Friday, September 30, 2011

Birds 9/30 - Avocets, White Red-tail, more

Early this morning, I set off with Jimmy in search of the American Avocets in Newport, which we were possibly the last people in RI to go see. We generally fail miserably when searching for reported birds; therefore, we very rarely do. However, the prospect of seeing such a beautiful bird (and 5 of them!) on such a nice day was too much, so we bit the bullet and went.

And we were not disappointed! The five birds put on a phenomenal show for the half hour we were there. We also met a couple other birders - nice guys, as usual - which is always a good thing.

Because Jimmy has a real job, I dropped him off in Providence and hit a few spots in northern RI by myself. The unquestionable highlight was the white Red-tailed Hawk in Lincoln (at Chase/Great/Butterfly Farm) who has been around longer than I have been birding - but I have seen him for the past 4 years. He was a bit distant, so I couldn't manage a better photo than this, but despite having seen him a few times, I have never gotten a picture of him before.

It seems that every year he has a different arrangement of colored feathers, I seem to remember seeing  only a couple red tail feathers last time.

This guy is always worth waiting around for - though the park is a hellhole of dogs off leashes, poop, and owners who don't give a hoot that their dogs are disturbing you (and are not afraid to tell you off for yelling at their dogs...). It is hard to birdwatch here, but a great place for raptors, as well as sparrows on the border of the farm nearby - where I found this puzzling bird:

I knew immediately what it was - a Brown-headed Cowbird - but a few things were odd about this one. It was incredibly dark and the white throat was much better defined than I have seen on other individuals.

I then hit Lonsdale Marsh, where the only birds of note were the first two Yellow-rumped Warblers (aka "butterbutts"). While they will be very common in another month, these were the first of the year for me.

The Cumberland Monastery had a Black-throated Green Warbler and a Swamp Sparrow, and the reservoir complex was empty short of a few geese and gulls.

Wednesday, September 28, 2011

A new addition

Clearly I am not committed enough to run a blog on my own. To that end, I have invited sir Jimmy Tarrant to co-write the blog. He was the second vice president of  the Brown Boobies and the third president - both highly esteemed positions. And that is why I can say: you, like the chickadee below, will be in good hands.

Cape Cod, 2010

 And from Nantucket in 2011:

Here Jimmy is at the top of the Great Point lighthouse, seconds before he sprinted down the stairs and across a half mile of beach to inform me that two Parasitic Jaegers were off the north side - which we were able to find and watch for another few minutes.
Parasitic Jaeger. August 2009, Maine

Tuesday, September 27, 2011

Identifying Dragonfly Skins?

Dragonflies are fascinating creatures and astoundingly good predators. Often ignored is that they spend most of their lives underwater as naiads - a technical term but nymph or larva is fine, too. Naiads eat anything that swims in front of them, catching it with a protrusible lower jaw. This includes aquatic insects, other dragonfly naiads, tadpoles and even small fish. When their time in the water is done, the naiad crawls up a piece of aquatic vegetation and sheds its exoskeleton. Now referred to as a teneral, it must dry out its exoskeleton and roll out its wings. But it leaves a shed skin, which we call an "exuvia" ("exuviae" is the plural - remember your latin?).

A teneral female Sympetrum vicinum, which will turn yellow in a few days as the exoskeleton dries

These exuviae stick to the plants for several weeks after the dragonfly emerges. Because they are the last exoskeleton of the larva, they retain all the larval characteristics. Through the hard work of many scientists - and amateurs - who have collected larvae and raised them up to see what hatches out, there are great keys available to identify larvae which also work for these exuviae. 

Common Green Darner, Anax Junius
The same species, adult male
This summer, I collected over 800 exuviae from two ponds on Nantucket and identified them. While this was a maddening task at first (how many dorsal hooks does it have, and what shape are they?), I got to be quite efficient after a few days of it. It is amazing how after awhile you learn to recognize general shape and size, characters not included in the keys, and can identify them correctly just by sight - despite that the technical ID requires counting spines. My results, albeit limited, showed that some adults at the pond do not reproduce there, as their exuviae were not found. This is a common and well-documented phenomenon in dragonfly communities and may represent marginalized individuals relocating to less-than-ideal breeding sites - i.e. places where their larvae do not survive.

A few more pictures to compare exuviae and adults:

The Blue Dasher, Pachydiplax longipennis
The same, an adult male

A meadowhawk: Sympetrum sp.

A Ruby Meadowhawk, S. rubicundulum

Collecting exuviae is great as you do not have to catch and identify adults and you get a permanent specimen out of it. Also, some dragonfly species are hard to find as adults, only flying in the early morning and at dusk, and thus it is easier to find the exuviae than the adults. Sampling for endangered odonates is often done by looking at exuviae instead of adults.

