PARK FLIGHT FINAL REPORT

Golden Gate National Recreation Area Point Reyes National Seashore

Project Contacts: Daphne Hatch

Wildlife Ecologist Golden Gate National Recreation Area Fort Mason, Building 201 San Francisco, CA 94123 (415) 331-0744 (415) 331-0851 FAX daphne_hatch@nps.gov Sarah Allen

Science Advisor Point Reyes National Seashore Point Reyes, CA 94956 (415) 663-8522 x 224 (415) 663-8132 FAX sarah_allen@nps.gov Project Title: Conservation of Neotropical Migratory Birds in Riparian Habitat (PMIS 70544) Amount Granted: $30,000

Brian O’Neill, General Superintendent Golden Gate National Recreation Area

Don Neubacher, Superintendent Point Reyes National Seashore

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Conservation of Neotropical Migratory Birds in Riparian Habitat

Melissa J. Pitkin and Thomas Gardali

Point Reyes Bird Observatory, 4990 Shoreline Highway, Stinson Beach, CA; mpitkin@prbo.org and tgardali@prbo.org

January 2003

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Introduction The Park Flight grant program is an excellent program for bird conservation because it combines funding for research and monitoring with funding for education and outreach. By allowing the science to guide the outreach, we are able to ensure that the public receives accurate and scientific information. This information will help them to make informed conservation decisions. The Park Flight grant awarded to Point Reyes National Seashore (PRNS) and the Golden Gate National Recreation Area (GGNRA) was used to conduct research and monitoring on three coastal creeks in Marin County. An education and outreach component was also conducted to increase the public’s understanding of the results of our research. Our project was highly successful, resulting in great partnerships between PRNS, GGNRA, PRBO and the neighboring communities. It also provided us with initial research and monitoring data that we hope to build upon in future Park Flight grants.

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Species assessment, protection, and management In order to protect and manage for songbirds it is vital to measure various demographic rates. We used several methods (see below) to achieve this goal. The advantage of using a multi-method approach is that it enables us to develop insights into the mechanisms that underlie observed population changes. For example, through mist-netting alone we may conclude that productivity appears to have declined over time for a species. But with nest-searching we can investigate whether clutch size or nestling survival, etc., can account for changes in productivity. Additionally, it is important to assess songbird fitness at various stages in their annual cycle (e.g., breeding and migratory seasons) and across several years. We used five standardized landbird monitoring methods to assess Neotropical migrant use of the study sites during the breeding season (variable circular plot point counts, territory mapping, nest monitoring, habitat assessment, and mist-netting). During migration we used mist-netting in combination with area searches. Here we provide only summary data for each of the primary methods employed. In the case of mist-netting we only summarized data for the Muddy Hollow site as an example. Area search data is not presented. Breeding Season

• We conducted variable circular plot point counts at Muddy Hollow, Redwood Creek, and Lagunitas Creek in the summer of 2002. A summary of detections by site is presented in Table 1. These data provide a measure of abundance that can be used to evaluate population trends.

Table 1. Total number of detections within 50 m of the observer over 3 visits. Species

with dashed lines (-) were detected flying over or greater than 50 m.

Species Lagunitas

Creek Muddy Hollow

Redwood Creek

Allen’s Hummingbird 15 26 36 American Crow 0 0 2 American Goldfinch 17 31 37 American Robin 6 14 24 Anna’s Hummingbird 3 4 8 Ash-throated Flycatcher 1 2 3 Barn Swallow 5 0 0 Belted Kingfisher 0 0 2 Bewick’s Wren 24 43 11 Brown-headed Cowbird 11 6 9 Black-headed Grosbeak 49 14 46 Black Phoebe 1 1 1 Brewer’s Blackbird 6 0 9 Brown Creeper 6 0 1 Band-tailed Pigeon 0 3 4 Bullock’s Oriole 1 0 0 Bushtit 22 4 14 California Towhee 9 3 14

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Table 1. Continued.

