Relaxing Morning

Visited Sand Prairie this morning before work with no specific goals in mind.  I hadn't been there in a couple of days and figured I would snoop around and see if I could find any new nests or observe any behavior.  I have ordered two new compact flash drives on which to record songs, and it looks like I should be able to obtain some data.  There were at least three birds still singing at 9AM this morning, following their usual habit of vocalizing from an elevated perch.  Many of them seem to enjoy short persimmons no higher than my waist, and many seem to favor a particular tree.

I revisited nest #5 and was surprised to find a second egg in the nest once again.  Just over a week ago I visited the nest (which initially had 2 eggs) and there was only a single egg.  This would indicate that the sparrows laid another egg in spite of losing the first one to predation.

I also visited nest #8 and did not see any sign of the young sparrows.  I am hopeful that their departure from the nest was a success.

On Monday I will surveying three new random plots and will be collecting plants to press.

Another Nest

My only intention yesterday was to sample the vegetation around nest #6 and nest #7.  Both of the nests were in the usual location; beneath a sedge, bluestem, or panic grass surrounded by an open sandy area with little other vegetation.  After I completed this I decided to walk to the northeast part of the conservation area to observe the pair of lark sparrows there.

It was very windy but I eventually saw a sparrow sitting atop a small tree, an insect in its mouth.  It then became a waiting game as I stood patiently until the bird return to its nest.  I was pleased to find a nest with three well developed young birds.  I estimated them to be at least 9-10 days old.

I began to take measurements of the young when I was able to witness something quite incredible.  One of the young birds hopped out of the nest and scurried across the ground, concealing itself beneath the surrounding panic grass.  It began to chirp loudly and its parents would reply with a high-pitched note.  They were quite restless, flying every few seconds and landing within 3-4 meters of me with food in their mouths.  After I finished measurements, a second youngster also departed the nest, begging for food as it went.  I imagine they will remain by the nest to be fed by their parents over the next couple of days.

I will revisit the site on Thursday to sample vegetation and to see whether the young birds are still in the vicinity.  I will also be collecting plants then and using a plant press for the first time.

Disappoinment

I arrived at Sand Prairie today with my banding gear, only to find nest #7 completely devoid of any birds.  I don't believe they fledged because they still had quite a lot of development to go and the unhatched egg had also disappeared from the nest.

It feels like quite an unlucky streak, but in fact my results are not too unexpected.  Some previous studies of lark sparrow breeding biology revealed a nesting success rate of only eight percent, which is fewer than one in ten.  I would imagine predation is quite high in a habitat like Sand Prairie.

There is a male bird in the far northeastern portion of the refuge that continues to sing.  I will try to record his vocalizations within the next week.  I have also seen a pair in that area but saw no indication of any nests.  The sheer remoteness of the pair has limited my exposure to them, however, so they may well be nesting.  I will be checking on them quite frequently in the coming weeks.

My focus will now shift to vegetation surveys.  There are currently no successful nests for me to monitor, and outside of the aforementioned pair I have seen no definitive parental action.  I will keep my eyes peeled while I collect the plants, however.

Updates

Yesterday's visit to Sand Prairie was a bit of a disappointment.  Nest #6, which I had discovered only days earlier, was discovered by a predator and three of the young were gone, with the remaining individual already dead.  Also, nest #5 only had one egg remaining, and the female was not incubating.  On a positive note I did discover another nest, and this one had much older birds, at least 5-6 days.  Their eyes were open and feathers were beginning to develop.  There were two young and one unhatched egg.  I am hoping to band them this weekend barring another instance of predation.

I spoke with Dr. Bornstein, Southeast Missouri State's botany professor, and he suggested that I collect vegetation samples to strengthen the credibility of my research.  I am fully on board with this idea and will be learning to press plants in the coming weeks.  I am fortunate that a previous student, Josh Wibbenmeyer, has already conducted a floristic survey of Sand Prairie Conservation Area; his samples are available to me at the school herbarium.  This makes identification much easier for me.

Finally, I will be undertaking a independent research project this fall to survey the fish fauna of Cape LaCroix Creek.  I enjoy jogging along the creek and have seen a wide variety of species just in passing.  I will post updates from that research on here as well.

