PRESCOTT COLLEGE KINO BAY CENTER FOR CULTURAL AND ECOLOGICAL STUDIES WATERBIRD MONITORING PROGRAM REPORT, Background and Description...

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1 SJV Small Grants Program Final Report July 2016 Prescott College Kino Bay Center for Cultural and Ecological Studies Waterbird Monitoring Program Principle Investigators: Lorayne Meltzer, Lindsay Adrean Table of Contents Background and Description Activities... 4 Summary of Waterbird Monitoring Results on Isla Alcatraz... 5 Summary of waterbird studies in four Sonoran estuaries Summary of pelagic seabird surveys Community Projects Information Sharing Conclusions and future priorities Literature Cited Publications resulting from the Waterbird Monitoring Program P a g e

2 Background and Description The Prescott College Center for Cultural and Ecological Studies (The Center) is located in the Midriff Island region of the Gulf of California, Kino Bay, Sonora, Mexico. Strong tidal currents and seasonal wind patterns create year-round upwelling that makes this part of the Gulf of California one of the most productive marine ecosystems in the world. Millions of waterbirds pass through the region seasonally, using the region s abundant food resources to fatten up before long migrations or in some cases to spend the winter or breed. Since 1997, The Center has conducted waterbird monitoring in one capacity or another. The Center has expanded its monitoring program from fall counts of nesting Double-crested Cormorants on Isla Alcatraz, to the current Waterbird Monitoring Program (WMP) which consists of several projects focused on resident and migratory waterbirds using various habitats in the region (Table 1). Projects occur local communities, in four estuaries, Tastiota, Cardonal, Santa Cruz, and Santa Rosa, on Isla Alcatraz, and offshore in the Gulf of California. Table 1. Current Prescott College Kino Bay Center WMP projects in the Midriff Island Region of the Gulf of California and wetlands of the Hermosillo Coast. WATERBIRD MONITORING PROGRAM PROJECTS Isla Alcatraz Double-crested Cormorant colony size and productivity Wading bird, Brown Pelican, and Yellow-footed Gull colony size American Oystercatcher population and productivity Esteros Cardonal, Santa Cruz, Santa Rosa, Tastiota Waterbird surveys Nesting waterbird observations Northwest Mexico Shorebird Surveys (Santa Cruz, Cardonal, and Tastiota) Osprey population and productivity monitoring (Santa Cruz, Cardonal, Tastiota) International Brant Monitoring Project At Sea Seabird species richness and Craveri s Murrelet distribution Community Projects Semana Santa outreach and protection effort on Isla Alcatraz Environmental education for five classes in Kino Viejo secondary schools Reto Alcatraz secondary school field trip to Isla Alcatraz Bird identification and monitoring training in Estero Santa Cruz Creation of local bird guide training tool for Estero Santa Cruz Wetlands Week outreach activities in Kino Viejo Waterbird monitoring and habitat protection collaboration with Comca ac community 2 P a g e

3 The WMP strives to support conservation initiatives in the region by: Monitoring the waterbird communities in the Eastern Midriff Islands and adjacent areas to detect changes in population, distribution, and timing; Collecting data that address gaps in regional waterbird knowledge and research; Involving Prescott College students and local community members in waterbird research; Connecting information about waterbird use and abundance with conservation and management efforts; Serving as an information center about regional waterbirds and serving to support/link waterbird research initiatives in the region; Building capacity for community participation in waterbird conservation both within the Kino Bay and Seri Territory communities. Structure: The WMP is a component of the Center s Research and Conservation Program (RCP), which works in collaboration with the Center s community outreach programs to address conservation priorities in the region. The RCP is coordinated by the Center s director with input and direction from the Center s Advisory Board and implemented by research fellows and interns. Advisory Board: The Advisory Board includes five regional waterbird experts listed in Table 2. Their role is to help develop and carry the direction of the WMP to maximize the contributions to conservation and regional research. This may take the form of suggestions for methodologies, collaboration on projects, proofreading manuscripts, and contributing to project prioritization. It is hoped that these advisors will eventually take on a larger role in the WMP. Table 2. Advisory Board members supporting the waterbird monitoring program. Name Enriqueta Velarde Eduardo Palacios Tom Fleischner Abram Fleishman Emily Clark Institution Universidad Veracruzana CICESE Unidad La Paz Prescott College Prescott College Barataria Terrebonne National Estuary Program Fellows: The Waterbird Monitoring Program is implemented by Research and Conservation Program fellows. These fellows have come from diverse backgrounds and each brings something new and different to the program. Fellows are responsible for data collection, entry and management, assisting in project design, analyzing and publishing the results of one dataset, overseeing interns, students, and community members involved in WMP projects, and attending Sonoran Joint Venture Technical Committee meetings twice annually in addition to other more general fellow activities coordinated by the research coordinator. 3 P a g e

4 Students: Prescott College and eco-league students have the opportunity to work with the WMP to take on one of the current projects or to develop their own project. They work with their advisor and the WMP Fellow to make their project of a professional quality so they contribute to regional conservation in a tangible way. Interns: Volunteer internships are often awarded to current or recent undergraduates with an interest in waterbird conservation. Local high school students are also selected to do internships as part of their professional practicum and social service requirements. Interns contribute valuable man-power to the projects and sometimes develop spin-off projects of their own that result in reports or manuscripts Activities Funding received from the USFWS Sonoran Joint Venture s small grants program was used to fund one third of our Waterbird Monitoring Program during the season. This year the program was implemented by one fellow with the assistance of three interns. This team worked under the supervision of the Research Coordinator and with support from one external advisor. Former fellows continue to contribute to the program via advising assistance and contribution to peer-reviewed publications. Some of the major activities and accomplishments of the WMP are listed below. Completed regular fieldwork, data analysis, and technical reporting for 11 monitoring projects Updated or created 13 protocol documents Created a three-year strategic plan Developed presentations for educational or training purposes for the local community, elementary and middle school students, and college students. Data sharing through professional networking and through regular contribution to E- bird, averaves, International Brant monitoring projects Continued the indigenous community partnership in waterbird conservation through the support of a Comca ac waterbird monitoring group. Decreased disturbance of nesting habitat on Isla Alcatraz during Semana Santa in collaboration with CONANP through education and community outreach. Produced one peer-reviewed publication. Presented one poster at a scientific conference. 4 P a g e