Species Lagunitas

Creek Muddy Hollow

Redwood Creek

California Quail 6 41 5 Chestnut-backed Chickadee 51 9 64 Cedar Waxwing 0 33 60 Chipping Sparrow 2 0 0 Cliff Swallow - - - Common Raven - - - Common Yellowthroat 0 19 2 Downy Woodpecker 3 4 12 European Starling 11 39 10 Gadwall 0 4 0 Great Blue Heron - - - Hairy Woodpecker 2 0 8 House Finch 7 0 28 Hutton’s Vireo 6 3 7 Lazuli Bunting 11 1 0 Mallard 0 1 7 MacGillivray’s Warbler 0 0 1 Marsh Wren 0 3 6 Mourning Dove 11 8 26 Northern Flicker 1 14 9 Nuttall’s Woodpecker 5 0 0 Orange-crowned Warbler 11 11 28 Oregon Junco 2 0 2 Olive-sided Flycatcher 1 15 4 Osprey - - - Pacific-slope Flycatcher 13 3 7 Purple Finch 10 4 5 Pygmy Nuthatch 0 0 2 Rose-breasted Grosbeak 0 1 0 Red-breasted Sapsucker 0 1 0 Red-shouldered Hawk - - - Red-tailed Hawk - - - Red-winged Blackbird 2 2 41 Song Sparrow 126 128 223 Spotted Towhee 9 27 18 Steller’s Jay 7 5 6 Swainson’s Thrush 72 86 93 Tree Swallow 2 7 2 Turkey Vulture 0 2 0 Violet-green Swallow 6 0 2 Warbling Vireo 72 4 19 White-crowned Sparrow 0 3 0 Western Bluebird 2 0 1 Western Scrub-Jay 7 16 9 Western Wood-Pewee 17 7 2 Wilson’s Warbler 80 52 108 Winter Wren 3 5 3 Wrentit 8 5 2

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• Nest monitoring at the Redwood Creek Study site. A total of 253 nests were

located and monitored for 29 different species (Table 2). The percent of successful nests (fledged at least one young) of the nests with known outcomes was 44% (108/243).

Table 2. Total number of nests, number fledged, number failed, and number unknown by

species at Redwood Creek in 2002. Species

Number of Nests

Number Fledged

Number Failed

Number Unknown

Mourning Dove 10 3 5 2 Anna’s Hummingbird 2 0 2 0 Allen’s Hummingbird 9 4 5 0 Red-shafted Flicker 3 2 1 0 Downy Woodpecker 4 4 0 0 Hairy Woodpecker 1 1 0 0 Olive-sided Flycatcher 1 1 0 0 Western Wood-Pewee 1 0 1 0 Black Phoebe 1 1 0 0 Pacific-slope Flycatcher 1 1 0 0 Tree Swallow 2 1 1 0 Violet-green Swallow 5 5 0 0 Steller’s Jay 6 2 4 0 Chestnut-backed Chickadee 13 10 1 2 Bushtit 6 6 0 0 Brown Creeper 3 2 1 0 Winter Wren 2 0 1 1 American Robin 10 4 6 0 Swainson’s Thrush 38 11 25 2 European Starling 1 0 0 1 Warbling Vireo 10 1 9 0 Orange-crowned Warbler 1 0 1 0 Wilson’s Warbler 24 7 16 1 Rose-breasted Grosbeak 2 1 1 0 Black-headed Grosbeak 21 9 12 0 California Towhee 1 1 0 0 Song Sparrow 63 29 34 0 American Goldfinch 11 1 9 1 House Finch 1 1 0 0 TOTAL NUMBERS 253 108 135 10

• Habitat assessment was conducted for each nest location and at each point count

location. These data can provide information of habitat associations and the influence of vegetation structure and composition on nesting success. Hence, management recommendations (e.g., important plant species for restoration) can be obtained (see Management below).

• Territory mapping was conducted at each nest searching plot at Redwood Creek.

