On August 7, 2020, iNaturalist user jjfish posted a photo of a baby whiptail lizard that he caught in his northern San Diego County yard two days earlier. As soon as I saw this observation, I started to worry. While the native Orange-throated Whiptail lives in the general area, I did not expect this species to be in a suburban neighborhood. Plus, this little whiptail lacked the bright blue tail typical of baby Orange-throated Whiptails. This appeared to be the non-native Sonoran Spotted Whiptail that has been rapidly spreading across Orange County. Had this non-native species jumped southward into San Diego County?

I shared jjfish’s observation with Dr. Robert Fisher (alazon on iNaturalist), a colleague at the United States Geological Survey’s Western Ecological Research Center in San Diego, and we started examining other whiptail observations posted to iNaturalist from the area. We discovered that deborah20 had also likely photographed a Sonoran Spotted Whiptail 26 months earlier and 3.3 km west of jjfish’s observation. This earlier observation had been identified by multiple people as the native Orange-throated Whiptail, but we were skeptical and asked deborah20 for any additional photos. Despite the two-year gap since the lizard was observed, she found and uploaded a second photo, and it was now clear this was a Sonoran Spotted Whiptail. With these two observations, it seemed likely that Sonoran Spotted Whiptails were now established in the city of Oceanside, more than 50 km south of the nearest known Sonoran Spotted Whiptails in Orange County.

These two observations kicked off a research project that culminated in a scientific paper published in the journal Frontiers in Conservation Science. The paper is open-access, which means that anyone can download and read it for free. Through multiple surveys of the Oceanside area with first author Sam Fisher (samfisher on iNaturalist), we documented the ongoing expansion of this non-native species, and more generally used this situation as an example of how to improve detection of non-native species when they look very similar to native species. Our goal with this post is to increase awareness about this species so that iNaturalist users can be on the lookout for it across Southern California, both when they are in the field and when viewing others' whiptail observations on iNaturalist.

Before the story continues, a big thank you to jjfish and deborah20 for posting lizard observations to iNaturalist. Without their observations, this non-native species would likely still be unknown from Oceanside.

The native and non-native range of Sonoran Spotted Whiptails

Sonoran Spotted Whiptails are native to Arizona, New Mexico, and adjacent northern Mexico. Since at least 2010, they have been in Orange County, CA where they are expanding extremely rapidly in urban and suburban areas. As mentioned above, the newly discovered population in Oceanside, San Diego County is approximately 50 km south of the nearest known individuals in Orange County. This past spring (on April 20, 2022), Dr. Jim Parham of CSU Fullerton posted an observation of a Sonoran Spotted Whiptail in Fullerton, a little more than 20 km north of their known range in Orange County. 



The appearance of Sonoran Spotted Whiptails in Oceanside and Fullerton highlight that human-assisted jump dispersal is ongoing. This could be from within-region movements of this species, or new translocations of individuals from their native range. This species has also shown up in Northern California, and we know from genetic analyses that the Northern CA and Orange County populations are from separate genetic stocks (meaning separate introduction events). We have observed spotted whiptails at several tree nurseries in Orange County, and we suspect that movement of larger plants in the nursery and landscaping trade is an important source of human-assisted translocations (by movement of eggs in the soil around the plants and by movement of juveniles and adults in larger shipments). 
 

Potential threats to native species

Sonoran Spotted Whiptails are a parthenogenetic species. This means that all individuals are females and can reproduce without mating. As a result, a single individual can establish a new population. Although they can reproduce without mating, individual lizards will very rarely mate with males of other species. For example, Sonoran Spotted Whiptails can hybridize with the Western Whiptail, which, along with the Orange-throated Whiptail, is native to coastal Southern California. There are no known hybrids between Sonoran Spotted Whiptails and Orange-throated Whiptails, but they have never before had overlapping ranges. Now that these two species increasingly occur together in Orange County, and will likely soon occur together in San Diego County, we advise that people be on the lookout for possible Sonoran x Orange-throat hybrids. In addition to hybridization, competition with native Western Whiptails, Orange-throated Whiptails, and other native lizards seems likely given their overlapping diets. Hopefully our work will encourage others to undertake more detailed dietary studies to understand whether the non-native Sonoran Spotted Whiptails compete with native species.

