A Pollinator's Perch

Credit: Image courtesy of Oxford University Press (OUP)

Small South African irises in the genus Babiana have evolved an upright perch to attract sunbirds to pollinate them.

The research consisted of fieldwork across the western Cape, examining Babiana and making observations of the sunbirds that pollinate them. Barrett said: "What we found is when sunbirds visit Babiana ringens, they always land on this perch and then turn upside down to feed on nectar from the the ground-level flowers. In contrast Babiana carminea doesn't have a perch, and here we found that sunbirds land on the ground and probe flowers to feed on nectar. Ground level flowers are highly unusual in bird-pollinated plants because of the likely predation risk and to find two contrasting feeding strategies among related species is remarkable."

"Babiana avicularis has a perch, but these plants are only visited by the southern double collared sunbird. This is a smaller sunbird, and it looks like Babiana avicularis may have evolved a specialised relationship with it. Larger malachite sunbirds don't visit this plant but are the exclusive pollinators of Babiana ringens which has larger flowers. No one had seen birds pollinate this plant before and it's now one of the smallest bird-pollinated plants known."

The image above shows a sunbird feeding on a Babiana flower from one of those evolved perches. There is also some variation in the size of the perch, with the perch length being longer wherever sunbirds visited Babiana more frequently.

"What we also found with Babiana ringens is that the perch length was smaller in the east of our survey area. This is the region where we saw fewest sunbird visits to plants. So with fewer pollinators around there's less natural selection to maintain large perches, and it also makes sense to have self-pollination as a back-up when the alternative may be no pollination at all."

Barrett is pleased that the work provides insight into the most specialized bird perch in the plant kingdom, but warns that there is still much that we do not know about how the perch evolved in the first place: "Our research shows a clear functional basis between perches and bird pollination, but that's not all it shows. At the same time we're also seeing self-pollination and it's clear Babiana can adopt different mating strategies in different locations depending on the availability of sunbirds."

The study was published in Annals of Botany.

An Eye-catching Mushroom

Unlike a lot of other wildlife preserves that maintain native wildflower meadows, the fields at Cold Brook Reserve are sowed with corn. The corn is planted and harvested by a local farmer, who works under contract with the county. While corn monoculture is not ideal for producing a diverse array of insects and breeding birds, it presumably leaves behind ample food for migrating and wintering birds.

On Saturday, there were a lot of these eye-catching mushrooms nestled in among the rows of corn. There are a few species with a similar shape and color, but I think these are Phallus rubicundus, also known as devil's stinkhorn. These are distinguishable from the similarly-colored Mutinus elegans by having a separate spore-bearing head (more evident in the photo below). These mushrooms have a red shaft and a pointed head that is covered with a greenish brown slime that contains the spores. The slime's odor attracts many insects, such as the picture-winged fly in the image below.

Phallus rubicundus is native to warmer regions and is widespread outside of North America. It is suspected that the mushroom spread north to the Midwest and Northeast via commercial mulch suppliers. It is associated with parks and gardens, as well as other sites where mulching is common. It is especially conspicuous in New York's Central Park.

Butterflies and a Moth at Cold Brook Preserve

Until Saturday, I had never visited Cold Brook Reserve, a small wildlife area in northern Hunterdon County. It has a reputation as one of the best places in northern New Jersey to look for sparrows and other open-country birds, particularly during autumn migration after the preserve's fields have been harvested. On Saturday the sparrow numbers were not very high yet, though I did see individual Song, Chipping, and Field Sparrows. However, I did see a Bobolink fly over one of the fields, and there were a few hatch-year Indigo Buntings around.

While there were not a lot of sparrows, there were a lot of butterflies around. Among the most common were sulphurs. An Orange Sulphur is above; the orange color is only obvious on the tops of the wings.

I was delighted to see a Common Checkered-Skipper, which has a beautifully intricate pattern on its wings.

Another skipper at the refuge was this Dun Skipper, which I found in the brushy edge bordering the stream that flows through the refuge.

A lot of Eastern Tailed-Blues were fluttering around in the grass. These small blue butterflies have tails and hindwing spots that give the appearance of an additional face at the back of the butterfly. It is thought that these might fool predators about which end is the true head.

