Arquivos de periódicos de abril 2019

09 de abril de 2019

Treefrog Problems

For the past three days, it rained nearly nonstop. I took this opportunity to catch and observe all the amphibians that would crawl out of the logs and debris in my property. I've heard the distinct croaking of chorus frogs for several weeks and I was desperate to get photos.

During my several day searches, I found and caught five different treefrogs to photograph. And I reported all of these treefrogs to the species I've learned to be the frogs I've seen the last four years, the (Northern) Pacific Tree Frog (Pseudacris regilla). However, iNaturalist @boattailedgrackle brought it up to my attention that my frogs may not be what they seem.

Boattailedgrackle suggested that my frogs were Sierran Tree Frog (Pseudacris sierra) and not the normal Pacific I thought I've been seeing. So immediately I was starting getting skeptical, especially since the only two species of frogs in Union County, Oregon was the Pacific Tree and the American Bullfrog. However, something kept bugging me and I decided to look over the species again in the "National Audubon Society Field Guide to North American Reptiles and Amphibians". What caught my eye was the fact the Pacific Tree Frog's range was much larger than what I saw on iNat. Second, I couldn't find the Sierran Tree Frog in the guide.

My next resource was the internet and I learned that in 2006, a herpetologist named Recuero split the Pacific Tree Frog into three different taxa; Northern Pacific (P. regilla) in Washington, W Oregon and Idaho, Sierrra (P. sierra) of California and southeastern Oregon and third in southern California and Baja. However, the taxonomic change is controversial as the research paper was based primarily on mitochondrial DNA and nothing else. Range maps and discussions on the differences between the species were never mentioned. However Amphibian Species of the World accepted this change.

What makes this situation worse for me is, I don't know what species I have. I went on looking for other resources on range of the species. iNat vague range maps say I'm well in range of Northern Pacific but just outside of Sierra but mere few miles. The United States Geological Survey (USGS) suggested the Northern Pacific's range ends on the Blue Mountain ridgeline and vice versa for the Sierra. That means my frogs are Sierra but the frogs literally on the other side of the mountain are Northern Pacific. Last but not least, California Herps says that the Northern Pacific is Washington coastline restricted, meaning I'm well in range of Sierra.

Those are just the three main sources I saw but the point still stands, who's right and what species do I have? And to top it off, if iNat and USGS are correct(ish), do I also need to deal with hybrids, making the id process even more challenging? The answer is simple, I can't. But that doesn't mean I can't give my own two cents worth on this issue.

Though I have no science backing me up, I fully agree that this taxon change was very narrow-minded and bias. To me, there is not enough information to back up Recuero's research. This isn't the first time this has happened either. Always remember, ornithologists split the Western Flycatcher (now Pacific-slope along the coast, Cordilleran in the Rocky Mountains) specifically because of mtDNA. Now look at the effects that change made on the birders. It's a headache identifying them because you can't because there's no plumage differences.

But this also leaves room for study. I think this incident is going to encourage me to continue what I'm doing though. I'm just going to continue catching tree frogs and photographing every single one I get my hands on. The only thing I don't have is a lab for DNA testing but if I can find visible differences between the frogs in different areas, maybe I can support the taxon change. I guess that means I'm going searching!

Posted on 09 de abril de 2019, 06:06 AM by birdwhisperer birdwhisperer | 4 observações | 0 comentários | Deixar um comentário

24 de abril de 2019

How to Enter Your Observations of Red Crossbill Types

Undoubtingly the most complex and confusing avian species in North America is the Red Crossbill. It wasn't in till 2011 when we started scratching the surface of the species. Several things were noticed in the crossbills across the continent, they all had different calls, beak shapes and trees they ate from. In the evaluation, 11 call "types" were described and in 2017, one of the call types was evaluated to the species status. Now, why am I'm explaining this when you can read the articles written by Matt Young and Tim Spahr on ebird? Because iNaturalist is breaking down the species to subspecies and not call types and I want to clear the confusion to those that will be identifying mine and other crossbill photos or audios.

Here's a brief rundown on Red Crossbill types and subspecies, according to the most recent revision by Matt Young.

Appalachian Crossbill (Type 1)
Taxonomy: Might be the type specimen of L. c. pusilla but has been often referred to L. c. neogaea (this subspecies is not in iNat). However it seems this call type needs a new name that hasn't been formally described yet.

Ponderosa Pine Crossbill (Type 2)
Taxonomy: Most appropriately placed with L. c. benti (Rocky Mountain Crossbill on iNat) but may also be L. c. bendirei (Bendire's Crossbill).

Western Hemlock Crossbill (Type 3)
Taxonomy: Likely L. c. minor (Lesser Crossbill) but Type 10 also falls into this subspecies category so a new subspecies may be described.

Douglas-fir Crossbill (Type 4)
Taxonomy: Unknown but it may be L. c. vividior (this subspecies not on iNat).

Lodgepole Pine Crossbill (Type 5)
Taxonomy: Most appropriately placed with L. c. bendirei (Bendire's Crossbill) but because of its range resemblance to Type 2, it may also be L. c. benti (Rocky Mountain Crossbill).

Sierra Madre Crossbill (Type 6)
Taxonomy: Very likely goes with L. c. stricklandi (Mexican Crossbill).

Enigmatic Crossbill (Type 7)
Taxonomy: Unknown but may be L. c. neogaea (not on iNat) or L. c. pusilla.

Newfoundland Crossbill (Type 8)
Taxonomy: Probably associated with L. c. percna. Also note that some authorities place L. c. pusilla as a synonym of L. c. percna.

Sitka Spruce Crossbill (Type 10)
Taxonomy: Best matches L. c. sitkensis (Sitka Crossbill on iNat) but is similar to Type 1, 3 or 4 and the type probably needs to be studied more.

Central American Crossbill (Type 11)
Taxonomy: L. c. mesamericana

So with all that information in front of you right now, here's how you'll enter your types in iNat if you wish to do so with subspecies.

Call Type Subspecies on iNat
Appalachian Crossbill (Type 1) L. c. pusilla
Ponderosa Pine Crossbill (Type 2) L. c. benti Rocky Mountain Crossbill, L. c. bendirei [Bendire's Crossbill]
Western Hemlock Crossbill (Type 3) L. c. minor [Lesser Crossbill]
Douglas-fir Crossbill (Type 4) Subspecies not on iNat
Lodgepole Pine Crossbill (Type 5) L. c. bendirei Bendire's Crossbill, L. c. benti [Rocky Mountain Crossbill]
Sierra Madre Crossbill (Type 6) L. c. stricklandi [Mexican Crossbill]
Enigmatic Crossbill (Type 7) L. c. pusilla
Newfoundland Crossbill (Type 8) L. c. percna
Sitka Spruce Crossbill (Type 10) L. c. sitkensis
Central American Crossbill (Type 11) L. c. mesamericana

As we continue to learn more information about the crossbill types, I will post more journal entries on them. I will try to be curator for iNaturalist to add the subspecies for Type 4. Hope you enjoyed and good luck looking for crossbills!

Posted on 24 de abril de 2019, 04:08 AM by birdwhisperer birdwhisperer | 0 comentários | Deixar um comentário