The territory mapping method is based on territorial behavior of birds. By marking the locations of birds on a detailed map throughout the breeding season, it is possible to count the number of territories in an area and estimate the density of birds. Future analyses will allow us to compare density estimates derived from variable circular plot point counts with estimates obtained from the territory mapping method.

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• Mist-netting was conducted once every 10 days per site at Redwood Creek, Muddy

Hollow, and Lagunitas Creek during the breeding season (1 May – 16 August) in 2002. These data can over time provide information on population trends, adult survival, and an index of reproductive success (young to adult ratio). March through August captures for all species at the Muddy Hollow Banding site are presented in Table 3. A total of 2045 net hours were accumulated at Muddy Hollow during this time period and the other sites were nearly identical.

Table 20. Total captures and individual captures at Muddy Hollow for March through

August. March-August

Species Total Total

YoungTotal

Individuals Young

Individuals American Goldfinch 4 1 4 1

American Robin 5 1 4 1 Bewick’s Wren 10 5 9 5

Black-headed Grosbeak 1 0 1 0 Bushtit 9 9 9 9

California Towhee 2 1 2 1 California Quail 5 4 1 0

Chestnut-backed Chickadee 13 10 11 8 Cedar Waxwing 2 0 2 0

Common Yellowthroat 15 7 13 7 Downy Woodpecker 4 3 4 3

Fox Sparrow 6 0 6 0 Golden-crowned Kinglet 1 0 1 0 Golden-crowned Sparrow 3 0 3 0

Hairy Woodpecker 2 0 1 0 Hermit Thrush 9 0 8 0 Hutton’s Vireo 2 1 2 1

MacGillivray’s Warbler 4 3 4 3 Myrtle’s Warbler 2 0 2 0

Nuttall’s White-crowned Sparrow 2 1 2 1 Orange-crowned Warbler 7 2 7 2 Pacific-slope Flycatcher 6 5 6 5

Purple Finch 1 0 1 0 Ruby-crowned Kinglet 6 0 6 0

Song Sparrow 109 61 87 53 Spotted Towhee 7 6 5 4

Sharp-shinned Hawk 1 0 1 0 Steller’s Jay 3 0 3 0

Swainson’s Thrush 83 24 67 22 Tree Swallow 1 0 1 0

Warbling Vireo 1 1 0 1 Wilson’s Warbler 55 24 45 24

Winter Wren 1 0 1 0 Wrentit 18 11 11 8

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Migratory Season

• Mist-netting was conducted once every 7 days per site at Redwood Creek, Muddy Hollow, and Lagunitas Creek during the migratory season (17 August – 31 October) in 2002. These data can be used to document the use of these riparian areas during migration in terms of species composition, abundance, and physical condition. One of the greatest constraints to migrants is the ability to obtain enough food to build fat stores. As an example of the type of analysis that can be done, we examined the relationship between body mass and time of day for the Pacific-slope Flycatcher controlling for date. Here we made the assumption that birds at a stopover site will show daily fluctuations in mass and that a “good” site should show a positive relationship with time of day. Figure 1 shows that Pacific-slope Flycatchers were able to put on fat reserves in our riparian study areas during the fall of 2002. It is important to note that this analysis is preliminary and is presented primarily as an example. Normally, we would not lump all study sites, but due to the small sample size it was necessary to do so.

• Area searches were conducted at each site during each day of mist-net operation.

These surveys are a compliment to the netting activities in that they detect many species not well sampled by mist-nets.

Figure 1. Multivariate regression of weight (grams), date, and time of day for Pacific-

slope Flycatchers at all sites combined (n = 39 captures, P = 0.004, correlation coefficient = 0.02 ± 0.008 [95% CI = 0.002 – 0.04], adjusted r-squared = 0.23).