Today's Discoveries

It turns out I never made it to Sand Prairie yesterday as planned.  Instead I visited the conservation area today after my summer class.  My plans were to record the weight of the eggs in nest #5 and to survey the vegetation immediately surrounding the nest.

I was delighted to find a bird incubating nest #5, indicating that it is still in use.  There were still only two eggs.  Measurements were taken for the eggs and the vegetation was sampled in a square meter plot surrounding the nest.  I wanted to make sure I did both at one time to minimize the number of nest disturbances.  To my surprise it took me awhile to relocate the nest, but while I searched two adult birds flew in rough circles above me.  They called sporadically but did not land, at least not near me.  I assumed they were the pair that had constructed nest #5, but since I later startled the female off the nest, this must have been a different pair.  My adviser, Dr. Eddleman, suggested the possibility of polygyny, where multiple females nest within the territory of a single male bird.  I will have to look into this further.

I also spent a good while observing birds around the dunes.  This is where four out of the first five nests were constructed and where I have seen the vast majority of birds.  Not far from nest #1 is a persimmon that is a favored perch for a particular pair of sparrows, most likely the ones who built the nest.  I observed a bird with an insect in its beak and waited patiently for it to fly to its nest.  It did not move but was soon joined by a second bird with an empty beak.  The second bird eventually flew to the west, while the bird with the insect flew a good distance south.  Both seemed to leave what I thought was their territory.

Several minutes later I located a different bird only a few meters in front me with a green caterpillar in its beak.  The bird remained motionless for a while before crouching down and walking stealthily to a concealed nest.  This nest was located beneath a plant that still needs to be identified and contained 4 young birds.  Because I had already disturbed the nest I decided to take the weight, length, and tarsal measurements of 2 of the young.  One of the birds weighed 6.1 grams, while the the other weighed only 3.1 grams.  Based on Baepler's (1968) weight measurements, I would estimate these birds to be between 2-3 days old.  Since Baepler's study indicates an increase of roughly 2-3 grams per day, the smaller bird may well have hatched one day later than the heavier one.  The larger bird had a total length of 43mm, while the smaller bird was 36mm in length.  Tarsi length was 13.5mm and 11mm, respectively.

I was able to locate the vicinity of another nest but was never able to find the nest itself.  Both parents returned to the area with insects in their beaks but neither entered a nest.  Instead they either remained still or crept slowly among the bunches of grass.  Both this pair and the pairs before indicate a high degree of caution among lark sparrows when it comes to concealing their nest.

Because both of these nests are located among the dunes, my hypothesis is that they are re-nesting attempts by the same pairs that previously experienced nest predation.  In order to lessen the risk of predation I do not intend on returning to these nests for at least 2-3 days.

Update

After my summer class today I visited Sand Prairie Conservation Area.  My main goal was to check on nest #5, which I had discovered May 30 in an open area in the southeast corner of the reserve.  It was located beneath a splitbeard bluestem (Andropogon ternarius), one of two plant species the sparrows seem to favor.  It still had two eggs in the nest, half the average clutch size of 4 and unchanged from when I visited it a week earlier.  According to Baepler's (1968) study in Oklahoma, females were hesitant to leave the nest when incubating, loyal to the point that he could grab one with his hand.  It seems odd to me that I have only seen two birds incubating during my countless visits to the prairie, and both times they flew away from the nest.  There were four lark sparrows near nest #5 which indicates a possible second nest.  The two pairs did not appear to be antagonistic.

Nest #1 is most certainly abandoned.  The eggs were laid over three weeks ago and are now completely covered in sand.  On Jun. 8 I intend to observe the dunes from a distance for parental activity.  Considering my current luck with eggs, I am hoping for a nest with chicks.

Nest Update

Thus far I have located five lark sparrow nests at Sand Prairie Conservation Area.  Although I have seen eggs in four of them, none of them have successfully fledged.  Two experienced predation while a third appears to have abandon, as the eggs have not hatched in over three weeks and are now covered in sand.  I am still holding out hope for a nest that I found in the 40 hectare portion of the reserve.  There is also another pair of birds in suitable habitat in the unburned prairie that have likely built nest already.  I plan on visiting the area tomorrow evening and will note whether the adult birds are bringing food to any young.

Welcome

This is my official research page for my thesis research.  Check back for regular updates.