Archivos de diario de diciembre 2022

03 de diciembre de 2022

Exponential rise in juvenile newts killed this season (2022-2023)

This year @merav and team have recorded an astounding number of juvenile newts killed on the road, and the migration season is just beginning! This is an exponential increase over previous years. See Merav's blog post for more information:
https://www.bioblitz.club/post/an-unusual-beginning-of-the-newt-season

Juvenile newt roadkill doesn't remain on the road for long. Most of them will disappear within 24 hrs, so the reported numbers are an undercount of the total mortality. One study found that 80% of the smaller bodied amphibian carcasses were gone from the road within 24 hours. "... the combination of small, soft-bodied amphibians with warm, wet surfaces results in rapid carcass destruction, removal by scavengers or decomposition and thus leaves very little evidence of road mortality events.” (Santos et al., 2011; Zhang et al., 2018).

Juvenile newt deaths have a high impact on population viability. Some conservationists have found that amphibian population viability is not particularly sensitive to adult survival, therefore mitigations directed towards juveniles have a stronger effect on population viability than those that improve adult survival. Petrovan, et al. stated: "We conclude from the review of amphibian population models that there is substantial evidence that the fate of juveniles is critical and represents in many instances the driving factor for amphibian population dynamics...” (Petrovan, et. al., 2019, p 254)

JuvenilesPerSeason

Updated March 26, 2023.

Publicado el diciembre 3, 2022 02:57 TARDE por truthseqr truthseqr | 2 comentarios | Deja un comentario

04 de diciembre de 2022

How to Identify Malva nicaeensis (Bull Mallow)

Malva nicaeensis is an annual or biennial herb in the Malvaea family known by the common names: bull mallow and French mallow. It is native to Europe, Asia Minor, and the Mediterranean. It has become naturalized in California.

Photo tips:

  • If there are multiple plants in the picture, crop your photo to focus on the plant of interest.
  • The following views are required to identify the species:
    ** A photo of the entire plant. Is it decumbent or upright? How tall is it?
    ** A side view of the flower. Are the petals the same length as the calyx? 2x? 6x? Are the epicalyx segments separate or joined? Wide or narrow?
    ** A close-up of the fruit enclosed in the calyx and one with the calyx peeled back or removed. Is the fruit smooth? Hairy? Wrinkled?

  • Note that Malva plants without flowers and fruits generally can’t be identified to species and should remain at the genus level (i.e., Malva).

How to identify Malva nicaeensis:

  • Height: Grows up to 6 dm (24 in).
  • Stems: Erect or ascending to decumbent, prostrate or trailing. Densely hairy.
  • Leaves: Round or kidney-shaped, 5 –7 shallow lobes with scalloped margins. The leaf blade is up to 12 cm (4.7 in) wide.
  • Flowers: 1-4 small flowers in leaf axils. Flowers are white with faint pink and pink at the apex. Petals are blue when dry. Filament tube is hairy. There are 5 petals that are up to 2x as long as the calyx. Flowering stalks are about the same length as the calyx.
  • Calyx/Epicalyx: The calyx grows larger after flowering, enclosing the fruit. The lower half of the epicalyx segments are generally fused to the calyx, not to each other.
  • Fruit: Strongly reticulate, mostly glabrous, rarely hairy.
  • Habitat: Disturbed places
  • Peak Flowering Time: March – June

Similar Species:

  • Malva multiflora (Cretan Mallow)
  • Malva neglecta (Dwarf Mallow)

How to differentiate M. nicaeensis from M. multiflora:

  • M. nicaeensis grows up to 6 dm (2 ft.); M. multiflora can be much taller (up to 10 ft).
  • M. nicaeensis has smaller petals (up to 12 mm in length); M. multiflora has petals more than twice as long (up to 30 mm).
  • M. nicaeensis petals dry bluish, usually with darker veins; M. multiflora petals dry brownish.
  • M. nicaeensis has epicalyx segments that are fused to the calyx, not to each other; M. multiflora has epicalyx segments that are united for about ¼ of their length.
  • M. nicaeensis has rugose (wrinkled) mericarps; M. multiflora has smooth mericarps.

Compare-1

References:

Publicado el diciembre 4, 2022 04:45 TARDE por truthseqr truthseqr | 4 comentarios | Deja un comentario

16 de diciembre de 2022

Bear Creek Redwoods - a magical place in the winter

It's been a long time since I've hiked Bear Creek Redwoods. I'd forgotten what a magical place it can be in the winter. So many beautiful mushrooms, lichens, ferns and moss.
I thought my camera's battery was fully charged, but I guess not. It ran out of juice halfway through my hike. Maybe the fact that I had to use the flash for almost all the photos drained the battery faster than usual. There were so many more things I wanted to photograph. I'll have to go back soon.

Publicado el diciembre 16, 2022 06:44 TARDE por truthseqr truthseqr | 29 observaciones | 1 comentario | Deja un comentario

19 de diciembre de 2022

Coyotes at Ed Levin County Park

It was the day of the coyote at Ed Levin. I saw three coyotes and got some good pictures. What beautiful animals! One climbed the hill and then sat down and watched me take pictures. I was able to get recordings of the coyotes, too. That was exciting!

Some people had a doberman off-leash and off-trail. The dog was following two coyotes. I told the guy to put a leash on his dog and he cussed me out. I was wondering if the two coyotes would kill that dog?

Publicado el diciembre 19, 2022 10:01 MAÑANA por truthseqr truthseqr | 5 observaciones | 2 comentarios | Deja un comentario