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Management Providing management recommendations based on data collected during a single season is likely problematic. Conditions and circumstances during any single season (year) may not be representative of other years and the “natural” range of variation cannot be measured. Additionally, data collected during a single season are often too few for analyses. However, we have been monitoring songbirds at many of these study sites (at various levels depending on funding) since 1997 and recently summarized our management recommendations in an article published in Park Science1. See Appendix 1 for a copy of the article.

1 Gardali, T., C. Shoulders, D. Hatch, A. L. Holmes, S. E. Scoggin, and G. R. Geupel. 2001. Songbird

monitoring in the Golden Gate National Recreation Area: a multifaceted tool for guiding the restoration of Redwood Creek. Park Science 21:28-32.

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Interpretation, environmental education and outreach The Park Flight program is an exceptional program because it combines funding for species assessment, protection, and management with interpretation, education and outreach. This combination of funding and programs ensures that the results of the research can be disseminated to a wide audience including managers, students, and the general public. It also ensures that environmental education is driven by science, ensuring the information disseminated is accurate. In our interpretation, environmental education and outreach projects, we focused on disseminating our results to the public, providing them with the information necessary to guide them to act as responsible stewards of the environment. The following list summarizes our accomplishments: • Field Trips

School field trips to observe mist-netting and bird banding occurred during the fall of 2001and spring/summer/fall of 2002 at the three monitoring sites, Muddy Hollow, Lagunitas Creek, Redwood Creek. Eleven school groups participated totaling 289 students. Each field trip lasts approximately one hour and students were given the opportunity to observe mist-netting demonstrations and interact first hand with biologists as they work. The chance to see these migratory songbirds up close and in the hand is a rare opportunity and instantly involves students in the conservation effort. (See Appendix 2 for photos)

• Special outreach to urban schools In partnership with the Muir Woods education staff, the Park Flight program was included in the Muir Woods Urban Schools outreach program. This provided 4 classes with bus transportation to Redwood Creek, a special visit to the classroom to prepare for the visit, preparation of curriculum materialsfor the classes, and a visit to Redwood Creek with a tour of the mist-netting and a follow-up trip at Muir Beach.

• Volunteer training Having volunteers conduct censuses to assess migratory songbird populations directly involves them in the conservation effort. From the fall of 2001 through the fall of 2002, we were able to train and work with 18 volunteers. Volunteers assisted in mist-netting for songbirds as well as conducting area search censuses of migratory songbirds using the three study areas.

• Bird curriculum to teachers The PRBO Teacher Resource Packets, containing 11 hands on activities for students of all ages focusing on bird conservation, were distributed to all the classes that participated in field trips, as well as to other teachers in the area. These packets are made available free of charge to any teacher requesting them. To view the PRBO Teacher Resource Packets, visit www.prbo.org/educ.htm.

• Bird lists for each site Using the data collected from the species assessment and monitoring component of the project, we have generated bird lists for each of the three project sites. We have these available for distribution to teachers and classes visiting these sites in future years.

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• International Park Flight education workshop PRBO Education and Outreach Director Melissa Pitkin, and GGNRA Resource Specialist Daphne Hatch, attended the November workshop held at the Grand Canyon National Park. Here we exchanged ideas and collaborated with other Park Flight participants from both North and Latin America

• International Park Flight Monitoring workshop Sarah Allen (NPS), Melissa Pitkin and Geoff Geupel (PRBO) attended the monitoring workshop in Honduras November 2002. Melissa provided a workshop on hosting groups at mist netting stations entitled “Public Outreach with Mist netting Demonstrations” (See Appendix 4 for associated handouts). This was particularly useful for participants who plan to combine outreach with their monitoring efforts. Geoff Geupel presented two talks, one focusing on translating monitoring information into useful resource management tools using examples from PRBO’s research in California, and the other gave examples of national monitoring programs which use monitoring data to influence management of National Parks using examples from PRBO’s research in PRNS and GGNRA. The workshop was a success for future ideas for collaborative work between parks in both the US as well as Mesoamerica.