Aeshna clepsydra, a species more common as exuviae than adults

Mushrooms aplenty

Late summer and fall represent the best time of the year for mushrooms. Generally distrusted and overlooked by most people, mushrooms are fascinating, and certain ones are delicious. I take a gastronomic approach to mycology - I know some non-edible fungi and I key them out if I find an interesting one - but I avidly search for the edible ones. A required book (for anyone, really) should be David Arora's Mushrooms Demystified. While not a field guide in the general sense of a small, portable book, it is a wonderfully complete, well-written and at times hilarious book that really does a great job in teaching a reader about all things mushroom. I learned almost all my mushrooming from that book and still consult it on an incredibly regular basis. What other field guide includes recipes?

Pictured is a batch of my two favorite mushrooms on earth: Chantarelles and Black Trumpets, which are occasionally, amusingly, referred to as Trumpets of Death. Both, interestingly, smell like apricots when fresh and after cooking, have a very distinct but delicate flavor. A fresh cream sauce for pasta is unbelievable with these. While I was doing thesis research in Maine, I found these both to be abundant in the midcoast area, while in southern New England I have found both, but never in great numbers. In the past week, hitting a few spots in northern RI, I managed to get enough trumpets for a sauce and just 4 chantarelles.

Trumpets can be maddeningly hard to find - they are small and blend in oh-so-well with leaf litter. Oftentimes, when I find an appropriate area I just stare at the ground and eventually they will either show up or I get distracted by a bug. The latter scenario occurs most commonly. I commonly find them on hills and in washes, and generally in early August until September.

In contrast to the hard-to-find and tiny mushrooms, there are a few quite common giants that are also good eating.

This is a rather small example of a species that you could call a number of names. If you are Japanese, you may prefer "Maitake", an old yankee: "Hen of the Woods",  Italian: "Signorina" or if you are a nerd, perhaps: "Grifola frondosa". This wonderful mushroom grows at the base of oak trees and is remarkable simply to find. I usually look up at the trees and check around the ones that show some dead branches - the fungus is reported to associate with sick trees and this generally proves true. I have never found a truly giant specimen, some are reported to be over 50 pounds, but I have come across a couple that were nearly 20 pounds. An hour of walking around your local park will almost certainly get you one of two of these - unless someone else got there first!

Recipes for this species abound - and if you search for the varying names, you get varying recipes - and it is really appropriate for any dish that you could use mushrooms or is perfect on its own simply sauteed with butter, salt and pepper. 

Keep an eye out for these now on oaks just about anywhere between August and November, I have seen them on Blackstone Boulevard in Providence, as well as deep in the New Hampshire woods.

Late September Bugs

An unseasonably warm spell lately has resulted in quite a few bugs that "should" have disappeared a few weeks ago - whether to hibernate or simply die from the colder weather depends on the species - still kicking around my local spots.

The Gray Hairstreak (Strymon melinus) above is one of the later flying butterflies normally, but this particular individual is showing some wear and if cold weather had occurred, may not have made it. However, he was flying around maniacally today as Hairstreaks tend to do.

In contrast, this Eastern-tailed Blue (Everes comyntas) from the same area is very fresh. This species is interesting as they have up to 3 broods a year, in contrast to most butterflies which have just one, or uncommonly, two.

From the same area, but last week, this Red-bellied Tiger Beetle (Cicindela rufiventris) was an adult that had survived long past when of his companions died off in late August. The larvae dig to below the frost line during the winter and emerge as adults the following summer.

Dragonflies and damselflies (like the male Ishnura hastata pictured) are often some of the last large insects flying in the year, certain species regularly flying into mid-late November. 

This guy - a male Sympetrum vicinum - is usually the last dragonfly on the wing in the fall, hence the common name of "Autumn Meadowhawk". This particular individual has his abdomen up in the air and is probably regulating his temperature that way - either by orienting to expose the maximum surface area to heat, or to minimize surface area exposed to cool down. The adaptations, both behavioral and physical, to control body temperature in animals could fill many a book (look up: elephant ears or termite nest construction).

I found a few more cool beetles that will be detailed in a later post. Until then, get out and enjoy the warm weather. Find some butterflies!

Wednesday, September 21, 2011

A Cuban Peewee

Abaco Island, Bahamas, Feb. 2011

An Overview of Tiger Beetles

While you are out in open, sandy areas on nice sunny days take a good hard look at the ground. Oftentimes you can see a little metallic flash zing away from you, either running or flying. Chances are you just saw a Tiger Beetle - a not uncommon group of ground-beetles (Carabidae).

