Friday, January 17, 2020

NJ Bird Declines: We've Been Asleep At the Switch

 [Above, Red Knots, Delaware Bay, Cape May County, NJ in May. Below, Piping Plover, a Cape May beach in late March. Two exceptions that prove the rule.]
This is the second and final preamble before I lay out what I think the top threats to NJ birds are, although what I'm about to say is a threat in and of itself. We lack defensible scientific information on the majority of NJ birds when it comes to population status, population trends, and/or the causes for those trends. And we have only ourselves to blame: birders and NJ agencies and organizations who profess to protecting birds.

Two examples to prove this, both exceptions. We all know or should know about the plight of the Red Knot, an NJ migrant species and occasional winter resident that went from over 100,000 birds on the Delaware Bay in May as recently as the 1980's to fewer than 20,000 currently. It got so bad that when my children were in elementary school, I made it a point to show them Red Knots, because I was not sure how much longer we would have this species. But we know what's going on with Red Knots thanks to an incredible team of scientists for whom I have the utmost respect.

Aerial surveys, ground surveys, and mark-recapture studies proved the decline. Recapture studies proved knots on the bay were not "making weight," i.e. not gaining enough fat to continue to the Arctic nesting grounds. Studies of horseshoe crabs proved crabs were declining because of overharvest, and proved there were fewer crab eggs on the bay beaches for birds to consume. Additional work showed knots were threatened by shooting on their wintering grounds in South America. It drives me bonkers that all this careful work was required to eliminate horseshoe crab harvest in some states and limit it in others. Will all this work succeed? Don't know. Climate change may eventually affect knot nesting success. Oil spills, even in Delaware Bay (an important oil shipping lane) threaten. But at least we know.

Piping Plovers are NJ beach nesters and migrants and a federally listed species. Thanks to incredible work by NJENSP/Conserve Wildlife Foundation and the USFWS, we know pretty much exactly not only what the NJ nesting population of Piping Plovers is, we know their annual nesting success, which is the single most important bit of information we need on any nesting species. Piping Plovers are relatively easy to monitor thanks to where they nest, but please understand this work is anything but easy, so hats off to the biologists and interns doing the work. Will Piping Plovers persist? Don't know, you'll be reading about sea level rise in the next post about all this.

Now, what about forest songbirds? Whip-poor-wills? Hell, what about Gray Catbirds, which are ridiculously common, right? But what is the catbird's population trend? Remember this: the time to save a species is while it is still common. When my wildlife biologist son was a lad, I told him about Passenger Pigeons and Eskimo Curlews and bison and he asked, "Dad, is that really true?" F--- yeah it is.

What should be done? Some suggestions:

1. eBird everything, with complete checklists and numbers, not X's. A very easy lift, coarse as that data is.
2. For god's sake, re-do the NJ Breeding Bird Atlas. NJ should be absolutely ashamed about the fact that we've done only one atlas, and that was 23 years ago. Again, the data is coarse, but we would at least know which species have retracted in statewide range. This would be an easy lift. 5 years, one coordinator, one data gnome, possibly a few paid observers for nocturnals and tough-to-reach blocks, partner with the Cornell Lab, all data entered digitally by volunteers overseen by volunteer regional coordinators.
3. Keep up the Christmas Bird counts. We know pretty well the ebbs and flows of wintering birds thanks to them.
4. Now, some heavy lifts. Pick a few poster species for each habitat and figure out a way to monitor nesting success. Analyze the data already out there, like banding data and radar studies. Stop banding without a defined purpose. Ringing and flinging migrants is no longer necessary, and before someone trolls me for being anti-banding, know that I support and have participated in sound banding programs like the MAPS program. Geolocators and transmitters are clearly the next big thing.
4. Establish June counts based on the CBC model.

[Ruffed Grouse, Washington state. It is telling I have no NJ grouse photos since I went to digital in 2007.]

Ruffed Grouse is a great example that follows the rule. We kind of know grouse have declined, and I am confident that they're gone from South Jersey, and all but gone from the Watchungs, Sourlands, and even the southern Highlands. Don't know about the Pine Barrens, maybe someone can fill us in. One NJ organization is touting starting grouse surveys. Everybody blames habitat loss. But riddle me this; why aren't there still grouse where there is plenty of habitat? One reason Northern Bobwhite is disappearing from south Jersey is that bobwhite habitat has now succeeded into grouse habitat. Pat Sutton used to run "Ruffed Grouse a'Drumming" programs down here. I used to see Ruffed Grouse happily chomping birch buds in front of my winter bowhunting stand on the Second Watchung Mountain, where my Dad and Uncle had logged our woodlot 10 years before. There is still habitat in the Watchungs, even allowing that a lot has been lost to McManshions.

A Pennsylvania Game Commission biologist named Lisa Williams has figured out part of the grouse answer, and it's not what you think. Go to pa ruffed grouse youtube webinar and you'll find a webinar she did (I don't know her, but she came from studying White Nose syndrome in bats, which is a clue). OK, I'll spoil it. It's West Nile virus plus habitat change and loss. The mosquito that is most responsible for West Nile in PA doesn't like elevations above 1200'. Guess where there are still grouse in NJ? There's hope, this is a classic genetic bottleneck and hopefully enough West-Nile-resistant grouse will survive and trickle back into good habitats.

Up next: The top threats to NJ birds.

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