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Love in the Time of Coronavirus: The Alligator Lizard Version

Help us study lizard behavior in your backyard!

Close-up of a male biting the head of a female.

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

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

A pair of southern alligator lizards, male is biting female's head and neck
A pair of southern alligator lizards observed by Jane Gao off Las Virgenes Road near Hwy 101 during the 2019 mating season. The male is biting the female’s head and neck region; this is termed the bite hold. Pairs may stay in the bite hold for several days even though mating only takes a small portion of this time. View on iNaturalist.
Jane Gao


Southern alligator lizards 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. In urban areas, including the Greater Los Angeles Area, they are the most widespread lizards. They can be found eating grubs and slugs in compost bins; hunting for spiders, caterpillars, and crickets in gardens; and sometimes taking an accidental stroll through a living room or garage. So get outside, soak in some spring sunshine, enjoy nature, and of course maintain social distancing---meaning that others should be looking for alligator lizards more than 6 feet away from you!

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 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 351 observations of mating southern alligator lizards, and 57 observations of northern alligator lizards. We are pretty sure that through community science, we have generated the largest dataset ever on lizard mating.

Alligator Lizard mating. Uncommon observation with three lizards, one male is holding on to another male.
Yuki Machida observed this unusual threesome in a Los Angeles backyard during the 2019 mating season. About 9% of alligator lizard mating observations involve two males with a female, but each male usually is biting the female. Yuki’s observation is especially uncommon because one male has a bite hold on another male. View on iNaturalist. 
Yuki Machida

 

What have we learned with all these observations? Here’s 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 five observations of mating activity for the 2020 season, but then the cooler mid-March weather in Southern California shut the season down. With temperatures starting to increase again, the mating season should rapidly progress, although it is now delayed by several weeks across Southern California.  

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 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 (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 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? In 2019, two dedicated community scientists repeatedly checked back on a pair and observed the lizards together for nearly 49 hours! This is a new record for this species! 

A pair of southern alligator lizards, in West LA
Katie Goldin, who is the creator and host of the Creature Feature podcast, observed these two alligator lizards on a Westwood sidewalk in April 2019. If Katie can find alligator lizards in busy Westwood (that’s West LA near UCLA for those not familiar with the area), you can find them in your neighborhood, too. View on iNaturalist.
Katie Goldin

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 9% of all observations in our dataset have two males and a female? 

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 take photos and ideally also video if they are being active. Then upload these to iNaturalist if you are already an iNaturalist user or send them to us at the Natural History Museum by emailing the photo to nature@nhm.org, or by using #NatureinLA on social media (Facebook, Twitter, Instagram), or by texting us your photos at (213) 663-6632. If you have photos from previous years, please submit those as well.

A pair of southern alligator lizards, male is biting female's head and neck
Mary Stein found these alligator lizards in a backyard in the town of Avalon on Catalina Island. When first found, there was a second male trying to interrupt these two but he wandered off. View on iNaturalist.
Mary Stein