5 Summary of Waterbird Monitoring Results on Isla Alcatraz Isla Alcatraz is a small (0.595 km2) island, located 1.4 km west of the town of Bahía Kino. The island is naturally split topographically. The southwestern portion is covered with typical Sonoran desert scrub; the northeastern portion is a halophytic flat. The island supports 13 species of nesting waterbirds with active nesting activity during 11 months of the year. Monitoring efforts from Prescott have been the only long term surveys on the island, and the projects are fundamental to the protection of the reserve. Double-crested Cormorant Colony Size and Productivity The Double-crested Cormorant colony was surveyed 16 times between September 18 th, 2015 and February 3 rd, The number of active nests (nests containing adults or chicks) rose steadily through the fall until the end of November when there was a slight decrease. The active nest count then rose to a high for the season of 1223 nests before decreasing steadily until the last survey on February 3 (Figure 1). This high count is close to the 11 year mean of 1262 breeding pairs nesting on the island (Figure 2). This is an indication that colony is recovering from the depressed nesting in the last two years, likely caused by El Niño conditions impacting prey availability. The productivity study was continued this year following the same protocol as the season. Active nests were identified in pre-selected plots that are representative of the varied habitats available on the colony. We obtained sufficient data for productivity analysis on a total of 61 active nests. We recorded a total of 51 fledglings from these nests, for a productivity rate of 0.84 fledglings per breeding pair. This is much higher than the productivity rates that were recorded for the last two years, 0.38 fledglings per breeding pair in and zero in The increased productivity this year further supports our hypothesis that impacts on the Double-crested Cormorants from the El Niño conditions were lessened this year. In the coming year we plan to continue studying Double-crested Cormorant productivity on Isla Alcatraz. As this is the largest colony in the Gulf of California we believe that it is important that the breeding ecology be understood not only to monitor changes to the regional population, but to the population of the entire Pacific Coast. 5 P a g e

6 # Nests PRESCOTT COLLEGE KINO BAY CENTER FOR CULTURAL AND ECOLOGICAL STUDIES Figure 1. Counts of Double-crested Cormorant active nests from September February Peak count is in bold Isla Alcatraz Double-crested Cormorant Nests Year Figure 2. High counts of active Double-crested Cormorant nests on Isla Alcatraz from No data are available for the 03/ 04, 04/ 05, 06/ 07, 07/ 08, and 08/ 09 seasons. 6 P a g e

7 California Brown Pelican Colony Size and Productivity Isla Alcatraz Brown Pelican Nests # Nests Year Figure 3. California Brown Pelican active nest counts on Isla Alcatraz from No data are available for 2005 and No Brown Pelicans nested on Isla Alcatraz this year, for the second year in a row, although they were observed on the island loafing near the water line frequently during observations in the fall and late spring (Figure 3). We suspect that the pelicans are roosting on the island overnight. This is the third consecutive year of no productivity for brown pelicans on the island. This data has been contributed to Dr. Dan Anderson at the University of California at Davis who is monitoring regional trends. The importance of Isla Alcatraz for this species has yet to be determined. With the low numbers that have regularly been reported, the island may serve as overflow to accommodate an increase in nesting during years in which forage fish are plentiful, or as an alternate site during years when forage fish are available in the Gulf of California but unavailable in other areas near the Pacific Coast breeding islands. This species may also be more susceptible to impacts from El Niño conditions as their foraging is limited to surface-schooling fish species. Continued monitoring will allow for these questions to be answered on the regional scale. 7 P a g e

8 Wading Bird Colony Size and Productivity Seventeen wading bird surveys were carried out between January 23rd and June 23 of Most species of wading birds continue to utilize the flat area of the island, mainly nesting in low-lying vegetation with the exception of the Great Blue Heron, who continues to select higher nesting locations in the cardón cactus. The boundaries of the wading bird colony do not change much between years, presumably because the location and availability of cardón cactuses and low bush vegetation have been relatively constant (Figure 4). The accuracy of wading bird nest counts has decreased since the start of the 2015 season due to the removal of a lighthouse that provided a high vantage point from which nests could be clearly seen. Counts are now conducted from a 10 foot tall ladder that is carried onto the island by the crew for each visit. Adults and nests are recorded, but all counts should be taken as minimums as visibility is very limited. The one species that is an exception to this is the Great Blue Heron because nests are elevated in the cardón cacti and still visible to observers. The Waterbird Monitoring Program produced a publication during 2015 entitled Diversity, abundance, and nesting phenology of the wading birds of Bahía Kino, Sonora, Mexico (Clark et al. 2015). This publication used data collected on the wading bird colony from and is helpful in providing a summary of past data with which to draw comparisons. Great Blue Herons were the first species to arrive on the island beginning in December. They began to occupy nests in January. They were followed by the Yellow-crowned Night Herons and Reddish Egrets in March, Black-crowned Night Herons, Snowy Egrets, and Tri-colored Herons in April, and finally White Ibises in May (Figure 5). In past years these species have been recorded arriving to the island in the same order, but approximately 2-4 weeks earlier. The reduced visibility may be a factor as low numbers of birds are more difficult to detect when they first arrive on the island. Great Egrets, Little Blue Herons, and Cattle Egrets were not seen on the island this year, but these species have only visited the island infrequently and in low numbers in the past. A single Great Egret was recorded on the island in 2013, one pair of Little Blue Herons were recorded with a nest in 2014, and only 12 and 5 Cattle Egret nests were recorded in 2014 and 2015, respectively (Table 3). The Snowy Egret remains the most abundant of the wading birds nesting on the island. Although the numbers of nests recorded in 2015 and 2016 are quite a bit lower than in past years, we suspect that this is due in great part to the decreased visibility as many nests are located deep in the vegetation. We are still recording high numbers of adults of this species on the island. 8 P a g e

