May 2015 Phenology

by Carl Strang

April’s phenological signal held true in May’s first flowering dates. This year continues to run ahead of most, but not by much.

Ohio buckeye was among the plants that bloomed in May.

Ohio buckeye was among the plants that bloomed in May.

Median first flower dates this May at Mayslake Forest Preserve were 7 days earlier than last year (54 species), 5 days earlier than in 2013 (70 species), 18 days later than in 2012 (69 species), 4 days earlier than in 2011 (68 species), 7 days later than in 2010 (45 species), and 3 days earlier than in 2009 (46 species).

Common spiderwort is peaking now, but started blooming in May.

Common spiderwort is peaking now, but started blooming in May.

The respective numbers for April were, in the same order: 6 days earlier, 9 days earlier, 25 days later, 6 days earlier, 9 days later, and 3 days earlier. On the whole this shows the usual trend of convergence among years as the season progresses.

A number of sedges first bloomed in May, including the small yellow fox sedge.

A number of sedges first bloomed in May, including the small yellow fox sedge.

Color Time

by Carl Strang

Today’s post is just a celebration of some of the colors that fill the landscape this time of year. Plants that blend unobtrusively into the general background of summer green suddenly announce themselves.

At a glance one can see how the shagbark hickories, large and small, are arrayed in the Mayslake woodland.

At a glance one can see how the shagbark hickories, large and small, are arrayed in the Mayslake woodland.

The varied reds draw the eye as well. Here are three.

Virginia creeper winds up its supporting trees with brilliant starbursts.

Virginia creeper winds up its supporting trees with brilliant starbursts.

The Ohio buckeye’s leaves range from red to orange.

The Ohio buckeye’s leaves range from red to orange.

Out in the prairies, tall coreopsis offers a red that leans toward maroon.

Out in the prairies, tall coreopsis offers a red that leans toward maroon.

It’s a time that reminds us to live in the moment. We all know what’s coming.

April Flowering Phenology

by Carl Strang

April was a cooler, more seasonable month than March, which had remarkably early flowering dates for the early plants (recap: March had medians of 32 days earlier than in 2009, 21 days earlier than 2010, and 31.5 days earlier than last year). Since flowering is related to cumulative soil warming, I expected April to show a continuation of the early season, though not necessarily as dramatic. Such was indeed the case.

Ohio buckeye was the most representative plant in April, blooming 25 days earlier than in 2009, 13 days earlier than in 2010, and 30 days earlier than last year.

The plants that bloomed in April this year at Mayslake Forest Preserve were a median 24 days earlier than in 2009 (25 species, range 14 to 55 days earlier), 13 days earlier than in 2010 (25 species, range 3 to 47 days earlier), and 27 days earlier than last year (31 species, range 12 to 37 days earlier).

Wayfaring tree bloomed 31 days earlier than last year, when I first found the plant on the preserve.

I don’t find every plant every year, but the sample size is large enough to be representative.

Pussytoes wasn’t included in any comparisons this year, because I did not find it until this spring. There may be only one tiny colony on the entire preserve.

So, plants continue to bloom 2-4 weeks early this year. The difference should decline each month, as soil heat approaches its effective maximum while later-season plants come into play.

Baltimore Oriole Dossier

by Carl Strang

It’s time to share another of my species dossiers. This one brings together my experiences with a bird that at the moment is to be found in the tropics. Spring can’t come too soon.

Male Baltimore oriole.

Oriole, Baltimore

This bird’s song is very loud, composed of clearly defined, sharp notes, usually a bundle of several with mixed pitches. The Baltimore oriole stays near treetops in feeding, generally. They nest in residential neighborhoods and open woods, especially beside ponds, lakes and rivers. The nest is a distinctive, unusual hanging basket, usually attached to an exposed, slender branch tip over water or a road. One spring I watched part of a nest-building, the female bringing long fibers and weaving them into a bag that already had its basic form. The stroking, pulling bill movements of the bird used the new fiber to fill a space and strengthen the bag.

Even as it deteriorates in winter, a Baltimore oriole nest is a beautiful object.

3JE86. A male foraged low in a crabapple, moving fairly quickly between perches, moving 2-3 feet at a time, looking among leaves, often burying his head among them and searching. Once he dropped to the ground in pursuit of a prey that jumped to evade him.

14JE87. Adult eating mulberries at Culver fish hatchery.

7MY88. Singing at Culver.

4MY99. First migrant noted at Willowbrook. Last spring migrant observed there 27MY.

11AU99. First fall migrant noted at Willowbrook. Last one noted 24AU.

This nest is relatively visible.

17JE00. Arboretum, Joy Path. Adult male foraging in the branch tips of a bur oak where leaves are clustered. It was searching and probing into clumps of dead leaves. It caught an adult moth, removed the wings, then flew straight to its nest overhanging the path at least 20 feet up. The moth was fairly large and heavy bodied, perhaps a noctuid. The nest is within a clump of leaves so that it does not appear suspended. Later, both the male and female were carrying food to the nest. When they were there, and for a few seconds after they left, a chorus of faint peepings was audible.

2JE01. Meacham Grove, east part. A female oriole led me to a nest that was so woven into the cluster of leaves at the end of a bunch of slender twigs that the nest was practically invisible.

There is a Baltimore oriole nest here, but it is well buried among the leaves.

16JE01. Newly fledged orioles still were close to the nest at the Arboretum, Heritage Trail. The nest was above a service road-trail just inside the fence separating the savanna area from Hidden Lake Forest Preserve, on the end of a descending oak branch’s lowest twigs. One of the fledglings was still perched just above the nest, the others were scattered on that branch and in nearby branches of other trees. They were essentially motionless for a long time, but very vocal, with distinctive calls: 3 quick identical notes that sounded like uninflected robin notes.