Cicindela purpurea, Nantucket 14-Sept-2011

These gorgeous little bugs are one of the major groups that has received state and federal protection via the endangered species act - eight of the nine "listed" beetles in Massachusetts are tiger beetles including the above species, the Purple Tiger Beetle. It is a rare and declining species in Massachusetts, many populations existed historically throughout the state, but very few are known now.
Notice the massive mandibles for catching prey on this C. repanda.

All tiger beetle species eat other invertebrates, often including ants, pillbugs and crickets. They run the prey down and grab it with their massive mandibles or scavenge dead or dying creatures.

Cicindela repanda, July, Nantucket
The life-history of these beetles is interesting. Certain species here live for two years; overwintering during the first year as a larva and the second as an adult, breeding in the spring of their second year. Others overwinter as larvae and emerge as adults in the summer then breed and die by fall. In one location you may find two species - often C. repanda and C. hirticollis - in the exact same areas, but almost never at the same time. Perhaps this is an adaptation to minimize competition, but no one has quite resolved that question yet.

C. hirticollis, an individual I collected as a larva and raised for several months
As insects go, these have proved quite easy to keep in captivity. The larvae can be fed small crickets or flour moths and the adults seem to enjoy crickets and pillbugs, though I also fed them dog food and they seemed to enjoy that as well. I have not tried overwintering any, as this process apparently is difficult.

Cicindela sexguttata, a common species that I cannot get to pose for a picture while alive.

Cicindela dorsalis dorsalis, collected in the 1920's by C.W. Johnson, now severely endangered

Separating Bahama Swallows from Tree Swallows

Seems easy, doesn't it?

That is until you see all the little bastards at 100 yards whipping around as swallows do, so I will make a point of the little things that field guides cannot teach succinctly in the quarter page each bird gets. I spent three weeks in the Bahamas, on Abaco Island, erecting nest boxes for Bahama Swallows. I found out how difficult separating these two species in flight can be, when a good birder, a local guide, called me and reported "thousands of Bahama Swallows". Being without a car, I hitchhiked the hour drive and came upon a group of thousands of Tree Swallows, a bit disappointing, to say the least.

Unfortunately, this post comes a bit late for the post-Irene fallout of Caribbean birds all over the east coast. I will muse a bit more on Bahama Swallows in the future, but suffice to say that the sightings of these birds drop way down between August-January and I don't have a clue why. So the chances of one having been whipped up were pretty high, in my opinion.

The easiest ID feature on the Bahama Swallow is that the white underside includes the underwing coverts, whereas there is no white on the underwing of a Tree Swallow. The second good feature is the tail of a Bahama Swallow is highly forked, whereas on Tree Swallows it is only mildly forked. However, keep in mind that alot of the time, Bahama Swallows fly with the tail somewhat “closed” and the forks cannot be seen well. They also have much more white on the “cheeks” than the tree swallows, which makes their heads look smaller.

Tree Swallow: Notice that white stops on body, none on wings, outer tail feathers are not significantly longer than the adjacent ones.

Bahama Swallow: notice the white underwing coverts and the deeply forked tail.

The color of Tree Swallows, in good light, is much more blue and Bahama Swallows more green; however, be careful with this as Tree Swallows can appear green in the right light. A more useful dorsal characteristic is that Tree Swallows appear very shiny while Bahama Swallows have bright colors, but little shine to the feathers on their backs with a little more towards the wings.

Bahama Swallow: notice the flat color of the dorsal side of the body, with iridescence on the coverts and the rump as well as the two outer tail feathers being far longer than the
inner ones.

Tree Swallow: note the iridescence on the entire upper body from any angle.

I have not seen Bahama Swallows feeding from bushes, whereas Tree Swallows often do – Myrtles on the east coast and some similar plant in the Bahamas. I heard a report that Bahamas will walk on the beach picking up prey, but I have not seen this behavior myself.

Now the more subjective tips to pick them up from afar: after watching a mixed group for several hours, I have found Bahama Swallows to appear more tapered and thinner. I think this is a result of holding their longer tail feathers together during most flight. The wings appear longer – whether this is true or simply a result of the body looking thin, I cannot say. They seem to forage higher than Trees, though the Tree Swallows here do fly very high while flocking, but not while foraging. They sound slightly different (Bahamas have less of a grating call). While I have seen good sized flocks of Bahama Swallows (20-30 individuals), they are not always in flocks, often there will be 1-6 in an area, whereas I have not seen any Tree Swallows in flocks smaller than ~50 in the Bahamas.