9 Great Blue Herons are the most habitat limited species nesting on the island. They have only been seen nesting in the mature cardón cacti which are mostly located on the slope of the hill. We can see from the photos taken of the colony that there is turnover in the availability of cacti as some die and are slowly replaced by younger plants. The mean number of nests is down slightly from 48.2 in to 30 nests in , but annual numbers have shown regular fluctuations since observations began in In spite of the decreased visibility, the number of White Ibis nesting on the island does appear to be stable or increasing as the numbers of nests recorded during 2015 and 2016 are higher than the mean reported for (Table 3). The greatest challenge due to the reduced visibility is counting adults and nests of Black-crowned and Yellow-crowned Night Herons and Reddish Egrets. The cryptic coloring of these species and their propensity to nest deep in the vegetation make them very difficult to count from the lower vantage point, so the adult and nest counts recorded in 2015 and 2016 should be taken as minimums only. Fledglings of all three species were observed near the waterline of the island by the end of June, so it can be concluded that all three species are achieving some level of productivity on the island. Figure 4. Isla Alcatraz wading Bird breeding areas during the 2011, 2014, and 2016 breeding seasons. 9 P a g e

10 Wading Birds of Isla Alcatraz 2016 WHIB REEG BCNH GBHE TRHE YCNH SNEG # of Adults January February March April May June Figure 5. Monthly adult high counts of wading birds on Isla Alcatraz in WHIB = White Ibis (Egretta albus), REEG = Reddish Egret (E. rufescens), BCNH = Black-crowned Night Heron (Nycticorax nycticorax), GBHE = Great Blue Heron (Ardea Herodias), TRHE = Tri-colored Heron (E. tricolor), YCNH = Yellowcrowned Night Heron (N. violacea), SNEG = Snowy Egret (E. thula). Table 3. Table of annual high nest counts for wading bird species nesting on Isla Alcatraz from Adult high counts are in parenthesis. 1 Decreased visibility in these years, counts are minimums only. 2 No surveys were conducted in June of Clark et al , Mean Mean Snowy Egret 243 (485) 58 (192) 71 (174) White Ibis 116 (135) 58 (74) 45 (71) Reddish Egret 71 (163) 32 (59) 15 (58) Black-crowned Night 5 (82) 7 (19) 2 (19) Heron Great Blue Heron 24 (33) 36 (50) 30 (37) Tri-colored Heron 36 (62) 3 (23) 16 (29) Yellow-crowned Night 7 (36) 1 (7) 0 (5) Heron Cattle Egret 12 (13) 5 (6) 0 (0) Little Blue Heron 1 (2) 0 (0) 0 (0) P a g e

11 # of Nests PRESCOTT COLLEGE KINO BAY CENTER FOR CULTURAL AND ECOLOGICAL STUDIES Yellow-footed Gull Colony Size The first Yellow-footed Gull nest was recorded on March 10. A walk-through census was conducted of the colony on April 5 to count nests and record GPS locations (Figure 6). Only the flat area of the island was censused due to the difficulty of traversing the terrain of the entire perimeter or hill of the island. It is estimated that the flat area accounts for at least 90% of nesting pairs on the island. This has been the case in past years as well, and there has been no shift in breeding colony location overall. Yellow-footed Gulls continue to nest on Isla Alcatraz in stable numbers (Figure 7). The mean number of nests for seven years between 2009 and 2016 is 272.4, slightly lower than the 291 nests recorded for this year. Productivity monitoring was attempted in After chicks hatched they became mobile and abandoned the original nest located very quickly, which prevented focal nests from being monitored until chicks fledged. A chick count was conducted on the island on June 23 rd and 65 fully feather chicks were recorded, but this count should be considered a minimum as it was conducted late in the season when many fledglings had probably already departed the island. Even as a minimum estimate, this is substantially higher than the estimate of five fledglings reported in 2014 at the height of El Niño conditions. Figure 6. Map of Yellow-footed Gull nest locations in Yellow-footed Gull Nests on Isla Alcatraz * Figure 7. Yellow-footed Gull nests on Isla Alcatraz *The count for 2013 is a minimum as the interior of the colony was not counted in order to avoid disturbance to nesting California Brown Pelicans P a g e Year

12 American Oystercatcher breeding population and productivity This year 11 pairs of American Oystercatchers were documented on Isla Alcatraz, the highest number of pairs on record for the island. From between four and 10 pairs were recorded. Four of the pairs observed this year did not show breeding activity, two pairs were believed to have a nest based on incubating behavior observed from the panga, and five pairs had confirmed nests. Of the five confirmed nests, two failed with eggs, one nest hatched one chick in late June and the fate of that chick is unknown, and two nests fledged one chick each (Figure 8). Although the number of oystercatchers found on Isla Alcatraz was at the highest on record this year, productivity remains low. Two fledglings is the highest recorded on the island, both in 2016 and in Predation by Yellow-footed Gulls and disturbance by humans remain the two greatest threats to American Oystercatchers on Isla Alcatraz. The Easter holiday weeks are typically when the most visitors land on the island. The holiday occurred in March before the start of oystercatcher nesting was documented in April, so human disturbance and resulting nest losses may have been lower this year. Predation by gulls was not observed by observers this year, but has been documented in the past. Figure 8. Map of the locations of American Oystercatcher pairs on Isla Alcatraz in P a g e

