Bring Out the Mushrooms!

The persistent rainstorms of the past two weeks have produced a full crop of mushrooms. Several dozen of the following were clustered around a dogwood tree, in variously-sized clumps. I am not really sure what these are since there are quite a lot of whitish fleshy mushrooms.

There are also several of these cup-shaped mushrooms in another location. Again, I am not absolutely sure of the identity, but it seems like a Common Brown Cup (Peziza badio-confusa).

What's Wrong with the Whooping Cranes?

An already bad year has now turned worse for Whooping Cranes. The cranes at Necedah NWR in Wisconsin have all abandoned their nests.

This spring, crane watchers were heartened by a record 12 nests in the 43,656-acre Necedah National Wildlife Refuge and surrounding areas in central Wisconsin.

But then adult cranes began leaving their egg-laden nests. The same thing happened in 2008.

Leading explanations: The cranes are suffering from an inadequate food supply or swarms of black flies are driving them from their nests.

Biologist Michael Putnam has been trapping minnows and scooping muck from the bottom of the refuge to see what kind of vegetation, snails and other animal life the cranes might be eating.

When he's lucky, he finds fresh feces and slips it into a plastic bag and freezes it for later analysis.

A lot of time is spent simply watching the movements of the birds and guessing what they're eating. Calculations are made based on crane movements, eating behavior and even their swallowing to guess the amount of calories they are burning.

Seven eggs were recovered from the nests for artificial incubation.

The flock at Necedah is the eastern migratory flock created through a captive breeding and reintroduction program. These are the birds taught to migrate by an ultralight plane during their first fall and spring seasons. Establishing an eastern migratory flock is considered an important goal, both to preserve some degree of genetic diversity and to avoid the danger of the species becoming extinct through a single disaster. The other migratory flock, the only truly wild one, winters in Texas and breeds in Canada.

This flock and Florida's nonmigratory flock have been subject to a series of mishaps in recent years. Some setbacks are to be expected, of course, and in the meantime there are enough captive birds to continue producing chicks. But if the flock is to become wild it will need to start breeding successfully on its own. Hopefully the biologists on the scene will figure out what caused the cranes to abandon their nests and whether they can solve the problem.

Meanwhile, the western wild flock is not doing too well, either. They started off the year by losing 7 adults and 16 chicks, representing 8.5% of the flock. That makes it the worst winter for whooping crane mortality. In this case, the problem appears to be lack of food sources caused by low water levels on the rivers feeding the estuaries of Aransas NWR.

Lower flows have a direct effect upon the natural productivity of the bays and estuaries. Species such as blue crab spend much of their lives moving from one portion of the estuary to another, in large part following or seeking a preferred salinity level. Except during spawning, when the female migrates to saltier water, the ideal salinity for the blue crabs is less than 15 parts per thousand (ppt).

Salinity levels in the whooping crane wintering grounds were high this year. An April 7, 2009, report revealed measurements at Aransas National Wildlife Refuge of 29 ppt at the refuge boat ramp and 39 ppt in the adjacent marsh. The Gulf of Mexico typically is 32 ppt whereas the estuary is usually much lower.

It is also clear that the marshes typically used by the cranes were devoid of blue crabs. In good years, crabs make up 85 percent of the whooping crane diet. Yet in January through April of this year, field surveys showed that there were alarmingly few blue crabs in these marshes. There is a strong correlation between the increased salinity and the absence of blue crabs as well as between the absence of crabs and the cranes dying of malnutrition.

Apparently the low levels this winter were linked to a drought and to human withdrawals of water from the Guadalupe and San Antonio rivers. It seems that in order to keep that crane flock stable, some minimum flow will need to be established and maintained. So far Texas has been unwilling to do this.

Halving Carbon Emissions to Prevent Some Warming

A new study reports that halving carbon emissions from 1990 levels by 2050 would likely be enough to keep total warming below 2°C.

“The behaviour of CO₂ in the atmosphere is best described as a full bathtub,” says Reo Knutti, professor at the Institute for Atmosphere and Climate at ETH Zurich, and co-author of one of the two studies. The inflow of the bathtub is large, but the drainage is small. The CO₂ emissions are increasing every year, but the CO₂ is only removed from the atmosphere very slowly. To not let the bathtub overflow, the inflow must thus be stopped early enough. “It is wrong to believe that the temperature will remain constant with constant emissions,” says Knutti.

The innovative aspect of the study is the fact that the probabilistic model does not perform just one individual simulation, but simulates thousands of combinations of scenarios and assumptions. Knutti adds that, in doing so, all known uncertainties are taken into account. For example, the physical uncertainties in feedback effects from clouds, uncertainties in the carbon cycle – e.g. how much CO₂ is absorbed by the oceans -, as well as uncertainties in the scenarios. These scenarios describe the time when the maximum “allowed” emission has been reached. The model also includes the overall effects of all greenhouse gases, such as CO₂, methane and nitrous oxide, as well as ozone and the aerosol effect.