It is often difficult to get a good look at the uppersides of an Eastern Tailed-Blue's wings, but one individual sat with its wings open for a long time. In contrast of its light undersides, the upperwings are a dark bluish-black.

Finally, I also saw a few small moths flutter in and out of the grassy trail. Most were crambid snout moths, but one of them was this lovely Chickweed Geometer.

Do You Come to a Cemetery to Pray?

Yesterday I visited Cold Brook Preserve in Hunterdon County for the first time; I will have more about that in a later post. On the way to and from the preserve, you pass through the town of Oldwick, an old farming village that dates back to the 18th Century. Near the center of town there is a historic Lutheran church with a very old cemetery. On one of the older gravestones there was a mantid. First it waited on the left of the stone, and then it crawled up onto the stone's rounded top.

This mantid appears to be a Chinese Mantid (Tenodera aridifolia sinensis). According to BugGuide, these are recognized by the tan forewing with a green stripe along the leading edge of the wing and by their eyes, which are chocolate brown at sunrise and pale tan at other times of day. Chinese Mantids were imported into the U.S. as a biological control agent beginning in 1896. Egg cases for this species continue to be widely available from gardening suppliers. Its value as a biological control is questionable. While it eats a large volume of insects, it eats a wide variety – the beneficial insects along with the pests.

Local Shorebirding

While Hurricane Irene did not bring me any tropical birds, it has created some good opportunities for local birding. The Raritan River flooded on Sunday and remained flooded on Monday, with the waters gradually decreasing since then. At this point, the flooding here is finished, but the river's level remains very high, so that areas that are normally exposed at low tide are still submerged. This leaves waders that depend on tidal mudflats looking for new locations for foraging and loafing. Meanwhile, with the river still high and the ground still saturated, a lot of fields have big wet areas.

One of the open areas by the old basketball courts in Donaldson Park was still flooded as of Thursday when I made my last visit there. More birds were using the wet area than I initially thought. There were a few dozen Mallards: some swimming and some roosting on the branches that had fallen in that area. When I walked around to get a closer view from the other side, I could see that there were many more birds than I initially thought. There were at least two dozen peeps (Least and Semipalmated Sandpipers – no Westerns that I could see), plus a few larger sandpipers (Solitary Sandpiper, Spotted Sandpiper, and Lesser Yellowlegs). None of these shorebirds are particularly rare, but seeing so many at once in this location is highly unusual.

Lesser Yellowlegs is probably the yellowlegs I see less frequently in New Jersey. I'm not sure if this reflects an actual distribution pattern or if it is just an impression.

Solitary Sandpiper is actually one of the more reliable sandpipers at Donaldson Park. Least Sandpiper is the sandpiper that one is most likely to see there. After that would come Spotted Sandpiper and Solitary Sandpiper. The Solitary Sandpipers that visit Donaldson Park seem to prefer the wet fields to the edges of the river, unlike the Spotted Sandpipers, which I usually see along the riverbank. This wet area was one that both could agree on. Contrary to its name, this Solitary Sandpiper was not solitary, as one or two others were nearby.

The floodwaters have receded, but there is still evidence of the torrents all over the place, with a few trees down, fences covered with debris, and even one bent fence.

Loose Feathers #306

Blue-winged Teal / Credit: Barbara Wheeler Photography, USFWS Volunteer

Birds and birding news

• Birds use a variety of means to survive hurricanes. Some hunker down in holes and bushes; others move to higher ground; still others get swept up in the storm's winds and ride them out as best they can.
• Hurricane Irene produced an abundance of storm-blown birds in New York City. 
• If you happened to see unusual birds as a result of the Hurricane Irene, make sure to submit them to eBird so that scientists have a complete record of birds carried by the storm and where and when they were observed. That links also has a summary of birds reported so far.
• The Greater Sage-Grouse is on the verge of extirpation in Alberta; there are at most 40 birds left in the province. Oil and gas development is the primary cause for their decline.
• An attempt to reduce Caspian Tern predation on endangered salmon failed when a relocated tern colony was joined by salmon-eating cormorants. Meanwhile, the tern colony fledged no chicks this summer because of harassment by Bald Eagles and egg predation by gulls. The bird colony may be relocated once again.
• A study of Great Tits found that males in urban areas sing higher-pitched songs to be heard over the ambient noise (provided by traffic, HVAC systems, and other sources). This interferes with females' reproductive choices since female tits prefer lower-piched songs.
• Here is a nice graphic for distinguishing Mallards in eclipse plumage.
• Scientists have found a record flock of Sociable Lapwings (numbering at least 650 individuals) in central Kazakhstan.
• Birds Australia runs a program to encourage birdwatching and better bird habitat in backyards.