31AU02. A Baltimore oriole in full male breeding plumage, singing at Lincoln Marsh from the very top of a tall tree. Not full volume, and only little chattering phrases, but clear oriole voice tones, whistles. Sang for several minutes.

27JE08. Baltimore oriole fledglings have a call that is a rapid series of clear notes rising as on a scale.

2MY09. An oriole at Fullersburg was taking nectar from buckeye flowers.

4MY09. Mayslake. Series of photos of an oriole probing clusters of oak flowers and opening leaves.

Foraging oriole at Mayslake.

1JE09. Mayslake. Pair of Baltimore orioles mobbing a fox squirrel in the medium-sized cottonwood closest to the SE corner of May’s Lake. They gave frequent, loud, identical, slightly slurring notes but did not attack the squirrel. I found the nest at the end of the lowest branch on the east side of the tree, 15-20 feet up. The squirrel eventually jumped to another tree without finding the nest, escorted by the male oriole, and the female almost immediately returned to the nest.

Here is the female giving her alarm calls.

10JE09. The same pair of the previous entry is feeding a cowbird fledgling just outside their nest. In the brief time I watched, the female fed the cowbird once, the male fed it once and a nestling once.

Cowbirds and orioles are in the blackbird family.

Apparently this episode of nest parasitism doomed the orioles’ own young, as I never saw any oriole fledglings from that nest.

More Mayslake Fruits

by Carl Strang

Earlier I featured several plants at Mayslake Forest Preserve that produce fruits timed to coincide with the fall migration of berry-eating birds. This mutualistic interaction for the most part benefits the birds, through nutritional provisioning, while the plants get their seeds dispersed. Today I want to feature some outliers to this pattern. Let’s start with Solomon’s plume, also known as false Solomon’s seal.

Solomon's plume fruit b

Like many fall fruits, these advertise themselves to birds with a bright red color. When analyzed, however, the berries proved to be junk food, or perhaps are more accurately described as food mimics (White and Stiles 1985, Ecology 66:303-307). The plants save their energy, investing no nutritional value in these fruits. The ruse works, apparently, by exploiting the naïve instinctive response of first-time autumn migrants, the young of the year. A little different from this is the offering of the European highbush cranberry.

European highbush cranberry fruit b

Another study (Witmer 2001, Ecology 82:3120-3130) showed that the nutritional value of these berries becomes available only when they are consumed along with a significant protein source. I was impressed to learn that, like the waxwings native to the shrub’s European home, our North American cedar waxwings ignore these tempting berries until spring, when cottonwoods or other poplars are flowering. Then the birds consume the berries along with cottonwood catkins, protein in the pollen providing access to the berries’ nutritional value.

Common buckthorn fruit b

These black berries are common buckthorn fruits. They generally are ignored by birds until late winter when, apparently, the better quality foods have been depleted. Then, robins and waxwings consume them, unfortunately dispersing the seeds throughout our woodlands. Buckthorns leaf out early and lose their leaves late, casting a shade so dense that no other plants can grow beneath them. This is why these Eurasian shrubs must be removed at the beginning of woodland restoration projects. A final fruit is of no interest to birds.

Buckeye fruit 2b

Ohio buckeyes in fact are largely ignored by animals generally. This opens the possibility that, like other trees I discussed earlier, buckeyes may have been dispersed by now-extinct mastodons and other large herbivores.

Mayslake Flowers Update

by Carl Strang

At the beginning of May the appearance of new wildflowers on Mayslake Forest Preserve accelerated. In some cases I have not made identifications, yet. For instance, there are a lot of small trees and shrubs in the rose family that probably are various crab apples and hawthorns, but may include introduced (and possibly horticultural) varieties that make identification difficult for a vertebrate ecologist. Among them are this one

Rosaceous small tree 1b

and this one.

Rosaceous small tree 2b

Here is an herbaceous plant flowering in the savanna that I can’t get a handle on, yet.

Mystery plant 1b

Its leaves are dense along the stem and embrace it like those of New England aster, but without the hairiness.

Mystery plant 2b

I suspect it may be in the mustard famiy, and if so should be able to get an identity as fruits appear.

Most new flowers I have been able to identify, though. Abundant swamp buttercups are flowering in the cleared area below the friary.

Ranunculus septentrionalis 2b

They, along with scattered small-flowered buttercups,

Ranunculus abortivus 1b

have joined the early buttercups already flowering there and elsewhere in the savanna. Also on that hill are red trilliums,

Red trillium 2b

yellow violets (there’s a contradiction in terms for you!),

Yellow violet 1b

and wood anemones.

Wood anemone 1b

Not flowering on that hill this year, but another good find, was bloodroot.

Bloodroot Mayslake b

Elsewhere on the preserve, appearances were made by the flowers of Ohio buckeye,

Buckeye b

choke cherry,

Prunus virginiana 2b

wild strawberry,

Strawberry 2b

purslane speedwell,

Veronica peregrina 2b

and golden Alexanders.

Zizia 4b

Non-native species include tartarian honeysuckle,

Tartarian honeysuckle b

shepherd’s purse,

Capsella 3b

and common chickweed.

Common chickweed b

Again, all I am doing for now is establishing local first flowering dates in what will be an ongoing phenology  study. No doubt I will return to some of these species for other future inquiries. For instance, what were all those ants doing on the golden Alexanders flowers?

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