How to differentiate Sonoran Spotted Whiptails from native whiptails in Southern California

Unfortunately, the Sonoran Spotted Whiptail is difficult to tell apart from our two native whiptail species, and especially from the Orange-throated Whiptail. Juvenile lizards are the easiest to identify. In the two native species, the latter half of a juvenile’s tail will have a blue coloration. Even subadults will have a blue tint to their tails. In juvenile Sonoran Spotted Whiptails, the tail will have a similar coloration to the body or have a red or pink tint. You can see this in jjfish’s photos.

In older individuals, the best character for identification (assuming the whiptail will hold still for a few seconds) is to look at the stripes on either side of the vertebral column. These are called the paravertebral stripes. In Sonoran Spotted Whiptails, these stripes remain parallel and then fade as they reach the tail. In Orange-throats, the paravertebral stipes merge usually in the hind-limb region forming a single vertebral stripe that continues onto the tail (note that in Baja California, the position of this merge varies, but the above description works well in Southern California). There are also several differences in the head scales of these whiptail species, but whiptails rarely let you get close enough to see these characters. If you want to learn more about these characters, check out Table 2 in the manuscript or the identification guide in the Supplementary Materials.

Final Thoughts

 
The rapid growth of iNaturalist and community science has greatly improved our ability to detect non-native species. These observations can help reveal potential threats of these non-natives, and can also reveal how non-native species are being moved from place to place. However, detecting non-native species is especially challenging when they look very similar to native species, as is the case here for the non-native Sonoran Spotted Whiptail and native Orange-throated Whiptail. Hopefully the linked paper and cheat sheet will make it easier for people to detect the non-native whiptail. Of course, even if you don’t know which species you are looking at, you can simply upload a photo identified as a whiptail (meaning only identified to genus) or even just labeled as a lizard. Tag one of us in the photo, and we can help you identify the lizard. Of course, other dedicated iNaturalist users are also likely to help make an identification as well.

iNat user dlbowls takes lots of nice photos, including these photos of a Sonoran Spotted Whiptail in Oceanside.

And again, my sincere thanks to jjfish and to deborah20, both of whom have now uploaded multiple observations of Sonoran Spotted Whiptails in Oceanside. Note that they are also mentioned in the first line of the acknowledgements of the published paper. The second line of that paper thanks other iNat users who are contributing photos and/or identifications of whiptails in Southern California. We are grateful to everyone who is helping to document the reptiles of Southern California.

The Reptiles and Amphibians of Southern California project just topped 50,000 observations! Let’s take a look back to consider all of the amazing people who have contributed observations, the stunning critters that have been documented, and the fun science that has resulted from these efforts.

Over 7,000 Amazing Community Scientists

Community science (also called citizen science) is often termed “crowdsourcing,” and the success of the RASCals project is entirely dependent on a truly remarkable crowd of observant naturalists. On the RASCals project page, the stats show that 6,927 people have contributed observations, but hundreds of people have also contributed observations through the Natural History Museum of Los Angeles County’s Nature in L.A. account through social media, e-mail, and text message submissions. Thus, the actual number of contributors is close to 7,500!

116 Native Species and 55 Non-native Species

Yes, that’s correct, 171 species of reptiles and amphibians! This number still shocks us. Southern California is home to diverse habitats from beaches to deserts to mountains over 11,000 feet tall. Some people have been lucky enough to see a Green Sea Turtle, Olive Ridley Sea Turtle, or even one of the few Yellow-bellied Sea Snakes ever documented in California. Others have recorded some of our higher elevation species like Northern and Southern Rubber Boas, Sagebrush Lizards, and San Gabriel Mountain Slender Salamanders.

