Field Note #9: numbers on an upswing.

Date of Survey: 022616

Official Low Tide: 4:36pm            Survey start time: 3:36pm  Survey end time: 5:00pm

Tide heights: -.02 feet/ -6 cm

Mudflats exposed? Y

Temperature:  70° F / 21° c

Cloud cover: 20%

Common Name	Counts of birds foraging on mud flats	Behavior Forage-F Rest/roost-R Fly over -FO	Disturbance (Flushing-F, displaced-D, agitated-A)	Feeding location *Primary flat (P)   Mangrove flat (M)
Great egret	1	FO		M
Snowy egret	2	F		M
Great blue heron	5	F,R,FO		P-1, M-4
Little blue heron	1	F		M
Roseate spoonbill	2	F		M
white ibis	8	F		P, M
Total	19

Notes:  2 kayakers today, but no disturbance was recorded during the survey time. Slightly higher count today than previous surveys. NO action on the main mudflat inside the Lake Worth Cove Park boundary. Minimal action on the main intracoastal mudflat. As per usual, the majority of activity is with the exposed flats associated with the mangrove lines and tree islands. The main flats remain parking lots for resting seagulls. This is not a bad thing, at least someone is utilizing the intertidal water flow. The ducks from last week were here again.

Side notes: Maybe someone should attempt an overall species survey at some point. It would be difficult—due to the size of the estuary. Recounts would be hard to avoid without large numbers of surveyors. The intern suggested we strap a camera onto his drone so we can survey the entire site. Good idea, but we would have to get a new permit—investigate how much disturbance that would cause to the birds. Also I do believe The Friends of John D. MacArthur Park have citizen bird watchers that take all animal counts on any given day.

Here are some white ibis. We did take photos, but left the camera at home, so this is a Wikipedia photo. By Hans Stieglitz - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11059636

Field Note #8: Just ducky

Weather Conditions: 
              Temperature:  72° F /22° C   
              Cloud Cover:  90% slight breeze

Official low tide time: 11:57am

Survey start time: 11:02 am   Survey end time: 1:00 pm

Tide heights: -0.1 feet / -3 cm

Mud Flats exposed? Y

Common Name	Counts of birds foraging on mud flats	Behavior Forage-F Rest/roost-R Fly over -FO	Disturbance (Flushing-F, displaced-D, agitated-A)	Feeding location *Primary flat (P)   Mangrove flat (M)
Great egret	1	F	D (P)	M
Snowy egret	3	F	D (P)-1	M
Great blue heron	3	F		P, M
Little blue heron	3	F	D (H)-1	M
Tricolored heron	1	F		M
white ibis	3	F		M
Total	14

Human counts (directly impacting mudflat): 2 fisherman; 5 kayakers; 2 paddle boarders

Notes: As noted at most surveys, most of the birds in the area are utilizing the mangrove lines throughout the park. The mudflats seem to be preferred roosting sites for seagulls and anhinga. There were several ducks in the area today (as seen above in the photo).

The ducks aided in the foraging success of the three snowy egrets and one pelican. The ducks would be chasing prey and moving them to the snowy egrets. Several pelicans were feeding in the deeper waters nearby.

The humans seem to use the mudflats more than the birds. Every single one observed walked directly over the main flats on both sides of the survey area. Often they stop and camp out there. Leaving the birds no place to forage.

images copyright Diane Arrieta/John D MacArthur Campus Library 

and can not be used without prior consent.

Water shortages and agriculture

Field Note #7 Finally flat

Survey #021016

Weather Conditions: 
Temperature  61° F /16° C   
Cloud Cover  80% ; Windy

Official low tide time: 3:29pm

Survey start time: 2:55pm   Survey end time: 4:45pm

Tide heights: -0.8 feet / -24 cm

Mud Flats exposed? Y

Common Name	Counts of birds foraging on mud flats	Behavior Forage-F Rest/roost-R Fly over -FO	Disturbance (Flushing-F, displaced-D, agitated-A)	Feeding location *Primary flat (P)   Mangrove flat (M)
Great egret	4	F, FO		M
Great blue heron	3	F,F,R	D (Human)	M, P
Little blue heron	3	R	D (Human)
Wood Stork	1	R	D (Human)	M
Roseate Spoonbill	1	F		P
White Ibis	4	R , FO	F (predator)

*Primary mud flats are large center exposed flats at either the intracoastal or Lake Worth Cove side of the park.

