CNDDB News Blog

Left: Orobanche parishii ssp. brachyloba (CRPR 4) by Katie Ferguson; Middle: Orobanche bulbosa, (common) by Kristi Lazar; Right: Orobanche fasciculata (common) by Katie Ferguson

These fascinating parasitic plants are always a treat to find in the wild with their alien-looking flower stalks emerging straight from the ground and no leaves to be seen.

The genus Orobanche is home to parasitic plants that lack chlorophyll, and therefore completely depend on their host plant for nutrition. Some species are only able to parasitize a single host species, while others can survive on a wide variety of hosts. If you spot one, be sure to note the other plant species growing nearby so you can identify potential hosts.

Orobanche are often referred to by their common name “broomrape” which comes from the English word broom (referring to the shrubby plants in the pea family that broomrapes often parasitize) and the Latin word “rapum” (which roughly translates to “tuber”). Although recent phylogenetic studies now place all broomrapes found in California into the genus Aphyllon, for now CNDDB still uses the former genus name Orobanche.

CNDDB currently tracks four species of Orobanche, including Orobanche parishii ssp. brachyloba (California Rare Plant Rank 4.2). O. parishii ssp. brachyloba is found in coastal bluff scrub and coastal dunes on the Channel Islands and southern coast of California, with its range slightly extending into Mexico. It is most commonly found near Isocoma menziesii, which is presumed to be the preferred host plant for this species. The few remaining mainland populations are highly threatened by coastal urban development; however it is found to be widespread on several of the Channel Islands. If you see O. parishii ssp. brachyloba or any other rare broomrapes in the wild, be sure to submit your observation with our CNDDB Online Field Survey Form!

Ardeidae is a family of wading birds that includes herons, egrets, and bitterns. These birds are often characterized by their long bills, necks, and legs. They forage predominantly on aquatic animals including amphibians, fish, crustaceans, and mollusks. Additionally, some birds can be found foraging for small mammals, reptiles, and insects in grassy fields.

When the breeding season arrives, most Ardeids, excluding bitterns, gather into colonies called rookeries or heronries. The males will begin nest building and displaying in attempt to attract a female. The birds will form monogamous pairs for the season and take turns incubating eggs, brooding chicks, and foraging. They can lay 2-7 eggs depending on the species. During feedings, nestlings compete for provisions brought in by the parents. In years when food is limited, competition among nestlings increases and can result in aggression and siblicide. Nestlings may also behave aggressively toward nestlings in adjacent nests.

One of our very own Environmental Scientists has been volunteering with the Audubon Canyon Ranch Heron and Egret Monitoring Project to assist in their effort to monitor Ardeid colonies in the Bay Area. At a snowy egret (SNEG, Egretta thula) and black-crowned night-heron (BCNH, Nycticorax nycticorax) rookery in a residential park in Fairfield, she monitors and records the heron behavior and nesting success on a weekly basis. The flexible branches of the nest trees and the high winds of Fairfield plus the aggressive nestling behavior result in numerous chicks falling from nests. The survivors get loaded into cat carriers by volunteers and are shuttled to International Bird Rescue in hopes that they will recover and return to the rookery next year.

California has seven native Ardeid species: great egret, snowy egret, great blue heron, black-crowned night-heron, green heron, American bittern, and least bittern. We have one naturalized species: the cattle egret, which is native to Africa. All these species, except for the green heron and cattle egret, are tracked by the CNDDB. Be sure to fill out an Online Field Survey Form if you come across a nest site!

Top Left: One of the many trees used by the Fairfield rookery. The white birds are the SNEG. For every SNEG in the photo, there is likely a black and white BCNH adult or brown and white BCNH juvenile present but blending in with the tree. Top Right: Closer image of SNEG. Bottom Left: Fledglings under one of the nest trees – 3 SNEG and 1 BCNH. BCNH are known to have a high tolerance for disturbance as is evident in the proximity of the rookery to homes, traffic, and park-goers. Bottom Right: BCNH fledgling on park sidewalk.

Please join our next Conservation Lecture Series talk that focuses on how extreme climatic events have recently impacted marine ecosystems around the world, including foundation species such as kelps. We quantify the rapid climate-driven catastrophic shift in 2014 from a previously robust kelp forest to unproductive urchin barrens in northern California. Bull kelp canopy was reduced by 93% along >350 km of coastline. Twenty years of kelp ecosystem surveys reveal the timing and magnitude of events, including mass mortalities of sea stars (2013-) and red abalone (2017-), extent of nearshore ocean warming (2014-2017), and the sea urchin population explosion (2015-). These stressors led to the unprecedented and long-lasting decline of the kelp forest and the ecosystem services is supports such as the red abalone and sea urchin fisheries.

Date: Thursday, July 18, 1:00 - 2:30 p.m.
Register to view online.

Questions? Contact: Whitney.Albright@wildlife.ca.gov