13 Summary of waterbird studies in four Sonoran estuaries The estuaries along the Sonoran coast are incredibly rich in biodiversity and are important nurseries for hundreds of species of invertebrates and fish, many of which are harvested commercially. Migratory birds use these estuaries as stopover, wintering, feeding, and breeding sites. Additionally, coastal wetlands are the only suitable habitat in Sonora for certain federally protected species like the clapper rail (Rallus longirostris). There are three mid-sized estuaries and one small estuary on the central Sonoran coast (Hermosillo coast); Esteros Tastiota, Cardonal, Santa Cruz, and Santa Rosa respectively. The shrimp aquaculture industry has proliferated along this coastline since 2000 and the estuaries have received little research or conservation attention while aquaculture has rapidly encroached on these sensitive and unique ecosystems. The Center conducts waterbird monitoring and community education forums in these estuaries and works with a variety of research, government, non-government and community groups to pursue effective legal protection, community involvement and co-management for the ecologically, economically and socially important wetlands. All of the estuary protocols were updated this year. Updates include: new pictures, the addition of survey equipment table, more detailed driving directions the addition of a table summarizing the survey site locations with GPS waypoints, the inclusion of an aerial map with the survey radius highlighted. Additionally, the focus of the estuary reporting shifted slightly this year to focus more on species richness (S), rather than on total number of birds seen within the estuary. Total numbers of birds are important to understanding the carrying capacity and efficacy of the estuary as a foraging/nesting site, however, species richness, or diversity, is a stronger measure of the importance of an ecosystem. New datasheets were also developed in 2015/2016 to facilitate ease of data recording, entry, and analysis. Additional activities in the estuary include the collection of osprey nesting data and the involvement of the WMP in the Migratory Shorebird Project for the Programa de Monitoreo Biológico en Áreas Naturales Protegidas (PROMOBI). Estero Tastiota For the monitoring season the existing protocol, originally developed in , was followed with only one slight modification. The Mudflat East survey point was removed because it does not represent unaltered estuary habitat. Tastiota was surveyed 15 times during this season (October- June), with the attempt being to survey at least once but preferably twice each month. Additional surveys were performed opportunistically when time allowed, such as in March, when a total of three surveys were taken. The total species richness for the monitoring season was 65 species (Table 4), with the season observing 64 species. Despite a difference of only one species, there were 11 different birds observed this year that were not recorded last season. Additionally, there were 10 different species observed in that were not recorded this season. For the first half of the monitoring season, the average species richness level was 43.8 species (October-February) and then peaked in March (S= 56; Figure 9). Total richness fluctuated with the presence and absence of migratory species, which reached their peak during March, as they began to move north toward breeding grounds. In April, richness fell to 42 species with a subsequent 45% 13 P a g e

14 decrease in May (S= 23), and further decline in June (S= 20). It s difficult to say if the May decline is meaningful, considering a similar but less dramatic decline was observed in the last two years (S=40 in April, S=29 in May of 2015) (S=44 in April, S=34 in May of 2014; Figure 1). Also, it s important to note that survey efforts were reduced to one survey in May and June, potentially providing a less complete picture of estuary use. When comparing the high count of individuals for each species observed, some interesting differences were discovered, such as a marked decrease in the number of recorded American Avocets (- 319), Red-breasted Mergansers (-278), Western Sandpipers (-1886), and Bonaparte s Gulls (-4,152). The observed decline in American Avocets and Red-breasted Mergansers could be marginal, given that both species are migratory and move in varying sized flocks. The number of individuals on any given day is random and larger flocks might have simply been missed. Western Sandpipers are also migratory, however, they can be observed in the estuary throughout the year, and have consistently been observed in lower numbers. The difference in numbers of Bonaparte s Gulls is most striking, with a high count difference of over four thousand between the last two seasons. At present, it is unclear as to what might be driving this downward shift in abundance. For the Migratory Shorebird Project, the WMP surveyed the estuary within a period of seven days in November, 2015 and again in January, Tastiota was surveyed in November on the 24 th, observing 43 different species and 2,104 total birds. The January 26 th survey yielded 44 species and 3,215 total birds. Osprey nesting data was also recorded in Tastiota this season beginning on January 21 st. There were a total of 14 active nests this season, 8 of which failed before chicks could be observed. Nine nests produced a total of 14 chicks. Six of the fourteen nests produced a total of 10 fledglings, making the productivity rate 0.71 fledglings per active nest. This marks a decrease in productivity from the 2013 monitoring season, which saw 1.18 fledglings per active nest. Seventeen nests were active in 2013, with a total of 19 fledged chicks produced. Compared to 2016, 2013 had slightly more nests (15), with double the amount of chicks produced (29), and half the number of failed nests (4). Nest data from 2015 was not used for comparison due to inconsistencies in the identification of adults and fledglings. One additional activity the WMP engaged in was nest searches for mangrove nesting birds via kayak. The continued monthly presence of Roseate Spoonbills all throughout the monitoring season and its tendency to aggregate in large numbers in the mangroves outside of the survey area (largest group #= 34 individuals), indicated that it might establish a small rookery. However, nesting wasn t documented this season, nor has it been recorded in previous seasons. We do believe that Clapper Rails (Ridgway s Rail, Rallus obsoletus) are nesting in the mangroves of this estuary. Although they were only observed during two waterbird survey, they were regularly heard during the kayak nest searches. Several pairs of American Oystercatchers are also believed to have nested in the Tastiota estuary this year. One pair with a large chick was seen at the Mudflat West survey site in early June. One pair was believed to be incubating on the southwest beach of the estuary, and another pair was believed to be incubating on the inside of the sandspit that is on the north side of the mouth of the estuary. 14 P a g e