  Mangrove mud flats are at the mangrove line or radiating from mangrove tree islands

**we are only counting birds foraging at exposed mudflats. We are not counting birds feeding at mangrove lines without exposed mud flats.

NOTES: 2 kayakers at the start of survey; 4 more kayakers 30 min. in. (on a Wed.!); There were a fair amount of birds roosting at the tree island and far edges of the intracoastal mangrove lines. Most of the birds seen were using the mangrove lines to forage and avoiding the two main mud flats. The Roseate spoonbill and one Great blue heron utilized the interior Lake Worth Cove mudflat for foraging and resting.

The Great blue heron and the spoonbill ignored each other. The spoonbill was foraging and the heron was resting. As the spoonbill got closer, the heron moved slightly out of his way. The Great blue heron did act aggressive to the seagulls who were feeding. 

Observations noted that the Great Blue Herons forage in one spot for a short time, then move to other locations. They also rest on the flats often without foraging for long periods of time. The Roseate Spoonbill utilized the same foraging location for long periods of time (30 minutes were observed at this survey).

Human disturbances included traffic noise and kayakers. 

Future research: Find intertidal mudflats in the area without human interference to compare bird usage, compare prey availability

Photos by Diane Arrieta

Field notes #6

#020616 John D MacArthur Park

Survey start: 12:00pm   Survey End:  1:30 pm

Official low tide: 12:20 pm

Conditions: clear 78°

Bird Counts (JDM)
	Count	Behavior observed	Disturbance
Great Egret	1	F
Great Blue Heron	1	F
Little Blue Heron	1	F	H,D
White Ibis	1	FO
Roseate Spoonbill	1	F
*F=foraging	R= roosting/resting	FO = fly over

Notes: Finally there were mud flats exposed at low tide. Surprisingly the only birds utilizing them as a resting or foraging area were pelicans and seagulls. The few Ciconiiformes that were recorded, were foraging along the mangrove tree lines. This seems to be the norm for this particular location this season.

All of the birds using the inter tidal mud flats were displaced by human disturbance. At the time of the survey there were three paddle boarders, one kayaker, two wading humans and a dog. The latter set up camp on the flats area and were fishing. After walking to the northern end of the survey area, six more paddle boarders were recorded. Turning to the other side looking directly into the Lake Worth Cove (interior) side of the park; at least 4 more kayakers were recorded. There were no exposed mud flats in the interior of the park on this particular day.

As the researcher left the area, one roseate spoonbill was recorded foraging in a very remote section of the park that had no access by humans.

According to Drake (2007, cited by Vegvari, et al., 2011) Human disturbance can play an important role on the distribution, ecology and behavior of animals. Peters and Otis, 2006, conducted studies to determine if human disturbance that causes flushing behavior translate into site avoidance. More research is needed, but this seems like it could be an early explanation of why there are very few birds in the open areas of the park. Water sport traffic has been steadily increasing in this area over the years (personal experience).

The other factors that should to be researched are population decline of overall wading birds in South Florida and changes is food availability/quality.

References:

Zsolt Végvári, Zoltán Barta, Pekka Mustakallio, Tamás Székely, 2011. Consistent avoidance of human disturbance over large geographical distances by a migratory bird. DOI: 10.1098/rsbl.2011.0295

Peters and Otis, 2006. Wading Bird Response to Recreational Boat Traffic: Does Flushing Translate into Avoidance? http://obpa-nc.org/DOI-AdminRecord/0063794-0063802.pdf