The Ceuta Snowy Plover Studies

Our work is an integral approach of research and conservation. It engulfs aspects of very different fields in biology including ecology, behavior, evolution and conservation.

We have the following objectives:

  1. Study Snowy Plover breeding behavior to understand the evolution of parental cooperation and sex-role reversal,
  1. Document  Snowy Plover behavior and breeding success to understand population demography during the challenging times of global change,
  1. Conserve one of the largest Snowy Plover breeding populations at the Pacific Ocean,
  1. Train future generations of field biologists and conservationists in Northwest Mexico,
  1. Educate and involve local people in conservation.

Why study Snowy Plovers at Bahía de Ceuta?

Bahía de Ceuta is one of the most important breeding sites of the Snowy Plover in North America. Every spring from April to July Snowy Plovers are breeding in  the abandoned salt works. During this time nests can be found all over the place. Actually the plovers are hanging around there long before and just waiting that the water retreats so that they can nest. Snowy Plovers love open sandy soil with little vegetation which is not far away from water where they can find food.

Every researcher is passionate about his research object and we love Snowy Plovers. And we think that many other people would love them too! Their downy chicks are just adorable and they are fun to watch! They have fascinating breeding behavior which is still poorly understood. At Ceuta most of the time the father is bringing up the young whereas the female deserts the family and re-mates with a new male. But this does not happen in all Snowy Plover families, which makes it such an interesting research topic. Especially late in the breeding season the pairs stay together and the female helps to bring up the young. Researchers have found that when breeding conditions turn bad in the related plover species both parents are needed to bring up the young and we see something similar at Ceuta. In 2010 for the first time we noted a male deserting the family to re-mate with another female. At the same time the abandoned female had to care for the small chicks.

Despite their interesting family life, Snowy Plovers fight for their survival. They are threatened because humans are increasingly using their natural habitats, sandy beaches and coastal wetlands, and leave little space for the plovers to thrive. At Bahía de Ceuta the local Snowy Plovers breed sparsely at the beach and abundantly in the abandoned salt works which is only a few hundred meters from the long sandy beach at the Pacific Ocean. The salt works holds now one of the largest breeding aggregations of Snowy Plovers at the Pacific.

Bahía de Ceuta is at Southern limit of the breeding distribution of the Snowy Plover. You can find Snowy Plovers there all year round. In winter the local population is joined by migrants from unknown origin and our Snowy Plovers seem also to wander around the coast. Right now Bahía de Ceuta is an important population stronghold. But it could be much better with more support, better water management and improved protection the current population could easily double or triple in size. We work to conserve it for future generations.

During our Snowy Plover family studies we have noted a lot of tragedies and exciting stories that can keep up with your favourite daily soap! We have observed chick adoption, mixing of broods, males neglecting their responsibility towards their own chicks to pair with a different mate, plovers chasing and injuring other plover chicks and so on. If you are interested you should follow our fieldwork blog. During the field season we will keep you updated with exciting news from the Ceuta Snowy Plovers. We are convinced that, the more people understand their needs and how exciting they are, the more they will care to protect them.

A short history of the Ceuta Snowy Plover Project

After the closure of the salt works biologists soon realized that Bahía de Ceuta is an important haven for threatened animals. The first project on breeding Snowy Plovers was carried out at Bahía de Ceuta by conservationists of Pronatura Noroeste, a local NGO in 2003/04. They started to band the Snowy Plovers with color bands and investigated nesting success. Our team took over in 2006 when Clemens was carrying out his PhD. Since then we have studied Snowy Plovers here every year.

Below is a representative map of the Snowy Plover nests that we found in 2010. The red dots represent nests from which chicks hatched  successfully, the white dots are nests that failed and for the yellow dots we don't know whether the nests hatched or failed because they were scheduled to hatch after we finished the fieldwork by Mid July.

Every spring we mark and follow the destiny of more than 95% of the breeding Snowy Plovers at Bahía de Ceuta. We are working in a small team that includes local students who are given the rare opportunity to experience field biological research first hand and gives them rare insights into data collection and basic analysis, hands-on conservation and working in an international research team. We also give talks and tours to local schools and the community.

During the work we search for nests and marked plovers and families. We regularly capture the Snowy Plovers to measure and mark them. From each Snowy Plover we take a small blood sample for subsequent genetic analyses. We also have started to take detailed photographs of all adult Snowy Plovers.

 Here is a short summary of the last Snowy Plover Breeding seasons at Bahía de Ceuta.

  200620072008 2009 2010  2011 2012 2013 2015 2016 2017 2018 2019
Nests found 161 140 76 73 96  70 34 3250
 Successful nests (%)46 65 59 64 62  50 38 565260
 Total breeders203 190 98 102 129  93 5745
 New breeders157 85 21 20 57  39 17 2244
 Hatchlings153 231 101 115 173  90 3138
 Fledglings25 53 18 36 43  41 0NA

As you can see from this table the population is fluctuating strongly between the seasons. This is largely due to the fluctuating environmental conditions mainly the variability of water levels. However, considering that the entire Pacific (or Western) Snowy Plover population is 3000-5000 adult plovers only, Bahía de Ceuta is very important for the future of its survival.

You will have probably noticed that breeding activity had markedly right until 2018. However, 2019 was a very strong year and the population has rebounded. We hope that this was not a one time outlier and hope that over the next few years some long planned conservation action can lead to a sustain recovery of breeding plovers at Bahía de Ceuta.

We are committed to continue the yearly breeding census, the monitoring and marking, our conservation and training programs as long as we find passionate people and funders who are willing support us.