February 28, 2018

Upcoming Citizen Science Lectures in Orange County and Palm Desert

If you would like to learn more about how citizen science observations, especially observations from the RASCals project, can be used for conservation, ecology, and behavior research, I will be giving two public lectures in the very near future. Both are free and open to the public.

Orange County
On Friday, March 2, I will be giving the Dr. Bayard H. Brattstrom Lecture in the Saddleback College Science Lecture Series. The event starts at 10 with the lecture beginning at 10:30. The title of this talk will be "Is Citizen Science the Next Revolution in Ecology and Behavior Research?"

You can find more information about this event here: http://www.saddleback.edu/science-lecture-series

Palm Desert
On Thursday, March 8, I will be in Palm Desert giving a presentation as part of UC Riverside's Deep Canyon Lecture Series. The lecture starts at 6pm and is entitled "The Value of Citizen Science for Urban Ecology and Invasive Species Research: Examples from the Reptiles and Amphibians of Southern California (RASCals) Project."

You can find more information about this event here: http://cnas.ucr.edu/deepcanyonlectures.html

Note that you should RSVP for the Deep Canyon Lecture Series. I hope we have a number of iNaturalist users in the audiences.

@cwbarrows @atrox77 @silversea_starsong @crtracy

Posted on February 28, 2018 06:04 PM by gregpauly gregpauly | 1 comments | Leave a comment

February 28, 2017

Hey Southern Californians: We Want Your Photos of Alligator Lizard Sex

Yes, you read that right. We need your help to study Southern Alligator Lizard breeding biology. Starting as early as February 9, alligator lizards in Southern California start mating. So far in 2017, we have received no reports of amorous alligator lizards, but that is likely to change in the next few days. Weather forecasts predict rising temperatures and increased sunshine (woohoo!!!); in other words, the weather is looking good for the start of the 2017 alligator lizard breeding season.

What does alligator lizard courtship look like? Check out these photos submitted to the RASCals project during the 2016 breeding season: 

Three Southern Alligator Lizards observed by Xan Sonn March 21, 2016 engaged in courtship behavior in the courtyard of a Pasadena apartment complex.

A pair observed in Coastal San Pedro by regular RASCals contributor CSPNL; Cheryl is especially observant and found paired up alligator lizards in her San Pedro backyard five times in 2015 and three times in 2016.

Southern Alligator Lizards observed by Kat Halsey April 17, 2016 mating in a barn at the Los Angeles Zoo.

Southern Alligator Lizards in a mating hold and very likely mating. Observed and photographed by Felix Langer and Teo Langer (aged 5 and 8, respectively when these lizards were observed April 10, 2016) with help from mom Ariel.

Many people who see alligator lizard courtship might think the lizards are fighting or that one is even cannibalizing the other, but in fact, this is alligator lizard love. The male bites the female on her neck or head and then uses his tail to attempt to lift the female’s tail. The female may refuse these advances hoping instead a male more to her liking comes along and displaces the first male. As a result, the pair may stay in this position for more than a day. If the female does decide to mate, she lifts her tail allowing the male to insert his hemipenis into the female’s cloaca.

What’s a hemipenis? It’s the intromittent organ (an external organ specialized to deliver sperm while mating) of male lizards and snakes. In other words, it’s the lizard equivalent of the mammalian penis, except that lizards and snakes have two and can use the left or right hemipenis depending on which side is closest to the female. In some species, the hemipenes (this is the plural of hemipenis) are covered in barbs and spines, but in alligator lizards, the hemipenes are relatively smooth and lack these structures.

In 2015, we started using the RASCals project to study the breeding behavior of these lizards. One of the main questions is to understand whether urban and rural lizards breed at the same time. Urban areas tend to heat up more than surrounding rural areas; this is termed the urban heat island effect. If the lizards are using temperature as a cue for when to mate, we might then expect that urban lizards breed earlier.

The challenge with studying the breeding biology of these lizards is that it would be very difficult to get a large number of observations across different habitat types. However, we can solve this problem by crowdsourcing; we can ask thousands of people to keep an eye out and document any breeding observations by sending us photos.

This approach has worked well. Citizen scientists documented 19 cases of breeding behavior in 2015, and 20 in 2016. We have also received a number of photos from earlier years, all the way back to 2008. Based on these observations, breeding in coastal areas of Southern California can be as early as February 9th, or as late as May 3rd, but the peak of breeding tends to be mid-March through mid-April. We are already seeing interesting variation from year to year. In 2015, 13 of the 19 observations occurred in a single peak of activity between March 17 and April 1. In 2016, we saw two peaks of activity—breeding activity increased in mid-March, but then ceased as a series of cold fronts in late March and early April passed through Southern California. We then had a second peak of activity in mid-April with the return of warmer temperatures and sunny skies.

What will the breeding season be like in 2017? We should know the answer soon, but only with YOUR HELP? If you see courting or mating alligator lizards, please take a photo and submit it to the RASCals project. If you have photos from previous years, please submit those as well. As the breeding season progresses, I’ll update this journal entry with some of the discoveries.