Unfortunately, with 22.5 million people and a relatively mild climate, many non-native species get introduced to Southern California, and some of these species become established. RASCals participants have documented 55 species of non-native reptiles and amphibians. Fortunately, most of these are escaped or released pets with no evidence of established populations in the area. However, others are thriving, and some, such as the American Bullfrog, Red-eared Slider, African Clawed Frog, Italian Wall Lizard, Green Anole, Brown Anole, and African Five-lined Skink are negatively impacting our native species. Community science provides an especially important method of improving detection of non-native species so that their impacts and any potential eradication strategies can be evaluated. As described below in the publication section, observations contributed to RASCals have been essential in documenting the arrival of non-native species and in tracking their spread once they are established.

12,799 Western Fence Lizards and 5782 Southern Alligator Lizards

Of the 171 documented species, 61 have five or fewer observations, and 25 of these have only a single observation. On the other end of the spectrum are our two most common lizards---25% of all RASCals observations are of the Western Fence Lizard. To me, this is especially positive because this is a species that doesn’t do that well in many urban neighborhoods. They are frequently documented because where they do occur, they are quite conspicuous as they bask prominently and do their push-up and head bob displays. Just because fence lizard observations are common does not mean each of these observations is not important. These 12,799 observations are especially useful to understand what aspects of urban areas affect whether or not fence lizards will survive there. Stay tuned for future posts about this exact subject, in which observations of our two most common salamanders are used to understand their distributions in urban areas.

Although less commonly observed than the Western Fence Lizard, the Southern Alligator Lizard is the most widespread lizard in urban areas of Southern California. This species has also been a major focus of research efforts with ongoing studies using RASCals observations to study mating behavior and to study how predation and parasitism vary from urban to rural locations. Stay tuned for future posts as these studies are published.

Over 14 Peer-reviewed Publications or Research Reports

At its core, community science IS science. iNaturalist observations are real data that can be used for many different analyses. RASCals was started to document the current distributions of reptiles and amphibians throughout Southern California. More specifically, the hope was 1) to document reptile and amphibian species to understand how they were responding to urbanization, and 2) to document and track introduced species. If this community science effort is “real science”, then the result should be easily measurable, as real science generates peer-reviewed publications and research reports that can impact conservation and land management decisions.

Over the last 8 years, RASCals data have been used for at least 14 publications and research reports. It’s challenging to keep track of all of the scientific publications that have used observations contributed to the RASCals project because researchers can use many records without crediting the project or informing RASCals or iNaturalist scientists. Thus, the actual number is certainly higher than 14, but 14 is the number summing across our own publications and those of other authors that we can quickly remember as we write this.

Analyses of RASCals observations have been published in high profile outlets like Frontiers in Ecology and Evolution and Biological Conservation. A second paper in Frontiers in Ecology and Evolution used thousands of RASCals observations from across the L.A. area; in total, that analysis, which was termed BAILA for Biodiversity Analysis in Los Angeles, used nearly 60,000 iNaturalist observations contributed by over 10,000 community scientists (obviously more than just the RASCals observations were used in that analysis)!

Sometimes a single observation is enough to trigger a research publication. Often such observations are those that document the first records of non-native species in California, such as Indo-Pacific House Geckos in Torrance or African Five-lined Skinks in the San Gabriel Valley. Another recent publication was based on a new high elevation record for the Southern Alligator Lizard, with the resulting publication referencing a number of other iNaturalist observations that were also from higher elevations. For all three of these publications, the original observer co-authored the manuscript, highlighting that community scientists can take part in the entirety of the scientific process from making observations to publishing research results in the peer-reviewed literature.

RASCals observations have also been used as part of several urban biodiversity assessments in the Los Angeles area. In these cases, the RASCals observations supplemented sampling by field biologists. The RASCals observations were especially important in providing species occurrence records from private property that the professional scientists could not easily survey themselves. These helped to inform management recommendations along the Los Angeles River and in the Baldwin Hills.