• International intern exchange As part of the Park Flight Project we received 3 intern biologists from Latin America to work with us on our bird monitoring projects. (Heriberto Verduga Munguia, Cesar Rodriguez, and Sophia Arensas Castillo; Figure 2). All three were trained in mist-netting as well as the area search method for monitoring songbirds, interpretation to students and the public, and gained exposure to many other methods for monitoring songbird populations.

Figure 2. Sofia Arenas Castillo measuring a Pacific-slope Flycatcher.

• International Migratory Bird Day Working with NPS (Muir Woods, Point Reyes National Seashore, & Crissy Fields) Activities • Mist-netting demonstrations at Redwood Creek and Palomarin on May 11 (7

AM – 12 PM): Present at mist-netting: Viola Toniolo, Renée Cormier, Cesar Rodruiguez, Miguel Demuelemeester, Americorps Volunteers. PRBO hosted

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approximately 30 visitors at Redwood Creek, 25 of which came by the Park Service Shuttle.

• PRBO/bird conservation informational display at Muir Woods, with informational posters (see below), and informational handouts, posters, stickers and tattoos free to the public. Present at the display was PRBO educator Gerick Bergsma, Americorps Volunteers, and Redwood Creek education staff. (see Appendix 3 for one of the posters depicting songbird territories and nests at Redwood Creek).

• PRBO stand-alone informational displays at Palomarin, Crissy Fields and PRNS consisting of three separate posters: You Can Help Birds Everyday, Park Flight & the Bay Area, and Migration: An Incredible Odyssey. PRBO hosted 16 visitors at the Palomarin Field Station during mist-netting demonstrations.

• Provided display space and additional materials at Muir Woods, Point Reyes National Seashore and Crissy Fields.

• Organized bird walk from Muir Woods to mist-netting at Redwood Creek. • Coordinated shuttle to mist-netting and beach, and provided volunteer

naturalists at various stops. • Coordinated Americorps volunteers. • As a result of the Muir Woods (GGNRA) education staff’s urging, shade

grown coffee is now being served at the Marin Headlands Visitor Center IMBD & PRBO products disseminated • IMBD posters • Kid’s magazine from IMBD: Exploring Habitats • IMBD stickers & tattoos • IMBD book mark with information on the Redwood Creek birds and habitat • PRBO white papers • PRBO Observer magazine • Keep Cats Indoors campaign brochures

Additional support for the project GGNRA and PRNS are working in partnership with PRBO to complete the proposed scope of work. PRBO plays the lead role in implementing the migratory songbird assessment component as well as the education and outreach component. Housing and office space for the staff and interns working on the project as well as the equipment needed to implement the project is being provided by PRBO as an in-kind contribution to the project. Media/Press The GGNRA developed a page for their website featuring the project on Redwood Creek. On this website the project is described and a schedule is posted inviting people to visit and interact with the biologists as they work. This website can be viewed at www.nps.gov/muwo/birds/research.htm GGNRA issued press releases regarding the International Migratory Bird Day Festivals in May 2002.

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Appendix 1. Summary of management recommendations as they appeared in Park Science.

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Appendix 1. Continued.

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Appendix 1. Continued.

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Appendix 1. Continued.

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Appendix 1. Continued.

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Appendix 1. Continued.

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Appendix 2 Photos

Park Flight Study Sites

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Appendix 2 continued Photos

Hosting GGNRA staff and volunteers at mist netting at Redwood Creek

Students observing a mist netting demonstration

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Appendix 3 Poster from Redwood Creek summarizing songbird territories and nest sites.

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Appendix 4

Park Flight Workshop- Interpretation at Mist netting stations handouts:

Commonly asked questions and answers when taking groups on net runs.

Having a set of questions and answers to distribute to your mist-netting and outreach staff is very helpful. Here are some examples

1. Do the bands hurt the birds? No, the band fits around their leg, loose like a bracelet, not as tight as a watch.

2. Does the band impede their flying? No, studies on captive birds have shown no effect. The bands are made of aluminum, (the same material soda cans are made from) and they are very light.