15 Estero Santa Cruz Santa Cruz was surveyed 24 times this past season (October-June), with the attempt being to survey once a week (3-4 times per month). Additional surveys were performed opportunistically when time allowed, such as in March, when a total of five surveys were taken. The total species richness for the monitoring season was 69 species (Table 4), higher than the 57 species recorded during the season. Twelve additional species appears to be a marked increase in richness but it s difficult to determine the cause. It could be associated with the difference in the number of surveys performed, which was an additional 8 for and could have provided the opportunity for more observations. There were 15 different birds observed this year that were not recorded last season. Of the fifteen, one was completely new to the estuary and to the WMP database, the Clarke s Grebe. It has been recorded in the Kino Bay area before but not during an official waterbird survey. There were only 3 different species observed in that were not recorded this season. During the first half of the monitoring season, the average species richness level was 45.4 species (October-February) with the monthly season peak recorded in March (S= 56; Figure 9). Total richness fluctuated with the presence and absence of migratory species, which reached their peak during March as they began to move north toward breeding grounds. In April, richness fell to 47 species. This decline was not unprecedented, with a sharper decline noted last year (S=27). The present year s May richness level was the same as in May of 2014 (S=34) (Figure 9). The estuary was not surveyed during May of 2015, so no comparison can be made during that month. When comparing the high count of individuals for each species observed, some interesting differences were discovered, such as a marked decrease in the number of recorded California Gulls (- 1,149), Laughing Gulls (-483), Western Sandpipers (-2,371), and Bonaparte s Gulls (-1,146). The observed decline in Gulls could be marginal, given that all are migratory and move in varying sized flocks. For example, the California Gull high count from the previous season becomes an outlier when all the data from the 20 different sightings since February, 2014 is compared. With the outlier (1,194 individuals), the average number of individuals recorded in a survey is Without the outlier, the average falls to 39.9 individuals. The high count for the current season is 45 individuals. Western Sandpiper numbers are also lower and more striking in Santa Cruz, especially when compared to the numbers amassed in the fall of 2013 and winter of 2014 where number of individuals was consistently over 1,000 with up to 5,453 observed on February 3 rd, At present, it is unclear as to what might be driving this downward shift in abundance, although a population decline of this species is suspected (Brown et al. 2001). the WMP surveyed the estuary within a predetermined period of seven days in November, 2015 and again in January, 2016 to comply with the protocol of the Migratory Shorebird Project. Santa Cruz was surveyed in November on the 28 th, observing 38 different species and 3,440 total birds. The January 20 th survey yielded 48 species and 3,170 total birds. Osprey nesting data was also recorded in Santa Cruz this season beginning on January 7 th. There were a total of 15 active nests this season, 6 of which failed before chicks could be observed. Eleven nests produced a total of 17 chicks. Nine of the fifteen nests produced a total of 10 fledglings, making the productivity rate 0.67 fledged chicks per active nest. This marks a decrease in productivity from the 2013 monitoring season, during which 22 active nests were 15 P a g e

16 monitored with a total 29 fledged chicks. Productivity in 2013 was higher with 0.75 fledged chicks per active nest. The difference is minimal and can be attributed to the fact that fewer nests were monitored this season due to accessibility within the estuary. Also, nests found beyond the estuary periphery, and within Kino Nuevo, were excluded. In the latter case, the estuary is most likely not the essential feeding ground for those Osprey pairs, thus the relevancy of their productivity in relation to estuary health is questionable. Again, nest data from 2015 was not used for comparison due to inconsistencies in the identification of adults and fledglings, which resulted in no fledglings being recorded for Santa Cruz. One additional activity the WMP engaged in was monitoring of the Yellow-crowned Night Herons, which had begun nesting west of the fishing settlement near Punta La Cruz survey site. On 05/17/2016, 17 YCNH adults and 11 nests were observed. On 05/24/2016, 19 adults and 13 nests were observed. The high counts were recorded on 6/14/2016, when 40 adults, 17 nests, and 7 chicks were observed. Estero Cardonal As in the other estuaries, the existing survey methods were used for the monitoring season, however the survey sites had to be changed to accommodate the changes in water level in the estuary. Two new sites were established, one to monitor the north-west region of the estuary, where Least Terns have been known to nest, and the other along the south-east edge of the estuary by the mouth. Cardonal was surveyed 15 times this past season (October-June), with the attempt being to survey twice a month. The total species richness for the monitoring season was 61 species (Table 4), with the season observing 56 species. Like Santa Cruz, there was a higher richness level this season (five species). The difference between seasons is minimal, however it could be associated with the difference in the number of surveys performed, which was an additional 7 for and could have provided the opportunity for more observations. There were 11 different birds observed this year that were not recorded last season. There were 6 species observed in that were not recorded this season; they were all migratory, with the probability of encountering large flocks being random. Of the eleven, one species, the Northern Shoveler (n= 6), was observed for the first time in Cardonal. Northern harriers (n= 1) and Green-wing Teals (n= 8) hadn t been observed in the estuary since 2008 and 2009, respectively. One surprising species that was observed only once this year is the Black Tern (06/28/2016), which has been observed every season since It was recorded in high numbers in the and seasons with sightings occurring in four and six surveys, respectively. Within the last two seasons ( , ), there were only three sightings each. As of yet, the number of sightings isn t necessarily an indicator of changing habitat conditions or species decline, but it warrants further monitoring to determine if a pattern exists. This season marked the highest species richness since the WMP began performing regular surveys in However, it s important to indicate that monitoring efforts were also the highest of any season, which might be positively correlated with the species richness. During the first half of the monitoring season, the species average richness level was 37.4 species (October-February) with the season peak in February (S= 43; Figure 9). Total richness fluctuated with 16 P a g e

17 the presence and absence of migratory species, which reached their peak during the end of winter just as they began to move north. Richness fell sharply in April and May, and then leveled off with 25 species in June. It s important to note that survey efforts were reduced to one day in May and June, potentially providing a less complete picture of estuary use. When comparing the high count of individuals for each species observed, some interesting differences were discovered, such as a marked decrease in the number of recorded Red-breasted Mergansers (-1,162) and Bonaparte s Gulls (-1,847). As with Tastiota, the observed decline in Mergansers could be a matter of chance with larger flocks occurring at random within the estuary. Though individual totals are low, the abundance of birds relative to the time of year they are observed follows a consistent pattern that has been identified in the data base. According to the data, Mergansers tend to gather in large numbers in November (n= 305 on 11/23/16), during the beginning of their overwintering, and in comparably high numbers in March (n= 170 on 03/09/16), when they initiate migration. As for the Bonaparte s Gulls, last year s high count was the highest ever recorded and possibly an outlier. However, in two of the last four seasons, large flocks have been recorded between late winter (n= 1,921, 19 Feb. 2015) and early spring (n= 569, 02 April, 2011). A season high of 78 individuals was recorded for This could be a decline or a random sampling issue. Cardonal was surveyed for the Migratory Shorebird Project on November on the 23 rd, observing 39 different species and 2,302 total birds. The January 24 th survey yielded 33 species and 763 total birds. Osprey nesting data was also recorded in Santa Cruz this season beginning on January 7 th. There were a total of 6 active nests this season, 5 of which failed before chicks could be observed. Three nests produced a total of 4 chicks. One of the 6 nests produced a total of 1 fledgling, making the productivity rate 0.17 chicks per pair. This marks a decrease in productivity from the 2013 monitoring season, which saw 0.75 fledglings per active nest. No nest data was recorded for the season for comparison. Least Tern nesting has also been known to take place at Cardonal, however, neither nesting nor courtship behavior was observed this season. This marks the second consecutive year of no nesting activity, however it is possible that Least Terns are nesting on the west side of the estuary mouth. The channel is too deep to cross so nesting surveys were not conducted on the outer beach and dunes. A Least Tern fledgling was observed along with adult terns foraging at the mouth of the estuary on June P a g e

