The population of one of the Great Lakes region’s most rare birds — the Kirtland’s warbler — increased for the seventh consecutive year in 2009.
U.S. Fish and Wildlife data shows that the population set a new record — 1,826 counted males – since the census began in 1951. Only males are audible and can be counted easily during the census season. Experts guess that for every male counted there is most likely a female.
But despite this new record, the bird still faces future challenges – like long-term funding and the consequences of climate change.
The 5-inch long, gray and yellow bird lives only in parts of Michigan, Wisconsin and Ontario.
“This is a very rare species, the rarest warbler in North America. There are around 4,000 individuals in the entire world and almost all of them nest in Michigan,” said Caleb Putnam, coordinator of the Audubon Society’s Michigan Important Bird Areas.
This rarity gives the bird worldwide recognition. In 2009, 35 international visitors – from countries like Australia, Sweden and the United Kingdom – went on guided tours in Michigan’s Huron-Manistee National Forest to catch a glimpse.
Ninety-seven percent of last year’s counted birds live on Michigan’s Lower Peninsula.
“A lot of people come from all over to see the Kirtland’s,” said Kim Piccolo, a wildlife biologist at the Mio Ranger District of Huron-Manistee National Forest.
The bird’s recorded population was the lowest in 1974 and 1987. Scientists counted 167 males those years. The average birds counted since 1951 is 602.
Experts attribute the low numbers to habitat loss and the brown-headed cowbird — a parasitic bird that lays its own eggs in the warbler’s nest to out-competes its young.
Males Counted in 2009
|Michigan — Lower Peninsula||1,780|
|Michigan — Upper Peninsula||33|
In 1972, cowbird control began and four years later a recovery plan began to protect habitat and monitor the species.
The current population is well above the original conservation goal of maintaining 1,000 pairs for five years. Each year since 2001 experts counted 1,000 males indicating the presence of 1,000 females to match.
But that doesn’t mean it’s in the clear yet.
And it may never be.
“We’re definitely not out of the woods. The second we stop any of that bird management that bird population is going to decrease,” said Chris Mensing, a fish and wildlife biologist of the U.S. Fish and Wildlife Service. This is his 11th year working with the bird.
According to Mensing, some species, like the wolf or bald eagle, have good outlooks for survival once they reach high populations.
But this isn’t true for the warbler.
“It’s survival is not guaranteed … just because it has a high population,” Mensing said.
This is because the warbler is conservation-reliant, unable to survive without consistent management efforts – efforts that may be required into the unforeseeable future.
“It’s a species that always requires some kind of management,” Mensing said.
This conservation-reliance stems from its needs of a specific habitat. The bird can only live in sandy areas with jack pine trees between the ages of 5 and 20.
This habitat requirement makes it unable to adapt easily.
“You can think of these birds as stuck in these islands of habitats that are very limiting,” Putnam said.
The conservation of the warbler seems to be successful. But management-reliant species peck at federal funds and time, leaving less money for other species.
For some people the money is well spent.
“For me it is worth every penny and more. Not only because it has attracted much interest and tourism from the birding community, but much more importantly, it is the right thing to do,” nature photographer James Ownby wrote in an e-mail. Ownby keeps an online travel diary of his experiences.
But whether this high level of management is sustainable in the long-term is unclear.
“From our standpoint, we want to, we need to protect these species. We need to look at how we can do this forever,” Mensing said.
To create a sustainable long-term management plan for the warbler, the U.S. Fish and Wildlife Service paired up with the National Fish and Wildlife Foundation that will raise money for an endowment.
“Would it be better to form a group of people to oversee — not to privatize — to utilize private money to create a fund?” Mensing said.
Utilizing private money would not only guarantee the warbler long-term management but free federal money to aid other species.
If done correctly this endowment-model could also be used for the management of other species.
“If we don’t do it right we’re back at square one. And if we do, do it right it could benefit the Kirtland’s warbler and many other species,” Mensing said.
But even if the endowment is set up correctly the unknown consequences of climate change loom.
“The Union of Concerned Scientists is predicting in Michigan…rising temperatures in winter and in summer, by the end of the century as high as 10 degrees Farenheit,” Putnam said.
It’s also predicted that this temperature shift will create dryer Michigan habitats for birds due to increased evaporation.
“It’s a huge concern. What can we really do about it at that point? Not much except to understand it, to have it in our mindset,” Mensing said.
A report released by the Audubon Society last February shows that in the last 40 years North American birds reacted to climate shifts by moving migration patterns further northward and inland.
But the same factor that makes the warbler conservation-reliant — its specific habitat needs — may make this migration change impossible.
“When you have a species that is rare and is very stuck in that habitat type, if the climate conditions change such that it makes them want to shift north, there may not be anywhere to go,” Putnam said.
Until climate change models become realities the exact consequences for the Kirtland’s warbler remain unidentifiable.
“The bird to some extent is proof of the old axiom that evolution is blind: it cannot look into the future and anticipate changes that might happen,” Ownby wrote.