The Next 50,000

Much has changed on iNaturalist since the RASCals project was initiated nearly eight years ago. Over the coming months, you might notice some updates to the RASCals project settings. This won’t impact users at all, but it will impact how quickly the project grows. Because of these changes, and because of the incredible growth of the iNaturalist user community, we should reach 100,000 much more quickly than we reached 50,000. As you’ll see in future journal posts (including one in 3–4 weeks announcing a new manuscript that started because of two RASCals observations), these observations will continue to provide the critical raw data for numerous research and conservation analyses.

1: For You, and For the Next Observation

All of this is ONLY possible because of dedicated community scientists like you. The research and management publications, the 50,000 observation milestone, and the contribution of information to state wildlife agencies that impacts conservation management are a direct result of this community effort (we haven’t discussed this final point as this post is already long enough). Thank you for contributing to the RASCals project and to iNaturalist. Your observations are vital for research and conservation.

With days getting longer and temperatures increasing, we are entering alligator lizard mating season, and we need your help to study their mating activity.

Five years ago, we realized that we could use crowdsourcing as a way to study mating behavior. At that time, there were only three dates reported in the scientific literature for when Southern Alligator Lizards had been observed breeding. We knew we could get more observations through community science, by crowdsourcing the study of this rarely documented behavior. We started asking people to send us photos and videos of mating pairs. We have now accumulated 360 observations of mating Southern Alligator Lizards, and 57 observations of mating Northern Alligator Lizards. We are pretty sure that through community science, we have generated the largest dataset ever on lizard mating!

What does mating behavior look like? Typically the male is biting the head and neck region of the female as you can see in these previous observations of mating behavior submitted to the RASCals project:
https://www.inaturalist.org/observations/22789660 (observation by @janegao)
https://www.inaturalist.org/observations/22533784 (9% of observations involve multiple males and a female)
https://www.inaturalist.org/observations/22517665
https://www.inaturalist.org/observations/24207931

What have we learned with all these observations? Here are three discoveries so far.

1. Weather has a huge impact on the timing of the breeding season. Cooler and wetter weather will delay the start of the mating season. If mating activity has already started, then bigger storm systems can shut down activity until weather improves. We received six observations of mating activity for the 2020 season, but then the cooler mid-March weather in Southern California shut the season down. As temperatures increase again through late March and April, the mating season should rapidly progress, although it is now delayed by several weeks across Southern California relative to more typical years. As forecast, after more than two weeks with no mating observations, the season is finally ramping up with three observations just on March 26th!

2. Wet years are the big breeding years. Although we started this research effort in 2015, people have submitted observations that date back to 2003 (woohoo for digital cameras!). Across these years, we see that drier years have reduced breeding activity. For example, the 2015, 2016, and 2018 mating seasons followed below average rain seasons, and we received 32–35 observations of Southern Alligator Lizards in the mating position. But following the wet 2017 and 2019 winters, we received nearly three times as many observations! The 2020 season is only just getting started in late March (all observations are still from the very southern end of the range), and it is especially hard to predict whether this will be a good or bad year. For much of California, the rain season started off with above average rainfall in December but then the state experienced an extremely dry January and February. We are now having enough rain that people are talking about another “Miracle March”, but this rain might be too late to trigger increased breeding activity. As observations get made, we’ll be able to better understand how the timing of rainfall impacts breeding activity.

3. Lizards can stay paired up for over two days! The actual act of mating likely takes place shortly after the lizards pair up. However, the male maintains the bite hold for a long time. This is most likely a type of “mate guarding”, in which the male is trying to make sure that no other males can mate with the female (but we still have more research to do before we are positive this is what’s happening). But how long might a male maintain the bite hold? In 2019, two dedicated community scientists (@molly91945 and @lemonbee) repeatedly checked back on a pair and observed the lizards together for nearly 49 hours! This is a new record for this species!