18 Estero Santa Rosa The existing protocol, originally developed in 2013, was utilized for the monitoring season with no modifications. This survey was performed in collaboration with the Comca ac birding Group, the Cooijac, thus due to scheduling logistics, the survey was only conducted in the morning between approximately 8:00 a.m.-12:00 p.m. on Saturdays. Santa Rosa was surveyed 11 times this season (October-June), taking place once a month but with additional monitoring opportunities taken when possible. The total species richness for the monitoring season was 48 species, with the season observing 49 species. Despite performing three more surveys than in the previous year, species richness was similar, which could be attributed to the limited visibility at four of the six site locations. Unlike the other estuaries, Santa Rosa has a narrow configuration which is composed of high density mangroves encompassing small, shallow water channels. The only open water habitat available is at the mouth and there is comparatively little exposed mudflat in this estuary. Due to the design of the estuary and these survey limitations, Santa Rosa normally has the lowest species richness. Average monthly richness is with the highest occurring in April (S= 33). The highest number of species recorded in one survey was 26, which also occurred in April. There were 7 different birds observed this year that were not recorded last season. Of the seven, one species, the Brown Booby (n= 1), was observed for the first time in Santa Rosa, however, this is a pelagic species that was observed near the mouth of the estuary and is not expected to use the estuary extensively. There were 8 different species observed in that were not recorded this season (Table 4). Five of these species were migratory, thus due to the reduced observation periods, many were most likely missed. One interesting omission is the California Gull, which winters all throughout the Mexican Pacific and Gulf of California. During the winter of 2014, groups ranging between individuals were observed multiple times. The monitoring season in Santa Rosa recorded only one individual on March 3 rd, Sightings of California gulls have been made in each of the other estuaries but records of individuals are low. Global populations are declining for this species, however, more information is needed to determine if this is a trend for this region. During the first half of the monitoring season, the average species richness level was 17.8 species (October-February) with the season peak projected to occur in January. Like the other estuaries, total richness appeared to be fluctuating with the presence and absence of migratory species, which reached their peak toward the end winter. However, the highest richness level was observed in April, which was a declining month for the other estuaries. This could be due to the fact that two surveys were taken in April, providing the opportunity to make additional observations. Richness then fell in May (S= 17) to a similar level observed in February (S= 18) and then declined dramatically to just 7 species in June (Figure 9). Data from Santa Rosa has been collected for only a short time, thus we only have two previous survey dates for June, both of which reported numbers lower than the current year. Combined with higher temperatures and the falling water level experienced at this time of the year, it appears to be a normal pattern. However, more information is needed to confirm this. Santa Rosa continues to be a relatively undisturbed estuary with human use limited to subsistence fishing, clamming, and crabbing by the Comca ac and occasional tourists. Waterbird individual numbers and richness levels are consistent with the last two years of surveying, with no obvious changes. 18 P a g e

19 Figure 9. Monthly species richness in the four estuaries from October to June. Table 4. List of species that were present in the estuaries throughout the season (October-June). A number in the box indicates that the species was present in the estuary and is the highest number of individuals for that species recorded in one survey. Species Santa Cruz Cardonal Tastiota Santa Rosa American Avocet American Coot 1 13 American Oystercatcher American White Pelican Belted Kingfisher Black Skimmer Black Tern 27 Black Turnstone 1 Black-bellied Plover Black-crowned Night-Heron Black-necked Stilt Blue-footed Booby Bonaparte's Gull Brant Brown Booby 1 19 P a g e

20 Brown Pelican Bufflehead California Gull Caspian Tern Cinnamon Teal 2 19 Clapper Rail Clarke's Grebe 1 Common Goldeneye 2 Common Loon Common Tern 2 Double-crested Cormorant Dowitcher sp Dunlin Eared Grebe Elegant Tern Forster's Tern Great Blue Heron Great Egret Greater Scaup 1 2 Greater Yellowlegs Green Heron 1 2 Green-winged Teal 8 Gull-billed Tern 1 1 Heermann's Gull Herring Gull 23 1 Horned Grebe 11 1 Killdeer 2 Laughing Gull Least Sandpiper Least Tern Lesser Scaup 7 5 Lesser Yellowlegs Little Blue Heron Long-billed Curlew Magnificent Frigatebird Marbled Godwit Northern Harrier 1 1 Northern Pintail P a g e

21 Northern Shoveler 6 Osprey Pacific Loon 2 1 Red Knot Red-breasted Merganser Reddish Egret Redhead Red-necked Phalarope 45 Red-throated Loon 1 Ring-billed Gull Roseate Spoonbill Royal Tern Ruddy Duck 43 Ruddy Turnstone 22 Sanderling Semipalmated Plover Short-billed Dowitcher 6 Snowy Egret Snowy Plover Spotted Sandpiper Tricolored Heron Western Grebe Western Sandpiper Whimbrel White Ibis White-faced Ibis 1 24 Willet Wilson's Phalarope 3 Wilson's Plover Yellow-crowned Night-Heron Yellow-footed Gull Total # of Species P a g e