3. Do birds ever die or get hurt in the net? Very rarely. We are very careful to always put the birds’ safety first. By watching how the birds are behaving we can tell if the bird is under stress and we would let a stressed bird go or put it in our hot box to warm up before letting it go.

4. The birds you are holding seems so calm, why is that? The way I am holding it keeps it from struggling. It’s wings are pressed against the back of my hands and my fingers are actually on its shoulders.

5. Do you ever catch the same bird twice, or twice in one day? Yes, about 30% of the birds we catch are re-captured. It is really our hope to re-capture birds. That way we can learn things such as how long birds live (survivorship) and how birds change in appearance as they age. When we re-capture migratory birds from season to season we are able to tell that that individual survived the winter and migration. We do also catch the same bird in one day, usually this occurs in the breeding season when birds are very distracted and are busy defending territories, and feeding young. Some individuals may learn where the nets are located but the fact that we catch them repeatedly even in a day suggests that learning to avoid the nets is not a major factor in the declines we notice.

6. If you catch a bird again, do you just let it go or do you still band it? If we catch a bird with a band already, we still process it, or take all the data, because this can teach us about how the bird has changed since we last captured it. If we catch the same bird twice in one day then we just let it go again.

7. Can I touch the bird? No, we can’t let you touch them because we don’t want to frighten or stress the bird any more then we need to.

8. Why are you banding birds? Mist-netting and banding birds allows us to follow individual birds throughout their lives. From this we can learn things such as; how long birds live, how many babies does this population of birds produce in a year, what are some of the birds here, how many different kinds of birds are here, does this bird migrate and if so, where does it go, etc. It is important to emphasize that mist-netting can allow you to look at trends. We often show a graph of total birds captured when discussing the many reasons for mist-netting birds.

The following are questions you should be able to answer based on your specific project or organization:

9. Tell me about your organization? 10. Where does your funding come from? 11. Can I volunteer? 12. How can I become a member of your organization?

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Appendix 4 continued: Park Flight Workshop- Interpretation at Mist netting stations handouts

Conducting Mist Netting Demonstrations Tips for Success Melissa Pitkin, PRBO Education Director (mpitkin@prbo.org)

Hosting groups at your mist-netting station is a unique opportunity for public outreach. Mist-netting demonstrations allow people to connect with birds they may not have know existed, connect and interact with biologists as they work, and learn about habitats and conservation in a fun and interactive way. At PRBO, we host approximately 4,500 people of all ages in mist-netting demonstrations in Marin County as well as inviting the public to 5 additional mist-netting sites throughout California. A visit usually lasts 1 hr allowing people to participate in 1-2 net runs and observe the banding process. Group field trips are facilitated by the mist-netting interns and one staff or intern from the education program. We are also open year-round at our Visitor Center for drop in visitors to observe mist-netting The following are some tips and suggestions for implementing an outreach program at your mist-netting station. Feel free to adapt them for your particular site. In general:

• Work in pairs: Always have two people who can extract birds from the net along when taking a group on the net trail.

• Help your partner out: Be aware of how the bird being extracted is caught. If it is really tangled, one person should take the class on to give the person extracting a bit of breathing room.

• Know your group! Walk slowly; be aware of the age of your group. Really young and old visitors can’t keep up with the fast pace. Stop periodically to let people catch their breath. Don’t let the group get spread out.

• Enjoy the surroundings: Point out birds flying over to the group, take time to point out things about the habitat and to listen to bird sounds.

• Leave extra stuff behind: Have students leave all backpacks on the deck; there just isn’t room on the trail.

• Try to make sure everyone sees a caught bird: If you catch a bird try to at least show the other group on the deck the live bird. This can be a brief walking around to let them see it up close.