Nature blogging

• March of the Fossil Penguins: Family Tree of the Living Penguins
• Audubon Guides: Willet stay? Willet go?
• BugBlog: Summer Hoverfly identification
• Myrmecos: A mural on moth wings
• View from the Cape: Hawkwatch: Day 1!
• The City Birder: Fetish Tern
• birdspot: On a lighthearted note – T-shirts!
• Extinction Countdown: Thylacine Hunted into Extinction for No Reason, Study Reveals

Environment and biodiversity

• Texas is in the midst of its worst single-year drought on record. The state has only received 6.5 inches of the 16 inches of rain that it normally has received by the end of August. Meanwhile, the Plains states overall broke heat records in July, with Texas and Oklahoma leading the way.
• The US Fish and Wildlife Service proposed a smaller critical habitat designation for the endangered California Tiger Salamander.
• The USFWS also produced a new recovery plan for desert tortoises in the Mojave Desert; it seeks to protect tortoises from livestock grazing, off-road vehicles, and non-native plants, but does not address other threats such as climate change and renewable energy development.
• Reintroduction of gray wolf populations seems to benefit the Canadian lynx by reducing competition for prey from coyotes. Meanwhile, there will be wolf hunts again this year in Idaho and Montana.
• A mountain lion was killed when it tried to cross the 405 Freeway in Los Angeles.
• The protest and civil disobedience at the White House against the Keystone XL oil pipeline continued this week, with some high-profile attendees. James Hansen was arrested on Monday, and Daryl Hannah was arrested on Tuesday. Mark Bittman offers his thoughts on why the pipeline should not be approved. The Keystone XL pipeline would carry bitumen from tar sands mines in Alberta south to refineries in Texas.
• A new study comes down on the side of strictly protecting some tracts of lands while intensively farming others as the best way to preserve biodiversity. However, there is substantial disagreement on that point among ecologists, and one model is not necessarily going to work for all regions.
• New Jersey and Maryland have approved a new contraceptive for use in white-tailed deer that not only prevents pregnancy but also reduces mating behaviors such as rutting and chasing after potential mates. The contraceptive may provide an effective way of controlling deer populations in suburban and urban areas where hunting is inadvisable.
• The access point for the Delaware and Raritan Canal at Rutgers Prep (DeMott Lane) is closed because flooding swept the footbridge away.

Blog carnivals

• Festival of the Trees #63
• Berry Go Round #43

Pelicans Dying from Puncture Wounds

By Jayson Mellom / TheTribuneNews.com

Some Brown Pelicans on California's Pacific coast have been appearing on beaches with odd puncture wounds, in some cases very large ones. Initially these were reported as possibly being the result of a knife attack.

Fifteen pelicans have died in recent days as a result of their chest wounds. Three were brought into the Pacific Wildlife Care center in Morro Bay on Thursday.

Two of the birds had to be euthanized because their injuries were so bad, and a third is being treated. Jeanette Stone, center director, said the wounds are more serious than the typical injuries pelicans receive from fishing hook and line entanglements....

A veterinarian examined the dead pelicans and found one to have wounds consistent with being caused by a knife or other sharp object. Wardens are continuing their investigation.

“We can’t rule out foul play,” Warden Sean Kenady said.

Now the state game wardens think the wounds may be the result of competition with sea lions.

Warden Sean Kenady said a kayaker saw a sea lion repeatedly pull a pelican under water until it failed to resurface. The department also got an email from the animal rescue group, Wild Rescue, which said its members had seen that behavior in the past....

Wardens think the injuries occurred when both animals were in a feeding frenzy on baitfish, with the pelicans feeding from above and the sea lions from below. The sea lions may have attacked the pelicans because they were competing for the same food source.

I would not have thought of pelicans and sea lions as being direct competitors, but they do share some habitats and both rely heavily on fish. So this explanation does make some sense. Confirmation (or refutation) of this explanation will come whenever the necropsies are completed.