This provides some additional scientific support for the widely cited political goal of reducing carbon emissions 80% by 2050. Since an increase of 2°C is often used as a shorthand for the maximum temperature increase that will not trigger catastrophic warming, this is good news. Preventing the worst may be possible. Further decreases beyond this study's 50% may have further salutary effects, such as preserving Arctic sea ice. Unfortunately, the news is not as good as it may seem. First, we have used up a lot of our time already.

The models show that there is a 75 percent probability that global warming will not exceed two degrees if a maximum of 1000 billion tonnes of CO₂ are emitted into the atmosphere from 2000 to 2050. This number seems high, but 234 billion tonnes had already been flung into the atmosphere between 2000 and 2006. If the emission remain at this high level, or even increase, the budget would be exhausted before 2030. The results show that time to act is short. Knutti is pleased that greenhouse gas emissions in Switzerland in 2007 were 2.7 percent lower than in 1990 but the values continue to be too high: at least a 50 percent reduction is needed worldwide by 2050; the global long-term goal would be less than one tonne per person per year. Currently, some 6 tonnes of CO₂ per person are emitted in Western Europe each year, 19 tonnes in North America and 3 tonnes in China – without taking into account grey energy.

That concentration has continued to increase over the past four years.

Second, a world with 2°C of warming is not necessarily going to be a pleasant place. True, it ought to avoid the worst effects, but even that small amount could force some major changes in world and local climates. In the Antarctic Peninsula, where the temperature has been rising much faster than the global average, this could reduce or eliminate some penguin species. Other species would presumably undergo similar declines or shifts in range.

According to the most recent IPCC report, a global average temperature rise of 2°C would still result in a sea level rise of 7-14 inches (18-38 cm) by 2100, in other words roughly the same increase as occurred in the 20th century. While smaller than the worst scenarios, such a rise would still imperil coastal wetlands through loss of subaquatic vegetation and changes in salinity. Note also that many of the effects of climate change on people start on the lower end of the scale, the increases of a degree or two, and build as the temperature rises further. This means at even 1-2° temperature rise we may see changes in our agriculture, water supply, health, and more.

The scenario presented in this article is not exactly rosy, but it may be the best we can hope for under current circumstances. Better yet, it may actually be achievable.

Update: Of course, it would be better to do this sooner rather than later.

Further update: Here is another take on the same articles.

Sleepless Birding

Thanks to a touch of insomnia, I happened to be awake for the start of the dawn chorus on Sunday morning. So, of course, I listened and kept notes until I finally fell asleep. It is not something I would recommend, but it was an interesting exercise while it lasted. It was pretty clear that the local birds wake up and start singing in waves.

Robins started singing around 4 am: first a few, and then a chorus swelling to what sounded like dozens. For a long time, robins were the only birds that appeared to be singing. About an hour later, the first cardinals and grackles joined them. Again, there was a period in which I could only hear these three species.

The next wave of sound came from some blue jays, a couple mourning doves, and a single fish crow. Shortly after I heard a white-throated sparrow and also noticed house sparrows for the first time. Now it may well be that these had been vocalizing all along; house sparrow "songs" are pretty nondescript and blend into the background easily. In due time I heard chimney swifts and tufted titmice add their voices to the chorus.

The last birds to vocalize before I finally got back to sleep were a few black-capped chickadees, a yellow-rumped warbler, a few red-winged blackbirds, and a gray catbird.

A few absent voices surprised me. First, while siskins appear to have departed, we still have plenty of house finches and goldfinches visiting our feeders. Yet I heard none of either local finch species. Second, two species with territories on the adjacent street – mockingbird and song sparrow – were curiously missing from the chorus. With all of these absent species I have to think that either the species is not awake and singing that early (rather odd) or that their songs simply does not carry far enough for me to hear them (still odd, but perhaps more plausible).

I was also a bit disappointed not to hear any other migrant warblers or thrushes, especially given the veery in the yard the previous night, but their absence was not surprising.

List the Red Knot

An op-ed in today's Home News Tribune argues for a quick listing of the Red Knot (Calidris canutus rufa) under the Endangered Species Act.

Quick and emphatic action is needed, none more so than the immediate federal listing of the red knot as an endangered species. Regretably and unbelievably, that hasn't happened, despite overwhelming evidence that the red knot might otherwise disappear from this side of North America.

What are federal officials waiting for? Washington's listing would deliver the urgently needed protections and resources required to help the red knot recover and survive. Anything less invites disaster, is careless, unthinking and backward science.

A big part of the answer resides in the antiquated and stingy policies of the Bush administration. Though the Endangered Species Act was a bipartisan initiative, created in 1973 under President Richard Nixon, the Bush White House removed all funding for its implementation, neutering the law for a full eight years. What resulted isn't surprising: today there exists a logjam of troubled species that desperately need federal aid and attention.

Unfortunately there are currently 252 candidate species for listing under the Endangered Species List – a massive backlog by any measure. These are all species that the Interior Department has acknowledged are in need of assistance but has not listed due to lack of funds. So the Red Knot will continue to wait in line for the near future.