22 Summary of pelagic seabird surveys This year marked the second year of seabird surveys. During the winter and spring seasons, starting February 12 th, the WMP accompanied the Marine Mammal Program on 13 different outings in order to gather data on the diversity and distribution of Seabirds in the eastern and coastal Midriff Island Region of the Gulf of California (Figure 10). The survey routes included areas around Kino Bay and the eastern five islands of the Midriff Region (Tiburon, Datil, Cholludo, Alcatraz, and San Esteban). The last survey was taken on June 10 th. Each survey consisted of two spotters scanning on both sides of the boat for the duration of the cetacean survey, which normally lasted around 6 to 8 hours. The monitoring protocol was simplified this year so that only the first encounter of each species was recorded for the survey. A species was recorded again if large flocks were encountered. Over the course of the season, 42 different species were recorded. Not all species were exclusively seabirds, with the total representing birds found predominantly at sea and some wading birds most often seen in estuaries (Table 5). Additionally, it s important to understand that the following results were opportunistically collected in the Eastern Midriff Island region and is only a list of the species present with preliminary information on their distribution. Over the course of the season some patterns began to emerge in seabird distribution and abundance in the eastern and coastal sections of the Midriff Islands. For example, many of the Craveri s Murrelets, a target species, were clustered around nesting islands like San Esteban and Alcatraz, and were absent from the open waters between Kino and the southern tip of Tiburon. In general, most of the pelagic species like Black-vented Shearwaters, Black storm-petrels, Craveri s Murrelets and phalaropes were seen beyond Isla Datil in the deep water channels (>200 m) where the water temperature drops considerably and food resources increase. These birds were seen in relatively small numbers in the area between the San Ignacio boat launch and the southern tip of Tiburon: a distance of about 34 km. Loons, Western Grebes, and phalaropes were occasionally mixed in with the pelagic species. Black Storm-Petrels were relatively common, especially around the cetaceans we encountered. The most common species observed were Brown Pelicans, Yellow-footed Gulls, Heermann s Gulls, Brown Boobies, and Eared Grebes. All but the Eared Grebe were often observed during feeding frenzies that often occurred in the channel between Tiburon and San Esteban. Bottlenose dolphins or Common dolphins were always seen participating in these frenzies. Though not as common, 22 Black-vented Shearwaters had been spotted over the span of seven outings. On March 30 th, a large group of Black Terns and a Sabine s gull flying towards San Pedro Martir were encountered. Sabine s gulls are a rare migrant in this region that passes through the gulf between the end of March and the beginning of May. Two were spotted: one on March 30 th and one on April 23 rd. Many of the pelagic species like storm-petrels, murrelets, phalaropes, jaegers and shear-waters were seen beyond the southern tip of Isla Tiburon. 22 P a g e

23 Figure 10. Seabird survey routes traversed during the winter and spring of Table 5: Complete list of species identified during surveys between February and June. Species Observed: February - June American Coot Heermann's Gull Red-necked Phalarope American Oystercatcher Horned Grebe Ring-billed Gull Belted Kingfisher Laughing Gull Royal Tern Black Storm-Petrel Least Storm-Petrel Sabine's Gull Black Tern Magnificent Frigatebird Snowy Egret Black-vented Shearwater Osprey Spotted Sandpiper Blue-footed Booby Pacific Loon Surf Scoter Bonaparte's Gull Parasitic Jaeger Surfbird Brant Peregrine Falcon Western Grebe Brandt's Cormorant Pomarine Jaeger Yellow-footed Gull Brown Booby Red Phalarope California Gull Brown Pelican Red-billed Tropicbird Great Blue Heron Common Goldeneye Double-crested Cormorant Common Loon Eared Grebe Craveri's Murrelet Elegant Tern 23 P a g e

24 Species richness was high at the beginning of the season with the monthly total peaking in March (S=33; Figure 11). April experienced a sharp decline with richness leveling off at 19 species and persisting at a similar level until the end of the season. In February there were four surveys and five in March, with only one outing in both April and May, and two in June. Having fewer surveys most likely had an effect on the total richness: more surveys lead to more opportunities to make observations, thus it s difficult to draw conclusions from the results of the latter three months. During the season 16 surveys were conducted between October and April with 32 different species recorded. Of the 32, five were not observed this season: Caspian, Common, and Forster s Terns, Horned Grebes, and Pink-footed Shearwaters. It is likely that the terns were not observed this year due to the absence of surveys earlier in the season. Of the 42 species of waterbirds that were recorded this year, six weren t observed last year including: Pomarine Jaegers, Least Storm-Petrels, Red Phalaropes, Sabine s Gulls, Surf Scoters, and Surfbirds. Figure 11: Total observed species richness over the 2016 season by month. There were 40 sightings of Craveri s Murrelets, comprised of 147 individuals. GPS coordinates were taken for all encounters (Figure 12). The first fledglings were seen on March 21 st. A total of 16 fledglings were observed over the course of the season. The highest density of murrelets was observed during a Marine Mammal Program (MMP) outing on the April 5 th when a seabird survey was not being conducted. On this day the MMP crew spotted 94 individuals. The majority of the fledglings (12) observed during the season occurred on this outing; they were encountered in the waters surrounding Isla San Esteban. Another species of interest was the Red-billed Tropicbird, which is experiencing a population decline worldwide. Tropicbirds are known to nest on Isla San Pedro Martir. Red-billed Tropicbirds were seen on 10 of the outings, during which 11 birds were seen. One juvenile was spotted on June 2 nd in the area south of Datil. These birds were mainly spotted in the area between Kino Bay and the southern tip of Tiburon. One additional juvenile was seen very close to the west side of Isla Alcatraz on May 29, but this observation was not made during a survey. 24 P a g e

25 Figure 12. Map of the eastern Midriff Island region displaying all Craveri s Murrelet sightings during seabird monitoring outings. Eared Grebes were most abundant early in the season, and were observed in large flocks which ranged from 50 to around 7,000 individuals. These aggregations were also documented last year and are likely a result of the rich waters cause by seasonal upwelling. Though they were distributed all throughout the survey area, large groups of Grebes were most commonly seen in the bay, around San Nicolas, and in the open waters east of Isla Datil. Many of these large groups were observed feeding alongside fin and humpback whales. Groups numbering in the thousands ceased to be observed in late March and number of observations rapidly declined in April and May. The WMP will continue to collect data on the birds of the eastern Midriff Island region of the Gulf of California. Having this data aids in the understanding of seabird habitat preference and seasonal distribution, for little information currently exists for this region. The limitations of these surveys lie in their opportunistic nature, which precludes use of distance sampling methods and subsequent results such as density estimates. The survey routes were based on the projected cetacean survey locations and altered when whales were encountered or seen off in the distance. This style of survey often took us in random directions, but ultimately a consistent pattern formed over the course of the season as numbers of whales declined and their locations shifted toward the middle and western sections of the Gulf (Figure 10). 25 P a g e