The Rules: Before beginning on the net trail, go over the rules. Here is what I say: 1. Stay on the trail: Who knows what poison oak is? Poison Oak is a part of the coastal scrub

habitat. It is an important part of the habitat for many birds. The Wrentit strips the bark of the poison oak and builds its nest with it. We keep the trails clear of poison oak so if you stay on the trail you wont get poison oak. (People often ask if birds get poison oak, no they don’t)

2. Keep voices down and walk: Remember, we are about to enter a study area. Who wants to catch birds today? Great, me too, and we will have a better chance of catching them if we are walking and talking quietly while we go on the net trail.

3. Keep out of the nets: The nets are very delicate and can tear easily. If you have any backpacks you can leave them next to the banding lab, and as we walk close to the nets, try to keep your arms in (demonstrate how) to make sure your watches or jewelry don’t get caught. (Remember, some kids and adults will always touch the nets, its inevitable and not the worst thing in the world. Don’t spend the entire hike telling kids to keep their hands out, there is a lot more interesting info to spend time on.)

Starting at the first net, have all the students stand to the side in the grass and view the net. Explain how the net is hard to see, have them try to look through it and focus on the tree through the net. It is hard to notice. Using a rolled up bird bag, toss the bag into the net to show how a bird gets caught. Talk about when you open the nets and when you close them. Remember to ask if the students have any questions.

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Proceed along the trail, again stopping to see how the group is doing. I like to stop at certain points along the way to point out changes in habitat or interesting notes about your site. Stop somewhere along the way and have them stand quietly to listen to how many different birds they can hear. If you did not get any birds, take the group back to the banding area and show them the bands, pliers, talk a bit about what you would have done if you had a bird. If you did get birds, take the group to the banding area, and go through the steps of banding with them. Once gathered, wait for the group to quiet down before taking out the bird. Ask them to be quiet, explain to them why instead of telling them to be quiet. Giving people an explanation usually works the best. Have one-person band and process the bird while the other narrates. Think about talking in basic terms so they can understand. Terminology like brood patch, ossification, even wing chord is unknown to them. Explain what those things mean. For example: Brood patch- When birds have eggs in the nest that they need to keep warm or incubate, they loose the feathers on their belly so that their warm skin comes in contact with the eggs. This featherless area on a bird’s stomach is called the brood patch. In most cases, only females develop a brood patch so it is very useful for determining males from females. Cloacal Protuberance- This is something that males develop in the breeding season only. The cloaca is the main organ for fertilization for birds and when males are ready to breed, it becomes enlarged. We can use this to help determine a male from a female. Skull ossification- When birds first hatch from an egg they have one thin layer of bone over their head. You can see right through the first layer and it looks pink. Then when the second layer grows over the top the bone becomes ossified or fused. We look through the birds skin to see if there is a contrast between white bone and pink. If we find a contrast we know that the bird is less then one year old. If it is solid white bone then it is at least one year old. You can use the skull poster as a tool for this. Wing Chord- This is a measurement we take on all birds. It is sort of the equivalent of measuring someone’s height. For some birds the length of a birds wing can also help us tell males from females. Molt- We also look at how a bird is molting or changing its feathers. We can sometimes determine a bird’s age by looking at how it molts its feathers. When finished let them watch you release the bird if it doesn’t need to go back to the net. Have them stand behind you so the bird will fly off into the trees. Splitting the Group We often split the group into two smaller groups of about 10-15 people each, especially with kids. While one group is accompanying the banders on a net run, the other is engaged in an activity such as looking at study skins (bird specimens), or observing birds with binoculars. This makes net checks a bit easier but requires extra staff to keep one group busy. Overall, try to be enthusiastic and smile! People respond to that. Kids are so curious and excited to be out of the classroom it is understandable to be a bit rowdy. I don’t recommend scheduling more then one group of about 30 kids in a day because it is a lot of work for the staff. For more information or if you have questions on this, please contact Melissa Pitkin at 415 868-1221 X 307 or email mpitkin@prbo.org.