What to look for? During mating season, males search out females. The male bites the female on her neck or head and may hold her this way for several days. Early in the encounter, the two may engage in a bit of a wrestling match (if you see this, please try to get videos). Sometimes, a second male shows up and we get even more interesting observations!

When to look? Because we have accumulated so many observations, we now know that the Southern Alligator Lizard mating season can start as early as early February in the southern part of the range and continues into early June in the northern part of the range and at higher elevations. In Southern California, most of the breeding activity is between mid March and late April. This year, the season is just getting started in late March, and mating pairs should be found in coastal Southern California through early May, with mating in more northern and higher elevation locations throughout May and June. For the Northern Alligator Lizard, breeding should start in early to mid April and continue through mid-June, again with lizards in the south and at lower elevation populations breeding earlier.

Where to look? Alligator lizards can be found from coastal sand dunes to high elevations in our mountains. And they do better than any other local lizard in urban areas. When in the bite hold, pairs are often found out in the open, on driveways, sidewalks, lawns, and in yards. It is also possible to find pairs several feet off the ground on fences and in shrubs.

How to document? Take photos! If the pair is actively wrestling, please take video as well. We are especially interested in how long pairs remain in the mating hold, so please check back every few hours and search for the pair in the general area.

If you see courting or mating alligator lizards, please upload photos to iNaturalist. If you are in Southern California, please tag observations to the RASCals project.

*With apologies to the late Gabriel Garcia Marquez for playing off the title of his excellent novel.

And with thanks to those who have made previous observations and/or helped get the word out (and with dread over the many names of amazing iNatters I've left off this list)!
@fundad @finatic @jaykeller @patsimpson2000 @dean_leavitt @mgruen @cspnl @scottmarnoy @annettemercer @breeput @biohexx1 @cdegroof @peggywu @jmaughn @caudisona @tothemax @scubabruin @atrox77 @sarahwenner @naturenate @kclarksdnhmorg @annetcurran @jmaley @ajzellmer @tenthousand_hz_legend @bbunny @j_mcgowan @yetikat @andrew_louros @silversea_starsong @jamesparham @mc_california @tiwane @mooseandsquirrel @emilychebul @monicawahl

MATING SEASON UPDATES
March 26. @diverbrian makes the first Northern Alligator Lizard mating observation of the 2020 season. He posted this March 26 but the observation was from March 23. https://www.inaturalist.org/observations/40803908

Our wet winter across the western U.S. is likely to make for an excellent spring mating season for alligator lizards, and, we need your help to study their mating activity.

The Southern Alligator Lizard can be found from northern Baja California to southern Washington, and their close relative, the Northern Alligator Lizard, can be found from central California to southern British Columbia. Within the ranges of these two alligator lizard species are a handful of major museums, hundreds of universities, and thousands of biologists, so you might think we must know everything there is to know about alligator lizards. Unfortunately, like most other species on this planet, we still have a huge amount to learn about the basic natural history of alligator lizards.

Five years ago, we realized that we could use community science as a way to study mating behavior. At that time, there were only 3 dates for when Southern Alligator Lizards had been observed breeding that were reported in the scientific literature. We knew we could get more observations through community science, by crowdsourcing the study of this rarely documented behavior. We started asking people to send us photos and videos of mating pairs. We have now accumulated 255 observations of mating Southern Alligator Lizards, and 37 observations of mating Northern Alligator Lizards. We are pretty sure that through community science, we have generated the largest dataset ever on lizard mating.

