The results of the City Nature Challenge CHWP BioBlitz are in!

On Saturday, April 30, the Friends of the Wilderness Park held a BioBlitz in the Claremont Hills Wilderness Park as part of the City Nature Challenge. (If you don’t know what a BioBlitz is, please check out our previous post.)

The City Nature Challenge official identification period is now over, and we are excited to report our results.  (Although if you have observations you haven’t posted yet from the BioBlitz, don’t worry, they will still be counted.)

Southern Bush Monkeyflower (Diplacus longiflorus). Observation by ©Vicki Salazar.

Overall results

Eight observers made 197 observations of 95 different species during the BioBlitz.  Eighty percent of the observations reached “Research Grade”, which means that the iNaturalist community agreed on species-level ID, with more than 2/3 of identifiers agreeing on the species ID. You can see all the observations from the BioBlitz by clicking here.

Most observed species

Not surprisingly – since it’s at its showy peak right now – the most observed species was Southern Bush Monkeyflower (Diplacus longiflorus).

New species observed

Most exciting to us was the addition of 14 new taxa to our Biota of the Claremont Hills Wilderness Park project.  They included:

San Luis Blazingstar (Mentzelia micrantha). Observation by ©Carol Blaney.
A Western Aphideater (Eupeodes fumipennis) – a syrphid fly. Observation by ©Carol Blaney.
  • Four plant species:
    • Southern California Clematis (Clematis pauciflora)
      This means we have two Clematis species in the Park
    • Pineapple-weed (Matricaria discoidea)
    • San Luis Blazingstar (Mentzelia micrantha)
    • Perennial Ryegrass (Lolium perenne)
      We’re not so excited about this non-native invasive grass, but it’s good to know it’s there
  • Nine insect taxa (1 bug, 4 beetles, a wasp, and 3 flies):
    • Aoplonema – a plant bug
    • Judolia sexspilota – a flower longhorn beetle
    • Ornate Checkered Beetle (Trichodes ornatus)
    • Apsena – a darkling beetle
    • Dichelonyx– a May beetle or Junebug
    • White-headed Bee Fly (Bombylius albicapillus)
    • Euodynerus – a potter wasp
    • Chrysopilus – a snipe fly
    • Western Aphideater (Eupeodes fumipennis)
  • One bird species:
    • Hutton’s Vireo (Vireo huttoni)
      You can listen to it here

Coolest observation

Vegetarian bugs go rogue and try to make a meal of blister beetles!

A mirid plant bug (Aoplonema sp.) attacking a Red-eared Blister Beetle (Lytta auriculata). Observation by ©Carol Blaney.

“Coolest” is, of course, subjective, but our pick is Carol Blaney’s observation of a pair of mirid plant bugs (Aoplonema sp.) attacking two mating Red-eared Blister Beetles (Lytta auriculata).  As she describes the encounter, “The Aoplonema pair advanced on the mating Lyttas. One mirid repeatedly probed the tarsal claws of the female, which she twisted away to avoid, as best she could while mating. The other probed the underside of the male Lytta (as shown in this photo).

What made this encounter strange is that the attacking bugs were mirids = plant bugs.  Aren’t they supposed to eat plants?  What were they doing going after blister beetles? A tip from identifier K. Schneider pointed us to the answer.

It turns out that some mirids are predatory and eat other insects, and that Aoplonema are particularly attracted to blister beetles.  These aptly named beetles secrete a compound, cantharidin, which causes severe blistering on the skin and is poisonous when ingested. Cantharidin is generally a defense against predators, and blister beetles coat their eggs with it to deter predators. Paradoxically, cantharidin is an attractant to Aoplonema. They use it to home in on blister beetles and then proceed to insect their mouth parts membranous regions between segments of the blister beetles’ hard exoskeletons to suck out their hemolymph.  Yikes!  It truly is a dog-eat-dog – or in this case a bug-eat-beetle – world out there!

The link to the observation with all the fascinating comments is:

Many thanks to:

  • All the folks who staffed our booth – Vicki Salazar, Meg Mathias, Scott Marnoy, Diego Tamayo, Glen Morrison, Drew Ready, and Nancy Hamlett.
  • All the observers who contributed their sightings – Carol Blaney, Dave Bedell, Donna Bedell, Vicki Salazar, Carson Barry, Mark Coast, Laura Roach, and Nancy Hamlett
  • All 43 identifiers!

BioBlitz in the Claremont Hills Wilderness Park – Saturday, April 30!

Please join the Friends of the Claremont Hills Wilderness Park on Saturday, April 30, for a Wilderness Park BioBlitz in conjunction with the City Nature Challenge

The Friends booth for the California Biodiversity Day BioBlitz in 2019.

What is a BioBlitz?

A BioBlitz is a communal citizen-science effort to record as many species within a designated location and time period as possible.  It’s a great opportunity to meet other naturalists, scientists, and curious members of the public to meet in person in the great outdoors and learn about the plants and animals that live in the Wilderness Park.

How will the BioBlitz work?

Observers will look for plants and animals in the Park, take a photo (or multiple) phots of an organism, and upload the photos to iNaturalist.

What is iNaturalist?

iNaturalist is an online social network of people sharing biodiversity information to help each other learn about nature. iNaturalist is a collaboration between National Geographic and the California Academy of Sciences.  Anyone can participate in iNaturalist!

Before arriving on Saturday please:

  1. Go to and create a free account. You should see “SIGN UP” featured prominently on the homepage.   Otherwise, there’s a “Sign Up” link in the top right corner.
  2. On your smart phone, go to the Apple Store or the Google Play store and download the iNaturalist app.
Vicki Salazar makes an observation with her smartphone.

