-nesting birds have other ways of avoiding predators… like teaming up with defenders. The red-breasted goose of Siberia nests next to peregrine falcons. The geese act as look-outs for foxes; the falcons attack. Some birds build their nests in ant or termite colonies to protect the eggs.
These sleeping bird babies, pictured, are cardinals. Their parents built this camouflaged nest in the crook of a pear tree. If dad hadn’t stopped by with some breakfast, I would have never realized they were there.
Collias, N.E. 1964. The Evolution of Nests and Nest Building in Birds. American Zoologist. 4: 175-190.
I grew up in the great apple-producing state of Michigan. If you haven’t been to an apple cider mill during October in the mitten state, you are missing out on one of the great joys of life.
Thousands of apple varieties grew in agricultural fields when nation’s founders declared independence. Today, 80% of that diversity is gone and with it, the genetic variation that can save apples from pests, weather, and disease.
Santayana said, “Those who cannot remember the past are condemned to repeat it.” The consequences of low crop diversity were felt during the Irish potato famine in the 1840s which caused the death or emigration of a quarter of Ireland’s citizens. A pathogen entered the potato fields and spread. Since the potatoes were genetically identical, a disease that affected one could infect them all.
Today, cost and transportation constraints benefit massive agricultural operations. The efficiency of monocultures, though, threatens our food and our health. To fight off disease in genetically-similar apples, we turn to pesticides. Apples are continually cited as worst offenders for chemical coatings (fyi, the American Chemical Society recommends a baking soda solution for washing). Today, about half of apples grown in the U.S. are Red Delicious (despite tasting like wood pulp).
Consider trying some local heritage apple varieties. Apple season starts in August!
P.S. An informative Smithsonian blog post about heritage varieties of apple includes a reference to an apple sleuth who lives just down the road from me!
I’ve always planted marigolds among my garden. I’ve heard these orange beauties have protective properties against herbivores. Is it true?
Hmm. Most researchers have found properties released from marigold roots inhibit bacteria, fungi, and/or nematodes (although this is extremely variable, depending upon the part of the plant used, how the marigolds are grown, and the pest species tested).
Most interesting sidetrack from my search… some research shows inhibition of Plasmodium, the microscopic organism that causes malaria (1).
Goodbye to our adored cat, Flea (if you’ve followed this blog for a while, you may remember her from the post on the impacts cats have on bird populations). She was 19 years old and the master of everyone and everything in our home. She was an excellent overlord.
There is surprisingly little research on pet death and grief, but all the studies I read concluded that level of attachment paralleled amount of grief (duh). Most research also found similar results to McKutcheon and Flemming (2001), which indicated certain “risk factors” for humans. If you’re a young-ish female living alone, be prepared for a healthy dose of distress. The one factor that surprised me was whether the pet died of natural causes or euthanasia. Owners who euthanized their pets felt LESS grief.
I thought that the heavy responsibility of decisions associated with euthanasia would result in more guilt or ethical dilemmas, and therefore more grief. Pet owners who choose euthanasia are also, generally, much more attached to their pets. But this study hypothesizes that the support of veterinary staff, feeling of control, and acknowledgement that the pet will not recover may contribute to the differences.
Michael and I thank Flea’s end-of-life veterinarians for making the process easier on all of us. Sweet dreams, squishy Flea.
McKutcheon, KA and SJ Flemming. 2001. Grief resulting from euthanasia and natural death of companion animals. Journal of Death and Dying. 44(2) 169-188.
The hard shell of an egg may seem like a thin yet impenetrable fortress. At the microscopic level, though, it’s more like a colander. Thousands of pores allow oxygen into the egg (and carbon dioxide out) so the developing embryo won’t suffocate.
Those pores could potentially allow bacteria into the egg. In most birds, though, a thin layer of protein called the cuticle (or bloom) is added to the outside of the shell just before it’s laid. That layer blocks bacteria from moving inside the egg. Considering that eggs and waste products all pass through the same opening in birds, that cuticle can be extremely valuable. If you’re looking for the cuticle on eggs you bought at the grocery store, you won’t find it. Eggs here in the U.S. are washed before heading to market. The process is surprisingly complex since washing eggs improperly can cause bacteria to enter through those pores. It’s also the reason you’ll find eggs in the refrigerated section. In Europe, the cuticle stays on and eggs are sold at room temperature.
Our understanding of eggshell microstructure impacts Canada Goose populations. The process of “addling” by wildlife management professionals controls the population size of the birds. A thin layer of oil is rubbed on the outside of the eggshell, cutting off the oxygen supply for developing goose. The parents, who see a whole nest full of eggs, stop laying more. But only the un-oiled offspring will survive to hatch. [FYI: it is illegal to do this without a permit – see the Migratory Bird Treaty Act of 1918.]
Dinosaur eggs had pores too, and the structure and placement of those pores tell paleontologists a thing or two about how dinosaurs lived. For instance, some dinosaurs laid eggs in an exposed nest while some buried their eggs. Exposed eggs generally have fewer pores than the buried ones since gas exchange proves more difficult underground. Fewer pores are also found in eggs laid in dry environments to limit water loss. The Museum of Paleontology at Berkley has an excellent site with more information about dinosaur eggs.
This “toasted marshmallow on a stick” is the egg case of a Chinese Praying Mantis (Tenodera sinensis), containing hundreds of developing youngsters. The eggs overwinter in this protective case until the spring’s warm weather triggers the eggs to hatch into tiny nymphs (mini-mantids). Nymphs grow into adults who enjoy their summer, snacking on any and all insects who cross their paths. In the fall, Praying Mantises mate, lay their eggs, and pass away.
A female mantid’s work may all be for naught if a tiny parasitic wasp interferes. The mantis lays her eggs in a frothy matrix that hardens around her offspring; but this mini wasp (sporting a ridiculously long ovipositor and rear legs that look like the mantids’ front legs) can lay her eggs inside the mantis case before it hardens. Since the wasps hatch first, they’ll use the mantis eggs as food.
Thanks to Mike Dunn (Roads End Naturalist) who recently presented a guide to winter wildlife – tracks, chew marks, and insect sign. Not only was I awed by his amazing photos, Mike also brought samples of all sorts of wintertime insect egg cases (including this one), cocoons, nests, tracks and galls.
p.s. If you see any artwork on either blog you’d like posted in the Shop, just comment below and I’ll add it ASAP. For instance, the illustration from my most popular blog post (Penis Bones) is not currently on the site. Hope you can see why! Haha!