Field Notes

This video is of a male San Clemente Loggerhead Shrike (Lanius ludovicianus mearnsi) [LOSH] vocalizing on the opposite rim across canyon from a male Homo sapien not vocalizing. The female LOSH of this pair is incubating a nest down in the canyon in a Rhus integrifolia. Rhus, the sumac genus, dominates some of the canyon slopes and bottoms on San Clemente Island. It also is a popular nesting substrate for LOSH this year.

There are many LOSH pair in the Incubation stage presently. Meaning, in the near future, the Shrike Monitoring Crew will become very busy checking on nestlings, and then banding, recording morphological data from, and pulling feather samples from them before they fledge.

The LOSH incubation period is generally 15-17 days. During this time the female will spend long times on the nest. Sometimes I won't even see her, even during observations over an hour long. Other times I will see her very briefly. During these short times off-nest, she will preen, stretch her wings, defecate, and otherwise perch for a moment. The male will periodically bring her food. As he approaches the nest, the incubating female will often give her begging call.

Otherwise, at a site still in the incubation stage, one generally sees the male out foraging for himself and sometimes for the female on nest.

Should everything go right, in 15-17 days, the successful incubation stage leads to these guys.

When a monitored site shifts to nestling stage, it is often quite apparent as the characterized description of "male seen foraging, bringing food to nest. female heard begging as he flew to nest site. female only seen twice during observation." moves to --> "both male and female seen bringing food to next every few minutes" or something similar.

There are far, far too many sites and too few personnel to visit every one of them every day. So when a site now is at Nestlings(NE), we don't know the exact moment, the very day the hatch took place. Some sites, that were not known to us earlier, may even be at NE. Nevertheless, we need to find out how many nestlings there are, and how old.

The above picture shows part of the methodology. We try to time when both parents are off the nest. It is then we hike, descend, ascend, slide gracefully, slide not-so-gracefully to the nest location. Using EXTREME caution not to destroy any surrounding vegetation on our way to, at and around, the nest, we use a "mirroring pole." A mirroring pole is precisely what its namesake is. It is a mirror affixed, often by wrapping of duct tape, at an angle at the end of a long pole. The pole is then carefully moved into a position...if possible... to an angle above the nest where we can take a picture of the bowl. This allows us to count how many nestlings there are and, by physical characteristics, age them.

How many nestlings do you count in the picture? They are 3-days-old, by the way.

When they become older, the absolute minimum is 9 days old, we band the chicks and take necessary morphological data and feather specimen from them.

Clutch size is usually around 4-7 eggs/nestlings. Ideally, the lower an organism is on the food chain the more offspring it produces; for reasons that become obvious if you think about it. The higher the organism on the food chain, the fewer offspring. Ideally.

Not all nestlings make it. One example of a nest site we are monitoring: the nest had 5 nestlings banded and worked up, it now only has two of those five that survived. Those two are quite the successful fledgelings and near the end of their "dependant" status. In fact, I believe that ends today. It's Saturday, right? A nestling becomes a fledgeling upon "first flight" or "first leaves the nest." When one approaches a nest to work on nestlings that are older, the biologist takes great care in not causing a "forced fledge." These kids, at a certain age, have a bit of locomotive ability. Atleast enough to jump out.

Anyhow, not all nestlings/nests make it. Its just part of it.

This vid is a nest predation event by an Island Fox (Urocyon littoralis clementae). The Island Fox is the smallest fox species in the U.S. Smaller than a house cat. Recall me alluding to the feral cat problem on the island, and for that matter on the continent? Native birds on the island have enough predator pressure on them already, from Island Fox to Common Ravens (Corvus corax). Native birds on the mainland have enough as well. Its a balance that was set a long time ago. We all know this. We all know this to some degree if we take a moment to think about it.

Now..., do we care?

Moving on. Regarding my work with the SC LOSH, I plan to share more pictures in the future directly illustrating methodologies and my time with this species.

The pictures of butterflies, other bird species, herps, canyon vistas, and beautiful mornings are all taken getting to work, after work has been finished, or my time off-island.

On the subject of beautiful mornings, I hope you are having one. If not, perhaps you can take a moment to step outside, if not able; just look outside, and make this morning what it is.

Good morning and watch your step.

Peace,

mwyork