March 11. The 2017 breeding season is now officially under way. Jim Julian documented the first breeding pair, which he found in Anaheim. Check out the first 2017 observation here: http://www.inaturalist.org/observations/5285174

March 16. The 2017 breeding season is finally getting going. We received two reports of breeding alligator lizards today. I expect the peak of the breeding season will be now through early April, likely with a decrease in activity March 21-23, with the arrival of a cold front. Of the observations today, one was in southern San Diego County, and the other was on the Occidental College campus in Los Angeles. You can see the second observation here: http://www.inaturalist.org/observations/5378139

March 23. We are now up to 9 observations of breeding for the 2017 season, with observations from San Diego (4), Los Angeles (3), Orange (1) and Ventura (1) Counties. The anticipated cold front was relatively weak, and breeding was observed March 21 and 23 but only in San Diego Counties. Keep an eye out as we should be averaging about one new observation per day into early April. If you do see a pair, try to check back on them every few hours. CSPNL did this and found the pair together over a 31-hour period!!! You can see that observation here: http://www.inaturalist.org/observations/5397189

April 3. We are now up to 30 observations for the 2017 breeding season. This is the largest number of observations we have received during a single mating season since starting this study in 2015.

This journal entry was modified from an article I wrote for the Natural History Museum's "Nature in L.A." blog. You can read the original here: https://www.nhm.org/nature/blog/dear-los-angeles-we-need-your-photos-alligator-lizard-sex

Posted on February 28, 2017 04:40 PM by gregpauly gregpauly | 4 comments | Leave a comment

March 07, 2016

Your Help Needed for Study of Alligator Lizard Breeding Biology

The RASCals Citizen Science Project was created to study how the ranges of various species have responded to urbanization and habitat modification. To do this, modern day citizen science records are being compared to historical distribution data from museum specimens. But photo vouchers can be used for much more than just understanding the ranges of species; photographs can also document interesting behaviors.

Right now, we are entering ALLIGATOR LIZARD MATING SEASON, and we need YOUR HELP in studying their breeding biology!

Starting as early as February, alligator lizards in our area start mating. Many people who see their courtship behavior might think it is a fight or even cannibalism, but in fact this is alligator lizard love. The male bites the female on her neck or head, and they may stay in this position for more than a day. It’s possible that they stay paired up for so long because the female is testing the strength of the male, but more research needs to be done on this.

Here are some observations of alligator lizard courtship previously submitted to the RASCals project:

If the pair are not disturbed by a predator or other male suitor, usually they end up mating. Here's an observation of a pair actually mating:

Last year, I realized that observations submitted to the RASCals project could be used to study the breeding behavior of these lizards. We put out our first call, and we have tallied 27 such observations submitted to RASCals so far. Based on these 27 observations, breeding in Southern California can be as early as February 9th, or as late as April 22nd, but appears to peak between mid-March and early April. It is probably later at higher elevations, but we have so few high-elevation records at this point that we can't say for sure.

We have already received our first observation this year. John8 (aka John Oliver) submitted an observation from March 1st in Deukmejian Wilderness Park, Glendale:

As we accumulate more records this year and in coming years, we can ask questions like how much variation is there in the timing of the breeding from year to year? Does the breeding season start earlier further south? Does it start earlier at lower elevations? Do lizards in urban areas breed at the same time as lizards in rural areas?

Of course, understanding the breeding biology is dependent on having lots of data points. This is why we need your help. If you see courting or mating alligator lizards, please take a photo and submit it to the RASCals project.

Fine print: this journal post was modified from the Natural History Museum's Nature in L.A. blog. You can read the original here:

Posted on March 07, 2016 05:49 AM by gregpauly gregpauly | 3 comments | Leave a comment

July 24, 2015

California Dreaming: The Math of Citizen Science

This week, the RASCals project has received some excellent coverage in a series of citizen science blogs. I wanted to share this with the many citizen scientists who contribute to this project, because without all of your help, we wouldn't have had so much success growing this project over the last two years.

The RASCals project was featured in a blog carried by SciStarter, PLOS Blogs, and Discover Magazine blogs. Here is the link to the SciStarter blog:


My favorites quote from the article should make it obvious why the subject of this post is about the math of citizen science:
"Pauly hopes to increase his citizen science counts–perhaps exponentially. If just a fraction of those 22 million southern Californians, as well as the many millions of visitors like me, would stop to look, to see, to record…if only one percent of the 10 million people in Los Angeles County would take their smartphones or cameras into their backyard…California dreaming. We’d have a lot of data."

Posted on July 24, 2015 03:23 AM by gregpauly gregpauly | 2 comments | Leave a comment

August 03, 2014

Accuracy: the least obvious, most important data element

The four most important elements of an observation are a photo, a date, the coordinates (i.e., latitude and longitude), and a community-supported identification. When an observation has these four elements, it is considered “research grade”. However, there is a fifth element that is nearly as important as these other elements in determining the value of an observation to researchers, but it often gets overlooked. This fifth element is accuracy, which is the proximity of the measured latitude and longitude to the actual location where the observation was made. The accuracy can be determined by a GPS device or manually by the user using a mapping app, such as the iNaturalist map function.