What does mating behavior look like? Here are some previous observations of mating behavior submitted to the RASCals project by iNat users @tonyrivard, @samfellows566, and @emilyd47:
https://www.inaturalist.org/observations/21925752
https://www.inaturalist.org/observations/21237128
https://www.inaturalist.org/observations/21987603

What have we learned with all these observations? Here are three discoveries so far:

1. Weather has a huge impact on the timing of the breeding season. Cooler and wetter weather will delay the start of the mating season. If mating activity has already started, then bigger storm systems can shut down activity until weather improves. Normally the first observations of the year are from the southern end of the range, usually San Diego County, and are around the second week of February. Following 2019’s cool, wet February, the mating season started about a month later in mid-March.

2. Wet years are the big breeding years. Although we started this research effort in 2015, people have submitted observations that date back to 2003 (woohoo for digital cameras!). Across these years, what we see are that drier years have reduced breeding activity. For example, the 2015, 2016, and 2018 mating seasons followed drought years or below average rainfall totals, and we received about 30 observations of Southern Alligator Lizards in the mating position. But following the wet 2016/17 winter, we received 87 observations! The 2019 season is only just getting started (all observations are still from the very southern end of the range), and we already have 35 observations, most of which are from early April. We expect many more observations through the 2019 season.

3. Lizards can stay paired up for over two days! The actual act of mating likely takes place shortly after the lizards pair up. However, the male maintains the bite hold for a long time. This is most likely a type of “mate guarding”, in which the male is trying to make sure that no rival males try to mate with the female (but we still have more research to do before we are positive this is what’s happening). But how long might a male maintain the bite hold? This year, two dedicated naturalists, @lemonbee and @molly91945, repeatedly checked back on a pair and observed the lizards together for nearly 49 hours! This is a new record for this species! You can check out one of their amazing observations in this multi-day sequence here:
https://www.inaturalist.org/observations/21425974

What to look for? During mating season, males search out females. The male bites the female on her neck or head and may hold her this way for several days. Early in the encounter, the two may engage in a bit of a wrestling match (if you see this, please try to get videos). Sometimes, a second male shows up and we get even more interesting observations! About 8% of all observations in our dataset have two males with a female (for example: https://www.inaturalist.org/observations/22333855 ).

When to look? Because we have accumulated so many observations, we now know that the Southern Alligator Lizard mating season can start as early as early February in the southern part of the range and continues into early June in the northern part of the range and at higher elevations. This year, the season is just getting started, and mating pairs should be found in coastal Southern California through early May, with mating in more northern and higher elevation locations throughout May and June. For the Northern Alligator Lizard, breeding has also just started and will continue through mid-June, again with lizards in the south and at lower elevations breeding earlier.

Where to look? Alligator lizards can be found from coastal sand dunes to high elevations in our mountains. And they do better than any other local lizard in urban areas. When in the mating hold, pairs can even be found out in the open, and are often observed on driveways, sidewalks, lawns, and in yards. It is also possible to find pairs several feet off the ground on fences and in shrubs.

How to document? Take photos! If the pair is actively wrestling, please take video as well, which you can email to me. We are especially interested in how long pairs remain in the mating hold, so please check back every few hours and search for the pair in the general area.

If you see courting or mating alligator lizards, please upload photos to iNaturalist. If you are in Southern California, please tag observations to the RASCals project.

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

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.
https://www.inaturalist.org/observations/2821128

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.
https://www.inaturalist.org/observations/2929389

Southern Alligator Lizards observed by Kat Halsey April 17, 2016 mating in a barn at the Los Angeles Zoo.
https://www.inaturalist.org/observations/2997229

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.
https://www.inaturalist.org/observations/2925244

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.

ALLIGATOR LIZARD UPDATES
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

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:
https://www.inaturalist.org/observations/2350559
https://www.inaturalist.org/observations/1330177
https://www.inaturalist.org/observations/1333553

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:
https://www.inaturalist.org/observations/1417721

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:
https://www.inaturalist.org/observations/2751460

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:
http://www.nhm.org/nature/blog/studying-lizard-love-through-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:

http://scistarter.com/blog/2015/07/california-dreaming/#sthash.sTgYW5hW.dpbs

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."

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

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.