Once you’ve signed up, you can enter observations from either your phone or computer.

Can I get help in learning to use iNaturalist?:

Yes, indeed!  If you’re new to iNaturalist and would like instruction or training on how to use the app, two great opportunities coming up just in time for the BioBlitz:

  • Virtual iNaturalist Training
    Tuesday, April 26, 7:00–8:00 pm
    Zoom (register to get the link)

    Free online iNaturalist training with experts from the Natural History Museum of Los Angeles County, Aquarium of the Pacific, and the National Wildlife Federation. Learn how to participate in the City Nature Challenge and other community science projects by turning your photos of plants, animals, and other wildlife into data points for science!
    Register in advance for Zoom link at (Event will also live stream on Youtube with captions)
  • Introduction to iNaturalist
    Saturday, April 30, 10:00am–12:00 pm
    California Botanic Garden
    Adult $16 | CalBG member $11 | Student $9

    The class will be led by botanist and photographer Keir Morse, who will break down the features of iNaturalist and teach you the best ways to log your finds and photograph plants so that they can be accurately identified. Keir will also introduce you to some of the more advanced features of the website. You can attend the class, then head over to the Wilderness Park while all of Keir’s tips are fresh in your mind.

Are guides or tutorials available for people who cannot attend an iNaturalist training event?

How do I add my observations to the BioBlitz record?

You don’t need to do anything to add your observations to the BioBlitz record.  All observations made in the Park on the BioBlitz day will be automatically collected and added to the City Nature Challenge and Biota of the Wilderness Park projects.

How does one sign up for the BioBlitz?

You can sign up here or you can register at the Park. You can also make observations without signing up, but if you sign up, you’ll get a report of the results.

Earth Day with the Friends

Since 1970, April 22 has been celebrated annually as “Earth Day” – a day to demonstrate support for environmental protection. This year’s theme for Earth Day is “Invest in Our Planet”, and the City of Claremont’s establishment of the Claremont Hills Wilderness Park is a fine example of investing in our planet by protecting the habitat, wildlife, and watershed of our hillsides.

The Friends of the Wilderness Park are celebrating Earth Day in two ways:

Celebration at Shelton Park on Sunday April 24

Sustainable Claremont is hosting an Earth Day Celebration in Shelton Park (the first in-person Earth Day celebration since 2019), and the Friends will be there! Stop by our booth and learn more about the Wilderness Park, what the Friends do, and how you can be involved in caring for the Park. We look forward to seeing you!

Date: Sunday April 24, 2022
Time: 8:30 AM – 12:30 PM
Where:  Shelton Park, Claremont (corner of Bonita Avenue & Harvard Avenue)

Trash Pick-up Kits

Last Saturday, at our Second Saturday event, the Friends gave out Trash Clean-up Kits containing gloves and trash bag with instructions to visit the Wilderness Park or another park and pick up trash and an encouragement to pick up trash every month.

Earth Day Trash Pick-up Kits waiting to be picked up.

All the kits were gone in 45 minutes. Some Park visitors picked them up for their children, and one pre-school teacher took some for her class. Why don’t we all take a few minutes to pick up some trash?

Question of the Day: Why did the tarantula cross the road?

If you’ve been to the Wilderness Park recently, you may have spotted tarantulas out on the fire trails, and you might well wonder:

Why are so many tarantulas out now?
Why are they crossing the roads?

The tarantulas you see out on the roads this time of year are all adult males, and they are out looking for females. They really have only one thing on their little tarantula minds, and they are pretty oblivious to anything else.

A male California Ebony Tarantula (Aphonopelma eutylenum) crossing Johnson’s Pasture Rd in the Wilderness Park. On the front legs you can see the tibial hooks or spurs that are used to grasp the female during mating. ©Nancy Hamlett.

The females are found in burrows that are scattered across the landscape, and the males search for them by alternating between walking in straight lines and walking in concentric circles until a female’s scent is detected, suggesting that a burrow is nearby. The males may travel as much as 3/4 of a mile looking for a mate, and if a road is in their path, they just trundle on across it.

Once a male has found a female’s burrow, he signals his presence by doing some fancy drumming on the ground at the burrow’s entrance. If the female likes his drumming, she will emerge from her burrow, and mating can commence. The male uses special hooks on its front legs (which you can see in photo above) to immobilize the female’s fangs and position her during mating.

Autumn is the mating season for tarantulas, so that’s when you’ll most likely spot the males out on their mating missions. If we look at the distribution of tarantula sightings reported on our iNaturalist project, you can see that over 80% of the observations were made in August – November.

Tarantula observations in the Wilderness Park by month. Nineteen of 23 iNaturalist observations (83%) were made in August – November.

It’s not clear exactly how many tarantula species reside in the Wilderness Park. Only one species – California Ebony Tarantula (Aphonopelma eutylenum) – has iNaturalist observations labeled as “Research Grade”, meaning that the identification has been confirmed by a consensus of other identifiers. Steindacher’s Ebony Tarantula (Aphonopelma steindachneri) has also been reported, but the identifications have not been confirmed.

Different Aphonopelma species look very similar and can be extremely difficult to distinguish without molecular data (see Hamilton et al., 2016), so we may never know whether one or two species are present in the Park. You can see all the reported iNaturalist observations of tarantulas in the Park here.

If you’d like to find out more about the tarantula’s life cycle, check out Ralph Washington, Jr.’s article in Bay Nature magazine.