The importance of having observations with high accuracy cannot be overstated. Only a small number of uses of iNaturalist observations can accept observations with low accuracy. For example, obtaining a species list for Griffith Park, Balboa Park, or one of the ten counties in southern CA, does not require observations with high accuracy. However, the vast majority of uses require high accuracy, which I am roughly defining as within 50 meters. For example, one of the key, immediate uses of RASCals observations is to understand how species distributions have responded to urbanization. Analyses will ask questions like, how are urban distributions correlated with lot size, age of the neighborhood, or distance from the nearest creek or urban park? Thus, small offsets of only 100 or 200m could dramatically alter the conclusions by moving observations onto house lots of different size, age, or distance to the nearest creek.

Thankfully, it is easy to assign accuracy with iNaturalist. The easiest approach is to use the iNaturalist smartphone app because the app will assign accuracy automatically. A good strategy here is to watch the accuracy value (labeled “Acc.”) in the “Location” section of the “Add observation” page. This is the page that automatically opens on the smartphone app when you click to add an observation. Once you open the app, the accuracy value will start dropping as your location gets pinpointed with greater accuracy. You can also see the accuracy improving by clicking on the map page in the app and watching as your phone’s GPS device narrows in on your location. The accuracy is depicted as a circle around your location; as this circle gets smaller, the accuracy is improving. Once the accuracy value has stopped decreasing, you can save the observation. Importantly, you do not need to wait for your GPS device or smartphone to pinpoint your locality before you take the photo through the iNaturalist app. As long as you stay stationary before hitting the save button, your phone will narrow in on your location and report a high accuracy for your observation.

If you are using the metadata from a photo to record the location, or using the map feature on iNaturalist.org, then you will need to manually add the accuracy value. (Note that accuracy values are typically not stored in the photo metadata.) When editing the observation on iNaturalist.org, click “edit” in the locality section, and the point will show up on the map. If there is not already a value listed for accuracy, enter a value and a red circle will show up around your point. You can drag that circle in and out until you have set it to an appropriate accuracy value.

Critically, the goal here is not to get the accuracy value as small as possible. The goal is to have a value that reflects you or your GPS device’s best assessment of accuracy. For example, if you are uploading a photo that lacks latitude and longitude data, and all you can remember is that you took the photograph while on a hike in Griffith Park, then the accuracy value should be several kilometers to accommodate the entire area in which you could have made the observation. This allows future users of the observation to appropriately assess your observation and decide whether or not it is appropriate to include in their analyses.

Here are some observations with appropriate accuracy values:

(http://www.inaturalist.org/observations/756344) – this observation has a small accuracy value, because I could tell that my phone’s GPS mapped the location to the exact piece of exposed concrete where I made the observation.

(http://www.inaturalist.org/observations/420731) – this observation has a large accuracy value. I took the photo with a digital camera lacking GPS capabilities while on a mtn. bike ride. When I submitted the photo, I could not be certain of the exact road cut where I made the observation. As a result, I placed the point at the most likely spot but gave a large value for accuracy to cover nearby road cuts where the observation could also have been made.

If you have questions about this post, please comment below or message me or Richard Smart through iNaturalist.

Greg Pauly: http://www.inaturalist.org/people/gregpauly
Richard Smart: http://www.inaturalist.org/people/rsmart

Posted on August 03, 2014 03:54 AM by gregpauly gregpauly | 6 comments | Leave a comment

September 17, 2013

The Origins of RASCals

In 2010, the Natural History Museum of Los Angeles County launched the Lost Lizards of Los Angeles (LLOLA) project. The goal of this project was to understand how urbanization has impacted the distribution of lizard species in the Greater L.A. Area. LLOLA had several major successes including documenting the first established Mediterranean House Gecko population in L.A. County and the first established Indo-Pacific Gecko populations in L.A. and Orange Counties. These latter two observations were also the first records for the state. LLOLA also demonstrated that citizen science can be a very effective tool for gathering observational records of lizards throughout the region. With these successes, we realized that LLOLA should be expanded to all reptiles and amphibians and also to all of southern California, hence RASCals – Reptiles and Amphibians of Southern California.

RASCals was developed with two main scientific goals in mind: 1) to document modern day occurrences that can be compared to historical museum records to assess how species have responded to the urbanization of southern California; and 2) to document and track introduced species.

We are dedicated to growing RASCals into an extremely successful citizen science project. We anticipate growing the number of RASCals partnering agencies, which should also result in more project goals and more accomplishments. As these lists of partners, goals, and accomplishments grow, we will keep you apprised of those developments here.

Posted on September 17, 2013 04:16 AM by gregpauly gregpauly | 0 comments | Leave a comment