Friday, June 10, 2011

Nature Detective

One or two events recently have found me kicking back to my childhood - a time in our lives when I reckon we all have the potential to get the most out of the natural world. The one thing that children do so well is ask questions - interminably! You know, "Are we nearly there yet?", "Are we going soon?", "Why did Johnny get more than me?" and the completely indescriminate "Why?" to just about everything. Applying this questioning to the natural world as we get a little more adventurous - and more focused and directional in our questioning - is how we learn and, as I said to someone just a couple of days ago, the day we stop asking questions is the day we stop learning anything new!

What am I babbling about? Well, here's a few pictures I took yesterday that should instill questions in us all. The sort of pictures that turn us into nature detectives...

I pass the wooden jetty on bunker pond almost daily and it can be easy to become glib about the Forster's Terns that are almost always there this time of year. Yesterday though, they caught my eye. Why? Well, there heads look a bit odd don't they? What are they doing? One thing I learnt a long time ago is that birds have much better eyes than me and are very good at spotting predators - they have to be! Birds eyes are fixed in their sockets (they can't look left and right before crossing the road!) so they have to turn their heads to look in different directions. These birds have their heads cocked to one side because they are looking up. Keep an eye out for this behavior and take a cue from the birds. I looked up and there was a Mississippi Kite! So high, I couldn't get a photo of it, but the birds had spotted it and were checking it out. I have seen many birds of prey in this way, by noticing the bird I am watching looking up...

Blue Dashers are very common dragonflies and one of the few that tolerate sub-optimum, disturbed habitats so do well at Cape May Point State Park. What we must ask about this guy is why is he trying to stand on his head?! The answer is that this behavior is called 'obelisking'. Why do they do it? It was pushing 90F lunchtime yesterday at the state park and the sun was high in the sky. The best way for a dragonfly to stay a little cooler whilst still being able to stay out and hunt for food is to minimize the surface area of its body that is presented to the sun. Pointing the abdomen straight up is the simplest solution - even if it does make you look a bit silly!

Anyone who has visited Cape May Point will know that Fish Crows are a serious problem down there, systematically working their way through all the eggs and chicks painstakingly cared for by Nature Conservancy and DEP staff. The solution is very simply but not popular, but while I was at the state park yesterday this bird flew past me and gave me another nature detective episode - what species of bird is it having for lunch? While the possibilities may seem endless, we can actually get there quite quickly. We can rule out pretty much all non-passerines by the long hind toe, which is as long as the fore-toes. Several groups can be ruled out by having black or gray legs, while others, such as woodpeckers and cuckoos have two toes forward and two back instead of three forward and one back. I quite quickly found myself reckoning this to be a pigeon of some sort, with the pale pink suggesting it is (or was) a young bird. I would therefore presume (it being Cape May) that it's either a Mourning Dove or Feral Rock Dove. I guess that's better than a Piping Plover...

My day of nature detection yesterday continued right through to the evening when I was about to brush this tiny ant off my shorts. Something somehow struck me as unusual so I gave it a second look. This thing is tiny (here it is on my finger nail), just like those annoying minuscule ants that seem to come as a compulsory extra in kitchens around here, yet it somehow seemed different.

Here's a closer look and we can now make a call on what it is. In both pictures, what should be apparent is that this minibeast comes in two - we could loosely call them a head and a body. Ants are typical insects and have three sections - the head, thorax and abdomen. In addition, this closer picture reveals at least six eyes - two of which are placed at the back of the elongated head. You can also just make out two large, forward facing eyes on the front, like a pair of goggles - and all of the eyes are simple, not compound. This is all pointing towards a spider, and that is what we have. An amazing spider which mimics ants as a way to get closde to its prey. It probably also means that it gets left alone by potential predators whi hdon't want to tangle with an ant and all that formic acid thing that they have going on! This looks like one of the antmimic jumping spiders so I'm hoping spider fanatic Dick Walton can help me with this one!

Just for balance, here's one I keep missing! My nature detective radar keeps letting me down on Roseate Terns, which pop up at time to time here - I've yet to see one at Cape May! This bird was photographed at the South Cape May Meadows yesterday afternoon by Karl Lukens. Roseate Tern is an intensively-studied species and pretty much all birds that turn up in Cape May are banded.

Suggestions for the weekend - water levels at the South Cape May Meadows are excellent at the moment and the site is currently attracting large numbers of terns and gulls and a few shorebirds, egrets and herons. Try an evening walk there, any time after 5PM and scan through the flocks in search of Black or Roseate Terns. Marsh Wren can be heard on the main (west) path and you might get Virginia Rail or  Black-crowned Night Heron too. (Don't forget to get your pass on the way in - $5 for the whole year is pretty good value for money and helps pay for habitat maintenance).

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