26 Community Projects Comca ac Waterbird Monitoring Collaboration This is the second year of a collaboration with the Comca ac indigenous community to provide training in waterbird monitoring. The WMP staff surveyed Estero Santa Rosa eight times this season with a group of six Comca ac bird monitors. Half of the participants were new this year, but the other three had participated last year and are now very comfortable with identification of the species seen in the estuary and helped train the new members. The veterans approached the WMP fellow at the beginning of the year with an inquiry about the possibility of starting a new project to protect an American Oystercatcher and Wilson s Plover nesting area located on a sandspit directly in front of their town of Punta Chueca. The WMP fellow helped the group to develop text and layout for the signs and provided materials for their construction. The Comca ac monitors then worked to translate the Spanish text into their native language, Cmiique Iitom. It was incredible to watch this process as the language has only been written for approximately 50 years and there was much disagreement over proper words and spelling. The group had a work party at the Kino Bay Center to paint the signs (Figure 13) and they were then installed on the sand spit with the help of other KBC staff (Figure 14.). In future years the group would like to learn more about nest monitoring and could be encouraged to work on community outreach regarding the nesting birds. The original plan for the season included training the veterans in the use of averaves so that they learn how to enter and track their own data. We did have one session on the computer at the KBC where they entered bird observation data, but the nesting habitat protection project took time away from furthering this task so the WMP crew continued to enter the data into ebird as has been done in the past. It is recommended that data management and analysis be a goal of the project in the coming year. The construction of an ecology center with computers during this season should make it logistically easier to provide this type of training right in Punta Chueca. Figure 13. Painting party at the Kino Bay Center with the Comca ac bird monitoring group. 26 P a g e

27 Figure 14. Completed bird nesting area sign on the Punta Chueca sand spit. Environmental Education classroom and guided visits and Reto Alcatraz This year the WMP had numerous opportunities to collaborate with the Environmental Education Program at the Kino Bay Center and in the local Kino Bay community. The WMP fellow and interns provided a bird presentation for five 6 th grade classes in the Kino Viejo elementary schools. The presentation included a powerpoint highlighting the avian ecology and the waterbirds of Isla Alcatraz, a tutorial on how to draw birds, show and tell of a collection of bird skulls, and an outdoor bird identification session (Figure 15). The fellow and interns also had the opportunity to give presentations on the importance of birds in the area and our projects during guided visits of the station for other school groups from middle schools and high schools. Figure 15. WMP fellow and intern instructing students on use of binoculars and bird guides. 27 P a g e

28 Prescott College Student Mentoring The WMP mentored one Prescott College student on a bird related project this year. The student developed a localized bird guide for Estero Santa Cruz that can be used as a training tool. This is a laminated guide of the most common species seen in the area that is appropriate for any age of beginning birder. There are English and Spanish versions of this guide to meet the needs of a broad range of the local community. The WMP staff also provided field methods training to five other Prescott College students with an interest in birds. These students accompanied the WMP into the field and were able to learn the methods and assist in data collection. Semana Santa Disturbance Minimization Effort Human disturbance to nesting birds on Isla Alcatraz is an annual issue during the Easter holiday weeks of Semana Santa and Semana Diabla. Tourists hire panga drivers to take them to the island to explore. The WMP fellow is responsible for developing a strategy to reduce disturbance to the nesting birds as much as possible. This year, the WMP fellow worked with the Community Projects Coordinator and the Environmental Education fellows to organize a talk for the five panga drivers who have permits to transport tourists. Sadly, only one panga driver attended the talk, but he seemed certain to share the information. The presentation included an overview of the birds nesting on the island during the spring season, and a proposal from the WMP to provide free interpretive talks to the tourists. The idea was that the WMP staff would wait at the island in a panga at anchor for the tourist pangas to arrive. WMP staff would then circumnavigate the island by boat with the tourists to provide natural history interpretation of the island. The WMP crew visited the island on Friday, March 25 th and while there were pangas with tourists circumnavigating the island, we did not see the driver we had presented to. No pangas were observed dropping people off on the island during the two hours the staff was there before the wind came up and the crew had to return to the boat launch. A representative from CONANP was present on this trip and also made note of the activities that were observed. On Saturday, March 26 th, a second visit was planned with the CONANP representative as well as two representatives from PROFEPA who would be able to write tickets should any tourists attempt to land on the island. Unfortunately the wind was too strong on this day and we could not reach the island. We instead drove to an overlook on the mainland and used the scope to observe any human presence at the island. Over the course of one hour we observed 19 people on the island. It is possible that just our presence in the anchored panga the day before had prevented panga drivers from allowing people onto the island. This year Easter was early and the Yellow-footed Gulls were the only species with active nests, all of which were still in the incubation stage. We do not know how many nests may have been lost due to human disturbance. We do believe this technique has promise for the future, especially with the support of CONANP and PROFEPA staff who have management authority of the island. 28 P a g e

29 Santa Cruz Bird Workshop Together with the Community Projects Coordinator, the WMP hosted a Bird Identification and Field Methods Workshop at the station this month. The workshop ran for three days from 4-7pm. The participants included residents of Kino Viejo (some from Grupo Tortuguero, some who volunteer for CONANP to do monitoring at San Pedro Martir, and a few people who just had an interest in birds) and university students from Hermosillo. The first two days were spent in the classroom and outside at the station reviewing basic concepts: Ecology, Anatomy, Classification, use of field guides, principles of identification, equipment, field notebooks and datasheets, and online databases (Figures 16 & 17). The last day was spent at Estero Santa Cruz identifying birds and concluded with a certificate ceremony. The hope is that by providing this type of workshop the local community can become stewards of the natural resources in the area. It was also very exciting to receive an inquiry from one of the participants about future volunteer or intern opportunities at the station. Figure 16. Pin the tail on the donkey bird anatomy activity. Figure 17. WMP fellow with bird workshop participants. 29 P a g e