Tuesday, November 15, 2011

Hairstreak Tree

Change occurs daily at Blue Jay Barrens. That’s just the way it is with natural systems. I accept that it has to be that way, but I’m still frequently disappointed by some of the changes I notice. The attack by a buck deer upon this small oak is one such occasion. This is the oak that annually supports a population of the uncommon Edwards’ Hairstreak butterfly. It’s unfortunate that the tree had to suffer this act.

A couple of twisted branches would be quickly replaced on most small oaks. This individual has been growing in this inhospitable site for over 30 years and is still less than five feet tall. Those damaged branches took ten or more years to develop.

This isn’t a wound that can be repaired. The torn and shattered wood will dry out and the branches will soon die.

Scrapes like this on the branches can possibly heal. What would have been destroyed are any hairstreak eggs that happened to have been laid in the bark crevices.

This branch only showed damage at the point of attachment to the trunk. Pressure on the branch caused it to split at the base and tear away. The attached part of the branch may survive, but I doubt that it would be strong enough to last for long.

The top of the tree recently died as a result of periodical cicada damage and two years of drought. Except for the butterflies it supports, this tree has very little to show for several decades of life.

This small cluster of branches is the healthiest section of the tree. These are the only really healthy looking leaves that appeared this season. The damaged limbs already seemed to be in decline, so the deer may have just hurried the inevitable.

The base and main trunk of the tree still seem to be in good shape. Limbs may die, but this part of the tree seems to have always remained healthy. Maybe the hairstreak eggs are in this more deeply furrowed section of bark. I hope that spring finds both tree and butterflies doing well.


  1. Very nice post. How often do we pass by little trees like this, without knowing about the butterflies it hosts, the cicadas and the deer that ram into it. So much life goes by that we would otherwise not know of if not for posts like yours:)

  2. Change in the natural world is constant, and it's not always easy to accept. I do think that observing the changes and coming to understand that they will continue is a help towards accepting them both in the natural world and elsewhere.

  3. The hairstreak larvae spend the winter in ant nests. So they should be safe. Here's a relevant link -- http://indyparks.blogspot.com/2008/06/nature-at-its-best-edwards-hairstreak.html -- that even mentions the charming Formica exsectoides.
    As for the oak, I have noted, and this is corroborated by some other folks I know that have grown them, that damaged saplings often react with vigorous growth. So I have good hopes for your buck-rubbed little tree.
    I can't tell for sure from the pictures -- Is this a post oak?

  4. Thanks Mona.

    Hi Carolyn. I accept that change occurs, but it still sometimes aggravates me.

    Hi James. That’s a Blackjack Oak. Unfortunately, the Edwards’ Hairstreak overwinters as an egg hidden in the deep crevices of the tree bark and hatches at the time of bud swell. They’re tended by the ants upon hatching and move into a nest at the base of the tree at their third instar. I’ve got an older article from the Journal of the Lepidopterists’ Society that is as close as I’ve come to finding a full life history account. I’ll scan and email it to you.